This report was prepared by Bob Boughton of the California Department of Toxic 

Substances Control, Office of Pollution Prevention and Technology Development. The 

project was co-funded by the USEPA under 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_auto_shredder_residue_final.pdf 

Acknowledgements

DTSC appreciates the generous time and 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 the 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 products, companies or technologies. 

All photos are from facility files; 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 20 

 
1 

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 scrap 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 landfilled. From both a resource conservation and 

good business practice perspective, recovery of the energy and mineral value of SR 

should be examined as an alternative to disposal. Compared to landfilling, material 

recovery and energy recovery are usually preferred because of conservation of nonrenewable resources and reduction 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 flexibility as well as the capability to use large 

quantities of materials. For these reasons, cement 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 fraction of SR by this 

industry. Due to the large scale of the cement industry in the US, a significant amount of 

SR is recoverable. 

The goal of this study was to identify the feedstock quality parameters needed to satisfy 

kiln operators and then to assess the mechanical means necessary to process SR into 

material acceptable as coal and mineral substitutes. To test this concept, the USEPA and 

the California Department of Toxic Substances Control (DTSC) funded this study to 

investigate inexpensive separation systems capable 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 removal of glass occurs at the dismantling yards before autos 

reach the shredding facility. As a result, recovery of SR for mineral content was not 

studied further. 

Sub-streams can be recovered from SR for energy value. In general, the fuel 

characteristics of SR as generated were found to be poor due to high ash, heavy metals, 

and chloride content. A literature review and discussions with shredder operators offered 

great insight into the equipment needed to upgrade SR to valued fuel. Technologies that 

have been used or could be used to recover valued sub-streams from SR include heavy 
2 

media separation, froth flotation, vibrating tables, optical sorting and air classification. 

With these technologies in mind, discussions with shredder and kiln operators lead to a 

conceptual system design to recover a fuel rich fraction from SR. 

To test this concept, field tests were conducted to separate and further beneficiate the SR 

waste stream. Flotation/density separation techniques commonly used by shredders in 

the past were tested to separate rubber 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 characteristics 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 separation system was compiled. Processing SR 

appears to be economically marginal considering 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 acceptable fuel supplement; however, barriers which 

inhibit economically viable recycling may need to be addressed. 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 significant barrier 

to overcome. Full scale demonstration is the next step. Some development of techniques 

to reduce the contaminant levels may be needed, followed by testing to show that no 

significant increases in emissions at kilns would occur. 
3 

BACKGROUND 

Shredder Residue 

Shredder waste or shredder residue (SR) is generated by businesses that recover ferrous 

and non-ferrous metals from waste automobiles, 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 are recycled at over 200 dedicated shredding 

operations nationwide (USEPA 2004c, Fisher 1999, ISRI 2004, Staudinger 2001). 

Roughly 20% of the feedstock becomes shredder residue comprised primarily of glass, 

plastics, textiles, rubber, and fines. Over three 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 generated 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, Environment Australia 2002). Recovering plastics 

for recycling, limited testing of SR as a pyrolysis 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 and low sulfur) for blast furnace fuel or for 

secondary material recovery are expensive 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 various systems (Mark 1999, CAC 1998, Zevenhoven 

2003, USDOE 1987, CMP 1990, Automotive Engineering 1994, Saxena 1995). Some 
4 

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 waste for energy recovery or as a blast furnace 

fuel was only be viable for half the SR waste stream (plastics and rubber) with highest 

energy and lowest ash content. The residual 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 solid and liquid wastes is 

widespread. The portland cement product quality and kiln air emissions are not impacted 

by contaminants in the commonly used alternative fuels even at up to 30% fuel 

supplement (USEPA 1995, Gabel 2005, Choate 2003). The most commonly used 

supplemental fuel, waste tires (which contain significant amounts of zinc) has 

contaminant levels similar to that of SR (USEPA 1991). 

Numerous studies discuss the very successful use of alternative 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, Prisciandaro 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 low and medium volatility heavy metal 

contents in mineral and fuel feedstocks are incorporated into the cement product. In 

contrast, air pollution control systems capture only about 50% of the highly volatile 

metals such as mercury (Seyler 2005, PCA 2005). Additionally, the large amount of 

limestone in the feed minerals effectively 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, aluminum production wastes, glass, industrial 

ashes, filter cake and mill scale. Considering 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 and mineral supplement. Plastics and rubber 

make up the majority of SR combustible content. But compared to the alternative fuels 

used at cement kilns today, SR is a heterogeneous 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) and may consist of up to 40% of mineral 

equivalent to that used in cement production (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 mining, transporting and preparation of coal 

and mineral ores. The potential impacts of landfill leachate contaminated with SR 
5 

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 lower carbon, nitrogen and sulfur content per unit 

of energy than coal yields lower carbon dioxide, nitrogen oxide and sulfur dioxide 

emissions (EPA 1995, Gabel 2005)). All these issues should be considered when 

evaluating resource recovery options (Boughton 2005). 

Project Goal and Description 

Discussions with cement manufacturing industry representatives indicate that the main 

barriers to the use of SR is the perception that it is too contaminated, too heterogeneous 

and of insufficient energy value for use as fuel (Bennett 2005, Meinen 2005, Shumway 

2005, Hawkins 2005, Mayes 2005). These became the key considerations to address in 

this study. The plastic, rubber 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 characteristics (proximate and ultimate 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 Scientific Laboratories of California to do the 

elemental analyses. We discussed the results with kiln operators to determine the 

considerations for supplemental fuel and mineral 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 scale 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 system 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 trommel 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 size reduction, but it could be separately 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 materials. These processes result in relatively clean 

and uniform sub-streams; hence smaller sample sizes should be adequate. 
6 

After sufficient time for the non-ferrous recovery 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 coarse material. Samples were taken from each 

of the five nonferrous recovery system discharge conveyance belts. In general, material 

from a one foot wide swath across each two foot wide discharge belt filled 1-gallon 

plastic bags. Larger cross sections were taken 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 February 11, 2005. Sampling both the <11⁄2” 

recombined sub-streams and the >11⁄2” sub-stream will help to characterize the total SR 

waste since the weight proportions of the individual sub-streams are not well known. A 

total of 33 samples were collected over the two days. All sample bags were sealed to 

retain moisture and sent for processing and analysis. Also, the laboratories reanalyzed 16 

samples to gather information on the heterogeneity of the samples and reproducibility of 

laboratory analyses. 

Field observations showed that the fines appeared very uniform, consisting mostly of 

fiber and dirt, and free of material larger than 1⁄2 inch. A portion of the fines material 

were sieved with several trays to examine the 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 fines samples, meaning glass recovery would 

likely not be feasible. All samples of SR larger 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 complete with the exception 

of small amounts of metals attached to plastic or rubber pieces (such as a hose clamp on a 

rubber hose or a small screw within a plastic piece), short lengths of copper wire 

entangled with other materials, as well as steel 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 determinations 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 reproducibility of the laboratory 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 rubber 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 concentrations except for volatile 

metals such as mercury, lead and cadmium. With the exception of mercury, analyses for 

total metals from other samples of SR material were gathered to fill this gap. 

The moisture content of the samples varied due to dust control sprays in the shredder and 

the non-ferrous separation system and may also 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 related 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 variation between the six 

samples in each size fraction was small. Duplicates showed only slight variation in 

results. Statistical confidence intervals were not determined, but the samples appear 

representative of each size fraction. 

Table 1 shows that the larger the material size, 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. However, 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, autos 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 chlorine to the total SR as was found. 

Laboratory data for the ash concentrations 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 stream 
8 

Table 2 presents the average values for several 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 fines 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 the fines showed little 

glass. After discussions with shredder 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 operating 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 supplement at most kilns (the exception being kilns 

with low alkali containing mineral feed stocks or kilns which can manage increased CKD 

generation). 

As shown in Table 3, with the exception of volatile metals shown, the elements generally 

were at the same levels as previous studies 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 fragments, many connected to or intertwined with 

other materials, were seen in the samples and 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 lead, vanadium, cadmium, arsenic, and zinc are 

underreported due to volatilization during ashing from the proximate/ultimate analyses. 

Table 4 shows losses due to volatilization during ashing range from 35% to 100% 

depending on the metal compared to SR as disposed (DTSC 2002). 

Table 2 - Averaged concentration 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 material 
9 

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 material 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. Tests for PCBs were not conducted on the size 

separated SR. PCB tests of disposed SR generated by several California facilities average 

total levels ranging from 16 to 82 ppm (DTSC 2002 and DTSC files). Levels above 50 

ppm trigger TSCA requirements for hazardous waste 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 samples showed that the laboratory preparation methods lead to 

well homogenized material for analysis and that the laboratory analytical methods were 

consistent (good reproducibility). The laboratories met all quality objectives via 

laboratory QA/QC including duplicates, matrix 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 content. A literature review 

and discussions with shredder operators offered 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 media separation, froth flotation, 

vibrating tables, optical sorting and air classification. In the 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 fraction 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 dense plastics and rubber has been demonstrated (TXI 2005, 

MBA 2005, Galloo 2005, Salyp 2004, Schut 2004). This 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-streams 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 interspersed. Hand sorting showed that only 3.5 lb 

of small plastic and rubber pieces were in the total sample. The material was sampled for 

lab analyses, but there was not enough plastic and rubber content to test density 

separation. 

The total 14 pounds of >11⁄2 inch coarse material was separated by hand to remove 

materials such as polyurethanes, copper wire and fiber from the plastics and rubber 

materials of interest. Seven different recovered fractions resulted; copper wire, 

polyurethanes, polystyrenes, carpet/textiles, mixed plastic/rubber, tire rubber, and a 

residual fibrous mix. The plastic/rubber fraction weighed about 8 pounds, the fibrous 

material weighed about 4 pounds, and the remaining materials collectively weighted 

about 2 pounds. The plastic/rubber fraction was retained for density separation, and the 

other materials were separately bagged for laboratory analysis. 

Small scale tests with salt water baths are commonly 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 were 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 and styrofoam. The floaters were collected 

and bagged for laboratory analysis. A set of salt 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 formulation) while the bulk of the less dense 

plastics and rubber will float. Mixed plastics and fillers used in specific plastics 
11 

formulations may lead to different specific material densities however. Hence, a range of 

bath density levels should separate the plastics/rubber sample 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 density above 1.3sg (observed to be mostly vinyl 

backing for floor mats), were collected and washed in hot water to remove residual salts 

and then bagged for analysis. The materials that floated at 1.3sg were 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 materials were collected. Relatively small 

amounts of materials were recovered at the mid range density splits and a majority of the 

rubber separated at 1.1 sg, while plastics appeared to be more distributed. The separation 

by density experiment lead to seven separated components from the baths which in 

addition to the six hand separated materials gave 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 the material above 1.3 sg including copper wire 

had a high relative chlorine content which supports the concept of density bath sink-float 

techniques separation from the other materials. Fibers were the major component by 

weight but not of high energy value. A large 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 11380 
12 

The sample total values were calculated by adding the individual component 

contributions. The net 26% ash, 2.4% chlorine 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 chlorine content. The proposed separation system design (as 

discussed later) includes a fiber separation system as a first step, followed by density 

separation of the remaining materials. The ordering of the sub-fractions in Table 5 

mirrors the proposed sequence of separation steps. For simplicity, the components shown 

in Table 5 were consolidated by grouping as follows: 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 cumulative contributions to the total sample for 

each of the groups. For example, the components of <1 sg contributed 22 % of the total 

sample weight of 5540 grams, 10% of the total chlorine, 9% of total ash, etc. 

Table 6 - Fuel value contributions 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 chlorine content. As can be seen from Table 6, 

processing the material in a sink/float system would result in different 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 characteristics 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 including 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 the same 1.2 sg separation cut-off discussed 

above. Low levels for nearly every 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 supplemental 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 benefit of the separation system, some of the copper (wire 

fragments) should be recoverable from the residuals sub-stream. The residual fraction 

showed only a 7.5 wt % net content of beneficial 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 volatilization 
14 

DISCUSSION 

Full Scale Considerations 

A list of specific requirements or contaminant limitations for cement kiln operators was 

not compiled. Because each kiln has mineral feedstocks with different characteristics, 

has different operating designs and has different environmental limitations, little 

guidance on common limitations for supplemental fuels or minerals was gathered from 

discussions with operators. What became clear was that some facilities could accept 

materials with certain characteristics while others 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, Neu 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 remove the very low density materials such as 

expanded polystyrene and polyurethane 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, resulting 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 chlorine content of 0.7 

wt%, while still leading to significant recovery of mass and BTU content (44% and 60% 

from Table 6). Alternatively, additional separations to further reduce the chlorine levels 

may be needed. Such separations have been demonstrated with mixtures of plastics and 

with SR (Galloo 2005, MBA 2005, Salyp 2004, WERG 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 resources could require fundamental changes in 

the waste versus non-waste regulatory construct embedded in RCRA (USEPA 2003). 

One such change may be needed in the federal 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, cryogenic 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 concept 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 total SR waste stream to be initially processed 

by cutting, vibrating tables and air classification to separate fibrous and entangled 

materials. The resulting plastics and rubber 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 This would lead to removal of the residual 

metal and PVC, with some tolerable loss of valued materials. An economic review of the 

entire process requires sizing each processing 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 recoverable plastics and rubber 

• 70% of that is less than 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 classification steps leads to recovery of 21 

tons/hour of relatively fiber free plastics and rubber pieces (with copper wire and PVC). 

An initial water bath would recover about 6 tons/hour of <1s.g materials from the mixed 

stream. A media bath processing the remaining 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 content) would be the 

final step. From the assumptions above, a net 15 tons per hour is recoverable 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 operations 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 conveyor system to remove rejected material 

from the bottom. This will work well for the initial water bath separation system, but 
16 

there are important considerations for the 1.2 sg media bath. A rotating drum design 

would provide the best recovery and separation quality. Density separation systems are 

most effective if the materials introduced are of the same size and shape. Chopping and 

shredding the recovered SR materials to pass a 1⁄2 inch screen would help the separation 

efficiency, but would add significant processing costs. However this may be the chosen 

method if the cement kiln operator requires the supplemental 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 considerations the media material chosen should be a ferrosilicate like magnetite. This natural ore is easy to magnetically recover from spent bath 

liquids and rinse waters, and inexpensive enough 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 required 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 system 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 show that there is minimal mass fraction in the 
17 

1.1-1.2 density range; hence a system can be optimized 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 final product to kiln operators because the iron 

content is beneficial. Recovery of the low density fluff (predominately 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, the 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 operators have experience with density baths to 

recover and separate non-ferrous metals from SR. Table 9 summarizes the capital and 

operating costs and resource recovery economic 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 (Andrusyshyn 2005, Perry 1997). The heavy media 

separation process is based on the design presented by the Bureau of International 

Recycling (BIR 2005) using a Protec drum separator (Protec 2005). Capital costs for a 

15t/hr media bath unit are $750,000 including all ancillary equipment (Osucha 2006, BIR 

2005, Protec 2005)). Assuming a 20 year operating term for all equipment (with a 10% 

interest rate) leads to total capital costs (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 maintenance personnel, and materials (including 

300lb/hr media loss, and $50,000/yr in general maintenance materials). Trucking costs 

are based on a 50 mile round trip to a landfill, or a 100 mile round trip to a cement 

manufacturing facility and $2 per mile averaged cost (significant savings could be found 

with rail transportation for long distances compared to trucks). Operating costs total 

$550,000/yr. The total cost of $700,000 per year will lead to recovery of 15t/hr of 

material (30,000 t/yr, based on 2000 hours per year) or $23/t recovered material. 

Current national landfill tipping fees range from $24-$70 per 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 was 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 will take the supplemental material for free leads to a near 

economic balance at his point. Revenues from additional recovered copper should be 

included as well. The >1/2 inch SR sub-stream contains about 2 wt% total copper (see 

Table 3 and Table 5) mostly as insulated copper wire. Conservatively assuming that only 

one third of the copper content (in the residual fraction shown in Table 8) is recovered 

gives 0.2 t/hr or 400 t/yr. The value of recovered copper wiring 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 revenues equal to total costs, the recovery of copper alone 

could become the focus of a shredder residue processing system. The greatest 

uncertainties are for the capital cost estimates and the landfill savings. Table 9 shows 

that a doubling the capital investment would still give an ultimate benefit of $400,000 per 

year (or over $13 per ton recovered material). 

It is useful to provide context for resource 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 consumption (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 annually. Considering the many conservative 

assumptions made for the economic analysis, the 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 separation systems should produce an acceptable 

fuel supplement. Considering the large scale 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 this 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 processing SR appears to be economically 

marginal considering avoided landfilling costs alone. However, significant economic 

benefits would result from additional non-ferrous metals recovery (principally copper). 

Remaining barriers to acceptance includes demonstration that a full-scale system will 

consistently produce high valued fuel with low concentrations of deleterious 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 located close to cement kilns could be cost 

effective. Other shredders may produce SR with significant glass content to be attractive. 

Shredder residue was found to have substantial recoverable energy value. Following 

industrial ecology and sustainability themes, materials now considered 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 the recovery of SR as well as the facilities 

interested in using these materials. Financial and environmental benefits would be 

realized by providing incentives 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 overcome for use of SR, few if any other options 

exist other than landfilling. Residual PCBs present a barrier for any recovery alternative 

but actually promote landfilling over resource recovery, 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 significant 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 needed, followed by testing to show that no 

significant increases in emissions 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 & Technical 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 Laboratory, accessed January 4, 2004, 

www.transportation.anl.gov/recycling/plastics.html

http://pe.es.anl.gov/What%27s%20New/FOAM.pdf, 

http://pe.es.anl.gov/What'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/aboutrecycling/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; Alternative fuels in cement manufacture, 

www.cembureau.be, accessed October 4, 2004 
21 

CIF (2003), Cement Industry Federation, Cement industry environmental report, 

www.cement.org.au/environment/case_studies/alternative_fuels_at_bcsc.pdf, accessed 

October 2003 

CMP (1990), Center for 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 waste 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/upload/HWMP_REP_ASW_draft.pdf

Dyckerhoff (2005), Dyckerhoff Company- Environmental Protection- 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/waste/elv/chapter11.html, accessed April 

10, 2004. 
22 

European Commission (2005), Management of end-of-life vehicles,

http://europa.eu.int/scadplus/leg/en/lvb/l21225.htm and End-of-life vehicles, 

http://europa.eu.int/comm/environment/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 4th 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., Simulating operational alternatives for future 

cement production, Journal of Cleaner Production, 13 (13-14) p1246-1257 

Hawkins (2005), Hawkins, G., Personal 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, Alternative fuels and raw materials, 

www.holcim.com/CORP/EN/oid/46240/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 materials from shredder residue, J 

Met 46 (2) p 40-43 

Keller, C., "Optimized disposal of automotive shredder residue" in Municipal Solid 

Waste Management- Strategies and Technologies for Sustainable Solutions, Ludwig, C., 

Hellweg, s., Stucki, S. (eds), Springer-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) 549-554 
23 

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, 1999-01-0990, Society of Automotive 

Engineers: Detroit, MI. 

Mayes (2005), Mayes, G., Personal 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 pollutant 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 2005 
24 

Redin (2001), Redin, L., et al, Co-combustion of shredder residues 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 recycling: science, technology and applications. 

Chichester, UK, John Wiley & Sons 

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

processors, Plastics Technology, accessed February 2006, 

www.plasticstechnology.com/articles/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- recovery of plastics form shredder 

ELV’s, Institute of Mechanical Engineers 6th international conference 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, University 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 2005 
25 

Toyota (2005), Toyota and Volkswagen cooperate in recycling and other areas, 

www.toyota.com/about/environment/partnerships/volkswagon_cooperate.html, accessed 

January 7, 2005 

Trouve (1998) Trouve, G., et al, Comparative thermodynamic and experimental study of 

some heavy metal behavior during automotive 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 Council for Automotive Research, USCAR celebrates a 

decade of automotive progress, www.uscar.org/Media/2002issue1/p1_celebrates.htm, 

accessed January 7, 2005 

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

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

USDOE (1987), U.S. Department of Energy, Power generation from automobile 

shredder waste fuel, Report DE-Pro7-871012704 

USEPA (1991), US Environmental 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 Environmental Protection Agency, Hazardous waste combustors – 

Maximum achievable control technology standards, accessed January 4, 2004, 

www.epa.gov/epaoswer/hazwaste/combust/ 

USEPA (2003), US Environmental Protection Agency, Beyond RCRA- Waste and 

material management in the year 2020, EPA530-R-02-009 

USEPA (2004c), US Environmental 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.isproductions.net/webmodules/webarticles/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 Using 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 Technology, Energy Engineering and Environmental 

Protection: Finland, http://eny.hut.fi/library/publications/tkk-eny/tkk-eny-14.pdf, 

accessed January 7, 2005 
27 

Appendix- ASR laboratory sample number 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 midsize 
28 

 

 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