This report was prepared by Bob Boughton of the California Department of Toxic Substances Control, Office of Pollution Pr evention and Technology Development. The project was co-funded by the USEPA unde r grant #X1-83200201-0 (project term 9/21/2004 to 12/31/05). A project description can be found at www.epa.gov/oswer/docs/iwg/fs_aut o_shredder_residue_final.pdf

Acknowledgements DTSC appreciates the generous time a nd cooperation provided by the individuals representing the companies participating in this assessment, especially Hugo Neu Corp. for providing SR material. The author also appreciates the input, review and direction provided by Professor Arpad Horvath from th e Department of Civil and Environmental Engineering at the University of California, Berkeley.

Disclaimer The mention of any products, companies, or technologies, their source or their use in connection with the information reported herein, is not to be construed as either an actual or implied endorsement of such produc ts, companies or technologies.

All photos are from facility file s; cover page kiln figure is reprinted with permission from Recicladora Temarry de México S.A. de C.V. ( www.temarry.com/Cement%20Kilns/Cement_Kiln2.htm )Table of Contents

PROJECT SUMMARY 1

BACKGROUND

Shredder Residue 3 Cement Manufacturing 4 Project Goal and Description 5

INITIAL SAMPLING RESULTS Waste Sampling 5 Laboratory Results 6

SR SEPARATION AND ANALYSIS RESULTS SR Materials Separation 10 Laboratory Results 11

DISCUSSION

Full Scale Considerations 14 Conceptual design 15

Economic Assessment 17

CONCLUSIONS 19

REFERENCES 201 PROJECT SUMMARY

Shredding 15 million tons of scrap automobiles, appliances and other light metal products results in recycling of about 12 million tons of ferrous and non-ferrous metals in the US each year. However, about 20% of the sc rap feed remains after metals recovery (consisting primarily of glass, plastics, rubber, fabrics, dirt and fines) . This material is commonly referred to as shredder residue (SR). Nearly all of the over 3 million tons of SR generated in the U.S. each year is landf illed. From both a resource conservation and good business practice perspectiv e, recovery of the energy and mineral value of SR

should be examined as an alternative to di sposal. Compared to landfilling, material recovery and energy recovery are usually preferred because of conservation of nonrenewable resources and re duction of waste disposal (Boughton 2005). However, because many reuse and recycling options may not be environmentally beneficial or cost effective, there is a need for further study.

The main barrier to recovery of energy value from SR has been the perception that it is too contaminated, has a low heating value and is heterogeneous. Recovery of materials and energy from SR has been studied, however past efforts to upgrade and purify SR to a suitable quality have proven uneconomic or impractical. A consumer of SR needs to have a robust process and operational flexibil ity as well as the capability to use large quantities of materials. For these reasons, cem ent kilns are the most likely user of SR as a supplemental fuel or for mineral recovery. Simplistic methods to separate SR into energy and mineral rich streams may facilitate the use of a sizable fr action of SR by this industry. Due to the large scale of the cemen t industry in the US, a significant amount of

SR is recoverable.

The goal of this study was to identify the feed stock quality parameters needed to satisfy kiln operators and then to assess the mechan ical means necessary to process SR into material acceptable as coal and mineral subst itutes. To test this concept, the USEPA and the California Department of Toxic Substa nces Control (DTSC) funded this study to investigate inexpensive separation systems cap able of producing acceptable fractions.

Initial physical and chemical test results allowed kiln operators to assess limitations of SR as a fuel or mineral substitute. Analyses included the moisture, volatile matter and mineral content, the calorific value, and elemental concentrations. Beneficial mineral content (namely silicon) was found to be much lower than expected, but not surprising since low glass content was seen in the fines. After discussions with shredder operators, it is clear that appreciable re moval of glass occurs at the dismantling yards before autos reach the shredding facility. As a result, r ecovery of SR for mi neral content was not

studied further.

Sub-streams can be recovered from SR fo r energy value. In general, the fuel characteristics of SR as generated were f ound to be poor due to high ash, heavy metals,

and chloride content. A liter ature review and discussions w ith shredder operators offered great insight into the equipment needed to upgr ade SR to valued fuel . Technologies that

have been used or could be used to recove r valued sub-streams fr om SR include heavy2 media separation, froth flotati on, vibrating tables, optical so rting and air classification. With these technologies in mind, discussions w ith shredder and kiln operators lead to a conceptual system design to recove r a fuel rich fraction from SR.

To test this concept, field te sts were conducted to separate and further beneficiate the SR waste stream. Flotation/density separati on techniques commonly used by shredders in the past were tested to separate rubb er and plastics from non-combustibles and contaminants (e.g., PVC and copper wire). A fraction constituting about 30 wt% of the

total SR was found to have fuel characteristic s mirroring those of coal . However, levels of potentially problematic constituents (e.g., total chlorine and heavy metals) may limit

use to a low relative addition rate.

An economic review of a full scale separa tion system was compiled. Processing SR appears to be economically marginal cons idering avoided landfilling costs alone. However, significant economic benefits would result from additional non-ferrous metals recovery (namely copper). The project results showed that commonly available separation systems can produce an acceptabl e fuel supplement; however, barriers which inhibit economically viable recycling ma y need to be addressed. Reducing the contamination of SR from components in the shredder feedstocks (eg, PCB laden capacitors, lead wheel weights, and mercury sw itches) may be the most significant barrier

to overcome. Full scale demonstration is the next step. Some development of techniques to reduce the contaminant levels may be n eeded, followed by testing to show that no significant increases in emissi ons at kilns would occur.3 BACKGROUND

Shredder Residue

Shredder waste or shredder re sidue (SR) is generated by bus inesses that recover ferrous

and non-ferrous metals from waste automobile s, appliances and other light scrap. The metallic feedstocks are collected from automotive parts reclaiming and dismantling yards, metal recyclers as well as appliance dealers and landfills. About 12 million tons per year of steel and nonferrous metals ar e recycled at over 2 00 dedicated shredding operations nationwide (USEPA 2004c, Fi sher 1999, ISRI 2004, Staudinger 2001). Roughly 20% of the feedstock becomes shredde r residue comprised primarily of glass, plastics, textiles, rubber, and fines. Over th ree million tons of SR generated in the U.S. each year are landfilled (USEPA 2004c, ISRI 2004).

Typical shredder residue The heterogeneity of shredder feed material makes it very difficult to quantify the composition of the

shredder residue waste stream (Ambrose 2000). Additionally, the physical nature of SR (see photo), cross contamination, weak markets for major recoverable materials (such as polyurethane foam, rubber and plastics) and significant processing needed to meet market specifications hampers recovery of specific materials

from SR.

The directive for end-of-life vehicles in Europe has gene rated numerous efforts to increase dismantling, and to recover plastics , other materials or energy value from SR (European Commission 2005, CARE 2005, Forton 2005, WERG 2002, Schut 2004, Schut 2001). As a result, many different recovery systems have been studied (Zevenhoven 2003). Similar efforts are also underway in the U.S., Japan, and Australia (Gallmeyer 2003, Kusaka 2000, USCAR 2002, Toyota 2005, Recycling Today 2005, Nissan 2004, APC 2005, CWT 2005, Environmen t Australia 2002). Recovering plastics for recycling, limited testing of SR as a pyr olysis feedstock, and as a fuel for waste

combustors and cement manufacture have also been performed (CARE 2005, Day1993a, Winslow 1998, 1999, and 2004, Plastics 2005, Keller 2003, Redin 2001). Systems to process SR to meet specifications (low ash a nd low sulfur) for blast furnace fuel or for secondary material recovery are expens ive and a significant residual waste volume remains (SALYP 2004, ANL 2004, American Plastics 2005, Das 1995).

Recovery of gross fuel value from wastes can provide a significant economic benefit to large energy consuming industries. Dry SR is about 50% combustible and 50% noncombustible (metals, glass, dirt, and residual ash). Others have studied the energy value of SR and energy recovery in vari ous systems (Mark 1999, CAC 1998, Zevenhoven 2003, USDOE 1987, CMP 1990, Automotive Engineering 1994, Saxena 1995). Some4 separation of the SR components was required to improve the energy value, as well as to

reduce residual ash or remove problematic constituents such as PVC. As a result, cocombustion of SR with municipal solid wast e for energy recovery or as a blast furnace fuel was only be viable for half the SR wast e stream (plastics and rubber) with highest energy and lowest ash content. The residua l fraction of the SR would need to be landfilled or managed in another way.

Cement Manufacturing Cement kilns can use a wide variety of different fuels without compromising cement product quality, plant operations or emissions. Kiln operator experience with substitute fuels such as waste plastics, tires, paint, used oil and other soli d and liquid wastes is widespread. The portland cement product quality and kiln air emissions are not impacted by contaminants in the commonly used alte rnative fuels even at up to 30% fuel supplement (USEPA 1995, Gabel 2005, Choa te 2003). The most commonly used supplemental fuel, waste tires (which c ontain significant amounts of zinc) has contaminant levels similar to that of SR (USEPA 1991).

Numerous studies discuss the very successful use of altern ative fuels and minerals in cement manufacturing, the resulting benefits of energy and raw materials savings, the incorporation of residual ash into the cement product, and the destruction of organic constituents in the fuel (PCA 2004, Pr isciandaro 2003, Taiheiyo cement 2004, RRF 1992, Cembureau 2004, WBCSD 2005, Lanoir 1997, Dyckerhoff 2005, Holcim 2005, USEPA 2004, Heart 1996, Denis 2000). Most of the lo w and medium volatility heavy metal

contents in mineral and fuel feedstocks ar e incorporated into the cement product. In contrast, air pollution control systems captu re only about 50% of the highly volatile metals such as mercury (Seyler 2005, PC A 2005). Additionally, the large amount of

limestone in the feed minerals eff ectively controls acid gas emissions.

Cement producers are also successfully using many different materials for mineral feed substitutes (Holcim 2005, van Oss 2002, van Oss 2003, Taiheiyo cement 2004, CIF 2003). These include spent catalysts, alum inum production wastes, glass, industrial ashes, filter cake and mill scale. Consider ing the alternative feedstocks that kiln operators currently use and the volume of SR generated each year, SR should be reviewed for its potential as both a fuel a nd mineral supplement. Plastics and rubber make up the majority of SR combustible conten t. But compared to the alternative fuels used at cement kilns today, SR is a hetero geneous mixture of many different materials with comparatively low BTU value and high ash content. Others have shown that SR has about 5000 BTU per pound (40% that of coal) a nd may consist of up to 40% of mineral equivalent to that used in cement producti on (silicates, calcium, aluminum and iron). Separating SR into high BTU and high mineral content fractions for recovery in cement

kilns could result in considerable coal and minerals conservation.

The avoided landfill fees for shredder operators, as well as fuel cost savings at kilns would need to offset the SR processing costs. Use of SR in kilns would also lead to reduced environmental impacts from less mini ng, transporting and preparation of coal and mineral ores. The potential impacts of landfill leachate contaminated with SR5 constituents would be avoided and landfill space would also be conserved. As a secondary benefit some emissions reductions may occur with substitute fuels such as waste tires, plastics and used oil (e.g., a lo wer carbon, nitrogen and sulfur content per unit of energy than coal yields lower carbon di oxide, nitrogen oxide and sulfur dioxide emissions (EPA 1995, Gabel 2005)). All thes e issues should be considered when evaluating resource recove ry options (Boughton 2005).

Project Goal and Description Discussions with cement manufacturing industr y representatives indicate that the main

barriers to the use of SR is the perception that it is too c ontaminated, too heterogeneous and of insufficient energy value for use as fuel (Bennett 2005, Meinen 2005, Shumway 2005, Hawkins 2005, Mayes 2005). These became th e key considerations to address in this study. The plastic, rubbe r and textile components of SR exceed the BTU value of coal. The inert content (namely glass, iron, calcium and aluminum) in SR can substitute for mineral feed-stock. The goal of this study was to assess the mechanical means necessary to separate and process SR into material acceptable for substitution for coal

and mineral feedstocks. The USEPA and DTSC funded this study to determine if an economical separation system appears capable of producing material acceptable for kiln

use.

The project was developed in phases. The first phase was to characterize the SR as generated. Samples of SR were taken at the Hugo Neu-Proler shredder facility in Los Angeles, California. Laboratory tests were conducted to assess SR characteristics including physical parameters, fuel characteri stics (proximate and ul timate analyses), as

well as beneficial elements and contaminant concentrations. Two contract laboratories were chosen, Hazen Research of Colorado to do the sample preparation and proximate/ultimate analyses, and American Scie ntific Laboratories of California to do the elemental analyses. We discussed the resu lts with kiln operators to determine the considerations for supplemental fuel and mine ral additives. In the second phase, we demonstrated separation techniques to recover valued streams. The final phase included the estimation of operating costs for a full sc ale separation system and comparison to the costs of SR landfilling.

INITIAL SAMPLING RESULTS

Waste Sampling SR sampling was conducted at the Hugo Neu-Proler over two days (February 10-11, 2005). The non-ferrous metals recovery sy stem produces <1⁄2”, 1⁄2-11⁄2”, and 11⁄2-4” size

sub-streams of SR material by trommelling. (A small volume stream of >4 inch oversized material passed through the trom mel and was noted to contain significant amounts of rubber and metallic material. This material was not sampled because it is

returned to the shredder for si ze reduction, but it could be sepa rately sorted to obtain the energy rich materials.) The trommelling and nonferrous metal recovery systems act to homogenize each sub-stream (helping to meet one of the identified barriers to SR use) and to separate fines from the larger material s. These processes result in relatively clean and uniform sub-streams; hence smaller sa mple sizes should be adequate.6 After sufficient time for the non-ferrous recove ry system operation to stabilize, sampling was conducted after shutting down the entire system three times on February 10, 2005. Two separate nonferrous metals recovery systems operate in series for the fines and midsize streams, and one system for the coar se material. Samples were taken from each of the five nonferrous recovery system discha rge conveyance belts. In general, material

from a one foot wide swath across each tw o foot wide discharge belt filled 1-gallon plastic bags. Larger cross sections were ta ken from the sparsely loaded belts (secondary discharge belts). For the >11⁄2- 4 inch coarse material, two or three bags were filled to adequately characterize the waste.

In addition to three samples from each of the sampling points described above, three samples were also taken from the recombined <11⁄2 inch materials (the <1⁄2 inch and >1⁄2 inch to <11⁄2 inch sub-streams) on Fe bruary 11, 2005. Sampling both the <11⁄2”

recombined sub-streams and the >11⁄2” sub-str eam will help to characterize the total SR waste since the weight proportions of the in dividual sub-streams are not well known. A total of 33 samples were collected over the tw o days. All sample bags were sealed to retain moisture and sent for processing and an alysis. Also, the labor atories reanalyzed 16 samples to gather information on the heteroge neity of the samples and reproducibility of laboratory analyses.

Field observations showed that the fines a ppeared very uniform, consisting mostly of fiber and dirt, and free of material larger th an 1⁄2 inch. A portion of the fines material were sieved with several trays to examine th e ability to further size separate the material (screen sizes included 19mm, 4.75mm, 2mm, and 0.85mm openings). In general the fines contain a significant amount of fibers that obstructed the 4.75mm screen. Very small amounts of glass were seen in the fi nes samples, meaning glass recovery would likely not be feasible. All samples of SR larg er than 1⁄2 inch size were relatively free of fines, and well mixed and fairly uniform in composition despite the diversity of materials within. Ferrous and nonferrous metal recovery seems to be comple te with the exception

of small amounts of metals att ached to plastic or rubber pi eces (such as a hose clamp on a rubber hose or a small screw within a plas tic piece), short lengths of copper wire entangled with other materials, as well as st eel cord wire imbedded in tire shreds.

Laboratory Results The laboratory processed the total volume of each sample, with the exception of some metal fragments and rocks that were removed during milling. Materials were cryogenically milled to pass a 2mm screen (which preserved the volatile components such as mercury). After through mixing, proximate and ultimate tests as well as elemental mercury and total chlorine determin ations were completed. Elemental analyses were then done on the ash resulting from the proximate analyses. Duplicate analyses for 16 of the 33 samples gathered information on the homogeneity of the processed sample material as well as the reproduc ibility of the labo ratory analyses. Standard laboratory QA/QC procedures were also performed.7 The laboratories reported the proximate, ultimate and elemental test results for all samples as well as duplicates. The nature of ru bber and plastics makes it very difficult to analyze for elemental concentrations because of the resistance to digestion. Tests on the

recovered ash should reflect the raw material elemental concen trations except for volatile metals such as mercury, lead and cadmium. With the exception of mercury, analyses for total metals from other samples of SR mate rial were gathered to fill this gap.

The moisture content of the samples varied du e to dust control sprays in the shredder and the non-ferrous separation system and may al so be significantly different depending on the season. Hence, all results are presented on a dry-weight basis to provide consistency and for comparison to other fuels. The fuel re lated results are presented in Table 1 as an average of the six samples for each sampling point (note that only three samples of the <1⁄2-11⁄2 inch combined material were taken). In general the vari ation between the six samples in each size fraction was small. D uplicates showed only slight variation in

results. Statistical confidence intervals we re not determined, but the samples appear representative of each size fraction.

Table 1 shows that the larger the material si ze, the lower the residual ash content and the higher the BTU value (as expected, BTU values inversely correlate with the residual ash content). The fines, which constitute about 30% of the total SR wastestream, had the highest ash content of 50-60% and the lowest BTU content of about 5000 BTU/lb. The 1⁄2 -11⁄2 inch mid-size fraction, also about 30% of the total SR wastestream, has marginal energy content. The coarse material, which constitutes about 40% of the total SR stream, had a BTU value comparable to coal. Howe ver, none of the size fractions yielded a chlorine content low enough to be valued. Chlorine levels were found to trend higher with larger material size. The net chlorine levels correlate with the PVC content in automobiles and appliances. For example, au tos typically contain 20 lb of PVC and yield 350 lb of SR after metals recovery. PVC is typically 50% chlorine by weight; hence the PVC should contribute up to 3 wt % of ch lorine to the total SR as was found.

Laboratory data for the ash con centrations of elements were converted to equivalent raw material concentrations using the residual ash wt % determined for each sample. The tables that follow present averaged results for each size fraction and each sampling point.

Table 1 -Averaged proximate/ultimate results for SR by size fraction sampled (dry weight basis, n=6)

Material fraction BTU/lb Ash wt% Chlorine wt% Sulfur wt%

Fines <1⁄2 inch 5880 54.4 1.0 0.24

Fines <1⁄2 inch 4650 61.4 0.6 0.30

1⁄2 -11⁄2 inch 8670 40.8 1.8 0.31

1⁄2 -11⁄2 inch 9420 33.4 2.3 0.31 **<1⁄2-11⁄2 (n=3) 7170 46.3 1.1 0.25

Coarse 11⁄2-4 inch 12900 20.5 3.2 0.49
** samples of facility recombined stream8 Table 2 presents the average values for severa l elements in SR that could substitute for mineral feedstock for cement manufacture, namely silicon, aluminum, calcium and iron. Generally, the levels of beneficial constituents decreased with larger material size as expected, but are lower than expected in the fi nes based on reports of others (cited in the Background section). Overall, none of the size fractions would be valued as kiln mineral

feed substitute. The fines could be beneficial as a mineral substitute if the silicate levels were higher. Others have found silicon levels of over 5 wt % in SR mostly due to the presence of glass. These results showed silicon concentrations below 0.5 wt %, much lower than expected, but not surprising after visual inspection of th e fines showed little glass. After discussions with sh redder operators, it is clear that a majority of auto glass is removed or broken at the dismantling yards before reaching the shredder facility.

High levels of deleterious elements reduce the value of SR as a mineral or fuel supplement for kilns. Excessive alkali content (namely potassium and sodium) will lead to cement kiln dust (CKD) generation or opera ting problems if not removed. In general, the smallest sized materials contain the highest levels of potassium and sodium (Table 2). These levels are too high for kiln fuel suppl ement at most kilns (the exception being kilns with low alkali containing mineral feed stoc ks or kilns which can manage increased CKD generation).

As shown in Table 3, with the exception of vol atile metals shown, the elements generally were at the same levels as previous studi es have found for SR. Mercury, beryllium, cadmium, selenium and thallium were non-detectable in every ashed sample. The high levels found for copper are unacceptable for kiln use of any fraction as a fuel. Considerable amounts of copper wire fragment s, many connected to or intertwined with other materials, were seen in the samples a nd are likely a major contributor to the copper levels. As expected, no mercury was found in the ashed materials. Mercury content before ashing was measured in the 1-2 ppm range and appeared to be higher in the

smaller size material. The results for lea d, vanadium, cadmium, arsenic, and zinc are underreported due to volatilization during ashi ng from the proximate/ultimate analyses.

Table 4 shows losses due to volatilizati on during ashing range from 35% to 100% depending on the metal compared to SR as disposed (DTSC 2002).

Table 2 - Averaged concentrati on of beneficial and deleterious elements in SR fractions (ppm dry weight basis, n=6)

Material fraction Aluminum Calcium Silicon Iron Potassium Sodium

<1⁄2 inch 11016 31094 2428 15218 740 5332

<1⁄2 inch 12655 31162 6379 24798 941 6162

1⁄2 -11⁄2 inch 8425 23363 4015 18701 517 3515

1⁄2 -11⁄2 inch 9214 25495 1584 6579 557 1377

**<1⁄2-11⁄2 inch 9120 27733 3779 22685 639 3423

11⁄2-4 inch 3549 17384 1092 14166 171 760
** 3 samples of facility recombined material9 Table 3 - Averaged elemental concentration in SR fractions (ppm sample dry weight basis, n=6)

Element <1⁄2 inch <1⁄2 inch 1⁄2 -11⁄2 inch 1⁄2 -11⁄2 inch <1⁄2-11⁄2 inch** 11⁄2-4 inch Antimony 101 98 113 165 117 125

Arsenic 8 9 5 3 5 4

Barium 828 987 636 376 676 110

Chromium 171 89 95 38 134 101

Cobalt 13 22 18 10 17 14 Copper 15333 16345 24461 29454 29560 15735

Lead 784 692 148 560 233 64 Molybdenum 17 30 30 103 21 23

Nickel 212 235 190 133 338 148 Magnesium 5008 4808 3385 2994 4156 1744

Silver 6 25 3 3 5 1.0

Titanium 538 643 706 704 639 386

Vanadium 9 15 15 11 12 7

Zinc 7092 6482 8868 9793 5089 3415
** 3 samples of facility recombined material

The presence of PCBs is a concern for any materi al returned to market or used as a fuel. Despite efforts to eliminate PCBs from metallic discards before shredding, low levels of

PCBs continue to be found in SR. Test s for PCBs were not conducted on the size separated SR. PCB tests of disposed SR gene rated by several Californi a facilities average total levels ranging from 16 to 82 ppm (DTS C 2002 and DTSC files). Levels above 50 ppm trigger TSCA requirements for hazardous wa ste management. SR with levels below 50 ppm can be landfilled or managed at TSCA permitted facilities.

Table 4 - Metal concentrations from other SR samples* and estimated loss from ashing

Metal Average ppm* Estimated % loss**

Cadmium 18 100%

Lead 3120 95%

Zinc 6890 35%

Arsenic 6 85%

Vanadium 29 65% Mercury* 2 100%
*Except for mercury, values for landfilled SR from numerous facilities (DTSC 2002); mercury results are for material before ashing ** % loss from ashing (present study results versus other SR as disposed)

Duplicate analyses of 16 sample s showed that the laboratory preparation methods lead to well homogenized material for analysis and th at the laboratory anal ytical methods were consistent (good reproducibility). The la boratories met all qua lity objectives via laboratory QA/QC including duplicates, ma trix spikes and blanks.10 SR SEPARATION AND ANALYSIS RESULTS

SR Materials Separation Based on the results for the size-segregated SR materials, further separation is needed to yield material with acceptable energy, metals and chloride c ontent. A literature review and discussions with shredder operators offere d great insight into the equipment needed to reduce the contaminant levels. Technologies that have been used or could be used to

recover valued sub-streams from SR include heavy medi a separation, froth flotation, vibrating tables, optical sorti ng and air classification. In th e past, shredders used density separation systems with heavy media baths to recover and separate non-ferrous metals from other SR constituents. This technique can also be used to recover a high energy content plastics and rubber fr action from SR. The density of metals, glass, and dirt are two to three times that of most plastics and rubber materials. Additionally, density separation of PVC from less de nse plastics and rubber has b een demonstrated (TXI 2005, MBA 2005, Galloo 2005, Salyp 2004, Schut 2004). Th is technique looks to be the least expensive and most well developed to affect a separation of SR to yield a low ash, low chlorine, and high BTU content material.

Five gallon containers of the <11⁄2 inch (the combined <1/2 inch and >1/2 to <11/2 inch material) and of the >11⁄2-<4 inch sub-str eams were separately collected on August 2, 2005. The 26.5 lb of <1 1⁄2 inch material was found to be highly fibrous with some plastic, rubber and copper wire pieces inters persed. Hand sorting showed that only 3.5 lb of small plastic and rubber pie ces were in the total sample. The material was sampled for lab analyses, but there was not enough plas tic and rubber content to test density separation.

The total 14 pounds of >11⁄2 inch coarse ma terial was separated by hand to remove materials such as polyurethanes, copper wi re and fiber from the plastics and rubber

materials of interest. Seven different recovered fractions resulted; copper wire, polyurethanes, polystyrenes, car pet/textiles, mixed plastic/ rubber, tire rubber, and a residual fibrous mix. The pl astic/rubber fraction weighe d about 8 pounds, the fibrous material weighed about 4 pounds, and the re maining materials collectively weighted about 2 pounds. The plastic/r ubber fraction was retained fo r density separation, and the other materials were separately bagged for laboratory analysis.

Small scale tests with salt water baths are co mmonly used to test density separations. A laboratory scale experiment was designed to test separations using Epson salts (MgSO4) in hot water. The plastic/rubber materials we re first placed into a hot water bath to separate floaters. A significant amount of material floated including plastics, wood, textiles, and paper as well as polyurethane a nd styrofoam. The floaters were collected and bagged for laboratory analysis. A set of sa lt water baths were then used to sink/float the dense materials for the remaining plastics and rubber. Bath densities were chosen based on those successfully used by others to separate mixed plastic wastes. The premise was that PVC should be separated by sinking at densities near 1.3 specific gravity (sg) (depending on specific plastic product formul ation) while the bulk of the less dense plastics and rubber will float. Mixed plastics and fillers used in specific plastics11 formulations may lead to diffe rent specific material densities however. Hence, a range of bath density levels should se parate the plastics/rubber samp le into fractions with the purpose of removing a majority of the overall chlorine content.

Actual bath densities achieved were >1.3, >1.275, <1.225, and <1.125 specific gravity. The material that sank in the initial water bath was transferred to the highest density bath (>1.3 sg). Sinkers, the material with a dens ity above 1.3sg (observed to be mostly vinyl backing for floor mats), were collected and wa shed in hot water to remove residual salts and then bagged for analysis. The materials th at floated at 1.3sg we re transferred to the next lower density bath. This sequential procedure was followed until the final 1.125 sg bath where both the sinking and the floating ma terials were collected. Relatively small

amounts of materials were recovered at the mi d range density splits and a majority of the rubber separated at 1.1 sg, while plastics appear ed to be more distributed. The separation by density experiment lead to seven sepa rated components from the baths which in addition to the six hand separated materials ga ve a total of thirteen separate components

sent for lab analyses.

Laboratory Results Table 5 shows the fuel value testing results for each of the 13 components on a dry weight basis. In general the results were as expected. The heating values were highest in plastic and rubber materials with the lowest residual ash weight. The materials below 1.1 sg had the lowest chlorine content. And th e material above 1.3 sg including copper wire had a high relative chlorine content which suppor ts the concept of dens ity bath sink-float techniques separation from the other materials. Fibers were the major component by weight but not of high energy value. A la rge amount of material was found to have a density less than water.

Table 5- Proximate/ultimate analysis results for coarse SR components (dry weight basis)

* based on individual component contributions to total sample

Component Weight -grams Wt % ash Wt % Cl BTU/lb carpet 283.9 41.0 2.1 6660

fiber 1557 45.8 1.6 6650 copper wire 282.5 71.0 12.0 8110 >1.35 sg 263.6 37.6 4.7 7730 >1.3 sg 163.6 25.9 12.5 10680 >1.2 sg 137.2 18.4 1.3 12330 >1.1 sg 425.7 8.2 3.7 13250 >1 sg plastic 291.2 5.0 1.2 15890 >1 sg rubber 616.4 4.1 0.10 15950

tire rubber 272.2 22.6 0.10 14900 <1.0 sg 1087 9.2 1.2 15750 polyurethane 119.6 21.3 0.35 10350 polystyrene 39.6 10.7 0.44 12460 Weighted Total * 5540 26.4 2.4 1138012 The sample total values were calculated by adding the individual component contributions. The net 26% ash, 2.4% chlori ne and 11,380 BTU/lb are in line with prior results for this size fraction of SR (see Table 1).

The goal of the project is to recover a significant volume of material with the most energy

value and the least ch lorine content. The proposed separation system design (as discussed later) includes a fibe r separation system as a first step, followed by density separation of the remaining materials. Th e ordering of the sub-fractions in Table 5 mirrors the proposed sequence of separation st eps. For simplicity, the components shown in Table 5 were consolidated by grouping as fo llows: fibers and carpet, >1.3 sg includes the >1.3 sg and the >1.35 sg components, > 1.0 sg includes the tire rubber as well as the separated plastics and rubber, and <1.0 sg includes the polyurethane and polystyrene. The values presented in Table 6 are the cumu lative contributions to the total sample for each of the groups. For example, the component s of <1 sg contributed 22 % of the total sample weight of 5540 grams, 10% of the to tal chlorine, 9% of total ash, etc.

Table 6 - Fuel value contri butions by component groups of coarse SR material

Component Percent cumulative contribution to the sample total

Group Weight Chlorine Ash BTU <1 sg 22.5 10.3 8.8 29.9 >1 sg 43.8 13.1 15.8 59.3 >1.1 sg 51.5 25.0 18.1 68.2 >1.2 sg 54.0 26.4 19.9 70.9 >1.3 sg 61.7 51.0 29.5 76.9 Copper wire 66.8 76.6 43.3 80.6 Fiber/carpet 100.0 100.0 100.0 100.0

Choosing the media bath density leads to a trade-off between recovering the most heating value while retaining the least chlori ne content. As can be seen from Table 6, processing the material in a sink/float system would result in differe nt recoveries. As shown in bold, a 1.2 sg density bath would result in recovery of nearly 70% of the initial heating value while only retaining 25% of the total chlorine and less than 20% of the ash content. The component contributions shown in Table 6 were further consolidated into two sub-streams at the 1.2 sg density cut-off. Two fractions result, half the mass as an energy rich material and half as a residual. The fuel rich sub-stream comprised of all materials under 1.2 sg, labeled fuel in Table 7

, would have characteri stics comparable to coal. The remaining material, labeled residual, would be burdened with a majority of the

ash and chlorine.

Other elements in SR are of concern includ ing heavy metals as well as the beneficial elements such as silicon, aluminum, iron and calcium. The elemental analyses results were compiled and shown in Table 8 for th e same 1.2 sg separation cut-off discussed above. Low levels for nearly ever y element are found in the in the fuel fraction.13 Table 7- Key fuel characteristics for separated coarse SR at 1.2 sg

Sub-fractions (11⁄2 - 4 inch)

Characteristic Fuel Residual

BTU/lb 13240 6560

Chlorine 1.2 wt % 3.7 wt %

Ash 9.3 wt % 44 wt %

Sulfur 0.59 wt% 0.44 wt %

Most of these levels fall into acceptable levels for supplemen tal fuel. However, about 1 ppm of mercury was found in the fuel fraction (measured before ashing), a level several

times that of coal. As a be nefit of the separation system , some of the copper (wire fragments) should be recoverable fr om the residuals sub-stream. The residual fraction showed only a 7.5 wt % net content of benefici al minerals (bottom four elements shown in Table 8), likely not high enough for further recovery for use as a kiln mineral feed

substitute.

Table 8 –Elemental analysis for separated coarse SR at 1.2 sg (ppm dry weight basis)

Sub- fractions (11⁄2 - 4 inch)

Element Fuel Residual Mercury 1 4.73 Antimony 130 371

Arsenic* 1.2 4

Barium 59 1170

Cadmium* 2 9

Chromium 17 123

Cobalt 24 23 Copper 914 56291

Lead* 94 1186 Magnesium 1203 4119 Molybdenum 9 37

Nickel 98 133

Silver 0.9 11

Vanadium* 6 15

Zinc 4954 5925

Potassium 244 802

Sodium 523 2810 Phosphorus 169 219

Tin 26 465

Strontium 22 244

Titanium 237 455 Tungsten 86 109

Aluminum 1101 9503

Calcium 7622 29892

Iron 5080 31559

Silicon 853 4299
* Concentrations shown are significantly lower than the actual concentrations due to volatilization14 DISCUSSION

Full Scale Considerations A list of specific requirements or contaminant limitations for cement kiln operators was not compiled. Because each kiln has mineral f eedstocks with different characteristics, has different operating designs and has di fferent environmental limitations, little guidance on common limitations for supplemental fuels or minerals was gathered from discussions with operators. What became cl ear was that some facilities could accept

materials with certain characteristics while ot hers could not. There also is considerable flexibility at some facilities depending on many factors. Some cement manufacturers will accept poor quality fuels based on the amount of payment offered for disposal, others have strict limits on specific constituents such as total alkali because of CKD generation.

Discussions with shredder operators lead to a conceptual system design to recover a fuel rich fraction from SR (Andrusyshyn 2005, Ne u 2005). A full scale system would likely need to first break up and separate entangled fiber material from the valued rubber and plastic pieces. Air classification could rem ove the very low density materials such as expanded polystyrene and polyuretha ne or this material may already be recoverable at the shredder. Following some cutting of fibers to disentangle the SR and further separation, density sink/float techniques will effectively recover a valued plastics/rubber stream.

Density separation at 1.2 sg appears to remove the majority of the chlorinated plastics and high ash bearing materials. However, resu lting chlorine levels of 1 wt % may mean that the final recovered fuel fraction (see Table 7) would be marginally valued and perhaps only useable at a few facilities or at very low substitution rates. Reducing the media bath density cut-off to closer to 1.1 sg should result in a ch lorine content of 0.7 wt%, while still leading to significant reco very of mass and BTU content (44% and 60% from Table 6). Alternatively, additional separa tions to further reduce the chlorine levels may be needed. Such separations have been demonstrated with mixt ures of plastics and with SR (Galloo 2005, MBA 2005, Salyp 2004, WE RG 2002). Texas Industries (TXI) apparently demonstrated such a system with SR but no information is available (TXI 2005, Schut 2004). However, it is notable that the reconstituted fuel material results from this study (shown in Table 6) are lower than the supplemental fuel requirements of less than 4% total chlorides stated by TXI for their cement facilities.

The presence of PCBs may impede the use of SR supplemental fuel in kilns. Creating a system oriented towards efficient use of re sources could require fundamental changes in the waste versus non-waste regulatory c onstruct embedded in RCRA (USEPA 2003). One such change may be needed in the fede ral scrap metal exemption rules so that nonmetallic materials recovery at shredders is allowed. Alternatively, SR could be

considered a mixed waste under RCRA to allow the SR derived fuel to be used despite traces of PCBs below TSCA limits (50 ppm).15 Conceptual full-scale design Some of the technologies that have been used or can be potentially used to recover valued sub-streams from SR include heavy media, froth flotation, cryogeni c grinding, vibrating tables, air classification, and optic sensors (Jody 1994, Buchan 1995, de Jong 1997, Scheirs 1998, Trouve 1998, Day 1999, Fraunholcz 2000, Singh 2001, Shen 2002, MBA 2005, SALYP 2004). With these technologies in mind, discussions with shredder and with kiln operators lead to a system c oncept to recover a valued fuel fraction (Andrusyshyn 2005, Osuscha 2006, Neu 2005) as described below.

A full-scale separation plant design assumes that a shredder operates a nonferrous recovery system that produces several size separated streams. Excluding the fines ( < 1⁄2 inch SR material) leaves about 66% of the tota l SR waste stream to be initially processed by cutting, vibrating tables and air classifi cation to separate fibrous and entangled materials. The resulting plastics and rubbe r rich stream (with copper wire and other dense materials) would then be placed in a water bath to separate the low density materials. The remaining material would be sent to a heavy media bath system with a density controlled between 1.1 and 1.2 sg Th is would lead to removal of the residual metal and PVC, with some tolerable loss of va lued materials. An economic review of the entire process requires sizing each processi ng unit. A mass flow assessment includes the following assumptions based on the results in Table 6 and conversations with shredder

operators:

• 66% of the total SR residue is over 1⁄2 inch

• 64% of that is recovera ble plastics and rubber

• 70% of that is less th an 1.2 sg and recoverable

• Ferrous and nonferrous metals are recovered from the sink fraction

The process steps outlined in Figure 1 would initially involve processing 33 tons/hour of

fines free material to remove fibers and free entangled pieces (based on 50 t/day SR generation). Separation by several air clas sification steps leads to recovery of 21 tons/hour of relatively fiber fr ee plastics and rubber pieces (with copper wire and PVC).

An initial water bath would recover about 6 tons/hour of <1s.g mate rials from the mixed stream. A media bath processing the remaini ng 15 tons per hour of >1sg residual from

the water bath would result in flotation of 9 tons/hour of materials and about 6 tons/hour of >1.2 sg materials (including copper and PVC with some carryover loss of desired materials). Further recovery of 0.2 ton/ hour of copper from the rejected fraction (conservatively assumed to be only one third of the total copper c ontent) would be the final step. From the assumptions above, a ne t 15 tons per hour is r ecoverable and 35 tons per hour of waste for disposal would result.

All the systems proposed are low technology processes that are familiar to shredder operators. Simple design and low labor opera tions are desired even at the expense of some loss of valued material. As the key piece of equipment, several media separation systems were investigated. One design is a cone shaped settling tank with a rotating skimming device at the surface and a screw conve yor system to remove rejected material from the bottom. This will work well for the initial water bath separation system, but16 there are important considera tions for the 1.2 sg media bath. A rotating drum design would provide the best recovery and separa tion quality. Density separation systems are

most effective if the materials introduced are of the same size and shape. Chopping and shredding the recovered SR mate rials to pass a 1⁄2 inch screen would help the separation efficiency, but would add signi ficant processing costs. However this may be the chosen method if the cement kiln opera tor requires the suppl emental fuel materials to be small enough for pneumatic transfer into the kiln.

Shredder residue generation 50 t/hr

fines >1/2 inch materials
↓ 34% ↓ 66%

17 t/hr waste

33 t/hr SR to air separation system

↓ 36% ↓ 64%

12 t/hr fiber waste

21 t/hr to water bath separator

↓ 70% sinkers ↓ 30% floaters
recover 6 t/hr <1sg

15 t/hr >1sg to media bath

↓ 40% sinkers ↓ 60% floaters
recover 9 t/hr <1.2sg

6 t/hr <1.2 sg to copper

recovery ↓ ↓

6 t/hr waste

0.2 t/hr copper

Figure 1 Processing steps and material partitioning for a conceptual separation system

For efficiency and cost cons iderations the media material chosen should be a ferrosilicate like magnetite. This natural ore is ea sy to magnetically recover from spent bath liquids and rinse waters, and inexpensive e nough that drag-out losses in the separated materials are tolerable. A washing step will maximize the recovery of the media and the recovered water should make up for losses to the SR materials and evaporation, etc. Periodic bleeding of the bath water will be re quired to remove suspended solids that may build up and cause a shift in bath density. Any waste water can likely be discharged directly to the storm water collection and treatment syst em at a shredder facility.

The media bath is sized to process 15 tons /hour of feed. The 1.2 sg separation cut-off

value is flexible. The results in Table 6 s how that there is minimal mass fraction in the17 1.1-1.2 density range; hence a system can be op timized to maximize recovery and reduce chlorine content, without substantial losses of valued materials. Both streams recovered from the density bath should be washed to recover magnetite. Some retention of magnetite will not reduce the value of the fina l product to kiln operators because the iron

content is beneficial. Recove ry of the low density fluff (p redominately polyurethane and polystyrene) at the shredder or with an air classifier will also reduce media losses. However, certain shapes of material will retain water. A shaker table or rotating screens will help remove retained water. Magnetic separation would then recover magnetite from wash waters. If needed, th e recovered SR product can be cut and shredded for efficient transportation and to facilitate the use of the material as fuel at a kiln.

Economic Assessment A low technology processing system using commercially available equipment and minimal labor is envisioned. Air separation and shaker table systems are commonly used equipment by shredders. Many shredder operato rs have experience with density baths to recover and separate non-ferrous metals from SR. Ta ble 9 summarizes the capital and operating costs and resource recovery econom ic benefits as described below.

Air classifiers and cutting systems and all conveyor systems are estimated to cost $350,000 (Andrusyshyn 2005, Perry 1997). An initial water bath of simple design is estimated to cost $200,000 (Andrusys hyn 2005, Perry 1997). The heavy media separation process is based on the design pr esented by the Bureau of International Recycling (BIR 2005) using a Protec drum se parator (Protec 2005). Capital costs for a 15t/hr media bath unit are $750,000 including a ll ancillary equipment (Osucha 2006, BIR 2005, Protec 2005)). Assuming a 20 year opera ting term for all equipment (with a 10% interest rate) leads to total capital cost s (P&I) of $150,000 per year (assuming complete depreciation over a 20 year period, taxes not included). Permitting fees, site acquisition and site preparation costs were not included. It is assumed that the operation would take place at a shredder facility and that those costs would be minimal.

Operations and maintenance costs include electricity to power a total of 300 hp for electric motors, 2 full time operator and main tenance personnel, and materials (including 300lb/hr media loss, and $50,000/yr in general maintenance ma terials). Trucking costs are based on a 50 mile round trip to a la ndfill, or a 100 mile round trip to a cement manufacturing facility and $2 per mile averag ed cost (significant savings could be found with rail transportation for long distances comp ared to trucks). Operating costs total $550,000/yr. The total cost of $700,000 per year will lead to recove ry of 15t/hr of material (30,000 t/yr, based on 2000 hours per year) or $23/t recovered material.

Current national landfill tippi ng fees range from $24-$70 pe r ton (depending on region) with an average of $34 in 2004 (Wastec 2005) . The current cost to dispose SR by landfilling may be lower if a discount is given for SR used as alternative daily cover. For the analysis to be conservative, $17 per ton wa s chosen. The avoided cost of trucking the recovered SR to landfills is $100,000/yr.18 Table 9 Estimated economic cost/benefits for recovering 15t/hr SR derived fuel (thousands of dollars)

Annual Costs Annual Benefits Capital investment costs (20 yr term) Pretreatment (33t/hr), $350K $18 Initial water separation, $200K $10 Media bath (15t/hr), $750K $37 Non-ferrous recovery, $100K $5 Interest (10%) $85 Operating costs Personnel (4000 hours, 45% benefits) $100 Electricity (300hp total, $0.08/kwh) $35 Media (loss of 20 lb/t SR processed) $120 Other (general maintenance materials) $50 Transportation (30,000 t/yr, 100 miles) $240

Benefits Landfill offset (30,000 t/yr at $17/t) $510 Transportation offset (30,000 t/yr, 40 miles) $100 Copper recovery (400t/yr at $1.85/lb) $680

TOTAL $700 $1,300

Assuming that a kiln operator wi ll take the supplemental material for free leads to a near economic balance at his point. Revenues fr om additional recovered copper should be

included as well. The >1/2 inch SR sub-st ream contains about 2 wt% total copper (see Table 3 and Table 5) mostly as insulated coppe r wire. Conservatively assuming that only one third of the copper content (in the residual fraction show n in Table 8) is recovered gives 0.2 t/hr or 400 t/yr. The value of recovered copper wiri ng is lower than the copper scrap price of about $2/lb. Assuming $0.85 /lb scrap value yields $680,000/yr revenue. Obviously, by generating revenue s equal to total costs, th e recovery of copper alone

could become the focus of a shredder re sidue processing system. The greatest uncertainties are for the capital cost estimat es and the landfill savings. Table 9 shows that a doubling the capital invest ment would still give an ul timate benefit of $400,000 per year (or over $13 per ton r ecovered material).

It is useful to provide context for res ource recovery savings potential for the US considering that the total generation of SR is over 3 million tons per year. Projecting the results of this study to the US would give about 1 million tons of shredder residue recovered for fuel. This amount would comprise about 6% of the US cement manufacturing industry’s energy consump tion (Choate 2003) and save $50 million annually (assuming $50/ton coal). The 1 million tons of avoided landfilling would amount to over $20 million savings annually. Further nonferrous metal recovery could yield revenues of over $20 million (based on 13, 000 tons of copper alone). The costs to process the SR would be about $20 million a nnually. Considering the many conservative assumptions made for the economic analysis, th e recovery of some portion of SR looks to be economically viable even if the shredder operator needs to pay transportation to far away kilns and pay a fee at the kiln.19 CONCLUSIONS

The study showed that size separation alone is likely not enough to provide usable SR fractions; however, commonly available sepa ration systems should produce an acceptable fuel supplement. Considering the large scal e and the number of cement plants in the US, a significant amount of SR is recoverable. Information on the equipment needed and the costs to process SR fractions to meet kiln operator specifications is critical to the acceptance, adoption, and implementation of th is resource recovery option. Kiln operators will embrace lower cost clean fuels, and shredder operators will favor avoiding the costs of landfilling while recovering more salable metals. An economic review of a full scale separation system shows that pr ocessing SR appears to be economically marginal considering avoided landfilling co sts alone. However, significant economic benefits would result from additional non-ferrous metals recovery (principally copper). Remaining barriers to acceptance includes de monstration that a full-scale system will consistently produce high valued fuel with low concentrations of delete rious materials.

Recovery of a mineral rich fraction of SR was not completed. There is less economic incentive for mineral substitute compared to landfilling because of the transportation costs for heavy materials like glass. For many shredders, it is possible that collection of a glass rich stream from dismantling yards lo cated close to cement kilns could be cost effective. Other shredders may produce SR with significant glass conten t to be attractive.

Shredder residue was found to have substant ial recoverable ener gy value. Following industrial ecology and sustainabi lity themes, materials now c onsidered wastes should be viewed as commodities. The environmental benefits of SR recovery as fuel in cement kilns look favourable compared to other management options (Boughton 2005). Policy makers could use the results herein to support th e recovery of SR as well as the facilities interested in using these materials. Fina ncial and environmental benefits would be realized by providing incentiv es for SR recovery, and by supporting markets for SR derived products.

Barriers inhibiting viable recycling alternatives may need to be addressed. If PCB and

other contaminant concerns cannot be overcom e for use of SR, few if any other options exist other than landfilling. Residual PCBs pr esent a barrier for any recovery alternative but actually promote landfilling over resource r ecovery, contrary to the principles of RCRA. The presence of mercury in SR also lowers the value of derived fuel. Other contaminants may be of concern as well. Reducing the contamination of SR from components in the shredder feedstocks (eg, PCB laden capacitors, lead wheel weights, and mercury switches) may be the most sign ificant barrier to overcome. Full scale demonstration of separation and use is the next step. Some development of techniques to reduce the contaminant levels may be need ed, followed by testing to show that no significant increases in emissi ons at kilns would occur.20 REFERENCES

Ambrose (2000), Ambrose, C., Singh, M., Harder, M., The material composition of

shredder waste in the UK , IWM Scientific & Technica l Review, November, p 27-35

American Plastics 2005, www.americanplasticscouncil.org , accessed July 2005

Andrusyshyn (2005), Personal communications , Nick Andrusyshyn, Schnitzer Steel,

www.schnitzersteel.com

ANL (2004), Argonne National Labo ratory, accessed January 4, 2004, www.transportation.anl.gov/ recycling/pl astics.html http://pe.es.anl.gov/What%27s%20New/FOAM.pdf

, http://pe.es.anl.gov/Wh at's%20New/FROTH.pdf http://www.techtransfer.anl.gov/ techtour/autoshredder.html

APC (2005), American Plastics Council, www.americanplasticscouncil.org , accessed June 6, 2005

Automotive Engineering (1994), Automotive shredder residue: three recovery choices

, Automotive Engineering 102(8), 29-31.

Bennett (2005), personal communication, John Bennett, Cal Portland Cement, www.calportland.com

BIR (2005), Bureau of International Recycling, Shredding and Media Separation, www.bir.org/aboutrecycl ing/EOLV/shred8.htm accessed December 2005

Boughton (2005), Boughton, B., Horvath, A., Environmental assessment of shredder residue management, Resources Conservation and Recycling, in press

www.elsevier.com/locate/resconrec , accessed December 2005

Buchan (1995), Buchan, R., Yarar, B., Recovering of plastics for recycling by mineral processing techniques, J Met, 47 (2) 52-55

CAC (1998), Competitive Analysis Center Inc., Automotive shredder residue; its application in steel mill blast furnaces , Study for the American Plastics Council, www.americanplasticscouncil.org

CARE (2005), Consortium for Automotive Recycling, www.caregroup.org.uk , accessed

December 2005

Cembureau (2004), European Cement Industry Association, Environmental benefits of using alternative fuels in cement production; Alternati ve fuels in cement manufacture

, www.cembureau.be , accessed October 4, 200421 CIF (2003), Cement Industry Federation, Cement industry environmental report

, www.cement.org.au/environment/case_studi es/alternative_fuels_at_bcsc.pdf , accessed

October 2003

CMP (1990), Center fo r Materials Production, Automobile shredder residue – The problem and potential solutions , CMP report #90-1

CWT (2004), Changing World Technologies, Small scale processing of shredder residue using the thermal conversion process

, www.changingworldtech.com , accessed January 7,

2005

Das (1995), Das, S., Curlee, T. R., Rizy, C. G., Schexnayder, S. M., Automobile recycling in the United States: energy impacts and waste generation, Resources, Conservation and Recycling 14, 265-284

Day (1993a), Day, M., Auto shredder residues- A wa ste or a valuable resource? , SAE 930562, p73

Day (1993b), Day, M., Characterization of auto shredder residue , Resources, Conservation and Recycling, 9, p255-279

Day (1999), Day, M., et al, Pyrolysis of auto shredder residues , J Anal Appl Pyrol 51(1- 2), p181-200

De Jong (1997), de Jong, T., Dalmijn, W., Improving jigging results on non-ferrous car scrap by application of an intermediate layer , Int J Miner Process 49, p 59-72

Denis (2000), Denis, S., et al., Experimental Evaluation of Emission Factors of Cement Kilns Burning Hazardous Wastes, Toxicological and Environmental Chemistry, 74, p155-163

DTSC (2002), California’s Automobile Shredder Waste Initiative , accessed January, 2006, www.dtsc.ca.gov/HazardousWaste/upl oad/HWMP_REP_ASW_draft.pdf

Dyckerhoff (2005), Dyckerhoff Company- Environmental Pr otection- Secondary Fuels www.dyckerhoff.com/_english/_firma /firma04.htm accessed December 2005

Choate (2003), Choate, W., Energy and Emission Reduction Opportunities for the Cement Industry , USDOE, www.eere.energy.gov/industry /imf/pdfs/eeroci_dec03a.pdf

Environment Australia (2002), Environmental impact of end-of-life vehicles: An Information paper

, www.deh.gov.au/industry/wast e/elv/chapter11.html , accessed April 10, 2004.22 European Commission (2005), Management of end-of-life vehicles, http://europa.eu.int/scad plus/leg/en/lvb/l21225.htm and End-of-life vehicles

, http://europa.eu.int/comm/e nvironment/waste/elv_index.htm , accessed June 14, 2005

Fisher (1999), Fisher, M., The role of plastics in automotive shredder residue , SAE Technical Study Series 1999-01-0664, Society of Automotive Engineers: Detroit, MI

Forton (2005), Forton, O., Harder, M., Moles, N., Value from shredder waste: Ongoing

limitations in the UK , Resources Conservation and Recycling in press

www.elsevier.com/locate/resconrec , accessed December 2005

Fraunholcz (2000), Fraunholcz, N., et al, A novel approach to the mechanical processing of ASR in Proceedings of the 4 th international symposium on recycling of metals and engineering materials, The Minerals , Metals & Materials Society, p1303-1314

Gallmeyer (2003), Gallmeyer, W., et al, USCAR U.S. Field Trial for Automotive Polymers Recycling , SAE 2003-01-0645

Galloo 2005, www.galloo.com/html/engels/groupgalloo_en.htm , accessed December

2005

Gabel (2005), Gabel, K., Tillman, A., Simu lating operational alternatives for future cement production, Journal of Clean er Production, 13 (13-14) p1246-1257

Hawkins (2005), Hawkins, G., Persona l contact April 2005, Portland Cement Association, www.cement.org

Herat (1996), Herat, S., Energy recovery from solid and hazardous wastes using cement

kilns , Journal of Waste Management and Resource Recovery, v. 3(3) p 111-115.

Holcim (2005), Holcim Ltd, Altern ative fuels and raw materials,

www.holcim.com/CORP/EN/oid/46 240/module/gnm50/jsp/templates/editorial/editorial.h

tml accessed June 2005

ISRI (2004), Institute of Scrap Recycling Industries, End-of-life vehicles: A proven path to recycling, www.isri.org/industryinfo/Elv.pdf , accessed March 3, 2004

Jody (2994), Jody, B., et al, Recovering recyclable materi als from shredder residue , J Met 46 (2) p 40-43

Keller, C., "Optimized disposal of automo tive shredder residue" in Municipal Solid Waste Management- Strategies and Technologi es for Sustainable Solutions, Ludwig, C., Hellweg, s., Stucki, S. (eds), Springe r-Verlag, Heidelberg, Germany 2003, p 294-307

Kusaka (2000), Kusaka, K., Iida, S., Sorting, compaction and solidification technologies for automobile shredder residue , JSAE Review 21 (2000) 549-55423 Lanoir (1997), Lanoir, D., Physical and chemical characterization of automotive

shredder residues , Waste Management & Research, 15, 267-276

Mark (1999), Mark, F., Environmentally sound energy recovery from automotive

shredder residue , SAE Technical Study Series, 1 999-01-0990, Society of Automotive Engineers: Detroit, MI.

Mayes (2005), Mayes, G., Pe rsonal contact May 2005, TXI, www.txi.com

MBA (2005), MBA Polymers, www.mbapolymers.com/whatwedo.htm , accessed December 15, 2005

Meinen (2005), personal contact M. Meinen, April 2005, Lehigh Cement, www.Lehighcement.com

Neu (2005), Personal contact, Jeffrey Neu, Sims- Hugo Neu, www.HNP.com

Nissan (2004), Eight carmakers form new alliance for shredder residue recycling

, www.nissan-global.com/EN/NEWS/2004/_STORY/040109-01.html accessed March 3,

2004

PCA (2004), Portland Cement Association, Manufacturing fact sheet

, www.cement.org/concretethinking/manu_facts.asp , accessed January 5, 2005

PCA (2005), Portland Cement Association, Behaviour and Measurement of Mercury in Cement Kilns, www.cement.org/manufacture/ mtc_milldb_detail.asp?id=941 , accessed

December 2005

Perry (1997), Perry, R., Green, D, Perry’s Chemical Engineers Handbook , seventh edition, McGraw Hill

Prisciandaro (2003), M. Prisciandaro, G. Mazziotti and F. Veglió, Effect of burning supplementary waste fuels on the po llutant emissions by cement plants Resources, Conservation and Recycling Volume 39, (2 ) , p161-184

Protec (2005), Heavy media separation plants, www.protec-srl.com/PDF/2029%20e.pdf

and www.protec-srl.com/ING/FRAMES/homeING.html accessed December 2005

Plastics (2005), Plastics in End-of-Life Vehicles

, www.plastics-in-elv.org , accessed January 7, 2005

Recycling Today (2005), Recycling Opportunities in Auto Shredder Residue and Newer

and Better

, www.recyclingtoday.com accessed October 200524 Redin (2001), Redin, L., et al, Co-combustion of shredder re sidues and municipal solid waste in a Swedish municipal solid waste incinerator , Waste Manage Res 19, p518-525

RRF (1992), Recycling Research Foundation, Shredder residue: Environmental information and characterization under RCRA , Washington, DC

SALYP (2004), www.salypnet.com and www.salypnet.com/environmentalimpact.htm

, accessed October 5, 2004

Saxena (1995), Saxena, S, Rao, N, Rehmat , A, Mensinger, M, Combustion and Cocombustion of Auto Fluff, Energy 20 (9), p 877-887

Scheirs (1998), Scheirs, J., Polymer recycli ng: science, technol ogy and applications. Chichester, UK, John Wiley & Sons

Schut (2001), Schut, J., Commingled plastic waste: ne w gold mine for automotive

processors , Plastics Technology, accessed February 2006, www.plasticstechnology.com/ar ticles/article_print1.cfm#

Schut (2004), Schut, J., Close-Up On Recycling: How to Turn Auto Shredder Waste Into 60 Million Lb of Plastic Pellets - www.plasticstechnology.com/articles/200410cu3.html

accessed December 2005

Seyler (2005), Seyler, C., et al, Life cycle inventory for use of waste solvent as fuel substitute in the cement industry, Int. J. LCA, 10(2) 120-130.

Shen (2002), Shen, H., et al, Selective flotation of plastics by chemical conditioning with methyl cellulose , Resource Conservation and Recycling 35(4) p229-241

Shumway (2005), Personal communications, Douglas Shumway, Mitsubishi Cement

Singh (2001) Singh, M., et al, Proving the principle- recover y of plastics form shredder
ELV’s, Institute of Mechanical Engineers 6 th international confer ence on engineering for profit from waste, p181-189

Staudinger (2001), Staudinger, J., Keoleian, G. A., Management of end-of-life vehicles (ELVs)

in the U.S.

, Center for Sustainable Systems, Univ ersity of Michigan, Report # CSS01-01.

Sullivan (1998), Sullivan, J. L., et al., Life Cycle Inventory of a Generic U.S. Family

– Sedan Overview of Results USCAR AMP Project , SAE Paper #982160, Society of Automotive Engineers: Detroit, MI

Taiheiyo Cement (2004), Environmental report 2004

, www.taiheiyocement.co.jp/english/envrpt2004/pdf/allenv2004.pdf accessed December 200525 Toyota (2005), Toyota and Volkswagen cooperate in recycling and other areas

, www.toyota.com/about/environment/par tnerships/volkswa gon_cooperate.html , accessed January 7, 2005

Trouve (1998) Trouve, G., et al, Comparative thermodynamic and experimental study of some heavy metal behavior during auto motive shredder residues incineration , Waste Management 8(5), p301-307

TXI (2005), Company Profile

, www.txi.com/company_overview/environment.html and Waste Management Methods www.facilityreview.com/Site %20Profiles%20m-z/TXI.htm accessed December 15, 2005.

USCAR (2002), United States Coun cil for Automotive Research, USCAR celebrates a decade of automotive progress

, www.uscar.org/Media/2002issu e1/p1_celebrates.htm

, accessed January 7, 2005

USCAR (2000), U.S.Field Trial for automobile pol ymers recycling: Interim findings

, Study 2000-01-0735, Society of Automotiv e Engineers: Detroit, MI

USDOE (1987), U.S. Department of Energy, Power generation from automobile shredder waste fuel , Report DE-Pro7-871012704

USEPA (1991), US Environm ental Protection Agency , PCB, Lead, Cadmium levels in

shredder waste materials , Report EPA 560/5-90-008A

USEPA (1995), US environmental Protection Agency, Air pollution emission factors – Portland cement manufacturing www.epa.gov/ttn/chief/ap42/ch11/final/c11s06.pdf

, accessed January 5, 2004

USEPA (2004), US Environm ental Protection Agency, Hazardous waste combustors – Maximum achievable control technology standards , accessed January 4, 2004, www.epa.gov/epaoswer/hazwaste/combust/

USEPA (2003), US Environm ental Protection Agency, Beyond RCRA- Waste and material management in the year 2020 , EPA530-R-02-009

USEPA (2004c), US Envir onmental Protection Agency, Municipal solid waste, Automotive parts

, www.epa.gov/garbage/auto.htm , accessed March 3, 2004

van Oss (2002), van Oss, H., Cement manufacture and the environment, Part I: Chemistry and technology , Journal of Industrial Ecology, 6(1)

van Oss (2003), van Oss, H., Cement manufacture and the environment, Part II: Environmental challenges and opportunities , Journal of Industrial Ecology, 7(1)26 Wastec 2005, NSWMA’s 2005 Tip Fee Survey, accessed February 2006, http://wastec.isproductio ns.net/webmodules/webarti cles/articlefiles/478- Tipping%20Fee%20Bulletin%202005.pdf

WBCSD (2005), World Business Council for Sustainable Development, Cement sustainability initiative

, www.wbcsdcement.org , and Fuels and Raw Materials report http://www.wbcsdcement.org/pdf/tf2/tf2_guidelines.pdf accessed January 4, 2006

WERG (2002), Waste and Energy Research Group, Towards processing polymers from

ASR

, www.bton.ac.uk/environment/research/ sustainability/werg/reports.htm , accessed

December 2005

Winslow (1998), Winslow, G., et al, Study of Plastic Material Recovery form Automotive
Shredder Residue, SAE 980093

Winslow (1999), Winslow, G., et al, Recovery of Selected Engineering Plastics from

Automotive Shredder Residue Usi ng Skin Flotation Technology , SAE 1999-01-0663

Winslow (2004), Winslow, G., et al, Advanced Separation of Plastics from Shredder

residue , SAE 2004-01-0469

Zevenhoven (2003), Zevenhoven R., Saeed, L., Automotive shredder residue (ASR) and compact disk (CD) waste: options for recovery of materials and energy , Report TKKENY-14, Helsinki University of Technol ogy, Energy Engineering and Environmental Protection: Finland, http://eny.hut.fi/libra ry/publications/tkk-eny/tkk-eny-14.pdf

, accessed January 7, 200527 Appendix- ASR laboratory sample nu mber key (to accompany data CD)

lab sample residue date of sampling tracking number sampling point

2/10/2005 143963 fines -secondary 143964 fines -primary 143965 midsize- primary 143966 midsize -secondary

143967 coarse

143968 coarse

143969 coarse 143970 fines -secondary 143971 fines -primary 143972 midsize- primary 143973 midsize -secondary

143974 coarse

143975 coarse 143976 fines -secondary 143977 fines -primary 143978 midsize- primary 143979 midsize -secondary

143980 coarse

143981 coarse

145269 dup 143963 145270 dup 143966 145271 dup 143967 145272 dup 143971 145273 dup 143975 145274 dup 143978 145275 dup 143980

2/11/2005 143982 fines -secondary 143983 fines -primary 143984 midsize- primary 143985 midsize -secondary

143986 coarse

143987 coarse

143988 mix of fines and midsize 143989 fines -secondary 143990 fines -primary 143991 midsize- primary 143992 midsize -secondary

143993 coarse

143994 coarse

143995 mix of fines and midsize 143996 fines -secondary 143997 fines -primary 143998 midsize- primary 143999 midsize -secondary

144000 coarse

144001 coarse

144002 mix of fines and midsize28 145276 dup 143982 145277 dup 143985 145278 dup 143987 145279 dup 143988 145280 dup 143990 145281 dup 143998 145282 dup 143993 145283 dup 144001 145284 dup 144002

8/3/2005 154177 < 1.5 inch fines/midsize

153768 poly styrene 153769 polyurethane 153770 copper wire 153771 carpet

153772 fiber

153773 fiber

153774 fiber

154176 tire 154178 <1.0sg 154179 <1.0sg 154180 >1 plastics <1.1

154181 >1 rubber <1.1 154182 >1.1 sank in 1.1 denstiy 154183 >1.2 sank in 1.2 density 154184 >1.3 sank in 1.3 density 154185 >1.35 sank in max density

initial sink-float tests on material types- milled to <1/2 inch size

6/2/2005 151298 rigid sheet plastic -sink 151299 rigid sheet plastic -float 151300 formed soft plastic -sink 151301 formed soft plastic -float

151302 rubber sink

151303 rubber float 151304 rigid formed plastic -sink 151305 rigid formed plastic -float 151306 soft sheet plastic -sink 151307 soft sheet plastic -float