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Scrap Tire Characteristics

1. Tire Derived Fuel Analysis
2. Typical Materials Composition of a Tire
3. Typical Composition by Weight
4. Densities of Shredded and Whole Tires
5. Rubber weight by tire component.
6. Tire Derived Fuel By-Products Analysis
7. Steel Tire Cord Analysis

1. Tire Derived Fuel Analysis

     

    Representative Analysis of TDF Produced By WRI

      (Source: TDF Produced From Scrap Tires with 96+% Wire Removed)
    Description %By Wt, As Received %By Wt, Dry Basis
    Proximate Analysis
    Moisture 0.62 ----
    Ash 4.78 4.81
    Volatile Matter 66.64 67.06
    Fixed Carbon 27.96 28.13
    Total 100.00 100.00
    Ultimate Analysis
    Moisture 0.62 ----
    Ash 4.78 4.81
    Carbon 83.87 84.39
    Hydrogen 7.09 7.13
    Nitrogen 0.24 0.24
    Sulfur 1.23 1.24
    Oxygen (by difference) 2.17 2.19
    Total 100.00 100.00
    Elemental Mineral
    Analysis (Oxide Form)
    Zinc 1.52 1.53
    Calcium 0.378 0.380
    Iron 0.321 0.323
    Chlorine 0.149 0.150
    Chromium 0.0097 0.0098
    Fluoride 0.0010 0.0010
    Cadmium 0.0006 0.0006
    Lead 0.0065 0.0065
    Others below detectable limits
    Heat Value BTU/lb kJ/kg
    HHV 16,250 37,798
    HV Ave 15,500 36,053
    TDF Combustion
    Characteristics ° F ° C
    Tires ignite (flash point) 550 - 650 288 - 343
    Carbon begins to burn 842 450
    Carbon completely burnt 1202 650

© 1986 Waste Recovery, Inc.
84% OF A TIRE,S WEIGHT IS FROM RUBBER COMPOUNDS. REMAINDER
IS BEAD AND BELT WIRE PLUS CARCASS AND CHAFER FABRIC

2. Typical Materials Composition of a Tire

    This table lists the typical types of materials used to manufacture tires.

    Typical Composition of a Tire

    Synthetic Rubber
    Natural Rubber
    Sulfur and sulfur compounds
    Silica
    Phenolic resin
    Oil: aromatic, naphthenic, paraffinic
    Fabric: Polyester, Nylon, Etc.
    Petroleum waxes
    Pigments: zinc oxide, titanium dioxide, etc.
    Carbon black
    Fatty acids
    Inert materials
    Steel Wire

     

3. Typical Composition by Weight

This lists the major classes of materials used to manufacture tires by the percentage of the total weight of the finished tire that each material class represents.

Passenger Tire

Natural rubber 14 %
Synthetic rubber 27%
Carbon black 28%
Steel 14 - 15%
Fabric, fillers, accelerators, antiozonants, etc. 16 - 17%
Average weight: New 25 lbs, Scrap 20 lbs.

 

Truck Tire

Natural rubber 27 %
Synthetic rubber 14%
Carbon black 28%
Steel 14 - 15%
Fabric, fillers, accelerators, antiozonants, etc. 16 - 17%
Average weight: New 120 lbs., Scrap 100 lbs.

4. Densities of Shredded and Whole Tires

APPROXIMATE DENSITIES
LOOSELY PACKED   DENSELY PACKED
550-600 lbs/yd3 single pass 1220-1,300 lbs/yd3
850-950 lbs/yd3 2" shred 1,350-1,450 lbs/yd3
1,000-1,100 lbs/yd3 1 1/2" shred 1,500-1,600 lbs/yd3
100/10Yd3 WHOLE TIRES
(PASSENGER/LIGHT TRUCK)
500/10Yd3
 
 
10 MESH- 29 lbs/ft3
20 MESH- 28 lbs/ft3
30 MESH- 28 lbs/ft3
40 MESH- 27 lbs/ft3
80 MESH- 25-26 lbs/ft3

5. Rubber weight by tire component.

A tire is manufactured from several separate components, such as tread, innerliner, beads, belts, etc. This table shows which components account for the rubber used to make the tire.

RUBBER PERCENT BY WEIGHT IN A NEW RADIAL PASSENGER TIRE
 
TREAD 32.6%
BASE 1.7%
SIDEWALL 21.9%
BEAD APEX 5.0%
BEAD INSULATION 1.2%
FABRIC INSULATION 11.8%
INSULATION OF STEEL CORD 9.5%
INNERLINER 12.4%
UNDERCUSHION       3.9%
  100.0%

6. Tire Derived Fuel By-Products Analysis

The data presented in the following two tables is analysis of bottom ash and fly ash from a facility combusting only Tire Derived Fuel. It would not be representative of facilities that use TDF as a supplement to another fuel, such as coal or wood.

PRELIMINARY RESULTS OF SLAG
(BOTTOM ASH) ANALYSIS

COMPOUND SAMPLE 1 SAMPLE 2 AVERAGE
Total Carbon -- % 0.071 0.258 0.164
Aluminum 0.128 0.283 0.206
Arsenic 0.002 ---- 0.001
Cadmium 0.001 0.001 0.001
Chromium 0.978 0.068 0.523
Copper 0.255 0.320 0.288
Iron 95.713 96.721 96.217
Lead 0.001 0.001 0.001
Magnesium 0.058 0.059 0.058
Manganese 0.058 0.307 0.416
Nickel 0.241 0.093 0.167
Potassium 0.010 0.015 0.012
Silicon 0.340 0.246 0.293
Sodium 0.851 0.701 0.776
Zinc 0.052 0.160 0.106
Tin 0.007 0.006 0.006
Sulfur 0.766 0.762 0.764
100.0 100.0 100.0

ANALYSIS OF SCRAP TIRE FLY ASH

Contents

Weight by Percentage
Zinc

51.48%

Lead

0.22%

Iron

6.33%

Chromium

0.03%

Copper

0.55%

Nickel

0.03%

Arsenic

0.02%

Aluminum

0.76%

Magnesium

0.50%

Sodium

0.01%

Potassium

0.01%

Magesium Dioxide

0.36%

Tin

0.03%

Silicon

6.85%

Cadmium

0.05%

Carbon

32.20%

  Total

99.43%

Note: These results are from incineration of 100% tire fuel.
Sources: Radian Corporation, Results From Sampling and Analysis of Wastes From the Gummi Mayer Tire
Incinerator, May 1985.

 

7. Steel Tire Cord Analysis

ASTM 1070 Steel Tire Wire

There are approximately 2.5 pounds of steel belts and bead wire in a passenger car tire. This material is made from high carbon steel with a nominal tensile strength of 2,750 MN/m2 and the following typical composition:

     

      STEEL BELTS BEAD WIRE
    Carbon 0.67 - 0.73% 0.60% min.
    Maganese 0.40 - 0.70% 0.40 - 0.70%
    Silicon 0.15 - 0.03% 0.15 - 0.30%
    Phosphorus 0.03% max. 0.04% max.
    Sulfur 0.03% max. 0.04% max.
    Copper Trace Trace
    Chromium Trace  Trace
    Nickel Trace Trace
    COATING 66% Copper
    34% Zinc
    98% Brass
    2% Tin