EnvironmentRecycling and Conservation |
What are the uses of discarded tires? |
During 2007, 4,596 thousand tons of tires were scrapped in the United States. Nearly 90 percent, or 4,106 thousand tons, of tires were sent to one of the three major markets for scrap tires—tire-derived fuel, ground rubber applications, and civil engineering. Tire-derived fuel (TDF) accounted for 54 percent or 2,484 thousand tons of the scrap tires generated. TDF is used in a variety of combustion technologies, including cement kilns, pulp and paper mill boilers, utility and industrial boilers. The TDF market is expected to continue to grow. Ground rubber applications, including new rubber products, playground and other sports surfacing, and rubber-modified asphalt, consumed 789 thousand tons (17 percent of the total) of scrapped tires. Another 562 tons (12 percent of the total) of tires were used in civil engineering applications. These include tire shreds used in road and landfill construction, septic tank leach fields, and other construction projects. An additional 594 thousand tons of tires were sent to landfills in 2007.
Tires may be disposed in either a landfill or a monofill, a separate landfill only for tires. In certain areas of the country, especially in the Western states, landfills are a more efficient option than other scrap tire markets. Landfills are also the only option for tires that are in such poor condition they are not candidates for the scrap tire market. Furthermore, landfills are an important disposal option for the residue and by-products from tire shredders.