MPCA Report Page 1 

### Package 1 **U.S. TACONITE IRON ORE INDUSTRY Part 1. Introduction**  Iron ore is mined and processed in the U.S. mainly on the Mesabi Range of northern Minnesota and the Marquette Range of the Upper Peninsula of Michigan. **Mesabi Range** The Mesabi Range, shown in Figure 1 and located approximately 65 miles north of Duluth, MN, consists of a belt of (the Animikie Biwabik) iron formation of approximately 120 miles long from Grand Rapids to Babbitt with a thickness of 400 to 750 feet. The iron- ore material that is mined, concentrated, and pelletized is magnetite (Fe 3 

### O 4

### ), or magnetic taconite. There are two ty

pes of magnetic taconite: 1) magnetite associated with minnesotaite, stilpnomelane, and cherty quartz with minor greenalite and carbonates, and 2) magnetite associated with iron amphiboles (grunerite, cummingtonite, actinolite), py roxenes, garnet, fayalite, and finely

granular quartz. The first ty pe occurs westward from near Aurora, where five taconite mining and processing companies (Ispat- Inland Steel Mining Company, EVTAC Mining, U.S. Steel Minnesota Ore Operations, Hibbing Taconite Company, and National Steel Pellet Company

) are located. The second ty pe is found from Aurora eastward, in an area where the iron formation has been metamorphosed by the intrusion, on the south, of the Duluth Gabbro. Northshore Mining Company and LTV Steel Mining Company are located in this area. See Table 1 for facility

locations. The difference in ore ty

pe affects grinding circuit design. According to one facility, a ty pi cal east Mesabi magnetic taconite concentrate ground to 90% finer than 325 mesh (43 m) contains about 8% slica. Half of the total silica is in the 10% by weight +325 mesh portion. Currently, a flotation step is added to further remove silica to make a marketable taconite concentrate for standard or fluxed pellet production. At a west Mesabi facility, ore ground to 75% finer than 325 mesh is all that is required. No flotation step is needed for further silica removal, in order to make a marketable taconite concentrate for standard pellet production. The difference in ore ty

pe also affects crushing circuit design. At the west Mesabi facility mentioned above, single stage crushing (gy ratory crushers) is used ahead of single stage autogenous (using large pieces of the ore to grind/mill the smaller pieces) grinding, although grinding is now enhanced with pebble crushers. Most facilities, especially those at the eastern end of the Mesabi Range, use three or four stages of crushing, followed by rod and ball grinding mills. The difference in ore ty

pe is also apparently

relevant to the content of mercury and fine mineral fibers in the taconite ore processed on the Mesabi Range, and hence also the emission rates of these constituents.MPCA Report Page 2 

### Marquette Range The Marquette Range is located in the northern part of the Upper Peninsula of Michigan with its eastern end 10 miles west of the Lake Superior port of Marquette. The range is approximately 30 miles long and 6 miles wide, including from east to west the towns of Palmer, Negaunee, Ishpeming, Humboldt, Republic, and Michigamme. Figure 2 shows the location of the Marquette Range in relation to the Mesabi Range as well as other iron ore deposits currently not being mined. Empire Iron Mining Partnership at Palmer and Tilden Mining Company at Ishpeming are the two facilities currently

operated on the Marquette Range. The Empire plant uses magnetite to make pellets, and the Tilden plant uses both hematite (Fe2 

### O 3 

### ) and magnetite. In the finished (fired) pellets, magnetite is converted to hematite. **Taconite Pellets -**  **Basics** Taconite concentrate pellets, or taconite pellets for short, are of 3/8 to 1/2 inches in diameter, made of taconite concentrate with a binding agent (e.g., 10 to 20 lb of powdered bentonite per ton of c oncentrate) and other additives and heat hardened at about 2400 °F. Taconite pellets have an iron content of about 65% by weight. Iron making blast furnaces have used taconite pellets for decades, because of their requisite strength, consistency

in size and chemical composition, and optimum metallurgical properties. If taconite concentrates, which are very fine particles, were used instead to build the burden of a blast furnace, they

would be blown out of the furnace before the metallurgical process star ts. The physical strength of taconite pellets also facilitates transportation and handling. **Pellet Types** There are basically

two ty pes of pellet products -- standard pellets (SP), often called “acid” pellets in the past, and fluxed pellets. Fluxed pellets contain a certain amount of fluxstone (limestone and/or dolomite) in addition to all the constituents of standard pellets. Fluxed pellets of equal to or greater than 1.0 basicity ratio can be called fully

fluxed pellets (FFP). As an industry

convention, the basicity

ratio is a mass ratio of several of the pellet constituents defined as (CaO + MgO)/(SiO 2 

### + Al2 

### O 3 

### ). Energy demand in the pelletizing process for fully fluxed pellets is increased due to the added calcination requirement for the fluxstone. Auxiliary burners are usually

added to the pelletizer (agglomerator or indurating furnace) in order to make fully

fluxed pellets. As a result, FFP production leads to higher emissions of air pollutants than SP production. Fluxed pellets of less than 1.0 basicity ratio, or partially

fluxed pellets (PFP), do not require auxiliary burners. The difference in emissions between PFP and SP production is often not apparent. The various pellet products are made to meet the blast furnace operator’s requirements. Blast furnace operators can build their burden with FFP without adding any more fluxing agent.MPCA Report Page 3 

### Alternatively, they

can build their burden with PFP or SP while also adding some additional fluxing agents. Pellet chips (PC) are broken pieces of fired pellets. They can be sent back to the balling process, after regrinding, and remade into furnace feed (unfired pellets or “green” balls). Pellet chips can be sold as feed to sinter plants. **Types of Pelletizers** The U.S. taconite iron ore industry uses three typ es of pelletizing machines or processes: straight grate (Figure 3), vertical shaft (Figure 4), and grate -kiln (Figures 5A and 5B), with their respective first units installed in 1954, 1957, and 1963. Based on published production data for 1995 through 1997, 63.0% of the total U.S. pellet production is made with the grate -kiln pelletizers, 24.5% with the straight grate pelletizers, and 12.5% with the vertical shaft pelletizers. An industry

profile is provided in Table 2. Inthe vertical shaft furnace (Figure 4), the feed (wet green balls) are distributed evenly over the top of the slowly

descending bed of pellets (1 to 11⁄2 inches per minute, or about 4 hours of residence time in the furnace). Gravitational force and actions of the chunkbreaker create the downward displacement movement of pellets. A rising stream of hot gas of controlled temperature flows counter to the descending bed of pellets. Fuel combustion chambers supply hot gas midway

between the top and bottom of the furnace. The oxidation of ferrous iron (Fe+2

### ) in the pellets, which is an exothermic or heat releasing reaction, also contribute to heating the pellets above the oxidation zone. ( According to one facility, a rule of thumb is that, for each percent increase in ferrous iron, approximately 25,000 BTU less fuel is need to process each long ton of pellets at its straight grate pelletizer, which is discussed in the next paragraph .) The oxidation of ferrous iron occurs for pelletizing magnetite, but not hematitic or limonitic ores. The vertical shaft furnace did not pass feasibility testing for making fluxed pellets, which have higher energy

demand than standard pellets. The furnace was considered more energy efficient, however, than the straight grate pelletizer of the 1950s, before the improvements and retrofits for heat recuperation were made to the straight grate pelletizer and also before a new ty pe of pelletizer, the grate -kiln system, entered the taconite ore processing industry. During a recent stack test, a ty

pical vertical shaft furnace made fired pellets at a rate of 54 ton/hour with heat input of 25 million Btu/hr and a waste gas flow rate of 43,200 ft3 

### /min (at dry, standard conditions). Inthe straight grate machine (Figure 3), a continuous bed of agglomerated green pellets is carried through different temperature zones with upward draft or downward draft blown through the pellets on the metal grate. Pellet residence time inside the machine is about 40 minutes. Fuel combustion chambers supply hot flue gas to a zone in the middle portion of the machine (combustion zone). (In order to make fully fluxed pellets, auxiliary

burners need to be added to the preheating zone.) Fired pellets are cooled on the remaining portion of the machine. To protect the metal grate and other p arts of the machine, about 20 percent of the cooled, fired pellets are used to make a hearth layer at the bottom and two sides of the pellet bed. In a recent stack test of a four- stack (see more description in the next paragraph ) straight grate machine, theMPCA Report Page 4 

### machine made fully

fluxed pellets at a rate of 377 ton/hour with heat input of 183 million Btu/hr and an exhaust gas flow rate of 148,000 ft3 

### /min per stack (at dry, standard conditions). For the straight grate machine, used process gas consists of exha ust gas from the updraft drying zone and exhaust gas closer to the firing zone. The former can be called “hood exhaust” and the latter “windbox exhaust.” For many straight grate machines, both hood exhaust and windbox exhaust are directed to one common header. The common exhaust header has one “hot side” inlet to receive windbox exhaust and one “cold side” inlet to receive hood exhaust. From the common exhaust header, the exhaust gas is vented through four parallel stacks, which are outfitted with air p ollution control equipment. For some older machines, two separate common headers are used to vent hood exhaust and windbox exhaust. The hood exhaust header vents through three stacks, and the wind exhaust (often referred to as “waste gas”) header vents through two stacks. The grate -kiln system actually consists of a traveling grate, a rotary kiln, and an annular cooler (Figures 5A and 5B). Pellet residence time inside the system is about 55 minutes (less than 10 minutes in the grate, about 20 minutes in the kiln, and about 30 minutes in the cooler). The grate -kiln system does not need a hearth layer for the grate, which handles only drying and preheating. The rotary

kiln does not need a hearth layer, either, because it is lined with refractory material . One waste gas stack, or two side -by- side waste gas stacks, are used for the grate -kiln system. In a recent stack test, a grate -kiln system made fully fluxed pellets at a rate of 459 ton/hour with heat input of 221 million Btu/hr and a waste gas flow rate of 340,000 ft3 

### /min through the waste gas stack (at dry, standard conditions). In another recent stack test, a different grate -kiln system, installed with two waste gas stacks, made partially fluxed pellets (no auxiliary burner at the preheating zone in the grate) at a rate of 697 ton/hr with heat input rate of 233 million Btu/hr and a waste gas flow rate of 232,000 ft3 

### /min per stack (at dry, standard conditions). The annular cooler for the grate -kiln system was installed originally without any

gas cleaning equipment for the cooler vent stack. Recent stack testing has found that the operator would need to be very careful in process control for the cooler vent stack to be in compliance with state rules on particulate emissions without adding any gas cleaning equipment. One reason is that more additives are now used than before in making the green balls, thus demanding more energy in induration. An example would be the calcination required as an integral part of the production of fully fluxed pellets. The pellet now reaches its peak temperature in the cooler, instead of the kiln, as originally

designed. This adds thermal buoyancy to the airborne particulates entrained into the gas stream through the stack. Various efforts are being made, include adding a wet scrubber by

one facility

to control some part of the dusty area near the vent stack entrance. Initial testing has shown that this wet scrubber addition was sufficient to bring the main cooler stack back into compliance with Minnesota emission limitations. Itshould be noted that, since the fired pellets have traveled through the combustion zone in the kiln, where the flue gas flows countercurrent to the fired pellets, only small quantities of volatile hazardous air pollutants are expected to be emitted from the cooler vent stack. No stack test had been conducted to validate this expectation, as this report was being finalized. On the otherMPCA Report Page 5 

### hand, stack testing results did show that the particulate emissions from the cooler vent stack tend to be coarse in size, limiting impact on ambient air quality due to rapid settling. Itis very common to use intermediate cyclones to clean the gas stream in the straight grate and grate -kiln pelletizers, as it is ducted to various locations in the grate. The cyc lones protect the blades of gas movers (fans) and recover good materials (particles of high iron content). I nclined plates are also used along with periodic water wash to remove “solid spills” under the grate to recover the iron units. These measures als o help reduce dust loading near the waste gas stack, even though they

are not considered air pollution control equipment. **Pelletizing Process** Pelletizing is a high temperature process with air in excess. The process is responsible for the largest portion of emissions of air pollutants from any individual taconite ore mining and processing facility. Natural gas is commonly used as the primary

fuel for pelletizing. Distillate fuel oil is often used as a back up fuel, especially during natural gas curtailment in winter. Other ty pes of fuel, e.g., coal, petroleum coke, and sawdust, are also being used. Many factors can significantly

influence the emissions from the pelletizing process. Take the binding agent (binder) for example. The majority of taconite concentrate pellets are made with bentonite clay

as a binder. Many

alternatives have been tried to replace bentonite clay for cost control and silica reduction reasons. However, most alternative binders are still not as strong as bentonite clay

in maintaining dry

strength of the green ball (unfired pellet). During a very brief time span in the pelletizer, when the moisture has evaporated and the small taconite concentrate particles have not fused together on the green ball surface, a green ball incorporated with an alternative binder can be more vulnerable to disintegration. Another example of a process parameter that affects air emissions is the intensity of heating. If the green ball, incorporated with either bentonite clay or an alternative binder, is not subjected to sufficiently high heat flux after the moisture has evaporated, it’s vulnerability to disintegration can increase as well. Disintegration of green balls and/or pellets often leads to a surge in the emission of particulate matter (PM) from the waste gas stack. Over the years, efforts have been made to recuperate some of heat loss associated with the various hot air streams associated with the pelletizers. For grate-kiln and straight grate pelletizers, most of the hot air in the cooling zone for fired pellets is directed to combustion zone and/or preheat and drying zones of the pelletizer. At the waste gas stack, the gas stream does not have much thermal energy to be recovered (gas temperature ranges from 100 to 150 °F for a stack contro lled with a wet scrubber or a wet wall electrostatic precipitator, and from 200 to 300 °F for a stack controlled with a multiclone or a simpler device). For the vertical shaft furnace, some heat recovery

has been achieved by

adding a concentrate slurry scrubbing unit (heat exchanger) to the existing top gas multiclone (stack gas temperature ranges from 125 to 150 °F with the heat exchanger, and from 230 to 300 °F without the heat exchanger). There are many

perspectives that can be used to evaluate the pelletizing operations at the different facilities. One simple way is to divide a facility ’s annual indurating energy consumption by

its annual pellet production (million BTU/ton pellets fired), which is given in theMPCA Report Page 6 

### ninth column of Table 2. From 0.277 million BTU/ton pellets fired for Hibbing Taconite Company to 0.668 million BTU/ton pellets fired for Northshore Mining Company, one should begin to appreciate the significant energy usage difference among the individual facilities. Most of the difference is attributed to a combination of the following: process equipment age, equipment retrofits, pellet products made, ore characteristics, process control, and operator’s training and skills. Ingeneral, a well managed pelletizing process, coupled with appropriate air pollution control equipment for waste gas cleaning, can attain and maintain compliance with existing emission limitations established in a facility ’s operating permit or applicable state rules. **Taconite Mining and Processing** As stated previously, pelletizing is responsible for the largest portion of the emissions of air pollutants from a taconite ore mining and processing facility. However, a taconite ore mining and processing facility

has unit processes other than just pelletizing. Some of thes e other processes such as mineral liberation and taconite concentrating are upstream of pelleting, while others such as pellet product storage and shipping are downstream of pelltizing. Figure 6 is a process diagram for a taconite ore mining and processing facility that uses the grate -kiln pelletizer to make fully

fluxed pellets. The following describes mineral liberation, taconite concentrating, pellet product storage and shipping. Liberation

– The first step in processing crude taconite ore is crushing and grinding. The ore must be ground to a particle size sufficiently close to the grain size of the ironbearing mineral to allow for a high degree of mineral liberation and removal of the waste material (gangue). Most of the taconite used today requires very

fine grinding. The grinding is normally

performed in successive stages of dry crushing, followed by

wet grinding in rod mills and ball mills. Gy ratory crushers are generally

used for primary

crushing, and cone crushers are used for secondary and tertiary

fine crushing. Intermediate vibrating screens remove undersize material from the feed to the next crusher and allow for closed circuit operation of the fine crushers. The rod and ball mills are also in closed circuit with classification systems such as cyclones. An alternative is to feed some coarse ore directly to wet or dry semiautogenous or autogenous (using large pieces of the ore to grind/mill the smaller pieces) grinding mills, then to pebble or ball mills. Ideally, particles of iron minerals and barren gangue should be removed from the grinding circuits as soon as they

are liberated, with larger particles returned for further grinding. Concentrating

– As the iron ore minerals are liberated by the crushing steps, the ironbearing particles must be concentrated. Since only about 33 percent of the crude taconite becomes a shippable product for iron making, a large amount of gangue is generated. Magnetic separation and flotation are most commonly used for concentration of taconite ore. Magnetite is concentrated by magnetic separation since most of the recoverable iron is magnetic. The crude ore may

contain 30 to 35 percent total iron by assay, but theoretically

only about 75MPCA Report Page 7 

### percent of this is recoverable magnetite. The majority of the remaining iron is discarded with the gangue. Nonmagnetic taconite ore (hematite and liminite) is concentrated by froth flotation or by

a combination of selective flocculation and flotation. The method is determined by the differences in surface activity

betwe en the iron and gangue particles. Sharp separation is often difficult. Various combinations of magnetic separation and flotation may be used to concentrate ore containing various iron minerals (magnetite and hematite) and wide ranges of mineral grain siz es. Flotation is also often used as a final polishing operation on magnetic concentrates. Pellet Product Storage and Shipping

– Fired pellets, just leaving the pelletizer, are conveyed to stockpiles for cooling and storage. Most pellet products are transported to blast furnaces in the Great Lakes region by

ships, which are loaded at Duluth, Silver Bay, Taconite Harbor, Escanaba, and Marquette at the shorelines of Lake Superior and Lake Michigan. Except for Northshore Mining Company, which is located on the shore of Lake Superior, the remaining taconite facilities use the railroad to transport their pellet products to the ports. Inthe winter, the Great Lakes are closed, and most pellets are stockpiled on site at the facilities or at the docks to wait for the next shipping season. A portion of the pellets produced on the Mesabi Range is shipped by railroad trains to other locations, for which transportation is carried out all year round. Simplification of Process Reference -- The process diagram for a taconite mining and processing facility can be simplified, for the purpose of estimating HAPs emissions, as “at-pellet firing” and “off -pellet firing” processes. For a grate -kiln pelletizer, drying and preheating of green balls in the grate, and pellet ind

uration in the rotary

kiln and the part of pellet coolers near the kiln are the “at-pellet firing” processes. Blasting in the mine pits, crude ore crushing, crushed ore grinding and concentrating, fired pellet cooling and handling (transfer, stockpiling, and loading out) are the “off -pellet firing” processes. **HAPs Emissions at Pellet Firing** Two categories of hazardous air pollutants (HAPs) are emitted from the pelletizer’s waste gas stack(s). The first is related to metal and non-metal elements naturally associated with taconite ore and other solid materials and fuels fed into the pelletizer. Emissions of most of these elements can be determined with stack testing using Reference Method 29 (manganese, arsenic, lead, nickel, chromium, selenium, antimony, cadmium, mercury, cobalt, and beryllium). Emissions of hydrogen chloride and hydrogen fluoride, or acid gases, also have been determined with stack testing. The second category

of HAPs emitted includes products of incomplete combustion (PICs), which are compounds in the gaseous state. Formaldehyde has been found through stack testing. Hexane, benzene, and toluene were found to be below respective detection limits, but are suspected to be present.MPCA Report Page 8 

### HAPs Emissions from Off **- Pellet Firing Processes**  The blasting operation can be omitted for HAPs emission estimation, because, while blasting may be a very significant event on a short-term time scale, it does not cause any significant air quality impact on an hourly

basis in the taconite mining area. Blasting i s conducted one to three times a week, depending on the facility. The blasting methods and technologies currently used in the taconite mining industry include most, if not all, of the following: 1) engineering a blast hole pattern to minimize the amount of blasting agent used and maximize fragmentation, 2) stemming blast holes to direct energy release horizontally, 3) computerizing blast hole delay to further enhance fragmentation, and 4) conduct blasting only when local meteorological conditions are acceptable. Federal and state rules do not allow blasting, when there is a temperature inversion in the atmosphere or when wind conditions would, with blasting, create excessive air shock (overpressure). Stack testing has not been conducted specifically for determining HAPs emissions from offpellet firing processes. However, chemical analysis has been performed on various materials for element composition. Assuming that the particulate matter (PM) emitted from the off -pellet firing processes has the same element composition as the feed to the processes, emissions of the Reference Method 29 elements can be estimated. Based on this assumption, PM emissions from off -pellet firing processes, available from Emission Inventory databases maintained at Minnesota P ollution Control Agency and from taconite facilities in Michigan, can be used for the HAPs emission estimation. Preliminary

review of HAPs emissions indicated that approximately 10% of the total facility HAPs emissions could be attributed to off -pellet firing processes. This suggests that attention should be focused on the pelletizing process in HAPs emission estimation for the taconite ore mining and processing industry. **Part 2. Individual Facilities** Below is a brief description and history for indivi dual taconite ore mining and processing facilities in Minnesota, in the descending order of production rates as shown in Table 2. **U.S. Steel Minnesota Ore Operations (Minntac)** Currently the largest taconite pellet producer in the U.S. with the latest rep orted plant capacity of 15.3 million long tons (17.14 million tons) per year, the Minntac pelletizing facility was built in three successive steps. Becoming operational in October 1967, Step I consists of taconite processing lines (or agglomerator lines as called at Minntac) 1, 2, and 3, each of which is rated at 2 million long tons of fired pellets per year (1 long ton is equal to 2240 lbs.). Step II was built in 1972, consisting of lines 4 and 5. Step III was built in 1978, consisting of lines 6 and 7, which are capable of firing with coal at the rotary kiln (other lines were designed to burn natural gas and fuel oil). Each line of Step II and Step III is rated at 3 million long tons of fired pellets per year. Lines 1 and 2 are no longer operational. Thus, the original capacity estimate for the overall plant remains about 14 million long tons (15.68 million tons) per year, which is very close to the average annual production level (15.55 million tons) shown in Table 2. Due to continuingMPCA Report Page 9 

### process changes, the overall plant capacity can change from one year to the next in the taconite processing industry. Over a period from 1987 to 1989, auxiliary burners were added to the traveling grate section of lines 3 through 7, achieving the capability of making fully

fluxed pellets. During this period, main burners of Step II and Step III were modified to accommodate sawdust firing. Nearly 400 emission units are listed in Minntac’s Part 70 permit application. **Mining** Minntac mines the crude ore with the current, conventional methods and technologies of the taconite mining industry. A significant distinction between Minntac and the other taconite mines is the practice of direct loading of rail transportation units (trains) instead of trucks in some parts of the mine. However, planning is under way to phase out the rail transport and to replace it completely

with truck hauling. **Crushing** Minntac uses a three - stage crushing system. The first and second stages are single pass. A screen after each second stage and each third stage crusher sends the fine (minus 0.5 inch) material directly

to the Concentrator. The third stage screen takes oversize material and returns it in closed circuit to the third stage crushers for further size reduction. A separate fluxstone (limestone and dolomite) unloading facility is located at the crushing plant for transferring the fluxstone from the common carrier railroad to the Concentrator. **Concentrating** Minntac’s concentrating process lines use a conventional three - stage grinding system, which consists of one rod mill and two ball mills. Each ball mill operates in closed circuit with a material classifier so that the oversize material returns to the ball mill until the optimum particle size is achieved. A magnetic separator follows each grinding mill to reject the non- iron bearing particles (tailings) from the grinding system. Finally, each grinding line uses fine screens to return any

remaining large iron bearing particles to the second ball mill. Following the grinding and magnetic separation section, the concentrate is delivered to a flotation system for the final silica reduction. One grinding line is reserved for fluxstone grinding. The ground concentrate and the ground fluxstone slurries are delivered separately to the Agglomerator. **Agglomerating (Balling and Pelletizing)** The fluxstone slurry

is metered into the concentrate slurry at a specific ratio. Following agglomeration in balling drums, five grate -kiln systems are used for indurating the pellets. Figures 5A and 5B show a schematic of the grate -kiln system at Minntac. Natural gas burners in the traveling grate preheat furnaces supplement the kiln burners for the total thermal requirement. Natural gas is the primary fuel in the kiln burners. Sawdust is co - fired with natural gas in three kilns. Pulverized coal is an alternative fuel in the two other kilns. Fuel oil No. 2 is an alternative in all five kilns. Waste gas stacks are equipped with a wet scrubber at Lines 4 through 7 and with “drop out boxes” (gravity collectors as indicated in Table 2) at Line 3. Heat recuperation is facilitated at Lines 4 through 7 to move hot air from the annular pellet cooler to the dry ing zone in the grate. Line 3 is not retrofitted with heat recuperation.MPCA Report Page 10 

### Hibbing Taconite Company **(HTC)** The latest plant capacity

of HTC is reported as 8.0 million long tons (8.96 million tons) per year. HTC uses Dravo/Lurgi traveling grate pelletizing machines at its processing facility. Figure 3 is a schematic of such a pelletizer. HTC’s Lines 1 and 2 started up in 1976 with a total annual capacity of 5.4 million long tons of pellets. Line 3, with an initial annual capacity of 2.7 million long tons of pellets, was added in 1979, thus making the overall plant capacity of 8.1 million long tons (9.0 7 million tons) per year. Continuing improvements over the years may have increased the overall plant capacity to 8.3 million long tons of fired standard pellets (9.30 million tons) per year, which is very close to the average annual production level (9.1 9 million tons) shown in Table 2. **Mining** Over 56 million tons of material must be mined annually to provide crude ore for current pellet production at full capacity. HTC uses 170 and 240 ton capacity trucks to haul crude taconite ore from mine pits to the processing plant. Mining tasks consist of overburden removal, drilling, blasting, and removal of waste rock and crude taconite ore from the pits. Rotary drills are used to bore 16” holes to a depth of about 55 feet. Less than one -half pound of explosives is used in blasting for each ton of broken taconite ore. In-pit crude ore loading is performed with 18 and 33 cubic yard shovels. **Crushing and Concentrating** Crude ore, containing about 20 percent magnetic iron, is delivered to two 60 × 109 inch gy ratory crushers for size reduction to 10 inch chunks, which are conveyed to a 450,000 ton capacity stockpile. Unlike some other facilities, HTC uses this single stage crushing. From the stockpile, crushed crude ore is conveyed into one of nine 36 foot diameter autogenous grinding mills, each of which is equipped with two 6,000 HP motors. Water is added and as the ore tumbles it reduces itself in size to 75 percent finer than 325 mesh (43 m). Autogenous grinding is now enhanced with use of pebble crushers. Following two stages of wet magnetic separation, without any

flotation step, a concentrate averaging 66 percent iron is delivered to the pellet plant. **Pelletizing** Inthe pellet plant, the concentrate is thickened. Vacuum disc filters reduce the concentrate’s moisture content to 9 percent. About 10 pounds of bentonite clay is added to one ton of moist concentrate. Large rotating drums are used to roll the resultant material into “green balls.” The unfired balls are next conveyed into one of three straight grate furnaces and heat hardened at about 2450 oF. The final product, a pellet averaging 66 percent iron, has physical characteristics such as size and durability that make it well suited for the iron making blast furnaces. **LTV Steel Mining Company (LTVSMC)** MPCA Report Page 11 

### With latest reported plant capacity at 8.0 million long tons (8.96 million tons) of standard pellets per year, the LTVSMC facility has operated on a continual basis since start-up in 1957. The average annual production, shown in Table 2, is 8.56 million tons. It is not unusual for a plant to produce more pellets in a year than originally expected (plant anticipated production rate is reported at the beginning of the year). Founded as Erie Mining Company, LTVSMC was one of the first taconite pro duction facilities on the Mesabi Range and in the iron mining industry as a whole. The pellet plant was expanded in 1967. LTVSMC ownership (including controlled- lease) includes approximately 65,000 acres (the largest track of land among taconite facilities in Minnesota), a company- owned railroad (approximately

74 miles in length to Taconite Harbor on Lake Superior), and a steam electric generating station and a dock facility at Taconite Harbor. LTVSMC remains a competitive taconite pellet producer, mainly because it generates its own electricity (slightly more than its own consumption), and it owns its railroad for transporting pellets to Lake Superior. **Mining** Millions of tons of overburden (rock and other surface material) must be removed before drilling and blasting can be performed. More than 28 million tons of magnetic crude ore are mined each ye ar to meet current production needs. Holes of about 16 inches in diameter and 45 feet in depth are drilled into the taconite ore. Explosives are pumped into the holes, and blasts are fired to free the magnetic taconite ore. Electric shovels with up to 33 cubic yard buckets load the crude ore into 170 and 240 ton haulage trucks, which transport the ore to loading pockets (including two Super Pockets), where it is transferred to 85 ton rail cars for transportation to the coarse crusher. **Crushing and Concentrating** Inthe first two stages of coarse crushing, crude ore is reduced from “run- of -mine” size to 6 inch size by 60 inch and 36 inch gy

ratory crushers. Two additional fine crushing stages use cone crushers to further reduce the material to about one inch. The crushed ore is then conveyed to the quarter-mile - long concentrator. Rod mills are used to grind crushed ore to nominal size of less than 1⁄4”. Ball mills are used to further reduce it to pass 10 mesh. Magnetic separation, hydraulic classification and silica flotation are used to make final concentrate. Before concentrate slurry goes to the vacuum disc filters from the thickener, it is pumped to the heat exchanger on top of 12 pelletizing furnaces (Figure 7) to recover some heat in the pelletizer’s waste gas, or “top gas” as it is called at LTVSMC. As this report was being finalized, LTVSMC had agreed to add heat exchangers or auxiliary emission control equipment to the remaining 12 pelletizing furnaces.MPCA Report Page 12 

### Pelletizing Inthe pellet plant, the concentrate slurry is thickened and vacuum filtered. The resultant concentrate, with about 10 percent moisture and 67 percent iron, is mixed with bentonite clay and rolled into “green balls” in balling drums. The green balls are charged at the top and descend through 24 vertical shaft furnaces, as shown in Figure 4, where they

are heat hardened at 2350 oF. Discharged pellets are screened and transferred on conveyor belts to stockpiles for cooling prior to shipping. All 24 furnaces are equipped with a multiclone for primary cleaning of top gas. The retrofit for heat recuperation of top gas of 12 furnaces (Figure 7), which resulted in lower particulate emissions, is like a spray

tower except that the scrubbing media is not pure liquid but taconite concentrate slurry. About 25 percent of the total air enters the furnace through the hot- gas inlet around 2350 oF. Pellets in this zone of the furnace reach temperatures of 2400 oF or higher due to the exothermic conversion from magnetite to hematite. The remaining 75 percent of the furnace air enters via the cooling- air inlet. Discharged pellets are at about 700 oF, and top gas temperature is below 400 oF before it reaches the multiclone. **EVTAC Mining, LLC** On December 1, 1996, EVTAC, a recently established Minnesota limited liability company, acquired the Thunderbird Mine and Fairlane Plant facilities from Eveleth Mines, a partnership. EVTAC and Northshore are the only two companies that have the pelletizing facility apart from the mining facility. The Thunderbird Mine is located at Eveleth. The Fairlane Plant is located near Forbes, 10 miles south of the Thunderbird Mine. Railroads, one of which is ten miles long and the other twelve miles long, connect the two separate facilities. The facilities were built in 1965 with the Fairlane plant having one pelletizer capable of making 1.7 million long tons (1.90 million tons) of fired standard pellets per year. Production capacity was expanded in 1976 with installation of another pelletizer capable of making 3.7 million long tons (4.14 million tons) of fired standard pellets per year. The overall plant capacity is 5.4 million long tons (6.05 million tons) per year. The average annual production, shown in Table 2, is 5.69 million tons. It appears that the concentrator is the bottleneck for the overall plant production. On February

15 1999, EVTAC decided to idle Line 1 by May 31, 1999, and to focus on continuing and enhancing taconite pellet production with Line 2. This action was similar to the one taken by

National Steel Pellet Company in January

1980. Based on published production data from 1995 through 1997, Line 1 made about 45% of the pellets Line 2 did, while Line 2 consumed about 45% of the energy Line 1 did. Being an old line, Line 1 is not retrofitted for heat recuperation. With Line 1 shut down, the latest plant capacity is reported as 3.5 million long tons (3.92 million tons) per year.MPCA Report Page 13 

### Mining and Coarse **Crushing** Taconite ore can be mined from the North and South Mines, though the South mine has been inactive for more than 5 years. The mining operations include the removal of overburden material, removal of waste rock material, and the mining of taconite ore. Crude taconite ore is loaded onto trucks and hauled to either the North or South Crusher (also inactive the past 5 years) areas for primary

and secondary

crushing. Crushed ore is then loaded onto railcars and transported to the Fairlane Pant for further processing. **Fine Crushing and Concentrating** Fine crushing is performed with third and fourth stage crushers at Fairlane Plant. Coarse tailings are hauled away

by trucks and used as construction material for the tailings basin sidewalls. Fine tailings are pumped in slurry form to the tailings basin. Grinding and magnetic separation are wet operations. Flotation is not used at EVTAC. **Pelletizing** At the pellet plant, the concentrate is mixed with various additives to produce a mixture, which can be formed into green balls in a balling drum. For many years, EVTAC has used organic binders as an alternative to bentonite clay. There are five balling lines upstream of Line 1 pelletizer (“etco,” as it was referred to in old documents) and seven balling lines upstream of Line 2 pelletizer (“exco”). EVTAC uses the grate -kiln pelletizers. Line 1 pelletizer is fired with natural gas. Line 2 can be fired with coal -petroleum coke blend fuel or natural gas. Like other taconite facilities, fuel oil is used as backup fuel, when there is a natural gas curtailment during the winter. Waste gas stacks of Lines 1 and 2 are cleaned with venturi wet scrubbers, not venturi -rod wet scrubbers commonly used in other taconite facilities. **National Steel Pellet Company (N SPC)**  InAugust 1997, NSPC became the first taconite mining and processing company to receive a Title V permit. The permit authorizes operations of Phase II equipment and a portion of the Phase Iequipment. NSPC has received MPCA approval for a fugitive emission control plan and an operation and maintenance plan for its air pollution control equipment. NSPC is a wholly- owned subsidiary of National Steel Corporation. The current company structure emerged after a year- long Company lockout from August 1, 1 993 through late in August 1994. Employees, now also owners of the company, participate in NSPC’s decision making process. Phase Iof the NSPC facility started up in June 1967, with a rotary hearth pelletizing process, which had never been tried before. After many months of unsuccessful operation, a more conventional grate -kiln system was installed (the period for construction was from September 1968 to March 1969). In 1977, Phase II expansion added another grate -kiln system. Phase I pelletizer was shut down in January 1980 and written off in 1983, according to Skillings Mining Review (July

25, 1998).MPCA Report Page 14 

### NSPC has shown its ability to operate a grate -kiln pelletizer well above design capacity, based on production data from 1967 through 1998. The maximum a nnual production for the Phase I, reached in 1971 (the second full calendar year after the grate -kiln system’s installation), was 2.81 million long tons (3.15 million tons) of fired standard pellets. The maximum annual production for Phase II,reached in 1998, was 5.29 million long tons (5.92 million tons) of fired partially fluxed pellets. This is an increase of 88 percent from the annual production of Phase II in 1979 (the second full calendar year after the installation of Line 2), which can be estimated as about 2.81 million long tons (3.15 million tons) of fired standard pellets. NSPC is well known in the taconite industry

for repeatedly

achieving annual, single - line production records. The latest plant capacity is reported as 5.3 million long tons (5.94 million tons) per year. **Mining** Mining activities include overburden removal, drilling, blasting, and removal of waste rock and crude taconite ore. NSPC blasts waste rock one to five times per year and crude ore once per week during daylight hours. Crude ore is hauled by trucks to the primary

crushers. **Crushing and Concentrating** Similar to HTC, NSPC crushes crude ore in a single stage. Chunks of crude ore as large as 5 feet are reduced to 6 inches in size or smaller by one of the two gy

ratory crushers. Crushed ore, minus six inches in size, is charged with forged steel balls, into 7 or 8 of 10 grinding lines, each equipped with a 27 - ft diameter wet semi - autogenous grinding (SAG) mills and Derrick screens, that are active at any one time. When red

uced to about the consistency of sand, the material is drawn out of the mills as a slurry. The remaining part of the concentrating circuit includes cyclones, hydroseparators, wet magnetic separators, ball mills, and screens. Flotation is not used at NSPC . **Pelletizing** Inthe pellet plant, about 16,000 long tons (near 18,000 tons) of pellets are made daily. After the dewatering step with vacuum disc filters, the concentrate (filter cake) is added to bentonite clay, or an alternative binder, and other additives such as fluxstone. The moist, solid material forms “soft” or “green” pellets in any one of the eight balling drums (12’ in diameter and 33’ in length). NSPC is permitted to make semi - fluxed pellets with fluxstone content up to 1.5 percent by

weight . Fired pellets are screened to remove fine particles. Phase II pelletizer is fired with natural gas as the primary fuel and distillate oil as the backup fuel. Each of the two waste gas stacks is equipped with a multiclone. **Northshore Mining Company (N MC)**  NMC, formerly

known as Reserve Mining Company, operates a taconite mine at Babbitt and a processing plant at Silver Bay. A 47 -mile rail road links the mine to the plant (Figure 1). The Silver Bay

plant is the oldest one in the U.S. taconite processing industry. Furnaces 1 through 6MPCA Report Page 15 

### were built in 1954 (Table 2), each of which was designed to make about 1 million long tons of pelleters per year. Furnaces 11 and 12 (manufactured by Arthur G. McKee Company, second generation of straight grate furnaces) were built in 1962, each of which was designed to make 2 million long tons of pellets per year. The tailings basin (“Mile Post 7”) was designed to handle the 10 million long ton production level. The latest plant capacity, with Lines 6, 11, and 12 in active production, is reported as 4.7 million long tons (5.26 million tons) per year. The first load of taconite pellets was shipped out of the plant on September 13, 1956. Figure 8 shows the history of NMC’s pellet production. Inthe 1970s, federal and state court decisions made the Reserve Mining Company change some of its production practices. Lake dumping of tailings was changed to on- land disposal at Mile Post 7, and most air pollution control measures at the Silver Bay plant were upgraded. Then, Furnaces 1 through 4 were shut down in 1981 (and removed in 1998), and Furnaces 5 and 6 were shut down in 1982. In 1986, Reserve filed for bankruptcy. Cy prus Amax Minerals Company was the successful bidder for the Reserve assets. Cy prus Northshore Mining Corp. resumed pellet production in 1990. In June 1995, Furnace 6 returned to production to supplement Furnaces 11 and 12. On June 30, 1994, Cleveland- Cliffs purchased Cy

prus Northshore Mining Corp. and renamed it Northshore Mining Company. NMC’s existing mining and processing operations are summarized in Figure 9. The reader can compare it to Figure 6 to learn from different process designs. Since 1998, NMC has proposed to replace the idle, yet still permitted Furnace 5, with a pig iron production line . The proposed project, already submitted for environmental review, consists of raw material handling processes, two Rotary Reduction Furnaces (RRFs), one Submerged Arc Furnace (SAF), three off

- gas conditioners (boilers, one for each furnace), and product handling processes. NMC is calling the project its direct reduced iron (DRI) project. **Mining** Inthe Reserve years, much of the overburden at the Babbitt Mine was removed. After blasting, crude ore is truck hauled to the coarse crushers for primary and secondary

crushing. Crushed crude ore is transported by railcars to the Silver Bay plant for subsequent crushing and further processing. **Crushing and Concentrating** As mentioned at the beginning of this Package, the ty pe of magnetic taconite near NMC’s Ba bbitt Mine and LTVSMC’s facility is different from others on the Mesabi Range. According to NMC, the crude ore is harder at the eastern part of the Mesabi Range than at the western part, demanding more energy

in crushing and grinding for NMC. Dry cobbers (dry

magnetic separators) were added as an additional removal step. At the concentrator, rod mills and ball mills are used for fine grinding. Each grinding step is followed with magnetic separation. The concentrating process ends with an amine flotation step.MPCA Report Page 16 

### Pelletizing NMC is the only

taconite plant that makes fully fluxed pellets (FFP, Table 2) without the need to add auxiliary

burners to the pelletizer (straight grate ty pe). Fluxstone content in the fired pellets is about 4.95% at NMC, compared to 8.15% at U.S. Steel Minntac and 10.7% at Ispat- Inland Steel Mining Company. Furnaces 11 and 12 have been retrofitted with heat recuperation. Being older, Furnace 6 does not have heat recuperation. Unlike HTC’s pelletizers (Figure 3), each of NMC’s Furnaces 11 and 12 have two common headers, one of which is connected to three hood exhaust stacks, and the other is connected to two waste gas stacks. All five pelletizer stacks are outfitted with wet wall electrostatic precipitators (WWESPs). **Ispat -** **Inland Steel Mining Company**  Formerly known as Inland Steel Mining Company or the Minorca Mine, the facility received its present name just before January 1, 1999. Ispat- Inland is the smallest taconite pellet producer in the U.S. taconite industry with one straight grate pelletizer. However, it does make fully fluxed taconite pellets (Table 2). The latest plant capacity is reported as 2.8 million long tons (3.14 million tons) per year. **Mining** After overburden and rock are stripped and trucked to stockpiles, taconite ore is drilled, blasted, and trucked to the processing plant. Unlike other facilities which have a complex system of haulage roads, Ispat- Inland has one 9 mile long, unpaved haulage road linking the mining areas to the processing plant. **Crushing a nd Concentrating**  Taconite ore is crushed to football size chunks in the primary crusher and moved by

conveyor belt to an intermediate stockpile. Fine ore results from second and third stage crushing. Then rod and ball mills grind the fine ore to face powder size to facilitate magnetic separation of ironbearing particles from waste material (tailings). **Balling** Different from other facilities, Ispat- Inland uses balling discs, rather than balling drums, to make green balls from moist concentrate. Discs take much less space than drums do. However, they present a challenge in size control of green balls (unfired pellets). Fluxstone (limestone and/or dolomite) is crushed and ground. It is then mixed with taconite concentrate and a binding agent. Itis rolled into marble size green balls with the balling discs. **Pelletizing** Pellets are heat-hardened at 2400 oF in a straight grate furnace fired with natural gas (distillate fuel oil is used as a backup fuel). Originally, Ispat- Inland’s pelletizer was very similar to the pelletizers used at Hibbing Taconite Company (Figure 3). In order to make fully fluxed pellets, the pre -heating zone was modified to add auxiliary burners. All four stacks of the pelletizer are controlled with wet scrubbers.MPCA Report Page 17 

### Package 2 **EMIS SIONS OF HAZARDOUS AIR POLLUTANTS AND PM**  **10**



### FROM U.S. TACONITE IRON ORE INDUSTRY Existing emission testing results, material composition data, pellet production, and indurating fuel usage data from the seven companies in Minnesota establish a broad informa tion base for emission estimates presented in this package. The two companies in Michigan also provided relevant process and emission information. See Table 3 for a summary description of past testing of the taconite facilities. Based on calculations made with existing information, each of the nine U.S. taconite mining and processing facilities emits more than 25 tons of all hazardous air pollutants (HAPs) combined, as shown in Table 4. This information was shared with all parties -- industry representatives, consultants, and staff of the Minnesota Pollution Control Agency (MPCA), Michigan Department of Environmental Quality (MDEQ), and the United States Environmental Protection Agency (EPA) -- at meetings and/or telephone conferences. It was also made available to local government representatives and the general public. Current air pollution control measures, which have been used primarily for PM emission control, have some widely

different effects on HAPs emissions from taconite ore mining and process ing facilities. For acid gases such as HCl and HF, wet control devices such as wet wall electrostatic precipitators and venturi -rod wet scrubbers have the capability of reducing HCl and HF emissions substantially, if the pH of the scrubbing liquid is maintained properly. In an engineering test at Northshore in January 1992, control efficiency

for HCl or HF was determined to vary from 74% for one run to 97% for another run. Dry control devices such as multiclones and gravity

collectors can be assumed to have no control of acid gas emissions. This is supported in part by

the August 1999 engineering test conducted at National Steel Pellet Company. It is well known and verified by the testing summarized herein that venturi -rod wet scrubbers and ESPs

– wet or dry ty pe – are more effective and efficient than multiclones and gravity collectors for PM emission control. Products of incomplete combustion (PICs) such as formaldehyde, benzene, toluene, and hexane do not appear to be affected by current air pollution control devices. Volatile elements such as mercury, arsenic, selenium and cadmium have shown a more complex picture on control equipment effects. Although boiling point temperatures for the volatile elements in pure substance (or element) form are lower than the peak gas stream temperature in the pelletizer (2400 oF), they are higher than the waste gas temperature at the stack (from 100 to 300 oF). Past testing of one straight grate and three grate -kiln pelletizers showed the following: more than 96 p ercent of the mercury captured with the Method 29 sampling train was found in the “back half,” more than 90 percent of the arsenic captured was found in the “front half,” cadmium captured in the “front half” ranged from 52 through 86 percent, and selenium captured in the “front half” ranged from 75MPCA Report Page 18 

### through 90 percent. This suggests that mercury is likely emitted in the vapor phase (“elemental mercury”), while arsenic, cadmium, and selenium are likely emitted with particulate matter (PM). Some of the current PM/PM 10 

### emission control measures can be considered as effective surrogate control measures for more than 95 percent, by weight, of the elements for Reference Method 29. This estimate is based on a preliminary level of review of the data and the following assumptions: 1) only

mercury and selenium are emitted in the vapor phase and all other Method 29 elements are emitted as PM; and 2) past Method 29 testing results are representative of current pelletizing operations. For this reason, stack testing re sults for emissions of particulate matter (PM) and particulate matter of 10 m or smaller (PM 10

### ) have been reviewed. Figures 10 through 12 show controlled PM 10 

### or PM emissions (individual run data) associated with wet scrubbers, electrostatic precipitators, and multiclones for the taconite pellet indurating process. ( Data for Line 3 of U.S. Steel Minntac are placed in Figure 12, even though its waste gas stack is equipped only with “drop boxes,” instead of a multiclone. The drop boxes are also called gravity collectors, as shown in Table 2. ) The curves plotted in Figures 10 through 12 represent Minnesota’s PM rule and are used as a benchmark. In general, if the average data point from a three -run test is below the curve in either one of the charts (a) and (b), the test is concluded to be in compliance with the PM rule. Table 5 provided the complete concentration data presented in chart (b) of Figures 10 through 12. Itshould be noted that the benchmarks are not meant to suggest a particular formulation for emission limits, which may be used for the taconite MACT standard. It should also be pointed out, that Northshore Mining Company ’s processing plant is subject to modeling based PM emission limits for all stacks, which are more stringent than the Minnesota’s PM rule. The air quality dispersion modeling was performed in the permitting process to authorize the resumption of pellet production at NMC’s plant in 1990. The MPCA has been working with the facilities that use grate -kiln pelletizers (U.S. Steel Minntac, EVTAC, and National Steel Pellet Company ) to bring the cooler vent stack PM emissions into compliance with the state’s PM rule. The original designer of the process equipment did not incorporate installation of any dust collector for the vent stack of the annular pellet cooler. Current operational practices (fully fluxed pellet production, alternative binders, and/or increased production rate) appear to have increased the PM emissions from this stack. For the remaining part of Package 2, infor mation will be presented for individual facilities in the following order. 1) If HAPs emission factors have been derived from a facility ’s own stack testing, a summary

of the HAPs testing results will be presented. 2) If material composition has been analy

zed for a facility, a summary of the analysis will be presented. 3) HAPs emission estimates will be presented, whether emission factors are source- specific or derived from HAPs testing elsewhere in the industry. 4) PM 10 

### or PM testing results in recent years will be presented. Of all HAPs, mercury

is the most tested one. All nine taconite facilities have conducted mercury emission testing at the pelletizer waste gas stack(s). Some facilities tested twice or three times.MPCA Report Page 19 

### Some facilities also performed a mercury mass balance for the pelletizing process to compare with the stack testing results. Mercury analysis of materials was also reported by most facilities in Minnesota. Many

of these voluntary

efforts in Minnesota were made in the wake of a report to the Minnesota Pollution Control Agency for Minnesota legislators on the mercury atmospheric emission from the state’s taconite pellet production (CMRL industry report, dated September, 1997). As of October 1999, the MPCA has provided the EPA three mercury mass balance reports (including the CMRL industry report) and nine mercury stack test reports (including one for the speciated mercury testing conducted at Hibbing Taconite Company from September 29 through October 2, 1998). As indicated in Package 1, mineral fibers (iron amphiboles

– grunerite, cummingtonite, actinolite

– and others) are found in ore deposits on the Mesabi Range east of Aurora (Figure 1 & Table 1). The Clean Air Act, as amended, lists “fine mineral fibers” as a hazardous air pollutant in Section 112 (b)(1). However, it is not clear if the amphibole fibers found at the eastern end of the Mesabi Range fall under the federal definition of fine mineral fibers, as far as regulatory applicability

is concerned. Public concerns on potential health implications of mineral fibers have largely been associated with Northshore Mining Company, especially its proposed new taconite ore processing technology

– direct reduced iron (DRI). DRI, including other variants of this technology, have been suggested as a way to add value to the current taconite concentrate pelletizing technology. In addition to the proposed DRI project by Northshore Mining Company, a new steel mill -- incorporating taconite mining and processing and direct reduction technology (Minnesota Iron and Steel Company ) has commenced the first stages of environmental review (Minnesota Department of Natural Resources is the responsible government unit). Inland Steel Mining Company and National Steel Pellet Company have proposed their own DRIprojects over the last few years but failed to get corporate funding. **U.S. Steel Minnesota Ore Operations (Minntac)** Minntac has made great efforts to generate its own mercury emission estimate for the pelletizing process. The CMRL

report’s mercury

mass balance study

was followed with an improved mass balance study

by the CMRLstaff and concurrent stack testing using Reference Method 29 for mercury. The resultant mercury emission estimate is used where appropriate. As shown in Table 3, Minntac has not conducted stack testing for any other HAP. The total HAPs emission estimate, of 342 tons of HAPs per year as shown in Table 4, is attributed mainly to the use of emission factors generated from other taconite facilities. Table 6 details HAPs emis sion estimates for pellet firing processes. Table 7 details HAPs emission estimates for offpellet firing processes. Figure 5B shows the gas and pellet flows of the grate -kiln system at Minntac. For grate -kiln system of higher capacity (for example, EVTAC’s Line 2 or NSPC’s Phase II), the waste gas stream is split into two, side -by- side, stacks.MPCA Report Page 20 

### The emission estimate for hydrogen chloride (HCl), in Table 6, needs some explanation. Fluxstone has been suggested as the major source of chlorine (Cl) to the pelletizer. One would suspect taconite ore as another possible source of chlorine. For pelletizers which have wet control devices for the waste gas stream, the following linear regression equation can be used to estimate controlled emissions of HCl.

EHCl 

### = 0.00448 + 0.09407  Rfluxstone 

### [1] Where EHCl 

### is the predicted controlled emission factor, lb HCl/ton pellets fired; Rfluxstone 

### is the mass fraction of fluxstone in the fired taconite pellet. Figure 13 is a graph of the equation and the data points resulting from four stack tests. The regression model has an R2 

### value of 0.591 and an adjusted R2 

### value of 0.386. The slope has a p value of 0.231. The intercept has a p -value of 0.332. Statistically, equation [1] is not a good fit because of limited stack testing data. An alternative HCl emission estimation method would be to use an EHCl 

### value of 0.01776 lb HCl/ton pellets fired, obtained from stack testing at Inland in June 1997. This alternative method would lead to a slightly inflated emission estimate for Minntac and very

significant over- estimations for other facilities that do not have the high fluxstone usage that Inland has. For pelletizers which have dry control devices for the waste gas stream such as Minntac’s Line 3, HCl emission estimate can be made with results of stack testing conducted at National Steel Pellet Company

in August 1999, 0.03096 lb HCl/ton pellets fired. The emission estimates for “metals” (the elements determined with Reference Method 29) atpelletizing, shown in Table 6 , need some further clarification. While most metal emission factors have been developed from stack testing conducted at pelletizers that are equipped with wet control devices, additional metal emission factors have been generated from the August 1999 stack testing at National Steel Pellet Company, which uses dry control devices (multiclones) for waste gas cleaning. For Minntac’s Lines 4 through 7, metal emission estimates are calculated with the emission factors associated with wet control devices. Metal emission estimates for Line 3 are calculated with the emission factors developed from the NSPC stack testing results. Table 7 also deserves some discussion. As stated in Package 1, for off -pellet firing processes, the PM emitted into the air is assumed to have the same element composition as the feed, so that emissions can be estimated by multiplying the PM emissions by the proper composition data. Since the available element composition data is limited to several solid materials, PM emissions, obtained from the MPCA’s Emission Inventory, are divided into several groups (for example, ore, bentonite, greenballs, fired pellets, and fluxstone unit processes). Since Minntac does not report composition data, for each group, composition data available from other mines are averaged and used for emission estimation for the off -pellet firing processes at Minntac. The data in Table 7 show that PM emissions for off -pellet firing processes vary widely from one facility to another, and from one year to the next for the same facility. There are reasons for these variations. PM emissions are no longer used to calculate emission fees, thus they are notMPCA Report Page 21 

### verified by

MPCA staff. In addition, MPCA staff made some policy changes during 1995 - 1997 regarding reported effici ency values for air pollution control devices for the Emission Inventory. Regardless of emission fee calculation and allowed control efficiency values in reporting, facilities such as Minntac that use three or four stage ore crushing circuits generally emit more PM than those using one stage ore crushing for that part of the overall ore processing operation. From the three annual sums of element emission estimates (1995, 1996, and 1997) in Table 7, the median value, 24.9 ton HAPs/year of 1995, is selected as the total HAPs emission estimate for off -pellet firing processes at Minntac. This is less than the “metals” emission estimate from the pelletizers, 54.6 ton/year, in Tables 4 and 6. Itshould be emphasized that, except for mercury, HAPs emissions may have been over- estimated for Minntac. This, however, follows the conservative conventions in regulatory applicability determination, when there is little source - specific emission information. Finally, source - specific stack testing results of PM 10 

### emissi ons at the pelletizers’ waste gas stacks are presented in Table 8. ( The data in Table 8 reflect “total catch,” which consists of “front half” and “back half.”) The information in this table has been used in Figures 10 and 12 as well as Table 5, in a general discussion of potential HAPs emission control by means of controlling a surrogate air pollutant. The reader is reminded that Minntac’s Lines 4 through 7 are equipped with venturi -rod wet scrubbers to control particulate emissions from each waste gas stack, and Line 3 is equipped with only “drop boxes” (gravity

collectors, as called in Table 2) for particulate emission control at the waste gas stack. Reference Method 5, which is for PM sampling at point sources, is used at Minntac’s Lines 4 through 7 to provide, in the MPCA’s view, a conservative estimate of the “dry catch” or “front half” data for PM 10 

### . The MPCA’s view is based on a recent testing study conducted by

a testing company for the MPCA on particulate matter testing methods at selected emission sources including a taconite pelletizer. Reference Method 202 is used to assess the “condensibles” or “back half” data. These two methods generated PM 10 

### emission estimates for Lines 4 through 7 with adequate data quality. Since Line 3 does not have as good a control device as a venturi -rod wet scrubber, Reference Method 201A was used, instead of Method 5, to get a realistic estimate of the “dry

catch” or “front half” data for PM 10 

### . The reader will find similar situations later in the tabulated PM 10 

### data of LTV Steel Mining Company and National Steel Pellet Company. **Hibbing Taconite Company (HTC)** HTC is one of the best tested facilities in the industry, as shown in Table 3. Emissions of mercury and other metals were determined by Braun Intertec during June 1994 performance test using Reference Method 29 (Table 9). HTC also analy zed the composition of some solid materials related to taconite pellet production (Table 10). MPCA staff has just completed a review of a speciated mercury emission study

done for HTC by

the University

of North Dakota Energy & Environmental Research Center (the testing period was from September 29 to October 2, 1998).MPCA Report Page 22 

### The resultant emission factors for total mercury emissions are close to each other, with 12.4 nanogram of mercury

per gram of pellets fired (ng/g) from the 1998 test and 11.4 ng/g from the 1994 test. The mass ratio of ng/g in SI units is equivalent to “parts of mercury per 1 billion parts of pellets fired, by

weight (ppbw),” which should not be confused with a concentration unit of “parts of a pollutant per 1 billion parts of fluid, by volume (ppbv).” Furthermore, “ppb” is used in this report for the mass ratio expressed in “ppbw,” to simplify presentation in the text and the tables. Test runs were from 120 to 150 minutes for the 1998 test, and 60 minutes for the 1994 test. All four stacks of Line 2 were tested in 1998, while two of the four stacks of Line 1 were tested in 1994. The 1998 test found that greater than 94 percent of the mercury emitted from the stacks were in element form (Hg0

### ), with the remaining part as oxidized mercury (Hg2+

### ) and very

little bound with particulate matter. Assessment of mercury control efficiency

of the venturi -rod wet scrubbers was attempted during the 1998 test by sampling at the two inlet ducts of the common exhaust header, in addition to the sampling of the four stacks. An estimate of 20 to 30 percent was made for the control efficiency of total mercury. This, however, should be used with caution, because a scientifically acceptable assessment on mercury control efficiency

requires six sampling trains be placed for simultaneous sampling at the four stacks and the two inlet ducts. The 1994 test did not involve any inlet sampling. Stack testing for the products of incomplete combustion (PICs), hydrogen chloride (HCl), and hydrogen fluoride (HF) was conducted at HTC, although the detection limits in chemical analysis were higher than desired for this review for some pollutants (Table 11). The HCl emission data contributed to the linear regression model, equation [1] and Figure 13, which made it possible to estimate HCl emissions from some untested facilities. With all the underlying source - specific information, HAPs emissions estimates for HTC may be of the highest quality for the entire taconite mining and processing industry. Table 12 shows HAPs emission estimates for at-pellet firing processes. Table 13 summarizes HAPs emission estimates for off

-pellet firing processes. The total HAPs emission estimate for HTC, as shown in Table 4, is 32.6 ton per year. This is the lowest HAPs emission estimate among the nine taconite ore processing facilities in the U.S. Still, it is greater than the threshold value of 25 tons per year for a major HAPs emission source. Thus, all taconite ore processing facilities in the U.S. should be considered as major sources for HAPs emissions. PM emission testing was done thoroughly at all three pelletizers at HTC in 1994 using Reference Methods 5 and 202. Since all pelletizer stacks were controlled with wet scrubbers, the testing results provide conservative estimates for PM 10 

### emissions. Line 2 was again tested in July 1999. Table 14 presents the testing results. As shown in Figure 3, straight grate pelletizers have at least four stacks. Sometimes, a straight grate facility

would choose to conduct stack testing at some of the stacks in order to save testing cost. However, HTC often conducted stack testing at all four stacks. Since stack variation is different from one pollutant to another, HTC’s approach of testing all stacks has been required for compliance testing and should be encouraged for voluntary testing.MPCA Report Page 23 

### LTV Steel Mining Company (LTVSMC) LTVSMC participated in the 1997 CMRL industry study for mercury

atmospheric emissions using a mass balance approach. The MPCA review of the study report suggested an emission factor of 1.91 ppb by

weight of pellets produced for mercury emissions from the vertical - shaft furnace top gas. The emission factor was the average value of 2.25 ppb calculated for a furnace without heat recuperation and 1.58 ppb calculated for a furnace with heat recuperation. Direct stack testing at the furnace without heat recuperation, conducted on April 15, 1998, resulted in an emission factor of 4.33 ppb. LTVSMC has conducted stack testing for benzene, toluene, hexane, and formaldehyde (Table 15). Among the three taconite facilities, which conducted stack testing for these products of incomplete combustion (PICs), LTVSMC used the lowest detection limits in the chemical analysis. No stack testing was conducted for the elements of Reference Method 29 (“metals”), hydrogen chloride, or hydrogen fluoride. Table 16 shows HAPs emission estimates for LTVSMC’s taconite pelletizers. Notice that, like in Table 6 for U.S. Steel Minntac, the metals emissions are calculated with different emission factors, depending on whether a wet control device is used for waste gas cleaning. Recall that all 24 pelletizers are equipped with a multiclone for top gas cleaning, 12 of which are added with a heat exchange (concentrate slurry scrubbing), somewhat similar to wet scrubbing. Metals emission estimates for off -pellet firing processes are given in Table 17. The total HAPs emission estimate for LTVSMC, summarized in Table 4, is 169 ton per year. PM 10 

### emission testing results at LTVSMC’s pelletizers’ top gas stacks are shown in Table 18. The information in this table has been used in Figures 10 and 12 as well as Table 5. As indicated in Package 1, mineral fibers (iron amphiboles

– grunerite, cummingtonite, actinolite

– and others) are found in ore deposits on the Mesabi Range east of Aurora (Figure 1 & Table 1). LTVSMC and NMC’s Babbitt Mine are in this area. LTVSMC closed its Dunka mine, which is east of Babbitt and known to contain mineral fibers; however, fibers are also found in ore from LTVSMC’s eastern mining areas.MPCA Report Page 24 

### EVTAC Mining, LLC Emission rates of mercury and other elements were determined through stack testing using Reference Method 29 at EVTAC’s Fairlane Plant in 1997. At the same time, the Coleraine Minerals Research Laboratory performed a mercury

mass balance study. Mercury emission factor from stack testing is 11.16 ppb by weight of pellets fired, compared to 10.48 ppb from the CMRLstudy. These values are the average of both pelletizer lines. Table 19 gives the stack testing results. Table 20 shows some composition data provided by EVTAC. No stack testing was conducted at EVTAC for benzene, toluene, hexane, formaldehy de, hydrogen chloride, or hydrogen fluoride. Highest values of relevant emission factors from other taconite facilities were used. HAPs emission estimates for the pelletizers are shown in Table 21. Notice that metals emission estimates are calculated from line - specific emission factors, shown in T able 19, weighted with line production data. HAPs emission estimates for off -pellet firing processes are summarized in Table 22. The total HAPs emission estimate for EVTAC, summarized in Table 4, is 74.9 ton per year. PM testing results with Reference Methods 5 and 202 are given in Table 23, as conservative estimates of PM 10 

### emissions. The information has been used in Figure 10 and Table 5. As noted previously, Line 1 has one waste gas stack and Line 2 has two, side -by- side waste gas stacks. Figure 5(b) shows the relative location of the waste gas stacks to the rest of the grate -kiln system. **National Steel Pellet Company (NSPC)** NSPC is the facility

that has done the most recent HAPs testing. The August 1999 stack testing results are summarized in Ta ble 24. Because NSPC uses dry control (multiclones) for waste gas cleaning, acid gas (HCl and HF) emissions are very high, while other HAPs emissions are low (Tables 25) due to the use of source - specific emission factors. Table 26 provides estimates of HAPs emissions from off -pellet firing processes. The total HAPs emission estimate for NSPC, summarized in Table 4, is 248 ton per year. NSPC has conducted stack testing for PM 10 

### emissions from one of the two pelletizer’s side -byside waste gas stacks using Reference Methods 201A and 202. Testing results are given in Table 27. The information has been used in Figure 12 and Table 5. **Northshore Mining Company (NMC)** Because the processing plant is on the shore of Lake Superior with a state highway (Minnesota Highway 61) running through the middle of the plant as well as its past practice of tailings disposal in Lake Superior, NMC has been under public scrutiny for many years. The recent DRI proposal has renewed public attention, especially with the issues of emissions of fine mineral fibers and mercury. While the stack testing and ambient monitoring results of mineral fibers generated by Northshore are of limited use to the other taconite companies in the U.S., NMC has conducted three stackMPCA Report Page 25 

### tests for metal s (mercury and others) emissions using Reference Method 29 and generated useful composition data for various materials. Table 28 shows Reference Method 29 testing results at NMC’s pelletizers. Table 29 summarizes composition data from NMC. It should be noted that metals testing was also conducted at gas stream inlets (common exhaust headers) during each stack test to assess collection efficiency of air pollution control equipment. However, because of data quality

problems, inlet testing or collection ef ficiency of metals are not presented in this Package. ( These subjects, especially mercury, are among the most important ones for the proposed DRI project; a complete analysis on control equipment performance for mercury emissions should include the gas stream, liquid stream, and the captured solid stream

-- NMC uses “wet-walled EPSs.”) NMC and Hibbing Taconite Company are the two taconite companies that generated their own HAPs emission information (emission factors and material composition data). As indicated before, each of NMC’s Furnaces 11 and 12 have two common exhaust headers, one of which is connected to the three hood exhaust stacks, and the other is connected to the two waste gas stacks. Ty

pically, NMC would conduct stack testing at one of the three exhaust hood stacks and one of the two waste gas stacks. Additional stacks were sometimes probed for flow distribution only. It also should be noted here that, inlet sampling for collection efficiency assessment at NMC’s Furnace 11 or 12 is more likely to succeed at the hood exhaust common header than at the waste gas common header, based on the flow balance seen in recent testing results. The problem may

be attributed to inlet turbulence. Table 30 shows stack testing for formaldehyde, benzene, toluene, and hexane, all products of incomplete combustion (PICs). Table 31 shows stack testing for hydrogen chloride (HCl) and hydrogen fluoride (HF). The hydrogen chloride emission data from NMC serve as the two data points in the middle of the chart of F igure 13, making it possible to generate a linear regression model for predicting HCl emissions from the untested taconite facilities. Table 32 summarizes HAPs emission estimates for the pelletizers at NMC. Table 33 gives HAPs emission estimates from off -pellet firing processes. The total HAPs emission estimate for NMC, summarized in Table 4, is 78.6 ton per year. Table 34 provides stack testing results for PM emissions (Reference Methods 5 and 202 or a Minnesota method for “back half” -- organic wet catch). It should be noted that NMC’s operating permit has an emission limit of 0.01 gr/dscf for PM at the pelletizer stacks, which are controlled with wet walled electrostatic precipitators (WWESPs). This is more stringent than the state’s PM rule (Minn.R . 7011.0735). **Ispat -** **Inland Steel Mining Company** Ispat- Inland has not tested for emissions of products of incomplete combustion (benzene, toluene, hexane, and formaldehyde). However, stack test information for other HAPs, PM, and PM 10 

### can be found in two testing reports.MPCA Report Page 26 

### InJune 1997, Inland conducted a voluntary test at all four stacks of the pelletizer for emissions of hydrogen chloride (HCl), hydrogen fluoride (HF), and PM 10 

### . Table 35 shows testing results from the test. InJuly 1994, Inland conducted an engineering test at Stack D, one of the four stacks of the pelletizer, for emissions of multiple metals, PM, hydrogen chloride (HCL) and fluorides. The reader is reminded of the previous discussion (last paragraph in the section for Hibbing Taconite Company ), in which testing all four stacks would be preferred. Table 36 summarizes the testing results. Table 37 shows composition data of samples of ore composite, green balls, and fired fluxed pellets. Stack D is one of the two “windbox exhaust” stacks at the “hot side” of the common exhaust header (Figure 3). Thus, company personnel considers it the dirtiest stack. Whether the information in Tables 35 and 36 justifies such labeling is subject to each individual’s opinion. For this reason, emission factors for HCl and fluorides in Table 36 are used in subsequent emission estimation calculations (Tables 38 and 39). With the HCl emission data (of HTC, NMC, and Ispat- Inland shown in Tables 11, 31, and 37) the detail of linear regression model analysis -- equation [1], which has been shown in Figure 13

-- can be presented, as in Table 38. Please recall that the resultant equation can be used only for pelletizers with wet control devices for waste gas cleaning. For pelletizers with dry control devices, the August 1999stack testing results from National Steel Pellet Company should be used, instead. Table 39 gives HAPs emission estimates from Ispat- Inland’s pelletizer. Table 40 summarizes HAPs emission estimates for off -pellet firing processes. The total HAPs emission estimate for Ispat- Inland, summarized in Table 4, is 52.3 ton per year.MPCA Report Page 27 

### Package 3 : Bibliography, Tables & Figures **Bibliography** 1. Lankford, William T., Jr.; Samways, Norman L .; Craven, Robert F.; McGannon, Harold E. (Editors). The making , shaping and treating of steel. 10th 

### edition. United States Steel.  1985 Association of Iron and Steel Engineers. 2. Skillings, David N. North American iron ore industry. Skillings’ Mining Review, last weekly issue in July, 1996, 1997, and 1998. 3. Agglomeration special short course. Society of Mining, Metallurgy

and Exploration (SME) Minnesota Chapter, Duluth, MN, April 13, 1999. 4. Jiang, Hongming; Wu, Chun Yi; Biewen, Todd. “Metals emissions from taconite ore processing facilities in Minnesota.” A paper presented at Emission Inventory: Living in a Global Environment, an international sy mposium organized by

Air & Waste Management Association, December 8 - 10, 1998, New Orleans, Louisiana. (Mr. David Z. Skolasinski, of Cliffs Mining Services Company provided Hongming Jiang with the industry ’s comments in his letters dated November 17 and November 20, 1998. The comments were received after the paper was finalized.) 5. Potts, Ray

mond D. Induration of taconite pellets using grate -kiln system at Minntac. Skillings’ Mining Review, August 17, 1991. 6. Minnesota Pollution Control Agency Air Emission Inventory

Database. Reports for 1995 through 1997 provide detailed indurating fuel usage and particulate matter (PM) emission data for the seven taconite companies. 7. Jiang, Hongming. Personal communication with the nine companies on fluxstone usage in taconite pelletizing process. January-February 1999. 8. Jiang, Hongming. Personal communication with Dennis Wagner on the designed capacities of the pelletizers and the fluxstone contents for the hydrogen chloride stack testing in 1992 and 1998 at Northshore Mining Company. September 1999. 9. Jiang, Hongming. Personal communication with Gustav Josephson on the fluxstone content for the hydrogen chloride stack testing in 1997 at Inland Steel Mining Company. September 1999. 10. Engesser, John; Niles, Harlan B. Mercury emissions from taconite pellet production. A report submitted to the Minnesota Pollution Control Agency from Coleraine Minerals Research Laboratory

(CMRL), Natural Resources Research Institute, University of Minnesota Duluth, September 1997. 11. Jiang, Hongming. Mercury atmospheric emissions from taconite pelletizing process. An office memorandum to Edward Swain, Ph.D., Multimedia Integration Unit, Environmental Research and Reporting Section, Environmental Outcomes Division, Minnesota Pollution Control Agency, September 15, 1998.MPCA Report Page 28 

### 12. Jiang, Hongming. Ambient air monitoring for mineral fibers near Northshroe Mining Company : How to evaluate the concentration data from statistic al perspectives? An office memorandum to interested parties. February 26, 1999. 13. Direct reduced iron (DRI) modification: Documentation of emission calculations. Prepared for Northshore Mining Company by Barr Engineering Company. October 1998. 14. Morey, Gl enn B. Chemical composition of the eastern Biwabik iron- formation (early Proterozoic), Mesabi Range, Minnesota. Economic Geology, 1992, 87, 1649 - 1658. 15. Morey, Glenn B.; Lively, R.S. Background levels of mercury and arsenic in paleoproterozoic rocks of the Mesabi Iron Range, northern Minnesota. Minnesota Geological Survey, Information Circular 43. University of Minnesota, St. Paul, 1999. Web site: http://www.geo.umn.edu/mgs. 16. Air toxics: Hazardous emissions from coal combustion. Clean Coal Today (a newsletter about innovative technologies for coal utilization). U.S. Department of Energy, Office of Fossil Energy. Issue No. 25, Spring 1997. DOE/FE - 0215P -25. 17. Moore, Michael P. A timeline of Minnesota’s iron ore industry. An exhibit presented at a conf erence sponsored by

the University

of Minnesota, February

28 and March 1, 1995. University

of Minnesota Office or Research and Technology Transfer. 18. Interpoll Laboratories. Results of the MPCA particulate and PM 10 

### comparative evaluation study. Prepared f

or Stuart Arkley, Minnesota Pollution Control Agency. Report Number 9 - 12423. June 14, 1999. 19. Bartlett, Robert V. The Reserve Mining Controversy: Science, Technology, and Environmental Quality. Indiana University Press, 1980. 20. Bastow, Thomas F. “This Vast Pollution...” United States of America v. Reserve Mining Company. Green Fields Books, Washington, DC. 1986. 21. Weiss, Norman L . (Editor). SME Mineral Processing Handbook. Volume 2. Section 20 (Iron Ore). Published by

Society of Mining Engineers of the American Institute of Mining, Metallurgical, and Petroleum Engineers, Inc. New York, NY. 1985. 22. U.S. Environmental Protection Agency. Compilation of Air Pollutant Emission Factors. AP 42, fifth edition. Volume I : Stationary Point and Area Sources. S ection 11.23. 1995. 23. Guthrie, George D.; Mossman, Brooke T. (Editors). Health Effects of Mineral Dusts. Review in Mineralogy, Volume 28. Mineralogical Society of America. 1993.MPCA Report Page 29 

### Table 1. U.S. Taconite Iron Ore Facility Location * **State Company**  **Mine P**  **elletizing Plant** Minnesota National Steel Pellet Company Keewatin

Hibbing Taconite Company Hibbing U.S. Steel Minnesota Ore Operations (Minntac) Mt. Iron EVTAC Mining, LLC Eveleth Forbes Ispat-Inland Steel Mining Co. Virginia LTV Steel Mining Company Hoyt Lakes Northshore Mining Company Babbitt Silver Bay Michigan Tilden Mining Company, LC Ishpeming

Empire Iron Mining Partnership Palmer * Companies from top down are listed in the order of the westernmost to the easternmost.MPCA Report Page 30 **Table 2. U .S. Taconite Iron Ore Industry Profile**  1 **Com pany**  **Production,** 2

**10 6**  **tons/yr Pelletizer** 

**Type Year(s) Built**  **Prim ary**  **Product** 3 **Second.**

**Prod.** 4 **Process Chem icals** 

**Used** 5 **Emission Control for**

**Waste Gas Stacks** 6 **Energy Used,** 7 **10 6**  **Btu/ton Prim** **ary Fuel Secondary**  **Fuel** USS Minntac 15.55 Grate -kiln 1967 1972 1978 SP, FFP DS, Flot, SM, Frz 1 unit: GC

2 units: WS 2 units: GC -WS 0.560 Natural gas and/or Gas/Sawdust Coal at Lines

6&7; fuel oil at others Hibbing Tac 9.19 Grate 1976, 1979 SP Frz 3 units: WS 0.277 Natural gas Fuel oil #2/#6 Empire 9.11 Grate -kiln 63, 66, 75, 80 SP, FFP Flot, Filt 4 units: DESP 0.482 Natural gas Coal LTV 8.56 Vertical shaft 57, 62, 67 SP PC Flot, CA, Filt 15 units: M

12 units: M -WS 0.459 Natural gas Fuel oil #6 Tilden 7.06 Grate -kiln 19 74 1978 SP, FFP Flot 2 units: DESP 0.589 Natural gas Coal EVTAC 5.69 Grate -kiln 1965 1976 SP, PFP PC DS, WS, CA, SM, Frz 2 units: WS 0.499 Natural gas & coal/coke Fuel oil National 5.65 Grate -kiln 1967, 1977 SP, PFP SM 2 units: M 0.386 Natural gas Fuel oil Northshore 4.52 Grate 1954, 1962 SP, PFP, FFP PC Flot, CA, Filt 4 units: WESP 0.668 Natural gas Fuel oil Ispat-Inland 3.02 Grate 1976 SP, FFP PC DS, Flot, CA, Filt 1 unit: WS 0.474 Natural gas Fuel oil **Total 68.35**  F ootnotes: 1. Except for the data on production and energy used, the information in this table was provided by David Z. Skolasinski, Chair, Taconite Industry MACT Work

Group, April 9, 1999. 2. Average production data of 1995 through 1997, as published in Skillings Mining Review, a trade journal. The average production of 7.06 million tons per year for Tilden in this period consisted of 5.04 million tons of hematite FFP per year, 2.02 million tons of magnetite FFP per year, and no SP. 3. SP is for standard p ellets (no fluxing additives); FFP is for fully fluxed pellets (greater than 1.0 basicity ratio); PFP is for partially fluxed pellets (equal to or less than 1.0 basicity ratio). 4. PC is for pellet chips, a substitute for iron ore sinter feed. 5. Chemicals listed here are not merely limited to the pelletizing process. DS is for dust suppressants; Flot is for flotation process chemicals; SM is for slag mo difier agents; Frz is for freeze conditioning agents; Filt is for filtration enhancement chemicals; CA is for chemical agglomeration agents; WS is for water softeners. 6. This column lists air pollution control equipment for the waste gas stacks. Dash between symbols means control equipment in series. M is for multiclone(s); WS is for wet scrubbers; DESP i s for dry electrostatic precipitators; WESP is for wet electrostatic precipitators; GC is for gravity collectors (“drop boxes ”). Although 15 units are listed here with symbol M for LTV, only 12 units were involved in production in recent years. Pelletizers with multiclone or drop box control contribute to less than 15% of the entire industry’s production, based on average data from 1995 through 1997. This includes 8.3% from National Steel Pellet Company’s Phase II (multiclones), 4.2% from the 12 LTV units (multiclones), and 2.4% from USS Line 3 (drop boxes). 7. This is a simplified, annual indurating energy consumption normalized to annual production based on average data from 1995 to 1997. Detailed data on pellet product types, fuel types, or specific lines used are not reflected in this column. The column is for a facility level overview of the indurating energy usage only. The data for Empire and Tilden were for one recent year, not averaged from 1995 to 1997.MPCA Report Page 31 

### Table 3. Taconite facilities: HAPs **emission testing status Pelletizer**  **type; % ind. production**  1 **Facility; %**

**industry production**  **Tested for**

**PICs?** 2 **Tested for HCl**

**and HF? Tested for** 

**Metals ?**  3 **Tested for**

**me rcury?**  Grate -kiln; US Steel; 22.8% No No No Yes 63.0% of all Empire (MI); 13.3% Yes No Yes Yes facilities’ Tilden (MI); 10.3% No No Yes Yes production EVTAC; 8.32% No No Yes Yes

National; 8.27% Yes Yes Yes Yes Straight- Hib Tac; 13.4% Yes Yes Yes Yes grate; 24.5% Northshroe; 6.62% Yes Yes Yes Yes

Ispat-Inland; 4.42% No Yes Yes Ye s Vertical shaft; 12.5% LTV; 12.5% Yes No No Yes **Sum: 100% 100%**  --- --- --- --- 1. Production data for 1995

– 1997 are taken from Skillings Mining Review, a trade journal. 2. Products of incomplete combustion, which include the four compounds

– formaldehyde (HCHO), benzene, toluene, and hexane

– that were suspected to be present in the pelletizer’s waste gas stream. 3. These are metal and non-metal elements emitted from the pelletizer’s waste gas stack(s), which are determined using Reference Method 29

– Antimony (Sb), Arsenic (As), Beryllium (Be), Cadmium (Cd), Chromium (Cr), Cobalt (Co), Lead (Pb), Manganese (Mn), Mercury (Hg), Nickel (Ni), and Selenium (Se). All the tested facilities in Minnesota also reported element composition information for concentrate, f ired pellets, coal, etc.MPCA Report Page 32 

### Table 4. HAPs emission estimates for regulatory applicability determination 1 

### (unit: ton/yr) **Facility HF**  **HCl**2 **HCHO** 3 **3 PICs**  4 **Metals @o**  5 **Metals @p**  6 **Total HAPs** National 158 87.5 0.780 0.605 1.13 4.03 **252** Northshore 12.7 17.4 32 .9 4.57 8.38 2.61 **78.5** Hibbing 1.81 18.1 1.34 8.18 0.136 3.04 **32.6** Ispat-Inland 3.82 26.8 15.6 4.60 0.532 0.980 **52.3** LTV 95.3 56.7 1.33 3.79 11.7 5.58 **174** EVTAC 16.0 14.6 30.8 9.10 2.72 1.59 **74.8** U.S. Steel 84.7 110 94.6 27.9 24.9 9.84 **352** Empire (MI) 12.2 30.3 2.20 1.85 0.948 0.932 **48.4** Tilden (MI) 9.45 30.8 2.55 1.45 0.455 0.826 **45.5 Sum**  **394 392**  **182 62.1**  **50.9 29.4**  **1110 Rank**  **35% 35%**  **16% 6%**  **5% 3%**  **100%** 1. This table is an integral part of Package 2 and should be used along with the text of Package 2. Emission estimates were calculated for a facility using its own testing data. If it does not have HAPs testing data, the worst values of the testing data from other facilities are used to calculate the emission estimates. 2. Chlorine (Cl) is thought to come from fluxstone and taconite ore. A linear regression model of HCl emissions on fluxstone content was developed from stack testing data. The model was used to estimate HCl emissions from pelletizers at untested pelletizers with wet control for waste gas cleaning. For those with dry control, results from an August 1999 stack test at National Steel Pellet Company should be used, instead. 3. Formaldehyde, one of the four products of incomplete combustion (PICs). 4. The three other PICs are benzene, toluene, and hexane. All were found below detection limits, but were suspected to be present. 5. These are estimates of the emissions of the Reference Method 29 elements for o ff -pellet firing processes. They were calculated from PM emissions reported to the state’s emiss ion inventory and available element composition data. No attempt was made to verify the reported PM emissions. 6. These are elements emitted from the p elletizer’s waste gas stack(s), which are determined using Reference Method 29

– Antimony (Sb), Arsenic (As), Beryllium (Be), Cadmium (Cd), Chromium (Cr), Cobalt (Co), Lead (Pb), Manganese (Mn), Mercury (Hg), Nickel (Ni), and Selenium (Se). Symbol “<” (less than) is used, because some of the elements were found below detection limits in emission testing.MPCA Report Page 33 

### T **able 5. Concentration data from existing stack testing results** 1 Gas flow, dscfm Loading,

gr/dscf Gas flow,

dscfm Loading,

gr/dscf Gas flow,

dscfm Loading,

gr/dscf Gas flow,

dscfm Loading,

gr/dscf Wet scrubbers PM 10 control performance

– data points plotted in Figure 11(b) 116900 0.0140 140700 0.0090 151700 0.0130 282378 0.0071 117600 0.0089 141327 0.0071 152300 0.0054 283006 0.0067 118800 0.0090 141400 0.0077 153700 0.0054 283687 0.0076 124500 0.0037 143473 0.0107 153800 0.0181 291402 0.0185 125200 0.0050 143700 0.0132 156800 0.0101 295241 0.0177 126200 0.0056 144600 0.0027 158600 0.0098 296681 0.0171 126200 0.0025 144634 0.0076 159700 0.0149 298179 0.0216 126300 0.0074 144969 0.0100 160000 0.0085 305001 0.0216 129400 0.0059 145207 0.0147 163800 0.0123 305961 0.0213 131700 0.0137 145900 0.0079 164700 0.0057 309551 0.0181 132700 0.0052 146700 0.0045 165400 0.0072 323559 0.0194 136300 0.0039 146900 0.0168 170600 0.0101 348649 0.0145 136700 0.0053 147135 0.0198 171300 0.0108 433690 0.0085 13700 0 0.0080 148009 0.0196 174200 0.0075 452410 0.0095 137000 0.0053 148200 0.0122 175000 0.0127 452858 0.0110 137200 0.0084 149200 0.0064 175200 0.0071 456712 0.0106 138928 0.0074 149200 0.0134 176000 0.0082 463696 0.0091 139000 0.0038 149600 0.0071 17900 0 0.0117 464145 0.0112 139500 0.0056 150321 0.0092 270438 0.0129 469552 0.0112 140090 0.0075 150400 0.0132 270920 0.0092 471755 0.0074 140600 0.0102 151200 0.0085 271351 0.0118 486968 0.0118 Electrostatic precipitators’ PM control performance

– data po ints plotted in Figure 12(b) 52507 0.0095 61671 0.0366 63698 0.0093 72787 0.0107 52937 0.0091 61752 0.0458 63717 0.0093 73133 0.0075 52961 0.0062 61764 0.0059 63727 0.0079 73739 0.0094 56129 0.0069 61812 0.0104 64551 0.0398 268604 0.0067 56134 0.0068 61825 0.0101 65952 0.0100 304507 0.0089 56746 0.0055 62059 0.0275 66236 0.0822 2 307235 0.0124 58484 0.0087 62062 0.0073 68343 0.0093 309457 0.0149 60125 0.0066 62176 0.0118 69067 0.0089 310075 0.0158 60661 0.0064 62321 0.0085 69343 0.0118 311932 0.0038 60740 0.0064 62512 0.0062 69427 0.0243 315844 0.0084 60998 0.0058 62573 0.0065 69437 0.0062 318262 0.0057 61258 0.0309 62729 0.0324 70134 0.0114 527086 0.0066 61312 0.0052 63577 0.0097 70315 0.0102 527779 0.0028 61536 0.0099 63698 0.0077 71070 0.0303 1. The benchmark PM concentration curve, also plotted in charts (b) of Figures 10 through 12, is generated from (gr/dscf) = 1.76 (dscfm) - 0.324 . Minn.R. 7011.0735 also specifies 0.100 gr/dscf for 7000 dscfm or less, and 0.020 gr/dscf for 1000000 dscfm or more. Tabulated in this table are individual run data. 2. This is the only data point that is above the benchmark PM curve. See Figure 12(b).MPCA Report Page 34 

### Table 5. Concentration data from existing stack testing results 1 

### (Continued) Gas flow, dscfm Loading,

gr/dsc f Gas flow,

dscfm Loading,

gr/dscf Gas flow,

dscfm Loading,

gr/dscf Gas flow,

dscfm Loading,

gr/dscf Multiclones’ PM 10 control performance (no enhancement)

– data points “+” in Figure 13(b) 46945 0.0704 57296 0.1220 254977 0.0227 303314 0.0769 49099 0.0 707 242840 0.0281 255129 0.0246 323362 0.0740 50134 0.1068 243330 0.0278 257601 0.1942 324473 0.0718 51599 0.0571 244830 0.0214 257654 0.1501 356930 0.3974 52410 0.0691 247815 0.0438 259967 0.2047 362663 0.2849 54388 0.1212 251145 0.0266 299513 0.0574 55806 0.0689 252076 0.0322 300352 0.0554 56772 0.0628 253275 0.0385 300650 0.0547 Multiclones’ PM 10 control performance (with enhancement)

– data points “  ” in Figure 13(b) 35542 0.0817 37513 0.0889 38691 0.0952 45663 0.0311 36713 0.0768 38074 0 .0277 39047 0.0271 46059 0.0169 37221 0.0456 38340 0.0384 40362 0.0195 46934 0.0150 1. The benchmark PM concentration curve, also plotted in charts (b) of Figures 10 through 12, is generated from (gr/dscf) = 1.76 (dscfm) - 0.324 . Minn.R. 7011.0735 also sp ecifies 0.100 gr/dscf for 7000 dscfm or less, and 0.020 gr/dscf for 1000000 dscfm or more. Tabulated in this table are individual run data. Data for gravity collectors (“drop boxes”), used at Line 3 of U.S. Steel Minntac, are lumped with the multiclone data for convenience.MPCA Report Page 35 

### Table 6. HAPs emission estimates for Minntac’s taconite pelletizers 1 

### Pollutant **Emission,**

**ton/year Emission** 

**factor E.F. unit**  **Emission factor source** Products of incomplete combustion based on annual heat input of 8,702,767 MMBtu/yr Benzene < 8.98 < 0.00206 lb/MMBtu HTC 7/96 Toluene < 9.98 < 0.00229 lb/MMBtu HTC 7/96 Hexane < 8.98 < 0.00206 lb/MMBtu HTC 7/96 Formaldehyde 94.6 0.02173 lb/MMBtu NMC 10/95 Emissions which are related to production level

-- 15,554,268 ton pellets/ year &8.15%

fluxstone usage Hydrogen chloride 110 From regression equation2 

### and NSPC 8/99 Hydrogen fluoride 84.7 0.00562 lb/ton pel. NMC 1/92; NSPC 8/99

Metals at

-

pellet firing 3 

### Emission **factor E.F. unit**  **Emission factor source** Antimony, Sb <0.189 < 13.3 ppb pellets Ispat-Inland 94 Arsenic, As 3.20 208 ppb pellets EVTAC L2 97 Beryllium, Be < 0.018 < 1.26 ppb pellets NMC 94 Cadmium, Cd 0.038 2.68 ppb pellets Ispat-Inland 94 Chromium, Cr 1.02 67.0 ppb pellets NMC 5/98 Cobalt, Co < 0.025 < 1.40 ppb pellets EVTAC L1 97 Lead, Pb 2.09 147 ppb pellets Ispat-Inland 94 Manganese, Mn 2.06 107 ppb pellets Ispat-Inland 94 Mercury, Hg 0.082 From direct stack testing & mass balance study Nickel, Ni 0.837 57.2 ppb pellets EVTAC L2 97 Selenium, Se 0.271 13.5 ppb pellets NMC 5/98 1. The algebraic symbol, “<” (less than), indicates that the emission factor was developed from a stack test for which the mass recovered was below the detection limit for that air pollutant. 2. See equation [1] in the Package 2 text, which is applied to Lines 4 through 7 (venturi -rod wet scrubber controlled pelletizers). HCl emission factor from National Steel Pellet Company, 0.03096 lb/ton pellets fired, is applied to Line 3 (dry control

– drop boxes or “gravity collectors,” Table 2). 3. Reference Method 29 is the stack testing method for the elements listed here. Two sets of emission factors are used. Listed here is the first set (for example, less than 13.3 parts of antimony in weight per 1 billion parts of pellets fired), which was applied to Lines 4 through 7. The second set, also in units of ppb of pellets fired, is taken from the August 1999 stack testing at National Steel Pellet Company (see Table 24). The second set of emission factors was applied to Line 3. About 89.5% of pellets are produced from Lines 4 through 7 from 1995 to 1997.MPCA Report Page 36 

### Table 7. HAPs emission estimation for off **- pellet firing processes at Minntac**  1 **Process group** 2 Ore Bentonite Greenballs Fired pellets Fluxstone Ore Bentonite Greenballs Fired pellets Fluxstone Year total Year PM from Emission Inventory, 3 ton/year Sum of element emissions for process groups, ton/year 1995 4269 24.6 1088 1619 139 22.2 0.013 1.04 1.64 0.029 **24.9** 1996 3453 18.1 651 1595 106 18.0 0.010 0.623 1.61 0.022 **20.2** 1997 12611 26 .3 1599 6756 261 65.6 0.014 1.53 6.83 0.053 **74.0 Elem** **ent** Composition of elements, ppm by weight Individual element emissions, ton/year ‘95; sum : 4 Antimony, Sb 8.07 1.00 4.41 0.414 0.417 3.44E - 02 2.47E - 05 4.80E - 03 6.70E - 04 5.81E - 05 4.00E - 02 Arsenic, As 14.7 3.31 12.1 4.88 3.60 6.28E - 02 8.15E - 05 1.31E - 02 7.91E - 03 5.02E - 04 8.44E - 02 Beryllium, Be 2.12 2.25 0.420 0.742 0.230 9.04E - 03 5.55E - 05 4.57E - 04 1.20E - 03 3.21E - 05 1.08E - 02 Cadmium, Cd 1.05 0.233 0.280 0.028 0.050 4.48E - 03 5.74E - 06 3.05E - 04 4.53E - 05 6. 97E - 06 4.84E - 03 Chromium, Cr 23.5 5.80 24.2 23.6 2.27 1.00E - 01 1.43E - 04 2.64E - 02 3.82E - 02 3.16E - 04 1.65E - 01 Cobalt, Co 10.0 3.23 3.83 7.06 0.67 4.25E - 02 7.96E - 05 4.17E - 03 1.14E - 02 9.30E - 05 5.82E - 02 Lead, Pb 13.1 34.4 2.53 0.580 1.97 5.61E - 02 8.47E - 04 2. 76E - 03 9.39E - 04 2.74E - 04 6.09E - 02 Manganese, Mn 5107 479 903 968 193 2.18E+01 1.18E - 02 9.83E - 01 1.57E+00 2.70E - 02 2.44E+01 Mercury, Hg 5.06 0.012 0.130 0.002 0.007 2.16E - 02 2.98E - 07 1.41E - 04 3.24E - 06 9.76E - 07 2.17E - 02 Nickel, Ni 7.04 5.83 3.43 5.64 2.00 3.01E - 02 1.44E - 04 3.73E - 03 9.13E - 03 2.79E - 04 4.33E - 02 Selenium, Se 10.8 0.267 3.53 0.280 0.233 4.61E - 02 6.56E - 06 3.84E - 03 4.53E - 04 3.25E - 05 5.04E - 02 Data source 5 (a) (b) (c) (d) (e) 1. Since average composition data are used (see footnote 4 below) , tracking of values of below detection limits is difficult. Thus, the algebraic symbol “<”, which is used in Table 6 (see footnote 1 of Table 6), is omitted. 2. Process group is used here to simplify data presentation. The ore group includes coarse and fine crushing. The fired pellets group includes pellet stockpiling & loadout. 3. PM emissions, reported to the Emission Inventory, are not verified by MPCA staff. 4. Sum of element emissions in 1995 for off -pellet firing processes is presented in Table 4. Individual element emissions for 1996 or 1997 are omitted to save space. All calculations were made using spreadsheets. 5. Composition data listed in this table are the average values reported by non-Minntac facilities. (a) For the ore group, the com position data are provided by Northshore Mining, Hibbing Taconite, Ispat-Inland, EVTAC, and Minnesota Geological Survey. (b) For the bentonite group, the composition data are provided by Northshore Mining and Hibbing Taconite. (c) For the greenballs group, the composition data are provided by Northshore Mining, Hibbing Taconite, and Ispat-Inland. (d) For the fired pellets group, the composition data are provided by Northshore Mining, Hibbing Taconite, Ispat-Inland, and EVTAC. (e) For the fluxstone grou p, the composition data are provided by Northshore Mining and Hibbing Taconite.MPCA Report Page 37 **Table 8. PM 10**  **stack testing results for Minntac’s pelletizers** 1 **Line 5 (Methods 5 & 202; 9/4/97)** 2 **Run 1 Run 2**  **Run 3 Average**  Mass recovered, ug 36700 30100 25000 30600 Sample gas volume, dscf 51.63 41.44 34.47 42.51 Stack gas flow, dscfm 452858 469552 464145 462185 Isokinetic variation, % 93.9 99.0 99.9 97.6 Stack emission, lb/hr 42.58 45.11 44.53 44.07 Concentration, gr/dscf 0.01 097 0.01121 0.01119 0.01112 Feed, long ton/hour 526 523 513 521 Pellets, long ton/hour 395 392 385 391 Line emission factor, lb/ton pellets fired 0.09637 0.10269 0.10333 0.10080 Notes: Stack gas flow has been corrected as per Minntac letter of 5/25 /99; this is an engineering test; MPCA review letter is dated 10/29/97. **Line 7 (Methods 5 & 202; 9/3/97) Run 1**  **Run 2 Run 3**  **Average** Mass recovered, ug 60400 59000 48000 55800 Sample gas volume, dscf 43.20 46.84 50.97 47.00 Stack gas flow, dscfm 2981 79 323559 348649 323462 Isokinetic variation, % 98.3 98.2 99.2 98.6 Stack emission, lb/hr 55.15 53.91 43.43 50.83 Concentration, gr/dscf 0.02158 0.01944 0.01453 0.01852 Feed, long ton/hour 530 531 531 531 Pellets, long ton/hour 398 398 398 398 Line emission factor, lb/ton pellets fired 0.12387 0.12086 0.09737 0.11403 Notes: This is an engineering test, reviewed by MPCA (10/29/97). **Line 5 (Methods 5 & Minn.R.; 4/28/93) Run 1**  **Run 2 Run 3**  **Average** Mass recovered, ug 20800 21000 24200 22000 Sample gas volume, dscf 33.89 35.80 35.08 34.92 Stack gas flow, dscfm 452410 463696 456712 457606 Isokinetic variation, % 97.7 100.7 100.1 99.5 Stack emission, lb/hr 36.73 35.98 41.68 38.13 Concentration, gr/dscf 0.00947 0.00905 0.01065 0.00972 Feed, long ton/hour 488 462 476 475 Pellets, long ton/hour 366 347 357 357 Line emission factor, lb/ton pellets fired 0.08960 0.09271 0.10423 0.09551 Notes: The PM part of the test is complied (conc.) with state’s PM rule (MPCA, 2/16/94). 1. Feed-to -pellets conversion is assumed to be 0.75. 2. Method 5 is for “front half” or “dry catch” for PM. It is often used to get a conservative estimate for PM 10 emissions at wet scrubber or ESP controlle d waste gas stacks (Lines 4 through 7), where Method 201A (the reference method for dry catch of PM 10) cannot be used due to high moisture content of the gas stream. Method 202 is for “back half” or the condensibles. In the past, “back half” was sometime s analyzed as per Minn. R. 7005.0500, and the result was termed “organic wet catch.”MPCA Report Page 38 **Table 8. PM 10**  **stack testing results for Minntac’s pelletizers** 1 **(Continued) Line 4 (Methods 5 & Minn.R.; 4/27/93)**  2 **Run 1 Run 2**  **Run 3 Average**  Mass recovered, ug 3 0100 28300 17200 25200 Sample gas volume, dscf 54.83 37.02 35.96 42.60 Stack gas flow, dscfm 433690 486968 471755 464138 Isokinetic variation, % 97.5 99.1 99.4 98.7 Stack emission, lb/hr 31.49 49.24 29.85 36.86 Concentration, gr/dscf 0.00847 0.01180 0.00738 0.00922 Feed, long ton/hour 505 495 495 498 Pellets, long ton/hour 379 371 371 374 Line emission factor, lb/ton pellets fired 0.07424 0.11843 0.07178 0.08815 Notes: The PM part of the test is complied (conc.) with state’s PM rule (MPCA, 2/16/94). **Line 3 (Methods 201A & 202; 6/16/98)** 3 **Run 1 Run 2**  **Run 3 Average**  Mass recovered, ug 440300 321900 446800 403000 Sample gas volume, dscf 34.99 33.10 33.68 33.92 Stack gas flow, dscfm 257601 257654 259967 25840 7 Isokinetic variation, % 104.7 105.0 104.5 104.7 Stack emission, lb/hr 428.8 331.4 456.2 405.5 Concentration, gr/dscf 0.19419 0.15008 0.20473 0.18300 Feed, long ton/hour 282 282 283 282 Pellets, long ton/hour 212 21 2 212 212 Line emission factor, lb/ton pellets fired 1.8101 1.3992 1.9190 1.7095 Notes: This is a voluntary test, reviewed by MPCA (9/22/98). Fluxed pellets were made. **Line 3 (Methods 201A & 202; 3/25/94) Run 1**  **Run 2 Run 3**  **Average** Mass recovered, ug 160500 154500 144700 153233 Sample gas volume, dscf 33.47 31.00 31.10 31.86 Stack gas flow, dscfm 323362 303314 324473 317050 Isokinetic variation, % 87.1 94.6 85.7 89.1 Stack emission, lb/hr 205.1 200.0 199.7 201.6 Concentration, gr/dscf 0.07400 0.07691 0.07180 0.07424 Feed, long ton/hour 311 313 318 314 Pellets, long ton/hour 233 235 239 236 Line emission factor, lb/ton pellets fired 0.78515 0.76054 0.74759 0.76443 Notes: This is an engineering test, not reviewed by MPCA. Standard pellets were made. 1. Feed-to -pellets conversion is assumed to be 0.75. 2. Method 5 is for “front half” or “dry catch” for PM. It is often used to get a conservative estimate for PM 10 emissions at wet scrubber or ESP controlled waste gas stacks (Lines 4 through 7), where Method 201A (the reference method for dry catch of PM 10) cannot be used due to high moisture content of the gas stream. Method 202 is for “back half” or the condensibles. In the past, “back half” was sometimes analyzed as per Minn. R. 7005.0500, and the result was termed “organic wet catch.” 3. The waste gas stack at Line 3 is controlled with gravity collectors (see Table 2).MPCA Report Page 39 **Table 8. PM 10**  **stack testing results for Minntac’s pelletizers** 1 **(Continued) Ln.3 (Meth's 201A & Minn.R.; 6/23/93)**  2 **Run 1 Run 2**  **Average** Mass recovered, ug 425000 295200 360100 Sample gas volume, dscf 23.02 11.47 17.24 Stack gas flow, dscfm 362663 356930 359797 Isokinetic variation, % 98.8 100 99.4 Stack emission, lb/hr 886 1216 1051 Concentration, gr/dscf 0.28492 0.39735 0.34113 Feed, long ton/hour 306 302 304 Pellets, long ton/hour 230 227 228 Line emission factor, lb/ton pellets fired 3.4457 4.7921 4.1189 Notes: This is a contractor study

- no MPCA review. Fluxed pellets were made. **Line 3 (Methods 201A & 202; 4/27/93) Run 1**  **Run 2 Run 3**  **Average** Mass recovered, ug 118000 109700 116000 114567 Sample gas volume, dscf 32.87 30.93 31.20 31.67 Stack gas flow, dscfm 3003 52 300650 299513 300172 Isokinetic variation, % 97.7 95.5 94.7 96.0 Stack emission, lb/hr 142.6 141.1 147.3 143.7 Concentration, gr/dscf 0.05540 0.05473 0.05738 0.05584 Feed, long ton/hour 292 289 293 291 Pellets, long ton/hour 219 217 220 219 Line emission factor, lb/ton pellets fired 0.58148 0.58103 0.59849 0.58700 Notes: This is an engineering test, not reviewed by MPCA. Fluxed pellets were made. 1. Feed-to -pellets conversion is assumed to be 0.75. 1. Method 5 is for “front half” or “dry catch” for PM. It is often used to get a conservative estimate for PM 10 emissions at wet scrubber or ESP controlled waste gas stacks, where Method 201A (the reference method for dry catch of PM 10) cannot be used due to high mo i sture content of the gas stream. Method 202 is for “back half” or the condensibles. In the past, “back half” was sometimes analyzed as per Minn. R. 7005.0500, and the result was termed “organic wet catch.” The waste gas stack at Line 3 is controlled wit h gravity collectors (see Table 2). 3. The waste gas stack at Line 3 is controlled with gravity collectors (see Table 2).MPCA Report Page 40 

### Table 9. Line 1 Reference Method 29 testing at HTC (6/28/1994) 1 **Stack A Stack D**  **Com mo**  **n data Run 1**  **Run 2 Run 1**  **Run 2** Samp le volume, dscf 105.64 139.42 65.08 66.64 Stack gas flow, dscfm 157900 170800 149500 155400 Line rate, ton pellets/hr 390 344 390 344 **Antim ony, Sb**  Line emission factor (EF): < 1.06E - 06 Mass recovered, ug < 0.40 < 0.40 < 0.40 < 0.40 Stack emission, lb/hr < 7.89E - 05 < 6.47E - 05 < 1.21E - 04 < 1.23E - 04 EF, lb/ton pellets fired < 2.02E - 07 < 1.88E - 07 < 3.11E - 07 < 3.58E - 07 **Arsenic, As** Line emission factor (EF): < 1.91E - 04 Mass recovered, ug < 58.2 < 269 < 16.3 < 24.0 Stack emission, lb/hr < 1.15E - 02 < 4.36E - 02 < 4.95E - 03 < 7.40E - 03 EF, lb/ton pellets fired < 2.95E - 05 < 1.27E - 04 < 1.27E - 05 < 2.15E - 05 **Cadm ium** **, Cd** Line emission factor (EF): < 2.51E - 06 Mass recovered, ug < 0.799 1.69 1.46 0.18 Stack emission, lb/hr < 1.58E - 04 2.74E - 04 4.45E - 04 5.65E - 05 EF, lb/ton pellets fired < 4.05E - 07 7.98E - 07 1.14E - 06 1.64E - 07 **Chrom ium** **, Cr** Line emission factor (EF): < 8.14E - 06 Mass recovered, ug < 1.90 < 4.20 < 2.92 < 3.25 Stack emission, lb/hr < 3.76E - 04 < 6.81E - 04 < 8.87E - 04 < 1.00E - 03 EF, lb/ton pellets fired < 9.64E - 07 < 1.98E - 06 < 2.28E - 06 < 2.92E - 06 **Cobalt, Co** Line emission factor (EF): < 1.17E - 05 Mass recovered, ug < 4.39 < 4.39 < 4.39 < 4.39 Stack emission, lb/hr < 8.68E - 04 < 7.11E - 04 < 1.33E - 03 < 1.35E - 03 EF, lb/ton pellets fire d < 2.23E - 06 < 2.07E - 06 < 3.42E - 06 < 3.94E - 06 **Manganese, Mn** Line emission factor (EF): 2.07E - 04 Mass recovered, ug 12.30 245.90 72.20 32.00 Stack emission, lb/hr 2.43E - 03 3.98E - 02 2.19E - 02 9.87E - 03 EF, lb/ton pellets fired 6.24E - 06 1.16E - 04 5.63E - 05 2.87E - 05 **Mercury, Hg** Line emission factor (EF): < 2.27E - 05 Mass recovered, ug < 6.21 < 4.28 < 9.69 < 11.14 Stack emission, lb/hr < 1.23E - 03 < 6.94E - 04 < 2.94E - 03 < 3.44E - 03 EF, lb/ton pellets fired < 3.15E - 06 < 2.02E - 06 < 7.55E - 06 < 9.99E - 06 **Nickel, Ni** Line emission factor (EF): 1.46E - 05 Mass recovered, ug 10.07 7.14 3.65 3.71 Stack emission, lb/hr 1.99E - 03 1.16E - 03 1.11E - 03 1.14E - 03 EF, lb/ton pellets fired 5.11E - 06 3.37E - 06 2.85E - 06 3.33E - 06 **Selenium , Se**  Line emission factor (EF): < 1.07E - 05 Mass recovered, ug < 3.98 < 9.29 < 2.44 < 2.68 Stack emission, lb/hr < 7.87E - 04 < 1.51E - 03 < 7.41E - 04 < 8.27E - 04 EF, lb/ton pellets fired < 2.02E - 06 < 4.38E - 06 < 1.90E - 06 < 2.40E - 06 1. There are four stacks for Line 1, Stacks A through D . Only Stacks A & D were tested with two runs at each stack. Line emissions are assumed to be equal to twice the amount from Stacks A & D combined. The algebraic symbol “<” for mass recovered means that it was under the detection limit.MPCA Report Page 41 

### Table 10. El**ement composition analysis from Hibbing Taconite Company (ppm by weight)** 1 

### Material Antimony Arsenic Beryllium Cadmium Chromium Cobalt Copper 2 

### Lead Manganese Nickel Selenium

Sb As Be Cd Cr Co Cu Pb Mn Ni Se Taconite 0.84 13.21 1.2 0.03 49.7 6.1 21.9 1 .3 3119 4.3 < 0.3 Std pellets 0.42 9.26 1.0 < 0.02 4.4 2.5 3.0 1.1 700 4.1 < 0.3 Limestone 0.19 1.32 0.4 0.11 1.8 0.9 2.9 3.6 494 3.3 < 0.3 Bentonite 1.09 5.84 2.2 0.25 9.9 5.6 7.7 34.9 597 8.9 < 0.3 Tails 1 1.05 12.36 1.1 0.04 55.8 3.0 15.2 1.7 4767 3 .0 < 0.3 Tails 2 0.90 11.58 1.1 < 0.02 55.8 5.8 13.2 1.0 4822 4.5 < 0.3 Conc 1 0.21 9.36 0.6 < 0.02 32.3 2.6 2.4 0.8 801 < 2.1 < 0.3 Conc 2 < 0.06 10.46 0.7 < 0.02 24.3 2.7 1.6 0.6 719 2.6 < 0.3 Conc < 0.06 8.83 0.9 < 0.02 29.3 2.6 1.9 0.6 669 < 2.1 < 0.3 Tails < 0.06 15.75 1.2 < 0.02 55.1 6.6 9.8 0.6 4391 3.6 < 0.3 Greenballs 0.52 11.98 0.7 < 0.02 26.0 1.7 1.7 1.1 685 < 2.1 < 0.3 Std pellets 0.19 8.67 0.9 < 0.02 26.3 2.1 5.9 0.6 632 < 2.1 < 0.3 1. Test date: March 1997. The algebraic symbol, “<” (less than), indicates that the mass used in the analysis was below the detection limit. 2. Copper is not listed as hazardous air pollutant. However, it is of concern to the Great Lakes program.MPCA Report Page 42 

### Table 11. Performance testing of products of incomplete **combustion and hydrogen chloride and hydrogen fluoride at HTC (July 1996)** 1 **Pollutant Param** **eter Stack E**  **Stack H Line 2**  **Common to 3 PICs below:** Run 1 Run 2 Run 3 Run 1 Run 2 Run 3 Run 1 Run 2 Run 3 Unit Sample volume, dscf 2.211 2.053 1.9854 2.1824 2.19 78 2.2304 89.7 98.1 95.3 MMBtu/hr, input Stack gas flow, dscfm 153,859 150,923 155,375 162,633 156,364 165,694 **Benzene** Mass recovered, ug < 5 < 5 < 5 < 5 < 5 < 5 < 0.00206 lb/MMBtu for Line 2

Stack emission, lb/hour < 0.046 < 0.049 < 0.052 < 0.049 < 0.047 < 0.049 < 0.191 < 0.191 < 0.202 lb/hour for Line 2 **Toluene** Mass recovered, ug 7.2 5.3 5.8 < 5 < 5 < 5 < 0.00229 lb/MMBtu for Line 2

Stack emission, lb/hour 0.066 0.052 0.060 < 0.049 < 0.047 < 0.049 < 0.231 < 0.197 < 0.218 lb/hour for Line 2 **Hex ane**  Mass recovered, ug < 5 < 5 < 5 < 5 < 5 < 5 < 0.00206 lb/MMBtu for Line 2

Stack emission, lb/hour < 0.046 < 0.049 < 0.052 < 0.049 < 0.047 < 0.049 < 0.191 < 0.191 < 0.202 lb/hour for Line 2 **HCHO** Sample volume, dscf 55.17 57.04 57.14 55.23 54.40 54.26

Stack gas flow, dscfm 151,887 156,181 156,152 165,692 162,516 162,033 Mass recovered, ug 68 72 65 62 65 62 0.00105 lb/MMBtu for Line 2 Stack emission, lb/hour 0.025 0.026 0.023 0.025 0.026 0.024 0.099 0.104 0.096 lb/hour for Line 2 **Common to HCl & HF:**  Run 1 Run 2 Run 3 Run 1 Run 2 Run 3 Run 1 Run 2 Run 3 Sample volume, dscf 48.22 47.88 47.45 48.65 48.56 48.17 391 439 438 ton pellets/hour Stack gas flow, dscfm 156,575 157,072 156,598 164,647 158,589 159,679 **HCl** Mass recovered, ug 1337 1234 1337 535 617 679 0.00395 lb/ton pellets fired for Line 2 Stack emission, lb/hour 0.574 0.536 0.584 0.239 0.267 0.298 1.63 1.60 1.76 lb/hour for Line 2 **HF** Mass recovered, ug < 60.0 < 54.8 < 60.0 57.9 147 200 < 0.00039 lb/ton pellets fired for Line 2 S tack emission, lb/hour < 0.026 < 0.024 < 0.026 0.026 0.064 0.088 < 0.103 < 0.175 < 0.228 lb/hour for Line 2 1. There are four stacks for Line 2, Stacks E through H. Only Stacks E & H were tested. Line emissions are assumed to be equal to twice the amount from Stacks E & H combined. The algebraic symbol “<” for mass recovered means that it was under the detection limit. Test date: July 16 - 17, 1996.MPCA Report Page 43 

### Table 12. HAPs emission estimates for HTC’s taconite pelletizers 1 

### Pollutant **Emission,**

**ton/year Emi** **ssion**

**factor E.F. unit**  **Emission factor source** Products of incomplete combustion based on annual heat input of 2,547,672 MMBtu/yr Benzene < 2.63 < 0.00206 lb/MMBtu HTC 7/96 Toluene < 2.92 < 0.00229 lb/MMBtu HTC 7/96 Hexane < 2.63 < 0.00206 lb/MMBtu HTC 7/96 Formaldehyde 1.34 0.00105 lb/MMBtu HTC 7/96

Emissions which are related to production level

-- 9,187,733 ton pellets/year Hydrogen chloride 18.1 0.00395 lb/ton pel. HTC 7/96 Hydrogen fluoride < 1.81 < 0.00039 lb/ton pel. HTC 7/96

Metals at

-

pellet firing 2 

### Emission **factor E.F. unit**  **Emission factor source** Antimony, Sb < 0.005 < 0.530 ppb of pel. HTC 6/94 Arsenic, As < 0.875 < 95.3 ppb of pel. HTC 6/94 Beryllium, Be < 0.012 < 1.26 ppb of pel. NMC 94 Cadmium, Cd < 0.012 < 1.25 ppb of pel. HTC 6/94 Chromium, Cr < 0.037 < 4.07 ppb of pel. HTC 6/94 Cobalt, Co < 0.054 < 5.83 ppb of pel. HTC 6/94 Lead, Pb 0.864 94.0 ppb of pel. HTC 5 - 10/94 Manganese, Mn 0.952 104 ppb of pel. HTC 6/94 Mercury, Hg 0.114 12.4 ppb of pel. HTC 9 - 10/98 Nickel, Ni 0.067 7.32 ppb of pel. HTC 6/94 Selenium, Se < 0.049 < 5.35 ppb of pel. HTC 6/94 1. The algebraic symbol, “<” (less than), indicates that the emission factor was developed from a stack test for which the mass recovered was below the detection limit for that air pollutant. 2. Reference Method 29 is the stack testing method for the elements listed here. See Table 9 for HTC’s emission factors. As an example, for antimony, the emission factor is 0.53 parts of the element in weight per 1 billion parts of pellets f ired. Lead (Pb) emissions were determined in several stack tests conducted at HTC from May through October 1994. Beryllium emission factor was obtained from Northshore Mining Company’s 1994 stack testing results.MPCA Report Page 44 

### Table 13. HAPs emission estimation f **or off -** **pellet firing processes at Hibbing Taconite Company Process group**  1 Ore Bentonite Greenballs Fired pellets Fluxstone Ore Bentonite Greenballs Fired pellets Fluxstone Year total Year PM from Emission Inventory, 2 ton/year Sum of element emissions for process groups, ton/year 1995 12.2 2.72 78.6 55.1 0.039 0.002 0.057 0.038 **0.136** 1996 11.5 3.76 52.9 51.8 0.037 0.003 0.039 0.036 **0.114** 1997 13.5 4.13 95.0 49.0 0.19 0.043 0.003 0.069 0.034 0.000096 **0.149 Elem** **ent** Composition of elements, 3 ppm by weight Individual element emissions, ton/year ‘95; sum : 4 Antimony, Sb 0.84 1.09 0.52 0.305 0.19 1.02E - 05 2.96E - 06 4.09E - 05 1.68E - 05 7.08E - 05 Arsenic, As 13.2 5.84 11.98 8.97 1.32 1.61E - 04 1.59E - 05 9.41E - 04 4.94E - 04 1.61E - 03 Beryllium, Be 1.20 2.2 0.7 0.95 0.4 1.46E - 05 5.98E - 06 5.50E - 05 5.23E - 05 1.28E - 04 Cadmium, Cd 0.03 0.25 < 0.02 < 0.02 0.11 3.65E - 07 6.80E - 07 1.57E - 06 1.10E - 06 3.72E - 06 Chromium, Cr 49.7 9.9 26.0 15.4 1.8 6.04E - 04 2.69E - 05 2.04E - 03 8.46E - 04 3.52E - 03 Cobalt, Co 6.1 5.6 1.7 2.3 0. 9 7.41E - 05 1.52E - 05 1.34E - 04 1.27E - 04 3.50E - 04 Lead, Pb 1.3 34.9 1.1 0.85 3.6 1.58E - 05 9.49E - 05 8.64E - 05 4.68E - 05 2.44E - 04 Manganese, Mn 3119 597 685 666 494 3.79E - 02 1.62E - 03 5.38E - 02 3.67E - 02 1.30E - 01 Mercury, Hg 0.11 0.0121 0.13 0.002 0.007 1.34E - 06 3.29E - 08 1.02E - 05 1.10E - 07 1.17E - 05 Nickel, Ni 4.3 8.9 < 2.1 3.1 3.3 5.22E - 05 2.42E - 05 1.65E - 04 1.71E - 04 4.12E - 04 Selenium, Se < 0.3 < 0.3 < 0.3 < 0.3 < 0.3 3.65E - 06 8.16E - 07 2.36E - 05 1.65E - 05 4.46E - 05 Data source for Hg Ispat-Inland NMC Ispat-Inland NMC NMC 1. Process group is used here to simplify data presentation. The ore group includes coarse and fine crushing. The fired pellets group includes pellet stockpiling & loadout. 2. PM emissions, reported to the Emission Inventory, are not verified by MPCA staff. 3. Except for mercury, composition data in this block are provided by HTC (Table 10). For mercury data source, NMC means Northshore Mining Company. 4. Sum of element emissions in 1995 for off -pellet firing processes is also shown in Table 4. Those for 1995 & 1997 are omitted here to save space. All calculations were made using spreadsheets.MPCA Report Page 45 

### Table 14. PM10 stack testing of HTC’s pelletizers (Methods 1 

### 5 & 202) **Line 1 (gas fired)** 2 

### Run 1 **Run 2 Run 3**  **Average Stack A**  Mass recovered, ug 14400 25100 24900 21467

Sample gas volume, dscf 44.18 43.08 43.22 43.49 Stack gas flow, dscfm 125,200 118,800 117,600 120,533 Isokinetic variation, % 101.7 103.5 104.1 103.1 Stack emission, lb/hr 5.40 9.1 6 8.96 7.84 Concentration, gr/dscf 0.00503 0.00899 0.00889 0.00764 Line, long ton pellets/hr 283 383 382 349 Stack ems/Line, lb/ton 0.01703 0.02134 0.02095 0.01977 **Stack B** Mass recovered, ug 25470 36426 16227 26041 Sample gas volume, dscf 47. 05 40.16 48.61 45.27 Stack gas flow, dscfm 137200 116900 132700 128933 Isokinetic variation, % 103.4 101.1 107.1 103.9 Stack emission, lb/hr 9.82 14.0 5.86 9.90 Concentration, gr/dscf 0.00835 0.01400 0.00515 0.0091 7 Line, long ton pellets/hr 371 378 372 374 Stack ems/Line, lb/ton 0.02364 0.03313 0.01406 0.02361 **Stack C** Mass recovered, ug 21840 16804 12836 17160

Sample gas volume, dscf 45.81 46.55 52.05 48.14 Stack gas flow, dscfm 126300 126200 139000 1 30500 Isokinetic variation, % 106.2 106.0 105.9 106.0 Stack emission, lb/hr 7.96 6.03 4.53 6.18 Concentration, gr/dscf 0.00736 0.00557 0.00381 0.00558 Line, long ton pellets/hr 379 367 375 374 Stack ems/Line, lb/ton 0.01876 0.01466 0.01080 0.01474 **Stack D** Mass recovered, ug 18935 10886 25188 18336

Sample gas volume, dscf 49.47 45.60 48.62 47.89 Stack gas flow, dscfm 129400 124500 137000 130300 Isokinetic variation, % 106.5 102.8 103.4 104.2 Stack emission, lb/hr 6.55 3.93 9.39 6.62 Concentration, gr/dscf 0.00591 0.00368 0.00800 0.00586 Line, long ton pellets/hr 377 382 381 380 Stack ems/Line, lb/ton 0.01552 0.00919 0.02200 0.01557 **Line Sum** Line emission, lb/hr 29.7 33.1 28.7 30.5

Line EF, lb/ton pellets 0.07495 0.07833 0.06781 0.07370 1. Method 5, used for “front half” or “dry catch” of PM, is used to get a conservative estimate for PM 10 

### emissions. Method 202 is for “back half” or “condensibles.” 2. Test dates: May 10 through 12, 1994.MPCA Report Page 46 

### Table 14. PM10 stack testing of HTC’s pelletizers (Methods 1 

### 5 & 202) (Continued) **Line 2 (gas fired)** 2 

### Run 1 **Run 2 Run 3**  **Average Stack E**  Mass recovered, ug 42800 75200 38200 52067 Sample gas volume, dscf 45.94 49 .01 47.60 47.52 Stack gas flow, dscfm 148705 151988 149838 150177 Isokinetic variation, % 98.0 102.3 100.8 100.4 Stack emission, lb/hr 18.33 30.85 15.91 21.69 Concentration, gr/dscf 0.01438 0.02368 0.01238 0.01681 Line, long ton pellets/hr 3 71 372 373 372 Stack ems/Line, lb/ton 0.04410 0.07404 0.03807 0.05207 **Stack F** Mass recovered, ug 38300 28000 25300 30533 Sample gas volume, dscf 48.20 48.31 49.40 48.64 Stack gas flow, dscfm 154454 155359 154403 154739 Isokinetic variation, % 99.0 98.7 101.5 99.7 Stack emission, lb/hr 16.23 11.91 10.46 12.87 Concentration, gr/dscf 0.01226 0.00894 0.00790 0.00970 Line, long ton pellets/hr 338 371 368 359 Stack ems/Line, lb/ton 0.04288 0.02866 0.02538 0.03231 **Stack G** Mass recovered, ug 23000 18500 22100 21200

Sample gas volume, dscf 54.03 54.86 54.86 54.58 Stack gas flow, dscfm 172111 174093 173255 173153 Isokinetic variation, % 99.6 100.0 100.4 100.0 Stack emission, lb/hr 9.69 7.77 9.23 8.90 Concentration, gr/dscf 0. 00657 0.00520 0.00622 0.00600 Line, long ton pellets/hr 370 368 367 368 Stack ems/Line, lb/ton 0.02339 0.01884 0.02246 0.02156 **Stack H** Mass recovered, ug 15400 23500 19100 19333

Sample gas volume, dscf 53.02 52.97 52.58 52.86 Stack gas flow, dscfm 169233 166183 165589 167002 Isokinetic variation, % 99.4 100.9 100.5 100.3 Stack emission, lb/hr 6.50 9.75 7.96 8.07 Concentration, gr/dscf 0.00448 0.00685 0.00561 0.00564 Line, long ton pellets/hr 322 328 367 339 Stack ems/Line, lb/ton 0.01803 0.02655 0.01936 0.02131 **Line Sum** Line emission, lb/hr 50.8 60.3 43.6 51.5

Line EF, lb/ton pellets 0.12840 0.14809 0.10527 0.12726 1. Method 5, used for “front half” or “dry catch” of PM, is used to get a conservative estimate for PM 10 

### emis sions. Method 202 is for “back half” or “condensibles.” 2. Test dates: July 11 through 14, 1999.MPCA Report Page 47 

### Table 14. PM10 stack testing of HTC’s pelletizers (Methods 1 

### 5 & 202) (Continued) **Line 2 (gas fired)** 2 

### Run 1 **Run 2 Run 3**  **Average Stack E**  Mass recovered, ug 8700 7400 15000 10367 Sample gas volume, dscf 49.32 46.55 43.54 46.47 Stack gas flow, dscfm 144600 126200 136700 135833 Isokinetic variation, % 95.6 95.4 95.8 95.6 Stack emission, lb/hr 3.37 2.65 6.23 4.09 Concentration, gr/dscf 0.00272 0.00245 0.00532 0.00350 Line, long ton pellets/hr 359 359 360 359 Stack ems/Line, lb/ton 0.00839 0.00660 0.01545 0.01015 **Stack F** Mass recovered, ug 14287 15624 21159 17023 Sample gas volume, dscf 48.55 45.46 50.77 48.26 Stack gas flow, dscfm 146700 137000 149200 144300 Isokinetic variation, % 98.7 97.4 97.7 97.9 Stack emission, lb/hr 5.71 6.23 8.22 6.72 Concentration, gr/dscf 0.00454 0.00530 0.00643 0.00543 Line, long ton pellets/hr 375 351 349 358 Stack ems/Line, lb/ton 0.01360 0.01584 0.02104 0.01683 **Stack G** Mass recovered, ug 26804 38601 17540 27648

Sample gas volume, dscf 45.99 48.79 50.27 48.35 Stack gas flow, dscfm 140700 148200 152300 147067 Isokinetic variation, % 99.3 98.5 98.7 98.8 Stack emission, lb/hr 10.8 15.5 7.03 11.1 Concentration, gr/dscf 0.00899 0.01221 0.00538 0.00886 Line, long ton pellets/hr 361 364 367 364 Stack ems/Line, lb/ton 0.02683 0.03805 0.0 1710 0.02733 **Stack H** Mass recovered, ug 30781 34101 40152 35011

Sample gas volume, dscf 46.61 53.58 45.09 48.42 Stack gas flow, dscfm 140600 158600 131700 143633 Isokinetic variation, % 99.2 100.6 101.0 100.3 Stack emission, lb/hr 12.3 13.4 15.5 13.7 Concentration, gr/dscf 0.01019 0.00982 0.01374 0.01125 Line, long ton pellets/hr 278 374 367 340 Stack ems/Line, lb/ton 0.01360 0.01584 0.02104 0.01683 **Line Sum** Line emission, lb/hr 32.2 37.7 37.0 35.7

Line EF, lb/ton pellets 0.06241 0.07633 0.07464 0.07113 1. Method 5, used for “front half” or “dry catch” of PM, is used to get a conservative estimate for PM 10 

### emissions. Method 202 is for “back half” or “condensibles.” 2. Test dates: May 10 through 12 , 1994.MPCA Report Page 48 

### Table 14. PM10 stack testing of HTC’s pelletizers (Methods 1 

### 5 & 202) (Continued)

**Line 2 (oil fired)** 2 

### Run 1 **Run 2 Run 3**  **Average Stack E**  Mass recovered, ug 17800 24600 12000 18133 Sample gas volume, dscf 48.87 49.35 47.93 48.72 Stack gas flow, dscfm 139500 141400 136300 139067 Isokinetic variation, % 103.8 103.4 104.1 103.8 Stack emission, lb/hr 6.72 9.32 4.51 6.85 Concentration, gr/dscf 0.00562 0.00769 0.00386 0.00573 Line, long ton pellets/hr 329 324 329 327 Stack ems/Line, lb/ton 0.01824 0.02569 0.01225 0.01873 **Stack F** Mass recovered, ug 28408 35238 18310 27319 Sample gas volume, dscf 51.68 54.02 52.39 52.70 Stack gas flow, dscfm 151200 156800 153700 153900 Isokinetic variation, % 100.5 101.3 100.2 100.7 Stack emission, lb/hr 11.0 13.5 7.11 10.5 Concentration, gr/dscf 0.00848 0.01007 0.00539 0.00798 Line, long ton pellets/hr 329 324 329 327 Stack ems/Line, lb/ton 0.02984 0.03728 0.01928 0 .02880 **Stack G** Mass recovered, ug 49365 28611 19717 32564

Sample gas volume, dscf 50.96 51.95 53.46 52.12 Stack gas flow, dscfm 159700 160000 164700 161467 Isokinetic variation, % 94.6 96.2 96.2 95.7 Stack emission, lb/hr 20.5 11.7 8.03 13.4 Concentration, gr/dscf 0.01495 0.00850 0.00569 0.00971 Line, long ton pellets/hr 329 341 337 335.6667 Stack ems/Line, lb/ton 0.05554 0.03052 0.02129 0.03578 **Stack H** Mass recovered, ug 42496 36010 27614 35373

Sampl e gas volume, dscf 53.22 55.01 56.45 54.89 Stack gas flow, dscfm 163800 170600 174200 169533 Isokinetic variation, % 95.5 94.8 95.3 95.2 Stack emission, lb/hr 17.3 14.8 11.3 14.4 Concentration, gr/dscf 0.01232 0.010 10 0.00755 0.00999 Line, long ton pellets/hr 329 341 337 336 Stack ems/Line, lb/ton 0.04696 0.03868 0.02986 0.03850 **Line Sum** Line emission, lb/hr 55.5 49.3 30.9 45.2

Line EF, lb/ton pellets 0.15057 0.13217 0.08269 0.12181 1. Method 5, used for “front half” or “dry catch” of PM, is used to get a conservative estimate for PM 10 

### emissions. Method 202 is for “back half” or “condensibles.” 2. Test dates: June 29 through 30, 1994.MPCA Report Page 49 

### Table 14. PM10 stack testing of HTC’s pelletizers (Methods 1 

### 5 & **202) (Continued) Line 3 ( gas fired)**  2 

### Run 1 **Run 2 Run 3**  **Average Stack J**  Mass recovered, ug 44474 61161 43719 49785 Sample gas volume, dscf 51.30 52.25 51.81 51.79 Stack gas flow, dscfm 149200 153800 151700 151567 Isokinetic variation, % 101.1 100.5 100.4 100.7 Stack emission, lb/hr 17.1 23.8 16.9 19.3 Concentration, gr/dscf 0.01338 0.01807 0.01302 0.01482 Line, long ton pellets/hr 391 389 388 389 Stack ems/Line, lb/ton 0.03907 0.05466 0.03896 0.04423 **Stack K** Mass recovered, ug 49898 29802 28130 35943

Sample gas volume, dscf 65.63 64.63 60.60 63.62 Stack gas flow, dscfm 179000 175200 165400 173200 Isokinetic variation, % 107.8 108.4 107.7 108.0 Stack emission, lb/hr 18.0 10.7 10.2 12.9 Concentration, gr/dscf 0.01173 0.00712 0.00716 0.00867 Line, long ton pellets/hr 389 397 397 394 Stack ems/Line, lb/ton 0.04132 0.02403 0.02284 0.02940 **Stack L** Mass recovered, ug 58799 46895 44906 50200 Sample gas vo lume, dscf 54.05 54.78 52.31 53.71 Stack gas flow, dscfm 146900 150400 143700 147000 Isokinetic variation, % 108.2 107.1 107.0 107.4 Stack emission, lb/hr 21.1 17.0 16.3 18.2 Concentration, gr/dscf 0.01679 0.01321 0.01325 0.01442 Line, long ton pellets/hr 395 387 398 393 Stack ems/Line, lb/ton 0.04778 0.03929 0.03661 0.04123 **Stack M** Mass recovered, ug 52466 43260 33600 43108

Sample gas volume, dscf 63.86 62.00 62.88 62.91 Stack gas flow, dscfm 175000 1 71300 176000 174100 Isokinetic variation, % 107.3 106.4 105.1 106.3 Stack emission, lb/hr 19.0 15.8 12.4 15.8 Concentration, gr/dscf 0.01268 0.01077 0.00825 0.01056 Line, long ton pellets/hr 392 389 393 391 Stack ems/Line, lb/ton 0.04332 0.03629 0.02826 0.03596 **Line Sum** Line emission, lb/hr 75.3 67.3 55.8 66.2

Line EF, lb/ton pellets 0.17149 0.15428 0.12668 0.15082 1. Method 5, used for “front half” or “dry catch” of PM, is used to get a conservative estimate for PM 10 

### emissions. Method 202 is for “back half” or “condensibles.” 2. Test dates: September 27 through October 12, 1994.MPCA Report Page 50 

### Table 15. Performance testing for PICs at LTV Steel Mining Company 1 

### Common to all compounds listed below: Run 1 Run 2 Run 3 Average Stack gas flow rate, dscfm 38,443 39,397 38,116 38,652 Heat input rate, MMBtu/hr 25 25 25 25 **Common to 3PICs listed below:** Sample gas volume, dscf 0.726 0.710 0.728 **Benzene** Mass recovered, ug < 2.1 < 2.1 < 2.1

Stack emission, lb/hr < 0.015 < 0.015 < 0.015 Line emission factor, lb/MMBtu < 0.00059 < 0.00062 < 0.00058 < 0.00060 **Toluene** Mass recovered, ug < 2.1 < 2.1 < 2.1

Stack emission, lb/hr < 0.015 < 0.015 < 0.015 Line emission factor, lb/MMBtu < 0.00059 < 0.00 062 < 0.00058 < 0.00060 **Hexane** Mass recovered, ug < 2.6 < 2.6 < 2.6

Stack emission, lb/hr < 0.018 < 0.019 < 0.018 Line emission factor, lb/MMBtu < 0.00073 < 0.00076 < 0.00072 < 0.00074 **HCHO** Sample gas volume, dscf 49.65 52.02 51.05

Mass rec overed, ug 290 100 110 Stack emission, lb/hr 0.030 0.010 0.011 Line emission factor, lb/MMBtu 0.00119 0.00040 0.00043 0.00067 1. There is only one top gas stack. Test date: November 21, 1995. The algebraic symbol “<” for mass recovered means that it was under the detection limit.MPCA Report Page 51 

### Table 16. HAPs emission estimates for LTVSMC’s taconite pelletizers 1 

### Pollutant **Emission,**

**ton/year Emission** 

**factor E.F. unit**  **Emission factor source** Products of incomplete combustion based on annual heat input of 3,930,631 MMBtu/yr Benzene < 1.17 < 0.00060 lb/MMBtu LTVSMC 11/95 Toluene < 1.17 < 0.00060 lb/MMBtu LTVSMC 11/95 Hexane < 1.45 < 0.00074 lb/MMBtu LTVSMC 11/95 Formaldehyde 1.33 0.00067 lb/MMBtu LTVSMC 11/95 Emissions which are related to production level

—8,559,040 ton pellets/year &0% fluxstone usage Hydrogen chloride 56.7 From regression equation2 and NSPC 8/99 

### Hydrogen fluoride 95.3 0.00562 lb/ton pel. NMC 1/92; NSPC 8/99

Metals at

-

pellet firing 3 

### Emission **factor E.F. unit**  **Emission factor sou rce**  Antimony, Sb < 0.082 < 13.3 ppb pellets Ispat-Inland 94 Arsenic, As 1.72 208 ppb pellets EVTAC L2 97 Beryllium, Be < 0.009 < 1.26 ppb pellets NMC 94 Cadmium, Cd 0.016 2.68 ppb pellets Ispat-Inland 94 Chromium, Cr 0.537 67.0 ppb pellets NMC 5/98 C obalt, Co < 0.018 < 1.40 ppb pellets EVTAC L1 97 Lead, Pb 0.923 147 ppb pellets Ispat-Inland 94 Manganese, Mn 1.61 107 ppb pellets Ispat-Inland 94 Mercury, Hg 0.043 5.02 ppb pellets LTV 4/1998 & 5/2000 Nickel, Ni 0.398 57.2 ppb pellets EVTAC L2 97 Sel enium, Se 0.221 13.5 ppb pellets NMC 5/98 1. The algebraic symbol, “<” (less than), indicates that the emission factor was developed from a stack test for which the mass recovered was below the detection limit for that air pollutant. 2. See equation [1] in the Package 2 text, which is applied to 12 of the 24 furnaces that use concentrate slurry scrubbing at the waste gas stream. HCl emission factor from National Steel Pellet Company, 0.03096 lb/ton pellets fired, is applied to the remaining furnaces. 3. Reference Method 29 is the stack testing method for the elements listed here. Two sets of emission factors are used. Listed here is the first set (for example, less than 13.3 parts of antimony in weight per 1 billion parts of pellets fired), which was app lied to the 12 furnaces with slurry scrubbing. The second set, also in units of ppb of pellets fired, is taken from the August 1999 stack testing at National Steel Pellet Company (see Table 24). The second set of emission factors was applied to the 12 furnaces without slurry scrubbing. In 1997, approximately 66.89% of pellets were produced from the furnaces with the slurry scrubbing retrofit.MPCA Report Page 52 

### Table 17. HAPs emission estimation for off **- pellet firing processes at LTVSMC**  1 

### Process group 2 

### Ore Bentonite Prod handl Ore Bentonite Prod handl Year total Year PM emissions, 3 

### ton/year Sum of element emissions, ton/year 1995 347 15.2 9792 1.80 0.008 9.90 **11.7** 1996 162 11.6 2582 0.844 0.006 2.61 **3.46** 1997 340 13.9 10334 1.77 0.01 10.45 **12.2 Element**  Compositi on, ppm by weight Individual element emission, ton/yr ’95 sum 4 

### Antimony, Sb 8.07 1.00 0.414 2.80E -03 1.52E -05 4.05E -03 6.86E -03 Arsenic, As 14.7 3.31 4.88 5.10E -03 5.02E -05 4.78E -02 5.30E -02 Beryllium, Be 2.12 2.25 0.742 7.34E -04 3.42E -05 7.27E -03 8.03 E -03 Cadmium, Cd 1.05 0.233 0.028 3.64E -04 3.54E -06 2.74E -04 6.42E -04 Chromium, Cr 23.5 5.80 23.6 8.15E -03 8.79E -05 2.31E -01 2.39E -01 Cobalt, Co 10.0 3.23 7.06 3.45E -03 4.90E -05 6.91E -02 7.26E -02 Lead, Pb 13.1 34.4 0.580 4.55E -03 5.22E -04 5.68E -03 1.08 E -02 Manganese, Mn 5107 479 968 1.77E+00 7.26E -03 9.48E+00 1.13E+01 Mercury, Hg 5.06 0.012 0.002 1.75E -03 1.83E -07 1.96E -05 1.77E -03 Nickel, Ni 7.04 5.83 5.64 2.44E -03 8.84E -05 5.52E -02 5.78E -02 Selenium, Se 10.8 0.267 0.280 3.74E -03 4.04E -06 2.74E -03 6.49E -03 Data source 5 

### (a) (b) (c) 1. Since average composition data are used (see footnote 4 below), tracking of values of below detection limits is difficult. Thus, the algebraic symbol “<” is omitted in this table. 2. Process group is used here to simp lify data presentation. The ore group includes coarse and fine crushing. The fired pellets group includes pellet stockpiling and loadout. 3. PM emissions, reported to the Emission Inventory, are not verified by MPCA staff. 4. Sum of element emissions in 1995 for off -pellet firing processes is also shown in Table 4. Those for 1996 and 1997 are omitted here to save space. All calculations were made using spreadsheets. 5. Composition data listed in this table are the average values reported by non-LTVSMC f acilities. (a) For the ore group, the composition data are provided by Northshore Mining, Hibbing Taconite, Ispat-Inland, EVTAC, and Minnesota Geological Survey. (b) For the bentonite group, the composition data are provided by Northshore Mining and Hibb ing Taconite. (c) For the fired pellets group, the composition data are provided by Northshore Mining, Hibbing Taconite, Ispat-Inland, and EVTAC.MPCA Report Page 53 **Table 18. PM 10**  **testing results for LTVSMC’s pelletizers’ top gas stacks** 1 **E2 (Methods 201A & 202; 4/1 4/98)**  2 **Run 1 Run 2**  **Run 3 Average**  Mass recovered, ug 164,900 134,300 228,500 175,900 Sample gas volume, dscf 35.98 29.44 33.02 32.81 Stack gas flow, dscfm 49,099 46,945 50,134 48,726 

### Isokinetic variation, % 110.8 117 108.8 112.2 Stack emission, lb/hr 29.77 28.33 45.89 34.66 Concentration, gr/dscf 0.07073 0.07040 0.10679 0.08264 Pellets, long ton/hour 48 48 48 48 Line emission factor, lb/ton pellets fired 0.55368 0.52693 0.85185 0.64415 Notes: This was a volunta ry, gas fired test. MPCA review letter is dated 6/9/98. **E2 (Method 5 & 202; 11/18 -**  **19/97) Run 1**  **Run 2 Run 3**  **Average** Mass recovered, ug 254,919 246,021 138,126 213,022 Sample gas volume, dscf 32.24 31.32 30.96 31.51 Stack gas flow, dscfm 57,296 54,3 88 55,806 55,830 

### Isokinetic variation, % 93.8 99.4 95.7 96.3 Stack emission, lb/hr 59.93 56.51 32.93 49.79 Concentration, gr/dscf 0.12202 0.12122 0.06885 0.10403 Pellets, long ton/hour 45.34 45.08 45.19 45.20 Line emi ssion factor, lb/ton pellets fired 1.1801 1.1193 0.65070 0.98336 Notes: This was a voluntary, gas fired test. MPCA review letter is dated 2/20/98. **E2 (Method 5 & 202; 11/18/97) Run 1**  **Run 2 Run 3**  **Average** Mass recovered, ug 124,605 150,584 136,506 137 ,232 Sample gas volume, dscf 33.69 33.61 33.55 33.62 Stack gas flow, dscfm 51,599 52,410 56,772 53,594 

### Isokinetic variation, % 99.6 103.2 94.1 99.0 Stack emission, lb/hr 25.24 31.06 30.55 28.95 Concentration, gr/dscf 0.05708 0.06914 0.06279 0.06300 Pellets, long ton/hour 45.49 45.47 45.53 45.50 Line emission factor, lb/ton pellets fired 0.49548 0.60991 0.59919 0.56819 Notes: This was a voluntary, fuel oil fired test. MPCA review letter is dated 2/20/98. 1. All f urnaces are equipped with a multiclone for top gas cleaning. Top gas cleaning is also enhanced for Furnace F3 (with a heat exchanger) but not for Furnace E2. 2. Method 5 is for “front half” or “dry catch” for PM. It is often used to get a conservative estimate for PM 10 emissions. Method 202 is for “back half” or “condensibles.”MPCA Report Page 54 **Table 18. PM 10**  **testing results for LTVSMC’s pelletizers’ top gas stacks** 1 **(Continued) F3 (Methods 5 & 202; 11/20/97)**  2 **Run 1 Run 2**  **Run 3 Average**  Mass recovered, ug 236,45 6 261,817 202,258 233,510 Sample gas volume, dscf 41.03 42.46 40.64 41.38 Stack gas flow, dscfm 37,513 38,691 36,713 37,639 

### Isokinetic variation, % 99.2 99.5 100.4 99.7 Stack emission, lb/hr 28.60 31.56 24.17 28.11 Concentration, gr/dscf 0.08894 0.09516 0.07680 0.08697 Pellets, long ton/hour 47.87 48.18 47.65 47.90 Line emission factor, lb/ton pellets fired 0.53338 0.58483 0.45287 0.52369 Notes: This was a voluntary, gas fired test. MPCA review letter is dated 2/20/98. **F3 (Methods 5 & 202; 11/20/97) Run 1**  **Run 2 Run 3**  **Average** Mass recovered, ug 103,550 119,990 207,672 143,737 Sample gas volume, dscf 41.62 40.61 39.23 40.49 Stack gas flow, dscfm 38,340 37,221 35,542 37,034 

### Isokinetic variation, % 98.4 98. 9 100.1 99.1 Stack emission, lb/hr 12.62 14.55 24.89 17.35 Concentration, gr/dscf 0.03840 0.04560 0.08169 0.05523 Pellets, long ton/hour 47.89 47.98 48.04 47.97 Line emission factor, lb/ton pellets fired 0.23525 0.27071 0.46256 0.32284 Notes: This was a voluntary, fuel oil fired test. MPCA review letter is dated 2/20/98. **F3 (Methods 5 & 202; 7/14/95) Run 1**  **Run 2 Run 3**  **Average** Mass recovered, ug 74,424 54,807 74,446 67,892 Sample gas volume, dscf 41.41 43.40 42.4 0 42.40 Stack gas flow, dscfm 38,074 40,362 39,047 39,161 

### Isokinetic variation, % 99.3 98.2 99.1 98.9 Stack emission, lb/hr 9.05 6.74 9.07 8.29 Concentration, gr/dscf 0.02774 0.01949 0.02710 0.02477 Pellets, long ton/hour 52.03 51.76 52.03 51.94 Line emission factor, lb/ton pellets fired 0.15533 0.11630 0.15562 0.14242 Notes: This was an engineering, gas fired test. MPCA review letter is dated 12/5/95. 1. All furnaces are equipped with a multiclone for top gas c leaning. Top gas cleaning is also enhanced for Furnace F3 (with a heat exchanger) but not for Furnace E2. 2. Method 5 is for “front half” or “dry catch” for PM. It is often used to get a conservative estimate for PM 10 emissions. Method 202 is for “back half” or “condensibles.”MPCA Report Page 55 

### Table 19. Reference Method 29 testing at EVTAC’s Pelletizers (Nov. 18 **- 20, 1997)**  **Line 1 Stack 2A of Line 2**  **Com mo**  **n data** Run 1 Run 2 Run 3 Run 1 Run 2 Run 3 Sample volume, dscf 83.22 86.37 86.91 97.06 95.41 101.03 Stack gas flow, dscfm 281,548 283,684 283,540 285,199 282,314 292,425 Line rate, ton pellets/hour 225 241 241 522 554 468 **Antim ony, Sb**  Line 1 emission factor: < 2.79E - 06 Line 2 emission factor: 1 < 2.09E - 06 Mass recovered, ug < 1.5 < 1.5 < 1.5 < 1.5 < 1.5 < 1.5 S tack emission, lb/hour < 6.71E - 04 < 6.52E - 04 < 6.47E - 04 < 5.58E - 04 < 5.67E - 04 < 5.63E - 04 EF, lb/ton pellets fired < 2.98E - 06 < 2.71E - 06 < 2.69E - 06 < 1.07E - 06 < 1.02E - 06 < 1.09E - 06 **Arsenic, As** Line 1 emission factor: 1.08E - 04 Line 2 emission factor: 3.8 8E - 04 Mass recovered, ug 60.5 58.2 54.8 367.1 151.4 312.0 Stack emission, lb/hour 2.71E - 02 2.53E - 02 2.36E - 02 1.37E - 01 5.73E - 02 1.17E - 01 EF, lb/ton pellets fired 1.20E - 04 1.05E - 04 9.82E - 05 2.62E - 04 1.03E - 04 2.26E - 04 **Beryllium , Be**  Line 1 emission factor: 3.26E - 07 Line 2 emission factor: 5.01E - 07 Mass recovered, ug 0.161 0.176 0.190 0.436 0.179 0.456 Stack emission, lb/hour 7.21E - 05 7.65E - 05 8.20E - 05 1.62E - 04 6.77E - 05 1.71E - 04 EF, lb/ton pellets fired 3.20E - 07 3.18E - 07 3.41E - 07 3.11E - 07 1.22E - 07 3.31E - 07 **Cadm ium** **, Cd** Line 1 emission factor: 2.76E - 06 Line 2 emission factor: 2.40E - 06 Mass recovered, ug 2.794 1.238 0.268 2.518 1.658 1.010 Stack emission, lb/hour 1.25E - 03 5.38E - 04 1.16E - 04 9.36E - 04 6.27E - 04 3. 78E - 04 EF, lb/ton pellets fired 5.55E - 06 2.23E - 06 4.80E - 07 1.79E - 06 1.13E - 06 7.33E - 07 **Chrom ium** **, Cr** Line 1 emission factor: 7.93E - 06 Line 2 emission factor: 3.48E - 05 Mass recovered, ug 4.549 4.199 4.009 53.139 9.119 12.339 Stack emission, lb/hour 2.04E - 03 1.82E - 03 1.73E - 03 1.98E - 02 3.45E - 03 4 .62E - 03 EF, lb/ton pellets fired 9.04E - 06 7.58E - 06 7.18E - 06 3.79E - 05 6.22E - 06 8.95E - 06 **Cobalt, Co** Line 1 emission factor: < 2.79E - 06 Line 2 emission factor: < 1.51E - 06 Mass recovered, ug < 1.5 < 1.5 < 1.5 0.916 < 1.500 0.856 Stack emission, lb/hour < 6.71E - 04 < 6.52E - 04 < 6.47E - 04 3.41E - 04 < 5.67E - 04 3.21E - 04 EF, lb/ton pellets fired < 2.98E - 06 < 2.71E - 06 < 2.69E - 06 6.53E - 07 < 1.02E - 06 6.21E - 07 **Lead, Pb** Line 1 emission factor: 2.46E - 05 Line 2 emission factor: 2.70E - 05 Mass recovered, ug 17.26 12. 72 9.27 23.46 10.94 23.40 Stack emission, lb/hour 7.72E - 03 5.53E - 03 4.00E - 03 8.72E - 03 4.14E - 03 8.77E - 03 EF, lb/ton pellets fired 3.43E - 05 2.30E - 05 1.66E - 05 1.67E - 05 7.47E - 06 1.70E - 05 **Manganese, Mn** Line 1 emission factor: 6.92E - 05 Line 2 emission factor : 7.16E - 05 Mass recovered, ug 40.99 38.05 32.05 71.38 37.18 45.49 Stack emission, lb/hour 1.83E - 02 1.65E - 02 1.38E - 02 2.65E - 02 1.41E - 02 1.70E - 02 EF, lb/ton pellets fired 8.15E - 05 6.87E - 05 5.74E - 05 5.09E - 05 2.54E - 05 3.30E - 05 **Mercury, Hg** Line 1 emission factor: 2.55E - 05 Line 2 emission factor: 2.12E - 05 Mass recovered, ug 14.3 13.9 12.8 15.10 15.64 15.00 Stack emission, lb/hour 6.40E - 03 6.04E - 03 5.52E - 03 5.62E - 03 5.92E - 03 5.62E - 03 EF, lb/ton pellets fired 2.84E - 05 2.51E - 05 2.29E - 05 1.08E - 05 1.07E - 05 1 .09E - 05 **Nickel, Ni** Line 1 emission factor: 6.57E - 06 Line 2 emission factor: 1.06E - 04 Mass recovered, ug 3.093 3.023 4.523 99.853 40.903 87.223 Stack emission, lb/hour 1.38E - 03 1.31E - 03 1.95E - 03 3.71E - 02 1.55E - 02 3.27E - 02 EF, lb/ton pellets fired 6.15 E - 06 5.45E - 06 8.11E - 06 7.12E - 05 2.79E - 05 6.33E - 05 1. A factor of 1.967 is used for Line 2 emission factor calculation with data for stack 2A. The factor was obtained by gas flow comparison between 2A (tabulated above) and 2B (272,885, 272,885, and 286,16 4).MPCA Report Page 56 

### Table 20. Composition data from EVTAC (ppm by weight) 1 

### Element Rod mill feed Concentrate Fired pellets Antimony, Sb 12 22 17 Arsenic, As 15 6 9 Beryllium, Be 5 9 6 Cadmium, Cd < 0.5 < 0.5 < 0.5 Chromium, Cr 24 80 124 Cobalt, Co 48 89 61 Lead, Pb 20 38 27 Manganese, Mn 3900 850 940 Mercury, Hg < 10 < 10 < 10 Nickel, Ni 13 4 5 Selenium, Se < 5 < 5 < 5 1. Test date: June 1994. The algebraic symbol, “<” (less than), indicates that the mass used in the analysis was below the detection limit.MPCA Report Page 57 

### Table 21. HAPs emission estimates for EVTAC’s taconite pelletizers 1 

### Pollutant **Emission,**

**ton/year Emission** 

**factor E.F. unit**  **Emission factor source** Products of incomplete combustion based on annual heat input of 2,834,396 MMBtu/yr Benzene < 2.93 < 0.00206 lb/MMBtu HTC 7/96 Toluene < 3.25 < 0.00229 lb/MMBtu HTC 7/96 Hexane < 2.93 < 0.00206 lb/MMBtu HTC 7/96 Formaldehyde 30.8 0.02173 lb/MMBtu NMC 10/95 Emissions which are related to production level

-- 5,685,120 ton pellets/year & 0.70% fluxstone usage Hydrogen chloride 14.6 From linear regression model 2 

### Hydrogen fluoride 16.0 0.00562 lb/ton pel. NMC 1/92

Metals at

-

pellet firing 3 

### Line 1, ppb **Line 2, ppb Data source**  Antimony, Sb < 0.007 < 1.40 < 1.04 EVTAC 11/97 Arsenic, As 0.863 53.9 194 EVTAC 11/97 Beryllium, Be 0.001 0.163 0.250 EVTAC 11/97 Cadmium, Cd 0.007 1.38 1.20 EVTAC 11/97 Chromium, Cr 0.076 3.97 17.4 EVTAC 11/97 Cobalt, Co < 0.005 < 1.40 < 0.753 EVTAC 11/97 Lead, Pb 0.075 12.3 13.5 EVTAC 11/97 Manganese, Mn 0.202 34.6 35.8 EVTAC 11/97 Mercury, Hg 0.064 12.7 10.6 EVTAC 11/97 Nickel, Ni 0.217 3.28 53.2 EVTAC 11/97 Selenium, Se 0.077 13.5 13.5 NMC 5/98 1. The algebraic symbol, “<” (less than), indicates that the emission factor was developed from a stack test for which the mass recovered was below the detection limit for that air pollutant. 2. See equation [1] in the Package 2 text for detail of the linear regression model. 3. Reference Method 29 is the stack testing method for the elements listed here. Except for selenium, for which stack testing results from Northshore Mining Company were used, the emission factors for Lines 1 and 2 can be found in Table 19. As an example, for antimony, the emission factor is less than 1.40 parts of the element in we ight p er 1 billion parts of pellets fired (ppb of pellets) for Line 1 and less than 1.12 ppb of pellets for Line 2. To calculate metals emission estimates, the line - specific emission factors were weighted with line production data. Based on the production data from 1995 through 1997, Line 1 was assumed to produce 30% of the pellets from the two - line, EVTAC facility. Also note that an EVTAC’s decision to idle Line 1 by May 31, 1999 did not affect the above HAPs emission estimates, which are based on average pro duction and emission data from 1995 to 1997.MPCA Report Page 58 

### Table 22. HAPs emission estimation for off **- pellet firing processes at EVTAC**  **Process group** 1 Ore Greenballs Fired pellets Fluxstone Ore Greenballs Fired pellets Fluxstone Year total Year PM from Emission Inventory, 2 ton/year Sum of element emissions for process groups, ton/year 1995 409 255 643 0.040 1.66 0.283 0.775 2.598E - 06 2.72 1996 404 239 369 0.040 1.64 0.267 0.445 2.598E - 06 2.35 1997 787 187 1582 0.090 3.19 0.208 1.91 5.846E - 06 5.30 **Elem ent**  Compos ition of elements, ppm by weight Individual element emissions, ton/year ’95 sum 3 Antimony, Sb 12 22 17 0.530 4.91E - 03 5.60E - 03 1.09E - 02 2.12E - 08 2.14E - 02 Arsenic, As 15 6 9 1.69 6.14E - 03 1.53E - 03 5.79E - 03 6.74E - 08 1.35E - 02 Beryllium, Be 5 9 6 1.380 2.05 E - 03 2.29E - 03 3.86E - 03 5.52E - 08 8.20E - 03 Cadmium, Cd < 0.5 < 0.5 < 0.5 0.305 2.05E - 04 1.27E - 04 3.22E - 04 1.22E - 08 6.54E - 04 Chromium, Cr 24 80 124 6.15 9.83E - 03 2.04E - 02 7.98E - 02 2.46E - 07 1.10E - 01 Cobalt, Co 48 89 61 7.85 1.97E - 02 2.27E - 02 3.92E - 02 3.14E - 07 8.16E - 02 Lead, Pb 20 38 27 1.25 8.19E - 03 9.67E - 03 1.74E - 02 5.00E - 08 3.52E - 02 Manganese, Mn 3900 850 940 35.5 1.60E+00 2.16E - 01 6.05E - 01 1.42E - 06 2.42E+00 Mercury, Hg < 10 < 10 < 10 0.058 4.09E - 03 2.55E - 03 6.43E - 03 2.32E - 09 1.31E - 02 Nickel, Ni 13 4 5 7.75 5.32E - 03 1.02E - 03 3.22E - 03 3.10E - 07 9.56E - 03 Selenium, Se < 5 < 5 < 5 2.50 2.05E - 03 1.27E - 03 3.22E - 03 1.00E - 07 6.54E - 03 Data source EVTAC 11/97 (Table 19) NMC 1. Process group is used here to simplify data presentation. The ore group include s coarse and fine crushing. The fired pellets group includes pellet stockpiling and loadout. 2. PM emissions, reported to the Emission Inventory, are not verified by MPCA staff. 3. Sum of element emissions in 1995 for off -pellet firing processes is also shown in Table 4. Those for 1996 and 1997 are omitted to save space. All calculations were made using spreadsheets.MPCA Report Page 59 **Table 23. PM 10**  **stack testing of EVTAC’s pelletizers (Methods 5 & 202)** 1 **Line 1 (Test date: 11/21/97) Run 1**  **Run 2 Run 3**  **Average** Mass recovered, ug 18,500 17,300 16,600 17,467 Sample gas volume, dscf 37.52 37.57 37.99 37.69 Stack gas flow, dscfm 283,687 282,378 283,006 283,024 Isokinetic variation, % 99.2 99.8 100.7 99.9 Stack emission, lb/hr 18.50 17.20 16.36 17.35 Concentration, gr/dscf 0.00761 0.00711 0.00674 0.00715 Line rate, long ton pellets /hour 213 213 226 217 Line emission factor, lb/ton pellets fired 0.07756 0.07210 0.06462 0.07143 Notes: This was an engineering, gas fired test; MPCA review letter is dated 6/5/98. **Stack 2A (Test date: 11/21/97) Run 1**  **Run 2 Run 3**  **Average** Mass recovered, ug 53,400 56,300 58,100 55,933 Sample gas volume, dscf 48.24 49 48.59 48.61 Stack gas flow, dscfm 296,681 295,241 291,402 294,441 Isokinetic variation, % 98.4 100.5 100.9 99.9 Stack emission, lb/hr 43.44 44.87 46.09 44.80 Concentration, gr/dscf 0.01708 0.01773 0.01845 0.01776 Line rate, long ton pellets /hour 489 489 489 489 **Line em ission factor**  , lb/ton pellets fired 0.15864 0.16386 0.16831 0.16360 Notes: This was an engineering, solid fuel (coal &petroleum coke blend) fired test; MPCA review letter is dated 6/5/98. It was assumed that Line 2 emissions = 2×Stack 2A emissions. **Line 2 (Test date: 1 2/3**  **- 4/96)**  **Run 1 Run 2**  **Run 3 Average**  **Stack 2A:** Mass recovered, ug 69,100 56,700 65,600 63,800

Sample gas volume, dscf 49.3 48.41 47.58 48.43 Stack gas flow, dscfm 305,001 309,551 305,961 306,838 Isokinetic variation, % 98.7 95.5 94.9 96.4 Stack emission, lb/hr 56.55 47.96 55.80 53.44 Concentration, gr/dscf 0.02163 0.01808 0.02128 0.02033 Line rate, long ton pellets /hr 526 526 526 526 **Stack 2B:** Mass recovered, ug 35,700 25,600 32,600 31,300

Sample gas volume, ds cf 42.83 42.96 42.74 42.84 Stack gas flow, dscfm 270,438 270,920 271,351 270,903 Isokinetic variation, % 96.7 96.8 96.1 96.5 Stack emission, lb/hr 29.82 21.36 27.38 26.18 Concentration, gr/dscf 0.01286 0.00920 0.01177 0 .01128 Line rate, long ton pellets /hr 519 519 519 519 **Line em ission factor**  , lb/ton pellets fired 0.14728 0.11815 0.14182 0.13575 Notes: This was a solid fuel (coal & petroleum coke blend) fired test, requested by MPCA (the review letter is dated 6/5/98). Line 2 emissions = Stack 2A emissions + Stack 2B emissions. 1. Method 5, used for “front half” or “dry catch” for PM, is used to get a conservative estimate for PM 10 emissions. Method 202 is for “back half” or “condensibles.”MPCA Report Page 60 **Table 24. HAP s Stack Testing**  1 **at National Steel Pellet Com pany in August 1999**  Waste Gas Stack 2A Waste Gas Stack 2B **Method 29, 8/10/99** Run 1 Run 2 Run 3 Run 1 Run 2 Run 3 Sample volume, dscf 84.04 82.69 84.38 77.90 76.40 76.30 Stack gas flow, dscfm 254,200 248 ,523 254,354 255,934 250,497 250,430 Line rate, ton pellets/hr 749 749 749 749 749 749 **Antim ony, Sb**  Line emission factor (EF): 3.93E - 06 lb/ton pellets Mass recovered, ug 14.9 1.00 1.00 1.53 1.000 2.26 Stack emission, lb/hr 0.00596 0.00040 0.00040 0.00066 0.00043 0.0010 EF, lb/ton pellets fired 7.96E - 06 5.31E - 07 5.32E - 07 8.87E - 07 5.79E - 07 1.31E - 06 **Arsenic, As** Line emission factor (EF): 3.72E - 04 lb/ton pellets Mass recovered, ug 311 374 341 325 341 318 Stack emission, lb/hr 0.124 0.148 0.136 0.141 0.148 0.138 EF, lb/ton pellets fired 1.66E - 04 1.98E - 04 1.82E - 04 1.89E - 04 1.97E - 04 1.84E - 04 **Beryllium , Be**  Line emission factor (EF): 1.17E - 06 lb/ton pellets Mass recovered, ug 0.766 0.852 0.812 1.17 1.39 1.25 Stack emission, lb/hr 0.00031 0. 00034 0.00032 0.00051 0.00060 0.00054 EF, lb/ton pellets fired 4.09E - 07 4.52E - 07 4.32E - 07 6.79E - 07 8.05E - 07 7.24E - 07 **Cadm ium** **, Cd** Line emission factor (EF): 7.11E - 07 lb/ton pellets Mass recovered, ug 0.758 0.568 0.560 0.704 0.647 0.597 Stack emission, lb/hr 0.00030 0.00023 0.00022 0.00031 0.00028 0.00026 EF, lb/ton pellets fired 4.05E - 07 3.01E - 07 2.98E - 07 4.08E - 07 3.75E - 07 3.46E - 07 **Chrom ium** **, Cr** Line emission factor (EF): 1.08E - 04 lb/ton pellets Mass recovered, ug 73.2 80.1 68.1 122 123 113 Stack emission, lb/hr 0.029 0.032 0.027 0.053 0.053 0.049 EF, lb/ton pellets fired 3.91E - 05 4.25E - 05 3.62E - 05 7.08E - 05 7.09E - 05 6.56E - 05 **Cobalt, Co** Line emission factor (EF): 6.74E - 06 lb/ton pellets Mass recovered, ug 6.11 4.69 5.21 7.47 6.12 6.60 Stack emission, lb/hr 0.0024 0.0019 0.0021 0.0032 0.0027 0.0029 EF, lb/ton pellets fired 3.26E - 06 2.49E - 06 2.77E - 06 4.33E - 06 3.54E - 06 3.82E - 06 **Lead, Pb** Line emission factor (EF): 5.90E - 05 lb/ton pellets Mass recovered, ug 45.1 51.4 51.8 51.1 60.2 5 8.1 Stack emission, lb/hr 0.018 0.020 0.021 0.022 0.026 0.025 EF, lb/ton pellets fired 2.41E - 05 2.73E - 05 2.75E - 05 2.96E - 05 3.49E - 05 3.37E - 05 **Manganese, Mn** Line emission factor (EF): 7.04E - 04 lb/ton pellets Mass recovered,ug 445 478 399 830 820 778 Stack emission, lb/hr 0.178 0.190 0.159 0.36 0.36 0.34 EF, lb/ton pellets fired 2.37E - 04 2.54E - 04 2.12E - 04 4.82E - 04 4.75E - 04 4.51E - 04 **Mercury, Hg** Line emission factor (EF): 1.98E - 05 lb/ton pellets Mass recovered, ug 14.0 20.6 16.7 17.5 19.3 18.9 Stack emission, lb/hr 0.0056 0.0082 0.0066 0.0076 0.0084 0.0082 EF, lb/ton pellets fired 7.48E - 06 1.09E - 05 8.86E - 06 1.01E - 05 1.12E - 05 1.10E - 05 1. This is the latest stack testing for HAPs emissions from the pelletizer from the entire industry.MPCA Report Page 61 **Tab le 24. HAPs Stack Testing**  1 **at National Steel Pellet Com pany in August 1999 (Continued)**  Waste Gas Stack 2A Waste Gas Stack 2B **Method 29 (Continued)** Run 1 Run 2 Run 3 Run 1 Run 2 Run 3 **Nickel, Ni** Line emission factor (EF): 4.94E - 05 lb/ton pellets Mass recovered, ug 168 19.5 20.3 29.1 19.1 16.5 Stack emission, lb/hr 0.067 0.0077 0.0081 0.013 0.0083 0.0071 EF, lb/ton pellets fired 8.97E - 05 1.03E - 05 1.08E - 05 1.69E - 05 1.11E - 05 9.53E - 06 **Selenium , Se**  Line emission factor (EF): 1.02E - 04 lb/ton pellets Mass recovered, ug 95.4 96.2 94.7 87.3 87.3 88.6 Stack emission, lb/hr 0.038 0.038 0.038 0.038 0.038 0.038 EF, lb/ton pellets fired 5.09E - 05 5.10E - 05 5.04E - 05 5.06E - 05 5.05E - 05 5.13E - 05 **PM (front half)** Line emission factor (EF): 9.03E - 01 lb/ton pellets Mass recovered, ug 557700 688500 580700 990500 1038800 968600 Isokinetic variation, % 101.6 102.3 101.9 100.3 100.6 100.5 Stack emission, lb/hr 223 274 232 430 451 421 Concentration, gr/dscf 0.1024 0.1285 0.1062 0.1962 0.2098 0.1959 EF, lb/ton pellets fired 2.98E - 01 3.65E - 01 3.09E - 01 5.74E - 01 6.01E - 01 5.61E - 01 Waste Gas Stack 2A Waste Gas Stack 2B **Method 26A, 8/11/99** Run 1 Run 2 Run 3 Run 1 Run 2 Run 3 Sample volume, dscf 41.66 41.66 41.60 38.70 38.44 38.12 Stack gas flow, dscfm 248,828 252,969 253,317 254,637 254,733 251,045 Line rate, ton pellets/hr 749 749 749 749 749 749

**HCl** Line emission factor (EF): 3.10E - 02 lb/ton pellets Mass recovered, ug 13700 13700 13900 13400 15200 13300 Stack emission, lb/hr 10.8 11.0 11.2 1 1.7 13.3 11.6 EF, lb/ton pellets fired 1.44E - 02 1.47E - 02 1.49E - 02 1.56E - 02 1.78E - 02 1.55E - 02

**HF** Line emission factor (EF): 5.59E - 02 lb/ton pellets Mass recovered, ug 24500 25500 25500 24100 26400 24400 Stack emission, lb/hr 19.4 20.5 20.5 21.0 23. 1 21.3 EF, lb/ton pellets fired 2.58E - 02 2.73E - 02 2.74E - 02 2.80E - 02 3.09E - 02 2.84E - 02

**Cl 2**  Line emission factor (EF): < 4.46E - 07 lb/ton pellets Mass recovered, ug < 0.20 < 0.20 < 0.20 < 0.20 < 0.20 < 0.20 Stack emission, lb/hr < 1.58E - 04 < 1.61E - 04 < 1.61E - 04 < 1.74E - 04 < 1.75E - 04 < 1.74E - 04 EF, lb/ton pellets fired < 2.11E - 07 < 2.14E - 07 < 2.15E - 07 < 2.32E - 07 < 2.34E - 07 < 2.33E - 07 1. This is the latest stack testing for HAPs emissions from the pelletizer from the entire industry.MPCA Report Page 62 **Table 24. HAPs Stack Testing**  1 **at National Steel Pellet Com pany in August 1999 (Continued)**  Waste Gas Stack 2A Waste Gas Stack 2B **Others, 8/12/99** Run 1 Run 2 Run 3 Run 1 Run 2 Run 3 Sample volume, dscf 43.32 42.00 43.42 38.80 39.17 38.55 Stack gas flow, dscf

m 257,226 260,312 258,814 262,212 257,287 256,680 Moisture, volume, wb 13.2% 11.2% 13.0% 12.2% 13.2% 12.2% Heat, n.g., MMBtu/hr 212 180 200 212 180 200 **Form aldehyde (Method 0011** 

**– SW 846)**  . Line emission factor (EF): 7.15E - 04 lb/MMBtu Mass recovered, ug 81 83 77 88 84 88 Stack emission, lb/hr 0.063 0.068 0.061 0.079 0.073 0.078 EF, lb/MMBtu 2.99E - 04 3.78E - 04 3.03E - 04 3.72E - 04 4.06E - 04 3.87E - 04 **Benzene (Method 18)** Line emission factor (EF): 4.17E - 04 lb/MMBtu MW: 78.113 Conc., ppbv (wet) 7. 2 35 11 4.6 5.2 3.0 Stack emission, lb/hr 0.026 0.125 0.040 0.017 0.019 0.011 EF, lb/MMBtu 1.23E - 04 6.94E - 04 1.99E - 04 7.90E - 05 1.04E - 04 5.33E - 05 **Toluene (Method 18)** Line emission factor (EF): 9.78E - 05 lb/MMBtu MW: 92.140 Conc., ppbv (wet) 1.0 7.9 0.78 0.82 1.9 0.49 Stack emission, lb/hr 0.0043 0.0332 0.0033 0.0035 0.0081 0.0021 EF, lb/MMBtu 2.01E - 05 1.85E - 04 1.66E - 05 1.66E - 05 4.49E - 05 1.03E - 05 **Hexane (Method 18)** Line emission factor (EF): < 3.91E - 05 lb/MMBtu MW: 86.177 Conc., ppbv (wet) < 0.96 0.93 < 0.96 < 0.96 < 1 < 0.98 Stack emission, lb/hr < 0.0038 0.0037 < 0.0038 < 0.0038 < 0.0040 < 0.0038 EF, lb/MMBtu < 1.81E - 05 2.08E - 05 < 1.92E - 05 < 1.80E - 05 < 2.21E - 05 < 1.92E - 05 1. This is the latest stack testing for HAPs emissions from the pelletizer from the entire industry.MPCA Report Page 63 

### Table 25. HAPs emission estimates for NSPC’s Phase II pelletizer 1 

### Pollutant **Emission,**

**ton/year Emission** 

**factor E.F. unit**  **Emission factor source** Products of incomplete combustion based on annual heat input of 2,181,102 MMBtu/yr Benzene 0.455 0.0042 lb/MMBtu NSPC, August 1999 Toluene 0.107 0.00010 lb/MMBtu NSPC, August 1999 Hexane < 0.043 < 0.00004 lb/MMBtu NSPC, August 1999 Formaldehyde 0.780 0.00072 lb/MMBtu NSPC, August 1999 Emissions which are related to production level

—5,651,147 ton pellets/year &1.05% fluxstone usage Hydrogen chloride 87.5 0.03096 lb/ton pel. NSPC, August 1999 Hydrogen fluoride 158 0.05594 lb/ton pel. NSPC, August 1999

Metals at

-

pellet firing 3 

### Emission **factor E.F. unit**  **Emission factor source**  Antimony, Sb 0.011 1.97 ppb of pel. NSPC, August 1999 Arsenic, As 1.05 186 ppb of pel. NSPC, August 1999 Beryllium, Be 0.0033 0.583 ppb of pel. NSPC, August 1999 Cadmium, Cd 0.0020 0.355 ppb of pel. NSPC, August 1999 Chromium, Cr 0.306 54.2 ppb of pel. NSPC, August 1999 Cobalt, Co 0.019 3.37 ppb of pel. NSPC, August 1999 Lead, Pb 0.167 29.5 ppb of pel. NSPC, August 1999 Manganese, Mn 1.99 352 ppb of pel. NSPC, August 1999 Mercury, Hg 0.056 9.92 ppb of pel. NSPC, August 1999 Nickel, Ni 0.140 24.7 ppb of pel. NSPC, August 1999 Selenium, Se 0.287 50.8 ppb of pel. NSPC, August 1999 1. The algebraic symbol, “<” (less than), indicates that the emission factor was developed from a stack test for which the mass recovered was below the dete ction limit for that air pollutant. 2. Reference Method 29 is the stack testing method for the elements listed here. The emission factors (for example, 1.97 parts of antimony in weight per 1 billion parts of pellets fired) are derived from the August 1999 stack testing shown in Table 24.MPCA Report Page 64 

### Table 26. HAPs emission estimation for off **- pellet firing processes at NSPC**  1 **Process group** 2 Ore Bentonite Greenballs Pellets hdl Ore Bentonite Greenballs Pellets hdl Year total Year PM from Emission Inventory, 3 ton/year Sum of element emissions for process groups, ton/year 1995 142 65.0 537 1364 0.74 0.035 0.515 1.380E+00 **2.67** 1996 55.6 32.0 234 597 0.29 0.017 0.224 6.037E - 01 **1.13** 1997 99.6 65.2 12.7 22.1 0.52 0.035 0.01 2.231E - 02 **0.59 Elem** **ent** Composition of elements, ppm by weight Individual element emissions, ton/year ’96 sum 4 Antimony, Sb 8.07 1.00 4.41 0.414 4.48E - 04 3.21E - 05 1.03E - 03 2.47E - 04 1.76E - 03 Arsenic, As 14.7 3.31 12.1 4.88 8.18E - 04 1.06E - 04 2.82E - 03 2.92E - 03 6.66E - 03 Beryllium, Be 2.12 2.25 0.42 0 0.742 1.18E - 04 7.20E - 05 9.83E - 05 4.43E - 04 7.31E - 04 Cadmium, Cd 1.05 0.233 0.280 0.028 5.84E - 05 7.46E - 06 6.55E - 05 1.67E - 05 1.48E - 04 Chromium, Cr 23.5 5.80 24.2 23.6 1.31E - 03 1.85E - 04 5.67E - 03 1.41E - 02 2.13E - 02 Cobalt, Co 10.0 3.23 3.83 7.06 5.53E - 04 1. 03E - 04 8.97E - 04 4.21E - 03 5.77E - 03 Lead, Pb 13.1 34.4 2.53 0.580 7.30E - 04 1.10E - 03 5.93E - 04 3.46E - 04 2.77E - 03 Manganese, Mn 5107 479 903 968 2.84E - 01 1.53E - 02 2.11E - 01 5.78E - 01 1.09E+00 Mercury, Hg 5.06 0.012 0.130 0.002 2.81E - 04 3.87E - 07 3.04E - 05 1.19E - 06 3.13E - 04 Nickel, Ni 7.04 5.83 3.43 5.64 3.92E - 04 1.86E - 04 8.04E - 04 3.37E - 03 4.75E - 03 Selenium, Se 10.8 0.267 3.53 0.280 6.00E - 04 8.52E - 06 8.27E - 04 1.67E - 04 1.60E - 03 Data source 5 (a) (b) (c) (d) 1. Since average composition data are used (see footnote 4 below), tracking of values of below detection limits is difficult. Thus, the algebraic symbol “<”, which is used in Table 6 (see footnote 1 of Table 6), is omitted. 2. Process group is used here to simplify data presentation. The ore group include s coarse and fine crushing. The fired pellets group includes pellet stockpiling and loadout. 3. PM emissions, reported to the Emission Inventory, are not verified by MPCA staff. 4. Sum of element emissions in 1996 for off -pellet firing processes is also shown in Table 4. Those for 1995 & 1997 are omitted here to save space. All calculations were made using spreadsheets. 5. Composition data listed in this table are the average values reported by non-NSPC facilities. (a) For the ore group, the composition data are provided by Northshore Mining, Hibbing Taconite, Ispat-Inland, EVTAC, and Minnesota Geological Survey. (b) For the bentonite group, the composition data are provided by Northshore Mining and Hibbing Taconite. (c) For the greenballs group, the composition data are provided by Northshore Mining, Hibbing Taconite, and Ispat-Inland. (d) For the fired pellets group, the composition data are provided by Northshore Mining, Hibbing Taconite, Ispat-Inland, and EVTAC.MPCA Report Page 65 **Table 27. PM 10**  **testing result s for NSPC’s Phase II pelletizer**  1 **Stack 2A (Method 201A&202; 10/22/97) Run 1**  **Run 2 Run 3**  **Average** Mass recovered, ug 62,800 49,500 59,400 57,233 Sample gas volume, dscf 39.38 33.66 34.4 35.81 Stack gas flow, dscfm 255,129 254,977 251,145 253,750 Isokinetic variation, % (MPCA calc.) 98.0 98.5 99.4 98.6 Stack emission, lb/hr 53.82 49.60 57.36 53.59 Concentration, gr/dscf 0.02461 0.02269 0.02665 0.02465 Line rate, 2 long ton pellets/hour 622 622 622 622 Line emiss ion factor, lb/ton pellets fired 0.15461 0.14249 0.16479 0.15396 Notes: This was an engineering, gas fired test. MPCA review letter is dated 12/12/97. **Stack 2B (Method 201A & 202; 8/1/97) Run 1**  **Run 2 Run 3**  **Average** Mass recovered, ug 84,600 94,000 71 ,300 83,300 Sample gas volume, dscf 33.92 33.10 34.22 33.75 Stack gas flow, dscfm 253,275 247,815 252,076 251,055 Isokinetic variation, % (MPCA calc.) 94.3 98.9 94.4 95.9 Stack emission, lb/hr 83.56 93.09 69.47 82.04 Concentration, gr/dscf 0.03849 0.04383 0.03215 0.03816 Line rate, 2 long ton pellets/hour 622 622 622 622 Line emission factor, lb/ton pellets fired 0.24005 0.26743 0.19958 0.23569 Notes: This was an engineering, gas fired test. MPCA review letter i s dated 10/15/97. **Stack 2B (Method 201A&202; 10/12/94) Run 1**  **Run 2 Run 3**  **Average** Mass recovered, ug 39,500 38,500 30,100 36,033 Sample gas volume, dscf 21.66 21.35 21.75 21.59 Stack gas flow, dscfm 242,840 243,330 244,830 243,667 Isokinetic variation, % 107.9 107.5 107.9 107.8 Stack emission, lb/hr 58.58 58.04 44.82 53.81 Concentration, gr/dscf 0.02814 0.02783 0.02136 0.02578 Line rate, long ton pellets/hour 618 618 618 618 Line emission factor, lb/ton pellets fired 0.16927 0.16771 0.12950 0.15549 Notes: This was an engineering, gas fired test. MPCA review letter is dated 12/6/94. 1. Phase II pelletizer has two stacks, 2A and 2B. For all the tests in this table, line emissions is assumed to be twice the stack emissions determined. 2. A conversion factor of 0.74 was assumed to estimate line production rate of fired pellets from the reported pelletizer feed rate of green balls.MPCA Report Page 66 **Table 28. Reference Method 12 testing at Furnace 12 of Northshore Mining Com pany**  1 Stack Hood exhst (1 of 3 stacks) Waste gas (1 of 2 stacks) Stack Hood exhst (1 of 3 stacks) Waste gas (1 of 2 stacks) **Test date: Septem ber 16**  **- 17, 1998 (three 2**  **- hour runs)**  **Com mon data**  Run 1 Run 2 Run 3 Run 1 Run 2 Run 3 Run 1 Run 2 Run 3 Run 1 R un 2 Run 3 Sample, dscf 84.43 89.57 87.97 81.14 82.02 83.67 **Cobalt, Co** Stack, dscfm 65474 67095 65368 61387 60998 62112 Mass recv,ug Bad data from waste gas samples Ton pel./hr 210 210 210 217 217 217 Stack, lb/hr made it impossible to generate line emission factor Multiplier 2 2.934 2.000 EF, lb/ton pel **Antim ony, Sb**  Line emission factor: 1.12E - 07 lb/ton pellets fired **Lead, Pb** Line emission factor: 4.57E - 05 lb/ton pellets fired Mass recv,ug 0.162 0.070 0.063 bad 0.040 0.006 Mass recv,ug 18.65 18.5 5 15.84 22.89 19.29 27.19 Stack, lb/hr 1.66E - 05 6.94E - 06 6.19E - 06 3.93E - 06 5.89E - 07 Stack, lb/hr 1.91E - 03 1.84E - 03 1.56E - 03 2.29E - 03 1.90E - 03 2.67E - 03 EF, lb/ton pel 7.90E - 08 3.30E - 08 2.94E - 08 1.81E - 08 2.71E - 09 EF, lb/ton pel 9.10E - 06 8.74E - 06 7.40E - 06 1.06E - 05 8.74E - 06 1.23E - 05 **Arsenic, As** Line emission factor: 9.93E - 06 lb/ton pellets fired **Manganese, Mn** Line emission factor: 1.32E - 04 lb/ton pellets fired Mass recv,ug 5.034 5.385 8.116 2.177 0.648 1.557 Mass recv,ug 30.69 21.81 185.9 9.217 22.16 41 .17 Stack, lb/hr 5.16E - 04 5.34E - 04 7.98E - 04 2.18E - 04 6.37E - 05 1.53E - 04 Stack, lb/hr 3.15E - 03 2.16E - 03 1.83E - 02 9.22E - 04 2.18E - 03 4.04E - 03 EF, lb/ton pel 2.46E - 06 2.54E - 06 3.79E - 06 1.00E - 06 2.94E - 07 7.04E - 07 EF, lb/ton pel 1.50E - 05 1.03E - 05 8.69E - 05 4.25E - 06 1.00E - 05 1.86E - 05 **Beryllium , Be**  Line emission factor: < 1.02E - 06 lb/ton pellets fired **Mercury, Hg** Line emission factor: 9.81E - 07 lb/ton pellets fired Mass recv,ug 0.580 0.739 0.667 < 0.023 < 0.026 0.263 Mass recv,ug 0.368 0.268 0.267 0.700 0.534 0. 608 Stack, lb/hr 5.95E - 05 7.32E - 05 6.56E - 05 < 2.30E - 06 < 2.56E - 06 < 2.58E - 05 Stack, lb/hr 3.77E - 05 2.66E - 05 2.62E - 05 7.01E - 05 5.25E - 05 5.97E - 05 EF, lb/ton pel 2.83E - 07 3.48E - 07 3.12E - 07 < 1.06E - 08 < 1.18E - 08 < 1.19E - 07 EF, lb/ton pel 1.79E - 07 1.26E - 07 1. 25E - 07 3.23E - 07 2.42E - 07 2.75E - 07 **Cadm ium** **, Cd** Line emission factor: 2.96E - 06 lb/ton pellets fired **Nickel, Ni** Line emission factor: 1.86E - 05 lb/ton pellets fired Mass recv,ug 2.829 1.480 0.861 0.710 0.528 0.513 Mass recv,ug 6.826 8.947 13.91 0.669 6.119 9.163 Stack, lb/hr 2.90E - 04 1.47E - 04 8.46E - 05 7.11E - 05 5.19E - 05 5.04E - 05 Stack, lb/hr 7.00E - 04 8.87E - 04 1.37E - 03 6.70E - 05 6.02E - 04 9.00E - 04 EF, lb/ton pel 1.38E - 06 6.97E - 07 4.02E - 07 3.27E - 07 2.39E - 07 2.32E - 07 EF, lb/ton pel 3.33E - 06 4.22E - 06 6.50E - 06 3. 08E - 07 2.77E - 06 4.15E - 06 **Chrom ium** **, Cr** Line emission factor: 8.42E - 05 lb/ton pellets fired **Selenium , Se**  Mass recv,ug 51.20 43.49 58.95 6.896 12.33 23.10 Mass recv,ug Samples were not analyzed Stack, lb/hr 5.25E - 03 4.31E - 03 5.79E - 03 6.90E - 04 1.21E - 03 2. 27E - 03 Stack, lb/hr for this element EF, lb/ton pel 2.50E - 05 2.05E - 05 2.76E - 05 3.18E - 06 5.59E - 06 1.04E - 05 EF, lb/ton pel 1. There are three hood exhaust stacks connected to a common exhaust header, and two waste gas stacks connected to another common exhaust header. Samples for laboratory analysis were taken from one of the three hood exhaust stacks and one of the two waste gas stacks for all three tests presented in this table. Line emission factors were then generated by summing of stack emissions multiplied by the proper multipliers. In general, the multiplier is assumed to be 3 for the hood exhaust stack emission and 2 for the waste gas stack emission. 2. For this particular test, the other two hood exhaust stacks were probed for gas flow rates to actually determine the multiplier for the hood exhaust stack emission.MPCA Report Page 67 **Table 28. Reference Method 12 testing at Furnace 12 of Northshore Mining Com pany**  1 **(Continued)** Stack Hood exhst (1 of 3 stacks) Waste gas (1 of 2 stacks) Stack Hood exhst (1 of 3 stacks) Waste gas (1 of 2 stacks) **Test date: May 19 -** **21, 1998 (three 1 -**  **hour runs) Com** **mon data** Run 1 Run 2 Run 3 Run 1 Run 2 Run 3 Run 1 Run 2 Run 3 Run 1 Run 2 Run 3 Sample, dscf 40.83 40.93 40.27 42.03 40.68 41.01 **Cobalt, Co** Line emission factor: < 2.44E - 06 lb/ton pellets fired Stack, dscfm 63097 63467 62167 64670 64820 66546 Mass recv,ug < 0.5 < 0.5 < 0.5 < 0.5 < 0.5 < 0.5 Ton pel./hr 205 205 205 222 222 222 Stack, lb/hr < 1.02E - 04 < 1.03E - 04 < 1.02E - 04 < 1.02E - 04 < 1.05E - 04 < 1.07E - 04 Multiplier 2 3 2 EF, lb/ton pel < 4.98E - 07 < 5.00E - 07 < 4.97E - 07 < 4.59E - 07 < 4.76E - 07 < 4.84E - 07 **Antim ony, Sb**  Line emission factor: < 9.77E - 06 lb/ton pellets fired **Lead, Pb** Line emission factor: 9.49E - 05 lb/ton pellets fired Mass recv,ug < 2 < 2 < 2 < 2 < 2 < 2 Mass recv,ug 24 21 21 13 15 18 Stack, lb/hr < 4.09E - 04 < 4.10E - 04 < 4.08E - 04 < 4.07E - 04 < 4.22E - 04 < 4.29E - 04 Stack, lb/hr 4.91E - 03 4.31E - 03 4.29E - 03 2.65E - 03 3.16E - 03 3.86E - 03 EF, lb/ton pel < 1.99E - 06 < 2.00E - 06 < 1.99E - 06 < 1.84E - 06 < 1.90E - 06 < 1.94E - 06 EF, lb/ton pel 2.39E - 05 2.10E - 05 2.09E - 05 1.19E - 05 1.43E - 05 1.74E - 05 **Arsenic, As** Line emission factor: 2.27E - 05 lb/ton pellets fired **Manganese, Mn** Line emission factor: 9.86E - 05 lb/ton pellets fired Mass recv,ug 6.9 6.1 6.2 1.7 1.4 2.6 Mass recv,ug 18 1 1 17 19 18 46 Stack, lb/hr 1.41E - 03 1.25E - 03 1.27E - 03 3.46E - 04 2.95E - 04 5.58E - 04 Stack, lb/hr 3.68E - 03 2.26E - 03 3.47E - 03 3.87E - 03 3.79E - 03 9.87E - 03 EF, lb/ton pel 6.87E - 06 6.10E - 06 6.17E - 06 1.56E - 06 1.33E - 06 2.52E - 06 EF, lb/ton pel 1.79E - 05 1.10E - 05 1.69 E - 05 1.75E - 05 1.71E - 05 4.46E - 05 **Beryllium , Be**  Line emission factor: < 1.46E - 06 lb/ton pellets fired **Mercury, Hg** Line emission factor: < 2.60E - 06 lb/ton pellets fired Mass recv,ug < 0.3 < 0.3 < 0.3 < 0.3 < 0.3 < 0.3 Mass recv,ug < 0.8 < 0.4 < 0.4 < 0.8 < 0.4 < 0.4 Stack, lb/hr < 6.13E - 05 < 6.15E - 05 < 6.13E - 05 < 6.11E - 05 < 6.32E - 05 < 6.44E - 05 Stack, lb/hr < 1.64E - 04 < 8.20E - 05 < 8.17E - 05 < 1.63E - 04 < 8.43E - 05 < 8.59E - 05 EF, lb/ton pel < 2.99E - 07 < 3.00E - 07 < 2.98E - 07 < 2.76E - 07 < 2.85E - 07 < 2.91E - 07 EF, lb/ton pel < 7.97E - 07 < 4.00E - 07 < 3.98E - 07 < 7.35E - 07 < 3.81E - 07 < 3.88E - 07 **Cadm ium** **, Cd** Line emission factor: 4.68E - 06 lb/ton pellets fired **Nickel, Ni** Line emission factor: 1.79E - 05 lb/ton pellets fired Mass recv,ug 0.8 1.0 1.0 1.0 1.0 1.0 Mass recv,ug 5 2 2 2 2 10 Stack, lb/hr 1.64E - 04 2.05E - 04 2.04E - 04 2.04E - 04 2.11E - 04 2.15E - 04 Stack, lb/hr 1.02E - 03 4.10E - 04 4.08E - 04 4.07E - 04 4.22E - 04 2.15E - 03 EF, lb/ton pel 7.97E - 07 9.99E - 07 9.95E - 07 9.19E - 07 9.51E - 07 9.69E - 07 EF, lb/ton pel 4.98E - 06 2.00E - 06 1. 99E - 06 1.84E - 06 1.90E - 06 9.69E - 06 **Chrom ium** **, Cr** Line emission factor: 1.34E - 04 lb/ton pellets fired **Selenium , Se**  Line emission factor: 2.70E - 05 lb/ton pellets fired Mass recv,ug 35 35 39 12 11 17 Mass recv,ug 7.6 7.1 7.2 3.0 2.9 2.3 Stack, lb/hr 7.15E - 03 7.18E - 03 7.96E - 03 2.44E - 03 2.32E - 03 3.65E - 03 Stack, lb/hr 1.55E - 03 1.46E - 03 1.47E - 03 6.11E - 04 6.11E - 04 4.94E - 04 EF, lb/ton pel 3.49E - 05 3.50E - 05 3.88E - 05 1.10E - 05 1.05E - 05 1.65E - 05 EF, lb/ton pel 7.57E - 06 7.10E - 06 7.16E - 06 2.76E - 06 2.76E - 06 2.23E - 06 1 . There are three hood exhaust stacks connected to a common exhaust header, and two waste gas stacks connected to another common exhaust header. Samples for laboratory analysis were taken from one of the three hood exhaust stacks and one of the two waste gas stacks for all three tests presented in this table. Line emission factors were then generated by summing of stack emissions multiplied by the proper multipliers. The multiplier is assumed generally to be 3 for the hood exhaust stack emission and 2 for the waste gas stack emission. 2. For this particular test, the generally assumed multipliers were used.MPCA Report Page 68 **Table 28. Reference Method 12 testing at Furnace 12 of Northshore Mining Com pany**  1 **(Continued)** Stack Hood exhst (1 of 3 stacks) Waste gas (1 of 2 stacks) Stack Hood exhst (1 of 3 stacks) Waste gas (1 of 2 stacks) **Test date: May 24 -** **26, 1994 (three 1 -**  **hour runs) Com** **mon data** Run 1 Run 2 Run 3 Run 1 Run 2 Run 3 Run 1 Run 2 Run 3 Run 1 Run 2 Run 3 Sample, dscf 45.00 46.40 47.56 46.61 45.18 45.19 **Co balt, Co**  Line emission factor: < 2.52E - 06 lb/ton pellets fired Stack, dscfm 61729 62123 63041 61911 62396 62023 Mass recv,ug < 0.6 < 0.6 < 0.6 < 0.6 < 0.6 < 0.6 Ton pel./hr 213 213 213 213 213 213 Stack, lb/hr < 1.09E - 04 < 1.06E - 04 < 1.05E - 04 < 1.05E - 04 < 1.10E - 04 < 1.09E - 04 Multiplier 2 3 2 EF, lb/ton pel < 5.12E - 07 < 4.99E - 07 < 4.94E - 07 < 4.95E - 07 < 5.15E - 07 < 5.12E - 07 **Antim ony, Sb**  Line emission factor: < 1.26E - 04 lb/ton pellets fired **Lead, Pb** Line emission factor: 3.23E - 05 lb/ton pellets fired Mass recv,ug < 30 < 30 < 30 < 30 < 30 < 30 Mass recv,ug 8.9 11.0 12.0 2.6 3.6 3.8 Stack, lb/hr < 5.44E - 03 < 5.31E - 03 < 5.26E - 03 < 5.27E - 03 < 5.48E - 03 < 5.45E - 03 Stack, lb/hr 1.61E - 03 1.95E - 03 2.10E - 03 4.57E - 04 6.58E - 04 6.90E - 04 EF, lb/ton pel < 2.56E - 05 < 2.50E - 05 < 2.47E - 05 < 2.48E - 05 < 2.58E - 05 < 2.56E - 05 EF, lb/ton pel 7.59E - 06 9.15E - 06 9.89E - 06 2.15E - 06 3.09E - 06 3.24E - 06 **Arsenic, As** Line emission factor: 1.13E - 04 lb/ton pellets fired **Manganese, Mn** Line emission factor: 5.31E - 05 lb/ton pellets fired Mass recv,ug 44.0 23.0 54.0 7.9 8.9 3.4 Mass recv,ug 7.7 7.9 11.0 25 19 11 Stack, lb/hr 7.98E - 03 4.07E - 03 9.47E - 03 1.39E - 03 1.63E - 03 6.17E - 04 Stack, lb/hr 1.40E - 03 1.40E - 03 1.93E - 03 4.39E - 03 3.47E - 03 2.00E - 03 EF, lb/ton pel 3.75E - 05 1.91E - 05 4.45E - 05 6.5 2E - 06 7.64E - 06 2.90E - 06 EF, lb/ton pel 6.57E - 06 6.57E - 06 9.06E - 06 2.06E - 05 1.63E - 05 9.38E - 06 **Beryllium , Be**  Line emission factor: < 2.52E - 06 lb/ton pellets fired **Mercury, Hg** Line emission factor: 3.63E - 06 lb/ton pellets fired Mass recv,ug < 0.6 < 0.6 < 0.6 < 0.6 < 0.6 < 0.6 Mass recv,ug 0.21 0.18 0.49 0.43 4.30 0.36 Stack, lb/hr < 1.09E - 04 < 1.06E - 04 < 1.05E - 04 < 1.05E - 04 < 1.10E - 04 < 1.09E - 04 Stack, lb/hr 3.81E - 05 3.19E - 05 8.59E - 05 7.56E - 05 7.86E - 04 6.54E - 05 EF, lb/ton pel < 5.12E - 07 < 4.99E - 07 < 4.94 E - 07 < 4.95E - 07 < 5.15E - 07 < 5.12E - 07 EF, lb/ton pel 1.79E - 07 1.50E - 07 4.04E - 07 3.55E - 07 3.69E - 06 3.07E - 07 **Cadm ium** **, Cd** Line emission factor: < 3.36E - 06 lb/ton pellets fired **Nickel, Ni** Line emission factor: 5.15E - 04 lb/ton pellets fired Mass recv,ug < 0 .8 < 0.8 < 0.8 < 0.8 < 0.8 < 0.8 Mass recv,ug 41 77 140 110 240 180 Stack, lb/hr < 1.45E - 04 < 1.42E - 04 < 1.40E - 04 < 1.41E - 04 < 1.46E - 04 < 1.45E - 04 Stack, lb/hr 7.44E - 03 1.36E - 02 2.45E - 02 1.93E - 02 4.38E - 02 3.27E - 02 EF, lb/ton pel < 6.82E - 07 < 6.66E - 07 < 6 .59E - 07 < 6.61E - 07 < 6.87E - 07 < 6.83E - 07 EF, lb/ton pel 3.50E - 05 6.41E - 05 1.15E - 04 9.08E - 05 2.06E - 04 1.54E - 04 **Chrom ium** **, Cr** Line emission factor: 1.10E - 04 lb/ton pellets fired **Selenium , Se**  Line emission factor: 1.54E - 05 lb/ton pellets fired Mass recv,ug 19 23 34 22 35 25 Mass recv,ug 2.1 2.6 2.6 6.2 5.3 5.1 Stack, lb/hr 3.45E - 03 4.07E - 03 5.96E - 03 3.87E - 03 6.39E - 03 4.54E - 03 Stack, lb/hr 3.81E - 04 4.60E - 04 4.56E - 04 1.09E - 03 9.68E - 04 9.26E - 04 EF, lb/ton pel 1.62E - 05 1.91E - 05 2.80E - 05 1.82E - 05 3.00E - 05 2.13 E - 05 EF, lb/ton pel 1.79E - 06 2.16E - 06 2.14E - 06 5.12E - 06 4.55E - 06 4.35E - 06 1. There are three hood exhaust stacks connected to a common exhaust header, and two waste gas stacks connected to another common exhaust header. Samples for laboratory analysis were taken from one of the three hood exhaust stacks and one of the two waste gas stacks for all three tests presented in this table. Line emission factors were then generated by summing of stack emissions multiplied by the proper multipliers. The multipli er is assumed generally to be 3 for the hood exhaust stack emission and 2 for the waste gas stack emission. 2. For this particular test, the generally assumed multipliers were used.MPCA Report Page 69 

### Table 29. Element composition analysis from Northshore Mining Company **(ppm by weight)** 1 

### Material Antimony Arsenic Beryllium Cadmium Chromium Cobalt Lead Manganese Mercury Nickel Selenium

Sb As Be Cd Cr Co Pb Mn Hg Ni Se Bentonite < 0.4 0.6 2.46 0.23 3.6 2.2 35.9 494 0.0121 2.5 < 0.2 Bentonite 1.52 3.49 2.1 0.22 3.9 1.9 32.5 345 6.1 < 0.3 Coal < 0.06 2.37 0.7 0.11 4.5 1.9 1.2 61 < 2.1 < 0.3 Coal < 1 < 1 2.06 < 0.5 7.8 13.8 1.3 10 0.0579 13.4 4.7 Coal ash 1.0 13.9 8.91 0.61 82.9 49.9 27.6 198 0.0242 51.6 8.9 Coal ash 1.42 11.21 6.3 1.81 74.0 29.6 40.4 180 5 7.4 6.2 Coarse tails 0.47 23.72 2.5 < 0.02 57.4 8.4 0.8 4813 3.7 < 0.3 Concentrate 0.21 5.07 0.6 < 0.02 41.5 9.3 < 0.5 919 6.4 0.4 Dry cob tails 0.23 37.08 1.7 < 0.02 56.4 6.1 0.8 3284 2.9 < 0.3 Fine tails 0.08 14.06 2.0 0.03 51.8 8.5 0.7 3811 2.8 < 0.3 Flux conc < 0.4 1.8 0.43 < 0.03 35.8 6.9 0.3 1821 0.0028 6.7 < 0.3 Flux pellets < 0.3 1.4 0.80 < 0.03 11.2 12.2 0.3 1347 0.0010 8.2 < 0.2 Flux stone 1.0 6.8 0.09 < 0.01 3.3 < 0.3 1.2 55 0.0070 0.6 < 0.1 Green balls 0.72 4.00 0.5 < 0.02 45 .7 8.9 < 0.5 945 7.8 < 0.3 Lime stone < 0.06 2.67 < 0.2 0.03 1.7 < 0.8 1.1 31 < 2.1 < 0.3 Pellets, fired 0.66 3.69 0.6 < 0.02 42.1 9.4 0.6 814 8.3 < 0.3 Plant feed 3.62 7.54 2.2 < 0.02 47.0 8.7 < 0.5 2578 3.5 < 0.3 Starch binder < 0.06 2.24 0.4 0.13 < 0.6 1.0 1.4 23 2.6 < 0.3 Starch binder < 0.3 < 0.4 < 0.02 0.06 2.1 0.4 0.4 31 0.0011 0.9 < 0.2 Std conc 1 < 0.4 2.3 0.56 < 0.03 29.2 12.1 < 0.3 1568 0.0029 8.3 0.6 Std conc 2 < 0.3 1.2 0.37 < 0.02 43.1 9.9 < 0.2 1487 0.0032 11.7 < 0.3 Std pellets < 0.5 1.4 0.41 < 0.05 34.0 9.1 0.3 1347 0.0030 5.5 < 0.3 1. Data were collected March 1994 and March 1997. The algebraic symbol, “<”, indicates that the mass used in the analysis was b elow the detection limit.MPCA Report Page 70 

### Table 30. Testing for product**s of incomplet combustion at NMC’s Furnace 12** 1 

### Line heat input 155 million Btu/hour Multiplier 3 (1 of 3 hood exhaust stacks) 2 (1 of 2 waste gas stacks) **Common:** 2 

### 3 PICs Run 1 Run 2 Run 3 Run 1 Run 2 Run 3 Sample volume, dscf 0.706 0.681 0.679 0.7 29 0.697 0.689 Stack gas flow, dscfm 68200 67800 67800 66100 63200 63200 **Benzene** Line emission factor: < 0.00098 lb/MMBtu Mass recovered, ug < 2.4 < 2.4 < 2.4 < 2.4 < 2.4 < 2.4 Stack emission, lb/hr < 0.031 < 0.032 < 0.032 < 0.029 < 0.029 < 0.029 **Toluene** Line emission factor: < 0.00098 lb/MMBtu Mass recovered, ug < 2.4 < 2.4 < 2.4 < 2.4 < 2.4 < 2.4 Stack emission, lb/hr < 0.031 < 0.032 < 0.032 < 0.029 < 0.029 < 0.029 **Hexane** Line emission factor: < 0.00106 lb/MMBtu Mass recovered, ug < 2 .6 < 2.6 < 2.6 < 2.6 < 2.6 < 2.6 Stack emission, lb/hr < 0.033 < 0.034 < 0.034 < 0.031 < 0.031 < 0.032 **Formaldehyde** Line emission factor: 0.02173 lb/MMBtu Sample volume, dscf 58.01 58.07 57.92 54.48 52.41 51.86 Stack gas flow, dscfm 68201 68266 67 832 66087 63202 62266 Mass recovered, ug 2700 2900 2700 6300 5700 7500 Stack emission, lb/hr 0.420 0.451 0.418 1.011 0.909 1.191 1. Test date: October 12, 1995. 2. There are three hood exhaust stacks connected to a common exhaust header, and two waste gas stacks connected to another common exhaust header. Samples were taken from one of the three hood exhaust stacks and one of the two waste gas stacks for all three tests presented in this table. Line emission factors were then generated by summing o f stack emissions multiplied by the proper multipliers. The multiplier was assumed generally to be 3 for the hood exhaust stack emission and 2 for the waste gas stack emission.MPCA Report Page 71 

### Table 31. Stack testing for HCl and HF at NMC’s Furnace 12

Run 1 Run 2 Run 3 Run 1 Run 2 Run 3 **Test date: Nov. 3, 1998 (Line prod. rate: 259 ton pellets/hour)** Multiplier 1 

### 3 (1 of 3 hood exhaust stacks) 2 (1 of 2 waste gas stacks) Sample volume, dscf 45.22 45.18 45.94 36.73 37.73 37.52 Stack gas flow, dscfm 69700 70391 70388 57928 57030 56964 **HCl** Line emission factor: 0.00614 lb/ton pellets fired Mass recovered, ug 1615 1395 1235 1874.6 1654.6 1804.6 Stack emission, lb/hr 0.329 0.287 0.250 0.391 0.331 0.362 **HF** Line emission factor: 0.00186 lb/ton pellets fired Mass recovered, ug 694 776 711 63 108 96 Stack emission, lb/hr 0.141 0.160 0.144 0.013 0.022 0.019 **Test date: January 1992 (Line prod. rate: 284 ton pellets/hour)** 2 

### Specific test date Jan. 7, 1992 Jan. 8, 1992 Sample volume, dscf 44.77 44 .77 44.69 44.00 44.47 44.11 Stack gas flow, dscfm 60200 60200 60200 58700 58700 58700 **HCl** Mass recovered, ug 8227 4988 4782 1142 1100 1142 Stack emission, lb/hr 1.463 0.887 0.852 0.201 0.192 0.201 **HF** Mass recovered, ug 737 1464 1938 1948 1369 3106 Stack emission, lb/hr 0.131 0.260 0.345 0.344 0.239 0.547 **Specific test date** Jan. 9, 1992 **Summary for** Sample volume, dscf 45.28 44.64 44.70 **line emission factors:** Stack gas flow, dscfm 62500 62500 62500 **HCl** Line emission factor: 0.00768 lb/ton pellets fired Mass recovered, ug 492.6 683.9 858.7 Stack emission, lb/hr 0.090 0.127 0.159 **HF** Line emission factor: 0.00562 lb/ton pellets fired Mass recovered, ug 1158.3 1895.4 2106.0 Stack emission, lb/hr 0.212 0.351 0.390 1. There are three hood exhaust stacks connected to a common exhaust header, and two waste gas stacks connected to another common exhaust header. Samples were taken from one of the three hood exhaust stacks and one of the two waste gas stacks for all three tests presented in this table. Line emission factors were then generated by summing of stack emissions multiplied by the proper multipliers. 2. This testing work was the earliest found in the MPCA file. The hood exhaust stack appeared to be tested twice (1/7/9 2 & 1/9/92), while the waste gas stack was tested only once (1/8/92). Line emission factors resulted from averaging the data from all three days of testing.MPCA Report Page 72 

### Table 32. HAPs emission estimates for NMC’s taconite pelletizers 1 

### Pollutant **Emission,**

**ton/ye ar**  **Emission**

**factor E.F. unit**  **Emission factor source** Products of incomplete combustion based on annual heat input of 3,023,583 MMBtu/yr Benzene < 1.48 < 0.00098 lb/MMBtu NMC 10/95 Toluene < 1.48 < 0.00098 lb/MMBtu NMC 10/95 Hexane < 1.61 < 0.00106 lb/MMBtu NMC 10/95 Formaldehyde 32.9 0.02173 lb/MMBtu NMC 10/95

Emissions which are related to production level

— 4,524,800 ton pellets/year Hydrogen chloride 17.4 0.00768 lb/ton pel. NMC 1/92 Hydrogen fluoride 12.7 0.00562 lb/ton pel. NMC 1/92

Metals at

-

pellet firing 2 

### Emission **factor E.F. unit**  **Emission factor source** Antimony, Sb < 0.285 < 63.0 ppb of pel. NMC 5/94 Arsenic, As 0.255 56.3 ppb of pel. NMC 5/94 Beryllium, Be < 0.006 < 1.26 ppb of pel. NMC 5/94 Cadmium, Cd 0.011 2.34 ppb of pel. NMC 5/98 Chromium, Cr 0.303 67.0 ppb of pel. NMC 5/98 Cobalt, Co < 0.006 < 1.26 ppb of pel. NMC 5/94 Lead, Pb 0.215 47.4 ppb of pel. NMC 5/98 Manganese, Mn 0.298 65.8 ppb of pel. NMC 9/98 Mercury, Hg 0.008 1.82 ppb of pel. NMC 5/94 Nickel, Ni 1.164 257 ppb o f pel. NMC 5/94 Selenium, Se 0.061 13.5 ppb of pel. NMC 5/98 1. The algebraic symbol, “<” (less than), indicates that the emission factor was developed from a stack test for which the mass recovered was below the detection limit for that air pollutant. 2 . Reference Method 29 is the stack testing method for the elements listed here. See Table 28 for NMC’s emission factors. For example, for antimony, the emission factor is less than 63.0 parts of the element in weight per 1 billion parts of pellets fired from the May 1994 test.MPCA Report Page 73 

### Table 33. HAPs emission estimation for off **- pellet firing processes at Northshore Mining Company**  **Process group** 1 Ore Bentonite Greenballs Fired pellets Coal handl Ore Bentonite Greenballs Fired pellets Coal handl Year total Year PM from Emission Inventory, 2 ton/year Sum of element emissions for process groups, ton/year 1995 966 10.1 58.5 6693 0.06 2.56 0.005 0.059 8.17 3.897E - 06 **10.8** 1996 574 8.30 130 1748 0.03 1.52 0.004 0.132 2.13 1.949E - 06 **3.79** 1997 723 11.2 131 5182 0.57 1.92 0.005 0.133 6.32 3.703E - 05 **8.38 Elem** **ent** Composition of elements, 3 ppm by weight Individual element emissions, ton/year ‘97; sum : 4 Antimony, Sb 3.62 0.96 0.72 0.487 0.53 2.62E - 03 1.07E - 05 9.42E - 05 2.52E - 03 3.02E - 07 5.24E - 03 Arsenic, As 7.54 2.05 4 .0 2.16 1.69 5.45E - 03 2.29E - 05 5.23E - 04 1.12E - 02 9.60E - 07 1.72E - 02 Beryllium, Be 2.2 2.28 0.5 0.60 1.38 1.59E - 03 2.55E - 05 6.54E - 05 3.13E - 03 7.87E - 07 4.81E - 03 Cadmium, Cd 0.02 0.23 0.02 0.03 0.31 1.45E - 05 2.52E - 06 2.62E - 06 1.73E - 04 1.74E - 07 1.92E - 04 Chromium, Cr 47.0 3.75 45.7 29.1 6.15 3.40E - 02 4.19E - 05 5.98E - 03 1.51E - 01 3.51E - 06 1.91E - 01 Cobalt, Co 8.7 2.05 8.9 10.2 7.85 6.29E - 03 2.29E - 05 1.16E - 03 5.30E - 02 4.47E - 06 6.05E - 02 Lead, Pb 0.5 34.2 0.5 0.40 1.25 3.61E - 04 3.82E - 04 6.54E - 05 2.07E - 03 7.13E - 07 2 .88E - 03 Manganese, Mn 2578 420 945 1169 35.5 1.86E+00 4.69E - 03 1.24E - 01 6.06E+00 2.02E - 05 8.05E+00 Mercury, Hg 0.11 0.0121 0.13 0.0020 0.0579 7.95E - 05 1.35E - 07 1.70E - 05 1.04E - 05 3.30E - 08 1.07E - 04 Nickel, Ni 3.5 4.3 7.8 7.33 7.75 2.53E - 03 4.81E - 05 1.02E - 03 3.80E - 02 4.42E - 06 4.16E - 02 Selenium, Se 0.3 0.25 0.3 0.27 2.50 2.17E - 04 2.80E - 06 3.92E - 05 1.38E - 03 1.43E - 06 1.64E - 03 Data source for Hg Ispat-Inland Ispat-Inland 1. Process group is used here to simplify data presentation. The ore group inc ludes coarse and fine crushing. The fired pellets group includes pellet stockpiling and loadout. 2. PM emissions, reported to the Emission Inventory, are not verified by MPCA staff. 3. Except for mercury, composition data in this block are provided by NMC (Table 29). 4. Sum of element emissions in 1997 for off -pellet firing processes is also shown in Table 4. Those for 1995 & 1996 are omitted here to save space. All calculations were made using spreadsheets.MPCA Report Page 74 **Table 34. PM testing results (Methods 5 & Minn.R. 7005.0500) for NMC’s pelletizers**  1 **Stack 1104 (waste gas; 7/31/96) Run 1**  **Run 2 Run 3**  **Average Rem** **arks** Mass recovered, ug 33300 17300 14100 21567 MPCA review letter Sample gas volume, dscf 43.40 41.45 41.86 42.24 (9/19/96) recognizes Stack gas f

low, dscfm 62176 60661 61312 61383 the stack tested is in Isokinetic variation, % 101.9 99.7 99.6 100.4 compliance with the Stack PM emission, lb/hour 6.31 3.35 2.73 4.13 PM emission limit of PM concentration in stack gas, gr/dscf 0.0118 0.0064 0.0052 **0.0078** 0.01 gr/dscf in Permit Line production rate, ton pellets/hour 311 311 311 311 No. 27A- 89 - OT - 1. Stack ems factor, lb/ton pellets (line) 0.02027 0.01076 0.00877 0.01327 **Stack 1105 (waste gas; 7/31/96) Run 1**  **Run 2 Run 3**  **Average Rem** **arks** Mass recovered, ug 18100 15600 16100 16600 MPCA review letter Sample gas volume, dscf 42.76 41.59 42.11 42.15 (9/19/96) recognizes Stack gas flow, dscfm 62573 60998 61764 61778 the stack tested is in Isokinetic variation, % 99.7 99.5 9 9.5 99.6 compliance with the Stack PM emission, lb/hour 3.50 3.03 3.12 3.22 PM emission limit of PM concentration in stack gas, gr/dscf 0.0065 0.0058 0.0059 **0.0061** 0.01 gr/dscf in Permit Line production rate, ton pellets/hou r 296 296 296 296 No. 27A- 89 - OT - 1. Stack ems factor, lb/ton pellets (line) 0.01185 0.01024 0.01056 0.01088 **Stack 1204 (waste gas; 7/30/96) Run 1**  **Run 2 Run 3**  **Average Rem** **arks** Mass recovered, ug 22200 17300 16900 18800 MPCA review letter Sample gas volume, dscf 39.16 40.47 41.03 40.22 (9/19/96) recognizes Stack gas flow, dscfm 58484 60125 60740 59783 the stack tested is in Isokinetic variation, % 99.1 99.6 100.0 99.6 compliance with the Stack PM emission, lb/hour 4.39 3.40 3.31 3.70 PM emission limit of PM concentration in stack gas, gr/dscf 0.0087 0.0066 0.0064 **0.0072** 0.01 gr/dscf in Permit Line production rate, ton pellets/hour 315 315 315 315 No. 27A- 89 - OT - 1. Stack ems factor, lb/ton pellets (line) 0.01391 0.01078 0.01 050 0.01173 **Stack 1205 (waste gas; 7/30/96) Run 1**  **Run 2 Run 3**  **Average Rem** **arks** Mass recovered, ug 13600 17000 16800 15800 MPCA review letter Sample gas volume, dscf 38.31 38.12 38.39 38.27 (9/19/96) recognizes Stack gas flow, dscfm 56746 56129 56134 56 336 the stack tested is in Isokinetic variation, % 99.9 100.5 101.2 100.5 compliance with the Stack PM emission, lb/hour 2.66 3.31 3.25 3.08 PM emission limit of PM concentration in stack gas, gr/dscf 0.0055 0.0069 0.0068 **0 .0064**  0.01 gr/dscf in Permit Line production rate, ton pellets/hour 318 318 318 318 No. 27A- 89 - OT - 1. Stack ems factor, lb/ton pellets (line) 0.00839 0.01043 0.01023 0.00968 1. For Furnaces 11 or 12, there are 3 hood exhaust stacks (Stacks 1101, 1102, and 1103; or Stacks 1201, 1202, 1203) connected to a common exhaust header and 2 waste gas stacks connected to another common exhaust header (Stacks 1104 and 1105; or Stacks 1204 and 1205). Minn.R. 7005.0500 is for “organic wet catch.”MPCA Report Page 75 **Table 34. PM tes ting results (Methods 5 & Minn.R. 7005.0500) for NMC’s pelletizers**  1 **(Continued) Stack 601 (Furnace 6; 10/10/95)**  **Run 1 Run 2**  **Run 3 Average**  **Rem arks**  Mass recovered, ug 23200 15100 22300 20200 MPCA review letter Sample gas volume, dscf 37.62 37.61 37.71 37 .65 (3/18/96) recognizes Stack gas flow, dscfm 52507 52961 52937 52802 the stack tested is in Isokinetic variation, % 99.9 99.0 99.3 99.4 compliance with the Stack PM emission, lb/hour 4.28 2.81 4.14 3.75 PM emission limit o f PM concentration in stack gas, gr/dscf 0.0095 0.0062 0.0091 **0.0083** 0.01 gr/dscf in Permit Line production rate, ton pellets/hour 123 123 123 123 No. 27A- 89 - OT - 1. Stack ems factor, lb/ton pellets (line) 0.03486 0.02289 0.03370 0.03049 **Stack 1104 (was te gas; 1/10/95)**  **Run 1 Run 2**  **Run 3 Average**  **Rem arks**  Mass recovered, ug 39100 29600 20900 29867 MPCA review letter Sample gas volume, dscf 51.28 51.49 51.63 51.47 (5/16/95) recognizes Stack gas flow, dscfm 69343 69067 69437 69282 the stack re -tested 2 is Isokinetic variation, % 99.5 100.3 100.0 99.9 in compliance with the Stack PM emission, lb/hour 6.99 5.25 3.72 5.32 PM emission limit of PM concentration in stack gas, gr/dscf 0.0118 0.0089 0.0062 **0.0090** 0.01 gr/dscf in Permit Line production rate, ton pellets/hour 319 319 319 319 No. 27A- 89 - OT - 1. Stack ems factor, lb/ton pellets (line) 0.02191 0.01645 0.01165 0.01667 **Stack 1105 (waste gas; 1/10/95) Run 1**  **Run 2 Run 3**  **Average Rem** **arks** Mass recovered, ug 34300 36600 37800 36233 MPCA review letter Sample gas volume, dscf 51.68 52.66 51.00 51.78 (5/16/95) recognizes Stack gas flow, dscfm 70316 72787 70134 71079 the stack re -tested 2 is Isokinetic variation, % 101.3 99.7 100.2 100.4 in compliance with the Stack PM emission, lb/hour 6.17 6.69 6.88 6.58 PM emission limit of PM concentration in stack gas, gr/dscf 0.0102 0.0107 0.0114 **0.01** 0.01 gr/dscf in Permit Line production rate, ton pellets/hour 319 319 319 319 No. 27A- 89 - OT - 1. Stack ems factor, lb/ton pellets (line) 0.01934 0.02096 0.02154 0.02061 **Stack 1204 (waste gas; 1/11/95) Run 1**  **Run 2 Run 3**  **Average Rem** **arks** Mass recovered, ug 24000 18400 23300 21900 MPCA review letter Sample gas volume, dscf 46.63 45.87 46.66 46.39 (5/16/95) recognizes Stack gas flow, dscfm 63727 62512 63698 63312 the stack re -tested 2 is Isokinetic variation, % 99.8 100.1 99.9 99.9 in compliance with the Stack PM emission, lb/hour 4.34 3.32 4.21 3.95 PM emission limit of PM concentration in stack gas, gr/dscf 0.0079 0.0062 0.0077 **0.0073** 0.01 gr/dscf in Permit Line production rate, ton pellets/hour 302 302 302 302 No. 27A- 89 - OT - 1. Stack ems factor, lb/ton pellets (line) 0.01435 0.01097 0.01391 0.01308 1. For Furnaces 11 or 12, there are 3 hood exhaust stacks (Stacks 1101, 1102, and 1103; or Stacks 1201, 1202, 1203) connected to a common exhaust header and 2 waste gas stacks connected to another common exhaust header (Stacks 1104 and 1105; or Stacks 1204 and 1205). Minn.R. 7005.050 0 is for “organic wet catch.” 2. The January 1995 performance testing of Stacks 1104, 1105, 1204, and 1205 was a re -test to resolve noncompliance issues associated with previous testing results (see next page). It should be noted that the 0.01 gr/dscf limit is more stringent than the state’s PM rule.MPCA Report Page 76 **Table 34. PM testing results (Methods 5 & Minn.R. 7005.0500) for NMC’s pelletizers** 1 **(Continued) Stack 1205 (waste gas; 1/11/95)**  **Run 1 Run 2**  **Run 3 Average**  **Rem arks**  Mass recovered, ug 29700 28100 27300 2 8367 MPCA review letter Sample gas volume, dscf 45.96 46.81 45.07 45.95 (5/16/95) recognizes Stack gas flow, dscfm 65952 63717 63698 64456 the stack re -tested 2 is Isokinetic variation, % 97.4 102.7 101.7 100.6 in complianc e with the Stack PM emission, lb/hour 5.64 5.06 5.10 5.27 PM emission limit of PM concentration in stack gas, gr/dscf 0.0100 0.0093 0.0093 **0.0095** 0.01 gr/dscf in Permit Line production rate, ton pellets/hour 302 302 302 302 No. 27A- 89 - OT - 1. Stack ems f

actor, lb/ton pellets (line) 0.01864 0.01673 0.01688 0.01742 **Furnace 12 (5/25/94) Hood exhaust stack (1 of 3)**  **Waste gas stack (1 of 2) (Electrics ON)**  **Run 1 Run 2**  **Run 3 Run 1**  **Run 2 Run 3**  Mass recovered, ug 20900 29600 31400 124700 93900 79500 Sample gas volume, dscf 44.36 46.34 46.38 48.30 44.79 44.56 Stack gas flow, dscfm 62062 61536 61812 64551 62729 62059 Isokinetic variation, % 95.0 100.1 99.7 103.7 99.0 99.5 Stack PM emission, lb/hour 3.87 5.20 5.54 22.0 17.4 14.6 PM concentration in stack gas, 2 gr/dscf 0.0073 0.0099 0.0104 **0.0398 0.0324**  **0.0275** Line production rate, ton pellets/hour 271 271 271 269 269 269 Stack ems factor, lb/ton pellets (line) 0.01427 0.01918 0.02042 0.08201 0.06472 0.05449 Line emission factor PM: 0.18802 lb/ton pellets f ired from Furnace 12 **Furnace 12 (5/24 -** **25/94) Hood exhaust stack (1 of 3)**  **Waste gas stack (1 of 2) (Electrics OFF)**  **Run 1 Run 2**  **Run 3 Run 1**  **Run 2 Run 3**  Mass recovered, ug 30000 26200 30700 105100 131300 88200 Sample gas volume, dscf 47.68 47.37 46.83 44. 34 44.26 44.06 Stack gas flow, dscfm 63577 62321 61825 61671 61752 61258 Isokinetic variation, % 99.6 101.0 100.6 99.7 99.3 99.7 Stack PM emission, lb/hour 5.29 4.56 5.36 19.3 24.2 16.2 PM concentration in stack gas, gr/dscf 0.0097 0.0085 0.0101 **0.0366 0.0458**  **0.0309** Line production rate, ton pellets/hour 271 271 271 269 269 269 Stack ems factor, lb/ton pellets (line) 0.01952 0.01682 0.01978 0.07194 0.09015 0.06035 Line emission factor PM: 0.20441 lb/ton pellets fired from Furnace 12 1. For Furnaces 11 or 12, there are 3 hood exhaust stacks (Stacks 1101, 1102, and 1103; or Stacks 1201, 1202, 1203) connected to a common exhaust header and 2 waste gas stacks connected to another common exhaust header (Stacks 1104 and 1105; or Stacks 1204 and 1205). Minn.R. 7005.0500 is for “organic wet catch.” 2. With the May 1994 stack testing, waste gas stacks (1104, 1105, and 1204) were found non- compliance with the PM emission limit of 0.01 gr/dscf in Permit No. 27A- 89 - OT - 1. Re -test was conducted in January 1995 ( see previous page). It should be noted that the 0.01 gr/dscf limit is more stringent than the state’s PM rule.MPCA Report Page 77 **Table 34. PM testing results (Methods 5 & Minn.R. 7005.0500) for NMC’s pelletizers** 1 **(Continued) Stack 1104 (electrics on; 5/26/94)**  **Run 1 Run 2**  **Run 3 Average**  **Rem arks**  Mass recovered, ug 79000 258600 29900 122500 MPCA review letter Sample gas volume, dscf 50.14 48.54 49.62 49.43 (1/11/95) notes that Stack gas flow, dscfm 69427 66236 68343 68002 the stack tested 2 is not Isokinetic variation, % 98.7 100.2 99.2 99.4 in compliance with the Stack PM emission, lb/hour 14.47 46.68 5.45 22.20 PM emission limit of PM concentration in stack gas, gr/dscf 0.0243 0.0822 0.0093 **0.0386** 0.01 gr/dscf in Permit Line production rate, ton pellets/hour 230 230 230 230 No. 27A- 89 - OT - 1. Stack ems factor, lb/ton pellets (line) 0.06302 0.20330 0.02373 0.09668 **Stack 1105 (electrics on; 5/26/94) Run 1**  **Run 2 Run 3**  **Average Rem** **arks** Mass recovered, ug 31300 25700 102900 53300 MPCA revi ew letter Sample gas volume, dscf 51.35 52.87 52.49 52.24 (1/11/95) notes that Stack gas flow, dscfm 73739 73133 71070 72647 the stack tested 2 is not Isokinetic variation, % 95.2 98.8 100.9 98.3 in compliance with the Stack PM emission, lb/hour 5.95 4.70 18.43 9.69 PM emission limit of PM concentration in stack gas, gr/dscf 0.0094 0.0075 0.0303 **0.0157** 0.01 gr/dscf in Permit Line production rate, ton pellets/hour 228 228 228 228 No. 27A- 89 - OT - 1. Stack ems factor, lb/ton p ellets (line) 0.02602 0.02058 0.08066 0.04242 1. For Furnaces 11 or 12, there are 3 hood exhaust stacks (Stacks 1101, 1102, and 1103; or Stacks 1201, 1202, 1203) connected to a common exhaust header and 2 waste gas stacks connected to another common exha ust header (Stacks 1104 and 1105; or Stacks 1204 and 1205). Minn.R. 7005.0500 is for “organic wet catch.” 2. With the May 1994 stack testing, waste gas stacks (1104, 1105, and 1204) were found non- compliance with the PM emission limit of 0.01 gr/dscf in P ermit No. 27A- 89 - OT - 1. Re -test was conducted in January 1995 (see previous page). It should be noted that the 0.01 gr/dscf limit is more stringent than the state’s PM rule.MPCA Report Page 78 

### Table 35. Inland’s voluntary stack testing (June 17**- 20, 1997)**  1 **HCl and H**

**F** 2 **Run 1 Run 2**  **Run 3 Average**  Sample volume, dscf Stack A 47.60 47.92 46.91 47.48 Stack B 46.45 47.39 47.57 47.14 Stack C 48.44 47.67 47.31 47.81 Stack D 48.65 48.56 48.17 48.46 Stack gas flow, dscfm Stack A 150762 150795 150006 150521 Stack B 149005 151650 150787 150481 Stack C 151818 151455 150446 151240 Stack D 140562 140719 142871 141384 Line rate, ton pellets/hr Stack A 381 364 364 370 Stack B 384 384 384 384 Stack C 391 391 391 391 Stack D 370 347 370 362 HCl recovered, ug Stack A 2777 4936 3908 3874 Stack B 6788 5451 5656 5965 Stack C 5245 5759 6171 5725 Stack D 535 617 679 610 HF recovered, ug Stack A 1053 1474 1158 1229 Stack B 347 347 484 393 Stack C 495 548 611 551 Stack D < 105.3 < 105.3 < 10 5.3 < 105.3 HCl emission, lb/hr Stack A 1.163 2.055 1.653 1.624 Stack B 2.880 2.307 2.372 2.520 Stack C 2.174 2.420 2.596 2.397 Stack D 0.2044 0.2365 0.2663 0.2357 HF emission, lb/hr Stack A 0.4412 0.6136 0.4899 0.5149 Stack B 0.1474 0.14 71 0.2031 0.1659 Stack C 0.2052 0.2301 0.2569 0.2307 Stack D < 0.0402 < 0.0404 < 0.0413 < 0.0406 HCl line emission factor 0.01776 lb/ton pellets fired HF line emission factor < 0.00253 lb/ton pellets fired 1. Testing was conducted when the line was fired with natural gas. 2. Reference Method 26 was used for HCl and HF.MPCA Report Page 79 

### Table 35. Inland’s voluntary stack testing (June 17**- 20, 1997)**  1 **(Continued) PM**  **10**2 Run 1 Run 2 Run 3 Average Mass recovered, ug Stack A 58200 59300 43400 53633 Stack B 29600 30500 21600 27233 Stack C 27400 21400 23000 23933 Stack D 21200 21300 20000 20833 Sample volume, dscf Stack A 45.90 46.28 45.49 45.89 Stack B 45.50 43.83 43.89 44.41 Stack C 45.81 46.31 45.14 45.75 Stack D 44.32 43.62 43.62 43.85 Stack gas flow, dscfm Stack A 148009 147135 145207 146784 Stack B 144969 143473 144634 144359 Stack C 150321 149600 145900 148607 Stack D 138928 140090 141327 140115 Isokinetic variation, % Stack A 99.8 101.2 100.8 100.6 Stack B 101.0 98.3 97.7 99.0 Stack C 98.1 99.6 99.6 99.1 Stack D 101.7 99.3 98.4 99.8 Stack emission, lb/hr Stack A 24.82 24.94 18.33 22.70 Stack B 1 2.48 13.21 9.416 11.70 Stack C 11.89 9.144 9.833 10.29 Stack D 8.790 9.049 8.571 8.804 PM 10 conc., gr/dscf Stack A 0.0196 0.0198 0.0147 0.0180 Stack B 0.0100 0.0107 0.0076 0.0095 Stack C 0.0092 0.0071 0.0079 0.0081 Stack D 0.0074 0.0075 0.00 71 0.0073 Line rate, ton pellets/hr Stack A 381 381 381 381 Stack B 403 403 384 397 Stack C 391 391 379 387 Stack D 370 347 370 362 PM 10 line ems factor 0.1399 lb/ton pellets fired 1. Testing was conducted when the line was fired with natural gas. 2. Reference Methods 5 and 202 were used. Method 5 provided conservative estimates for PM 10 for the “front half,” and Method 202 determined “condensibles” in the “back half.”MPCA Report Page 80 **Table 36. Inland’s engineering testing at Stack D (6/29 -** **30/1994)** 1 **Ref. Method 29: Run 1**  **Run 2 Run 3**  **Average** Sample volume, dscf 44.09 42.21 42.64 42.98 Stack gas flow, dscfm 161349 149095 150526 153657 **Antim ony, Sb**  Line emission factor: < 2.67E - 05 lb/ton pellets fired Mass recovered, ug < 6 < 6 < 6 < 6 Stack emission, lb/hr < 2.90E - 03 < 2.80E - 03 < 2.80E - 03 < 2.84E - 03 **Arsenic, As** Line emission factor: 2.42E - 05 lb/ton pellets fired Mass recovered, ug 3.7 2.1 10.6 5.5 Stack emission, lb/hr 1.79E - 03 9.81E - 04 4.95E - 03 2.57E - 03 **Beryllium , Be**  Line emission factor: < 1.33E - 06 lb/ton pellets fired Mass recovered, ug < 0.3 < 0.3 < 0.3 < 0.3 Stack emission, lb/hr < 1.45E - 04 < 1.40E - 04 < 1.40E - 04 < 1.42E - 04 **Cadm ium** **, Cd** Line emission factor: 5.37E - 06 lb/ton pellets fired Mass recovered, ug 1.9 0.8 0.9 1. 2 Stack emission, lb/hr 9.20E - 04 3.74E - 04 4.20E - 04 5.71E - 04 **Chrom ium** **, Cr** Line emission factor: 1.59E - 05 lb/ton pellets fired Mass recovered, ug 4.5 3.6 2.6 3.6 Stack emission, lb/hr 2.18E - 03 1.68E - 03 1.21E - 03 1.69E - 03 **Cobalt, Co** Line emission factor: < 1.33E - 06 lb/ton pellets fired Mass recovered, ug < 0.3 < 0.3 < 0.3 < 0.3 Stack emission, lb/hr < 1.45E - 04 < 1.40E - 04 < 1.40E - 04 < 1.42E - 04 **Lead, Pb** Line emission factor: 2.93E - 04 lb/ton pellets fired Mass recovered, ug 68.0 64.7 65.3 66.0 Stack emission, lb/hr 3.29E - 02 3.02E - 02 3.05E - 02 3.12E - 02 **Manganese, Mn** Line emission factor: 2.14E - 04 lb/ton pellets fired Mass recovered, ug 27.4 31.1 86.8 48.4 Stack emission, lb/hr 1.33E - 02 1.45E - 02 4.05E - 02 2.28E - 02 **Mercury, Hg** Line emission factor: 1.06E - 05 lb/ton pellets fired Mass recovered, ug 1.6 2.9 2.7 2.4 Stack emission, lb/hr 7.75E - 04 1.35E - 03 1.26E - 03 1.13E - 03 **Nickel, Ni** Line emission factor: 4.08E - 05 lb/ton pellets fired Mass recovered, ug 9.6 13.1 4.8 9.2 Stack emiss ion, lb/hr 4.65E - 03 6.12E - 03 2.24E - 03 4.34E - 03 **Selenium , Se**  Line emission factor: 1.54E - 05 lb/ton pellets fired Mass recovered, ug 3.3 3.4 3.7 3.5 Stack emission, lb/hr 1.60E - 03 1.59E - 03 1.73E - 03 1.64E - 03 1. Stack D is at the “hot side” (windbox) of the common exhaust header. Line rate of production was 426 ton pellets fired/hour. Line emission factors are calculated with a multiplier value of 4 for emission conversion from Stack D to the line.MPCA Report Page 81 **Table 36. Inland’s engineering testing at Stac k D (6/29**  **- 30/1994)**  1 **(Continued) For HCl & Fluorides:**  **Run 1 Run 2**  **Run 3 Average**  Stack gas flow, dscfm 138119 153177 145425 145574 **Ref. Method 26 (HCl)** Line emission factor: 0.08049 lb/ton pellets fired Mass recovered, ug 4217 710 720 1882 Sample volume, dscf 4.114 3.921 4.196 4.077 Stack emission, lb/hr 18.7 3.67 3.30 8.56 **R.M.13B (Fluorides)** Line emission factor: 1.47E - 05 lb/ton pellets fired Mass recovered, ug 2 7 3 4 Sample volume, dscf 47.21 50.94 50.25 49.47 Stack emission, lb/hr 0.00077 0.00278 0.00115 0.00157 **Particulate Matter** 2 Line emission factor: 0.1709 lb/ton pellets fired Mass recovered, ug 55300 43200 43200 47233 Sample volume, dscf 52.09 51.88 50.68 51.55 Stack gas flow, dscfm 151973 150280 147836 150030 Isokinetic variation, % 101.5 102.2 101.5 101.7 Stack emission, lb/hr 21.34 16.55 16.67 18.19 Concentration, gr/dscf 0.01638 0.01285 0.01315 0.01413 1. Stack D is at the “hot side” (windbox) of the common exhaust header. Line rate of production was 426 ton pellets fired/hour. Line emission factors are calculated with a multiplier value of 4 for emission conversion from Stack D to the line. 2. PM emission rate was determined with Method 5 for both “front half” and “back half”. The “back half” was analyzed for “organic wet catch” as per Minn. R. 7011.0725. 

### Table 37. Composition analysis from Inland 1 **Elem ent**  **Fluxed pellets Green balls**  **Ore com posite**  Antimony, Sb < 12 < 12 < 12 Arsenic, As < 20.2 < 20.2 < 20.2 Beryllium, Be 1.1 0.06 0.8 Cadmium, Cd < 0.8 < 0.8 < 0.8 Chromium, Cr < 1.0 < 1.0 < 1.0 Cobalt, Co 0.8 0.9 6.9 Lead, Pb < 6 < 6 < 6 Manganese, Mn 330 1080 4700 Mercury, Hg 0.08 0.13 0.11 Nickel, Ni < 0.4 < 0.4 1.5 Selenium, Se < 10 < 10 < 10 1 . Samples were collected on 7/1/1994 and analyzed on 7/6/1994, except for mercury, which was analyzed on 7/7/1994.MPCA Report Page 82 

### Table 38. Predicting HCl emissions from fluxstone fraction in fired pellets for some pelletizers 1 **Input Data for Linear Regression Re**  **gression Statistics** Fluxstone fraction HCl, lb/ton Source Multiple R 0.76876 0 0.00395 HTC96L2 R^2 0.59099 0.01 0.00768 NMC 92 Adj. R^2 0.38649 0.0738 0.00614 NMC 98 Std Error 0.00479 0.10346 0.01776 Inland 97 Observations 4 **Analysis of Va riance (ANOVA)**  df SS MS F Significance F Regression 1 6.622E - 05 6.622E - 05 2.8899 0.23124 Residual 2 4.853E - 05 2.291E - 05 Total 3 0.000112

Coeff Std Error t Stat P- value Lower 95% Upper 95% Intercept 0.00448 0.00353 1.26983 0.33190 - 0.01070 0.01965 Fluxstone fraction 0.09407 0.05533 1.69997 0.23124 - 0.14402 0.33215 1. The fitted model presented in detail here is for equation [1] of package 2 of this report. Since the data points were for the wet scrubber or wet ESP controlled pelletizers, the fitted model can be applied only to pelletizers with wet control devices. Extending the application of the fitted model to pelletizers with dry control devices (multiclones or gravity collectors) is not appropriate. For pelletizers with dry control devices, testing results from National Steel Pellet Company in August 1999 may be used to derive HCl emission factors.MPCA Report Page 83 

### Table 39. HAPs emission estimates for Ispat**- Inland’s taconite pelletizer**  1 

### Pollutant **Emission,**

**ton/year Emission** 

**factor E.F. unit**  **Em ission factor source**  Products of incomplete combustion based on annual heat input of 1,431,704 MMBtu/yr Benzene < 2.63 < 0.00206 lb/MMBtu HTC 7/96 Toluene < 2.92 < 0.00229 lb/MMBtu HTC 7/96 Hexane < 2.63 < 0.00206 lb/MMBtu HTC 7/96 Formaldehyde 15.6 0.02173 lb/MMBtu NMC 10/95

Emissions which are related to production level

—3,020,267 ton pellets/year Hydrogen chloride 26.8 0.01776 lb/ton pel. Inland 97 Hydrogen fluoride < 3.82 < 0.00253 lb/ton pel. Inland 97

Metals at

-

pellet firing 2 

### Emission **fact or**  **E.F. unit Emission factor source**  Antimony, Sb < 0.040 < 13.3 ppb of pel. Inland 94 Arsenic, As 0.037 12.1 ppb of pel. Inland 94 Beryllium, Be < 0.002 < 0.666 ppb of pel. Inland 94 Cadmium, Cd 0.008 2.68 ppb of pel. Inland 94 Chromium, Cr 0.024 7.95 ppb of pel. Inland 94 Cobalt, Co < 0.002 < 0.666 ppb of pel. Inland 94 Lead, Pb 0.443 147 ppb of pel. Inland 94 Manganese, Mn 0.323 107 ppb of pel. Inland 94 Mercury, Hg 0.016 5.31 ppb of pel. Inland 94 Nickel, Ni 0.062 20.4 ppb of pel. Inland 94 Se lenium, Se 0.023 7.70 ppb of pel. Inland 94 1. The algebraic symbol, “<” (less than), indicates that the emission factor was developed from a stack test for which the mass recovered was below the detection limit for that air pollutant. 2. Reference Method 29 is the stack testing method for the elements listed here. See Table 36 for Inland’s emission factors.MPCA Report Page 84 

### Table 40. HAPs emission estimation for off **- pellet firing processes at Ispat** **- Inland**  1 **Process group** 2 Ore Bentonite Greenballs Pellets hdl Ore Bentonite Greenballs Pellets hdl Year total Year PM from Emission Inventory, 3 ton/year Sum of element emissions for process groups, ton/year 1995 57.8 2.49 41.3 547 0.27 0.001 0.047 2.090E - 01 **0.532** 1996 57.1 2.47 40.8 540 0.27 0.001 0.046 2.064E - 01 **0.526** 1997 123 0.02 33.1 1366 0.58 0.000 0.04 5.225E - 01 **1.14 Elem** **ent** Composition of elements, ppm by weight Individual element emissions, ton/year ’95 sum 4 Antimony, Sb 12.0 1.00 12.0 12.0 6.93E - 04 2.50E - 06 4.95E - 04 6.56E - 03 7.75E - 03 Arsenic, As 20.2 3.31 20.2 20.2 1.17E - 03 8.24E - 06 8.34E - 04 1.10E - 02 1.31E - 02 Beryllium, Be 0.800 2.25 0.060 1.10 4.62E - 05 5.61E - 06 2.48E - 06 6.01E - 04 6.56E - 04 Cadmium, Cd 0.800 0.233 0.800 0.800 4.62E - 05 5.81E - 07 3.30E - 05 4.37E - 04 5.17E - 04 Chromium, Cr 1.00 5.80 1.00 1.00 5.7 8E - 05 1.44E - 05 4.13E - 05 5.47E - 04 6.60E - 04 Cobalt, Co 6.90 3.23 0.900 0.800 3.99E - 04 8.05E - 06 3.72E - 05 4.37E - 04 8.81E - 04 Lead, Pb 6.00 34.4 6.00 6.00 3.47E - 04 8.57E - 05 2.48E - 04 3.28E - 03 3.96E - 03 Manganese, Mn 4700 479 1080 330 2.72E - 01 1.19E - 03 4.46E - 02 1.80E - 01 4.98E - 01 Mercury, Hg 0.110 0.012 0.130 0.080 6.35E - 06 3.01E - 08 5.37E - 06 4.37E - 05 5.55E - 05 Nickel, Ni 1.50 5.83 0.400 0.400 8.67E - 05 1.45E - 05 1.65E - 05 2.19E - 04 3.36E - 04 Selenium, Se 10.0 0.267 10.0 10.0 5.78E - 04 6.64E - 07 4.13E - 04 5.47E - 03 6.46E - 03 Data source NMC; HTC 1. Since average composition data are used for bentonite, tracking of values of below detection limits is difficult. Thus, the algebraic symbol “<”, which is used in Table 39 (see footnote 1 of Table 39), is omitted. 2. Process group is used here to simplify data presentation. The ore group includes coarse and fine crushing. The fired pellets group includes pellet stockpiling and loadout. 3. PM emissions, reported to the Emission Inventory, are not verified by MPCA staff . 4. Sum of element emissions in 1995 for off -pellet firing processes is also shown in Table 4. Those for 1996 & 1997 are omitted here to save space. All calculations were made using spreadsheets.