tire recycling, or rubber recycling, is the process of recycling waste tires that are no longer suitable for use on vehicles due to wear or irreparable damage. these tires are a challenging source of waste, due to the large volume produced, the durability of the tires, and the components in the tire that are ecologically problematic. because tires are highly durable and non-biodegradable, they can consume valuable space in landfills. if waste tires are improperly managed they may cause rubber pollution. in 1990, it was estimated that over 1 billion scrap tires were in stockpiles in the united states. as of 2015, only 67 million tires remain in stockpiles. from 1994 to 2010, the european union increased the amount of tires recycled from 25% of annual discards to nearly 95%, with roughly half of the end-of-life tires used for energy, mostly in cement manufacturing. pyrolysis and devulcanization could facilitate recycling. aside from use as fuel, the main end use for tires remains ground crumb rubber. in 2017, 13% of u.s. tires removed from their primary use were sold in the used tire market. of the tires that were scrapped, 43% were burnt as tire-derived fuel, with cement manufacturing the largest user, another 25% were used to make ground rubber, 8% were used in civil engineering projects, 17% were disposed of in landfills and 8% had other uses. globally, tire graveyards are a common environmental hazard, with significant pollutants and other challenges. for example, the sulaibiya tire graveyard in kuwait has had repeat highly toxic fires. ship breaking a 30- to 40-year-old general cargo ship anchored off cap-haïtien, haiti, before being broken up. this section is an excerpt from ship breaking. removing steel plates from a ship using cranes at alang ship breaking yard (india) ship-breaking (also known as ship recycling, ship demolition, ship dismantling, or ship cracking) is a type of ship disposal involving the breaking up of ships for either a source of parts, which can be sold for re-use, or for the extraction of raw materials, chiefly scrap. modern ships have a lifespan of 25 to 30 years before corrosion, metal fatigue and a lack of parts render them uneconomical to operate. ship-breaking allows the materials from the ship, especially steel, to be recycled and made into new products. this lowers the demand for mined iron ore and reduces energy use in the steelmaking process. fixtures and other equipment on board the vessels can also be reused. while ship-breaking is sustainable, there are concerns about the use by poorer countries without stringent environmental legislation. it is also labour-intensive, and considered one of the world's most dangerous industries. in 2012, roughly 1,250 ocean ships were broken down, and their average age was 26 years. in 2013, the world total of demolished ships amounted to 29,052,000 tonnes, 92% of which were demolished in asia. as of january 2020, alang ship breaking yard (india) has the largest global share at 30%, followed by chittagong ship breaking yard (bangladesh) and gadani ship breaking yard (pakistan). the largest sources of ships are china, greece and germany, respectively, although there is a greater variation in the source of carriers versus their disposal. the ship-breaking yards of india, bangladesh, china and pakistan employ 225,000 workers as well as providing many indirect jobs. in bangladesh, the recycled steel covers 20% of the country's needs and in india it is almost 10%. as an alternative to ship-breaking, ships may be sunk to create artificial reefs after legally mandated removal of hazardous materials (though this does not recycle any materials), or sunk in deep ocean waters. storage is a viable temporary option, whether on land or afloat, though most ships will be eventually scrapped; some will be sunk, or preserved as museums. textiles in many countries, there is an active market in re-selling used clothes. in britain, this dominated by charity shops who sell donated clean clothes. less saleable clothes are put into the re-cycling waste stream. textiles are made of a variety of materials including cotton, wool, synthetic plastics, linen, modal and a variety of other materials. the textile's composition will affect its durability and method of recycling. textiles entering the re-cycling stream are sorted and separated by workers into good quality clothing and shoes which can be reused or worn. there is a trend of moving these facilities from developed countries to developing countries either for charity or sold at a cheaper price. many international organisations collect used textiles from developed countries as a donation to those third world countries. this recycling practise is encouraged because it helps to reduce unwanted waste while providing clothing to those in need. damaged textiles are further sorted into grades to make industrial wiping cloths and for use in high quality paper manufacture or material suitable for fibre reclamation and filling products. if textile reprocessors receive wet or soiled clothes, however, these may still be disposed of in a landfill, as the washing and drying facilities may not be present at sorting units. fibre reclamation mills sort textiles according to fibre type and colour. colour sorting eliminates the need to re-dye the recycled textiles. the textiles are shredded into "shoddy" fibres and blended with other selected fibres, depending on the intended end use of the recycled yarn. the blended mixture is carded to clean and mix the fibres and spun ready for weaving or knitting. the fibres can also be compressed for mattress production. textiles sent to the flocking industry are shredded to make filling material for car insulation, roofing felts, loudspeaker cones, panel linings and furniture padding. according to earth911.com, "metal hangers, while made of steel, can be difficult to recycle because their hooks can damage recycling equipment and some have a petroleum coating. some curbside recycling programs do accept them.... many dry cleaners take back hangers, too...." chat and furnace slag in north america, mine chat waste can be used on snow-covered roads to improve traction; as gravel; and as construction aggregate, principally for railway ballast, highway construction, and concrete production. furnace slag and to a lesser degree coal slag have been used in lieu of construction and railway ballast gravel in the uk. clinker, slag, fly ash and in some cases ashes have all historically been used in places such as the industrial parts of yorkshire and south wales to make domestic cinder paths.