Worn-out Automobile Tires – A World Report
According to the forecasts of UN Conference on environment and development (Rio de Janeiro), the solid wastes volume will rise by 4 -5 times, till 2025. The global reserves of worn – out automobile tires are assessed at 25 to 39 million tonnes, while their year increase is no less than 7 million tonnes. The European countries account for 3 billion pieces of worn – out automobile vehicle tires (nearly 2 million tonnes). In US, over 280 million of used vehicle tires are accumulated every year, and their total stock, for the last year has exceeded 2 billion pieces. The tires must be stored and secured, as during their combustion they oust a great quantity of toxic elements into the atmosphere. Only 23% of world used tires are subsequently used (export to other states, burning for energy reception, mechanical pulverisation for roads paving, etc.). The other 77% of used tires are not utilised, because the absence of profitable way of their utilisation.
During the incineration of tires chemical combinations are created, which, after entering the atmosphere, become a source of hazards for human: biphenyl, anthracene, fluorethane, pyrene, benzpyrene. Two combinations among the abovementioned (biphenyl and benzpyrene) belong to the strongest carcinogens.
The tires which were dumped or buried degrade in natural conditions for no less than 100 years. Contact of tires with rainfalls or subsoil waters is accompanied by ablation of a number of toxic combinations: dyphenilamine, dibutyl phthalate, phenanthrin etc. All these combinations subsequently enter the soil. The gum which is the high-molecular material belongs to thermoset polymers cannot be reprocessed in high temperatures, which creates a serious problem in recycling of gum waste.
According to ETRA (European Tire Recycling Association) the European Union has prohibited the burying of integer tires, since 2003, and has prohibited burying of cut tires, from 2006. From 2003 the ban is in force for tire burning. Economically effective tires recycling technology will allow not only resolving an ecological problem, but will also ensure profitability of such recycling plants. Many developed countries are ready to pay for utilisation of tires, from 100 to 150 EUR per ton.