Many of us have seen news footage of a major fire involving stacks of discarded tires. These fires can rage on for days, weeks or even months if the conditions are right, leaving ground and air pollution in their wake. These massive fields of discarded tires may soon become a relic of a wasteful past if new uses for recycled tires become more popular. Recycled tires contain enough fuel to power furnaces, and potentially enough retrievable oil to ease consumer demand. There are a number of other uses for old tires, from clothing to child safety to environmental protection.
One of the most common uses for recycled tires is as an alternative fuel source for certain industries. Concrete manufacturers, for example, must use kilns to dry their products before shipping. These massive kilns are large enough to accommodate whole tires in their furnaces.
Other industries, such as steel and glass production, use shredded tires to augment their usual coal or natural gas fuel sources. The tires must be shredded in order to fit through the feeder grates of the furnaces. One drawback is the presence of steel belts in many tires, which can build up over time and block the feeder chutes.
In order to meet strict environmental guidelines, many landfills must provide a safe covering over each day's deliveries. Instead of using a layer of fill dirt, some landfill operations are now using a layer of shredded recycled tires as a daily cover. Instead of piling whole discarded tires in a hazardous tire pile, landfill operators can receive tire shreds from a local recycling center or invest in their own tire shredding machinery.
Old tires are also used as a cushioning material in playgrounds and other public areas popular with children. Sometimes, the shredded tires are spread over the area like a mulch, which can cushion the fall of a child or reduce the impact of playground equipment. Recently, recycled rubber from old tires has been combined with other binders and foam to produce a solid safety mat for playgrounds and schoolyards.
Even certain clothing manufacturers have discovered the benefits of using recycled tires. Material made from them is now used to form the rubber sole of some athletic shoes and work boots. Discarded tires may one day be turned into other rubber-based clothing and accessories, such as raincoats, boots, umbrellas and hats.
One recent use of recycled tires may become a trend in larger cities. Traditional concrete sidewalks can now be replaced with similar-sized panels constructed from recycled tires and other materials. Proponents of these new sidewalk panels claim they are more resistant to the damage caused by tree roots, and they provide more stability for pedestrians. While the current cost per panel is higher than traditional concrete forms, the new rubberized panels should require far less maintenance throughout their lifespan.
Since recycled tires contain oil and carbon black, two very useful substances, scientists are still seeking ways to retrieve these materials from discarded tires. If these researchers are successful in their quest, the huge piles of scrap tires we see today will ultimately become nothing more than a memory. They may provide enough reclaimed oil to make them worth salvaging, instead of merely discarding.
By Michael Pollick