![Holice, hromada pneumatik (01)](https://upload.wikimedia.org/wikipedia/commons/2/27/Holice%2C_hromada_pneumatik_%2801%29.jpg)
Tire recycling, or rubber recycling, is the process of
recycling
Recycling is the process of converting waste materials into new materials and objects. The recovery of energy from waste materials is often included in this concept. The recyclability of a material depends on its ability to reacquire the p ...
waste
tires
A tire (American English) or tyre (British English) is a ring-shaped component that surrounds a Rim (wheel), wheel's rim to transfer a vehicle's load from the axle through the wheel to the ground and to provide Traction (engineering), t ...
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
Rubber pollution, similar to plastic pollution, occurs in various environments, and originates from a variety of sources, ranging from the food industry processing chain to tire wear. Synthetic and natural rubber dust and fragments now occur in fo ...
. 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
The pyrolysis (or devolatilization) process is the thermal decomposition of materials at elevated temperatures, often in an inert atmosphere. It involves a change of chemical composition. The word is coined from the Greek-derived elements ''py ...
and
devulcanization could facilitate recycling. Aside from use as fuel, the main end use for tires remains ground
crumb rubber
Crumb rubber is recycled rubber produced from automotive and truck scrap tires. During the recycling process, steel and tire cord (fluff) are removed, leaving tire rubber with a granular consistency. Continued processing with a granulator or cr ...
.
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
Tire-derived fuel (TDF) is composed of shredded scrap tires. Tires may be mixed with coal or other fuels, such as wood or chemical wastes, to be burned in concrete kilns, power plants, or paper mills. An EPA test program concluded that, with t ...
, 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 Sulaibiya is a small town in Al Jahra Governorate, Kuwait. It holds the record of for the highest temperature in Asia and third highest in the world.
Sulaibiya has two Industrial Areas containing several construction materials industries and a Res ...
tire graveyard in Kuwait has had repeat highly
toxic fires.
Tire life cycle
The tire life cycle can be recognized through the following steps:
#Product developments and innovations such as improved compounds and camber tire shaping increase tire life, increments of replacement, consumer safety, and reduce tire waste.
#Proper manufacturing and quality of delivery reduces waste at production.
# Direct distribution through retailers, reduces inventory time and ensures that the life span and the safety of the products are explained to customers.
# Consumers' use and maintenance choices like
tire rotation and alignment affect tire wear and safety of operation.
# Manufacturers and retailers set policies on return,
retread
Retread, also known as "recap", or a "remold" is a re-manufacturing process for tires that replace the tread on worn tires. Retreading is applied to casings of spent tires that have been inspected and repaired. It preserves about 90% of the mat ...
, and replacement to reduce the waste generated from tires and assume responsibility for taking the 'tire to its grave' or to its reincarnation.
#Recycling tires by developing strategies that combust or process waste into new products, creates viable businesses, and fulfilling public policies.
Landfill disposal
Tires are not desired at
landfills
A landfill site, also known as a tip, dump, rubbish dump, garbage dump, or dumping ground, is a site for the disposal of waste materials. Landfill is the oldest and most common form of waste disposal, although the systematic burial of the waste ...
, due to their large volumes and 75% void space.
[Liu,H., Mead, J., Stacer, R. Chelsea Center For Recycling And Economic Development. (1998). Environmental Impacts of Recycling Rubber in Light Fill Applications: Summary & Evaluation of Existing Literature University of Massachusetts] Tires can trap
methane
Methane ( , ) is a chemical compound with the chemical formula (one carbon atom bonded to four hydrogen atoms). It is a group-14 hydride, the simplest alkane, and the main constituent of natural gas. The relative abundance of methane on Eart ...
gases, causing them to become buoyant, or
bubble
Bubble, Bubbles or The Bubble may refer to:
Common uses
* Bubble (physics), a globule of one substance in another, usually gas in a liquid
** Soap bubble
* Economic bubble, a situation where asset prices are much higher than underlying fundame ...
to the surface. This 'bubbling' effect can damage
landfill liner
A landfill liner, or composite liner, is intended to be a low permeable barrier, which is laid down under engineered landfill sites. Until it deteriorates, the liner retards migration of leachate, and its toxic constituents, into underlying aquif ...
s that have been installed to help keep landfill contaminants from polluting local surface and
ground water
Groundwater is the water present beneath Earth's surface in rock and soil pore spaces and in the fractures of rock formations. About 30 percent of all readily available freshwater in the world is groundwater. A unit of rock or an unconsolidated ...
.
The EU
Landfill Directive
The Landfill Directive, more formally Council Directive 1999/31/EC of 26 April 1999 is a European Union directive that regulates waste management of landfills in the European Union. It was implemented by its Member States by 16 July 2001.
The D ...
prohibits the disposal of used tyres in landfill.
Shredded tires are now being used in landfills, replacing other construction materials, for a lightweight back-fill in gas venting systems,
leachate
A leachate is any liquid that, in the course of passing through matter, extracts soluble or suspended solids, or any other component of the material through which it has passed.
Leachate is a widely used term in the environmental sciences wher ...
collection systems, and operational liners. Shredded tire material may also be used to cap, close, or daily cover landfill sites.
Scrap tires as a back-fill and cover material are also more cost-effective, since tires can be shredded on-site instead of hauling in other fill materials.
Stockpiles and legal dumping
![Tires and shredded](https://upload.wikimedia.org/wikipedia/commons/0/01/Tires_and_shredded.JPG)
Tire stockpiles create a great health and safety risk.
Tire fire
Tire fires are events that involve the combustion of large quantities of tires, usually waste tires, typically in locations where they are stored, dumped, or processed. They exist in two forms: as fast-burning events, leading to almost immediat ...
s can easily occur, burning for long periods, up to a month and also creating substantial
pollution in the air and
ground. Recycling helps to reduce the number of tires in storage. An additional health risk, tire piles provide harborage for vermin and a breeding ground for
mosquitoe
Mosquitoes (or mosquitos) are members of a group of almost 3,600 species of small flies within the family Culicidae (from the Latin ''culex'' meaning "gnat"). The word "mosquito" (formed by ''mosca'' and diminutive ''-ito'') is Spanish for "lit ...
s that may carry diseases.
Illegal dumping
Illegal dumping, also called fly dumping or fly tipping ( UK), is the dumping of waste illegally instead of using an authorized method such as curbside collection or using an authorized rubbish dump. It is the illegal deposit of any waste onto l ...
of scrap tires pollutes ravines, woods, deserts, and empty lots; which has led many states to pass scrap tire regulations requiring proper management. Tire amnesty day events, in which community members can deposit a limited number of waste tires free of charge, can be funded by state scrap tire programs, helping decrease illegal dumping and improper storage of scrap tires.
Tire storage and recycling are sometimes linked with illegal activities and lack of
environmental awareness
Environmentalism or environmental rights is a broad philosophy, ideology, and social movement regarding concerns for environmental protection and improvement of the health of the environment, particularly as the measure for this health seeks ...
.
Uses
Although tires are usually burnt, not recycled, efforts are continuing to find value. Tires can be reclaimed into, among other things, the hot melt
asphalt
Asphalt, also known as bitumen (, ), is a sticky, black, highly viscous liquid or semi-solid form of petroleum. It may be found in natural deposits or may be a refined product, and is classed as a pitch. Before the 20th century, the term a ...
, typically as
crumb rubber
Crumb rubber is recycled rubber produced from automotive and truck scrap tires. During the recycling process, steel and tire cord (fluff) are removed, leaving tire rubber with a granular consistency. Continued processing with a granulator or cr ...
modifier—recycled asphalt pavement (CRM—RAP), and as an aggregate in
Portland cement
Portland cement is the most common type of cement in general use around the world as a basic ingredient of concrete, mortar, stucco, and non-specialty grout. It was developed from other types of hydraulic lime in England in the early 19th c ...
concrete
Concrete is a composite material composed of fine and coarse aggregate bonded together with a fluid cement (cement paste) that hardens (cures) over time. Concrete is the second-most-used substance in the world after water, and is the most wi ...
Efforts have been made to use recycled tires as raw material for new tires, but such tires may integrate recycled materials no more than 5% by weight, and tires that contain recycled material are inferior to new tires,
[ suffering from reduced tread life and lower traction. Tires have also been cut up and used in garden beds as bark mulch to hold in the water and to prevent weeds from growing. Some "green" buildings, both private and public, have been made from old tires.
]Pyrolysis
The pyrolysis (or devolatilization) process is the thermal decomposition of materials at elevated temperatures, often in an inert atmosphere. It involves a change of chemical composition. The word is coined from the Greek-derived elements ''py ...
can be used to reprocess the tires into fuel gas
Fuel gas is any one of a number of fuels that under ordinary conditions are gaseous. Most fuel gases are composed of hydrocarbons (such as methane or propane), hydrogen, carbon monoxide, or mixtures thereof. Such gases are sources energy that c ...
, oils, solid residue (char), and low-grade carbon black
Carbon black (subtypes are acetylene black, channel black, furnace black, lamp black and thermal black) is a material produced by the incomplete combustion of coal and coal tar, vegetable matter, or petroleum products, including fuel oil, fluid ...
, which cannot be used in tire manufacture. A pyrolysis method which produces activated carbon
Activated carbon, also called activated charcoal, is a form of carbon commonly used to filter contaminants from water and air, among many other uses. It is processed (activated) to have small, low-volume pores that increase the surface area avail ...
and high-grade carbon black has been suggested.
Cement manufacturing
Old tires can be used as an alternative fuel in the manufacturing of Portland cement
Portland cement is the most common type of cement in general use around the world as a basic ingredient of concrete, mortar, stucco, and non-specialty grout. It was developed from other types of hydraulic lime in England in the early 19th c ...
, a key ingredient in concrete. Whole tires are commonly introduced into cement kiln
Cement kilns are used for the pyroprocessing stage of manufacture of portland and other types of hydraulic cement, in which calcium carbonate reacts with silica-bearing minerals to form a mixture of calcium silicates. Over a billion tonnes of ...
s, by rolling them into the upper end of a preheater kiln, or by dropping them through a slot midway along a long wet kiln. In either case, the high gas temperatures (1000–1200 °C) cause almost instantaneous, complete and smokeless combustion of the tire. Alternatively, tires are chopped into 5–10 mm chips, in which form they can be injected into a precalciner combustion chamber. Some iron input is required in manufacturing cement, so the iron content of steel-belted tires is beneficial to the process.
Tire-derived products
Tires can be reused in many ways, although most used tires are burnt for their fuel
A fuel is any material that can be made to react with other substances so that it releases energy as thermal energy or to be used for work. The concept was originally applied solely to those materials capable of releasing chemical energy but ...
value. In a 2003 report cited by the U.S. EPA
The Environmental Protection Agency (EPA) is an independent executive agency of the United States federal government tasked with environmental protection matters. President Richard Nixon proposed the establishment of EPA on July 9, 1970; it be ...
, it is stated that markets ("both recycling and beneficial use") existed for 80.4% of scrap tires, about 233 million tires per year. Assuming per tire, the 2003 report predicts a total weight of about from tires.
New products derived from waste tires generate more economic activity than combustion
Combustion, or burning, is a high-temperature exothermic redox chemical reaction between a fuel (the reductant) and an oxidant, usually atmospheric oxygen, that produces oxidized, often gaseous products, in a mixture termed as smoke. Combusti ...
or other low multiplier production, while reducing waste stream without generating excessive pollution and emissions from recycling operations.
*Construction materials. Entire homes can be built with whole tires by filling them with earth and covering them with concrete, a common material in earthship
An Earthship is a style of architecture developed in the late 20th century to early 21st century by architect Mike Reynolds (architect), Michael Reynolds. Earthships are designed to behave as Passive solar building design, passive solar earth s ...
s. They are used in civil engineering applications such as sub-grade fill and embankments, back-fill for walls and bridge abutments, sub-grade insulation for roads, landfill
A landfill site, also known as a tip, dump, rubbish dump, garbage dump, or dumping ground, is a site for the disposal of waste materials. Landfill is the oldest and most common form of waste disposal, although the systematic burial of the waste ...
projects, and septic system drain fields. Tires are also bound together and used as different types of barriers such as: collision reduction, erosion control
Erosion control is the practice of preventing or controlling wind or water erosion in agriculture, land development, coastal areas, river banks and construction. Effective erosion controls handle surface runoff and are important techniques in ...
, rainwater runoff, blasting mats, wave action that protects piers and marshes, and sound barriers between roadways and residences.
*Artificial reef
An artificial reef is a human-created underwater structure, typically built to promote marine life in areas with a generally featureless bottom, to control erosion, block ship passage, block the use of trawling nets, or improve surfing.
Many re ...
s are built using tires that are bonded together in groups, there is some controversy on how effective tires are as an artificial reef system, an example is The Osborne Reef
Osborne Reef is an artificial reef off the coast of Fort Lauderdale, Florida. Originally constructed of dolos, concrete jacks, it was the subject of an ambitious expansion project utilizing old and discarded tires. The expansion ultimately fai ...
Project which has become an environmental nightmare that will cost millions of dollars to rectify.
*The process of stamping and cutting tires is used in some apparel products, such as sandals and as a road sub-base, by connecting together the cut sidewalls to form a flexible net.
*The markets predicted by the 2003 report were: tire derived fuel (TDF) using 130 million tires, civil engineering projects using 56 million tires, ground rubber turned into molded rubber products using 18 million tires, ground rubber turned into rubber-modified asphalt using 12 million tires, Exported items using 9 million tires, cut, stamped and punched products using 6.5 million tires, and agricultural and miscellaneous uses 3 million tires.
*Shredded tires, known as Tire Derived Aggregate (TDA), have many civil engineering applications. TDA can be used as a back-fill for retaining walls, fill for landfill gas
Landfill gas is a mix of different gases created by the action of microorganisms within a landfill as they decompose organic waste, including for example, food waste and paper waste. Landfill gas is approximately forty to sixty percent methane, ...
trench collection wells, back-fill for roadway landslide repair projects as well as a vibration damping material for railway lines.
*Ground and crumb rubber, also known as size-reduced rubber, can be used in both paving type projects and in mold-able products. These types of paving are: Rubber Modified Asphalt (RMA), Rubber Modified Concrete, and as a substitution for an aggregate. Examples of rubber-molded products are carpet padding or underlay
Underlay may refer to flooring or roofing materials, bed padding, or a musical notation.
Flooring
Underlay or underlayment"Underlayment." ''The Oxford English Dictionary''. 2nd ed. 1989. generally refers to a thin layer of cushioning made of mate ...
, flooring materials, dock bumpers, patio decks, railroad crossing blocks, livestock mats, sidewalks, rubber tiles and bricks, movable speed bumps, and curbing/edging. The rubber can be molded with plastic for products like pallets and railroad tie
A railroad tie, crosstie (American English), railway tie (Canadian English) or railway sleeper (Australian and British English) is a rectangular support for the rails in railroad tracks. Generally laid perpendicular to the rails, ties transfer ...
s. Athletic and recreational areas can also be paved with the shock absorbing rubber-molded material. Rubber from tires is sometimes ground into medium-sized chunks and used as rubber mulch Rubber mulch is a type of mulch used in gardens and landscaping that is made from recycled rubber, most often crumb rubber sourced from waste tires.
Composition
Rubber mulch generally consists of either waste tire bits or nuggets of synthetic ru ...
. Rubber crumb can also be used as an infill, alone or blended with coarse sand, as in infill for grass-like synthetic turf products such as Field-turf.
*Steel mill
A steel mill or steelworks is an industrial plant for the manufacture of steel. It may be an integrated steel works carrying out all steps of steelmaking from smelting iron ore to rolled product, but may also be a plant where steel semi-finish ...
s can use tires as a carbon source, replacing coal or coke in steel manufacturing.
*Tires are also often recycled for use on basketball courts and new shoe products.
Tire pyrolysis
The pyrolysis
The pyrolysis (or devolatilization) process is the thermal decomposition of materials at elevated temperatures, often in an inert atmosphere. It involves a change of chemical composition. The word is coined from the Greek-derived elements ''py ...
method for recycling used tires is a technique which heats whole or shredded tires in a reactor vessel containing an oxygen-free atmosphere. In the reactor, the rubber is softened after which the rubber polymers break down into smaller molecules.
These smaller molecules eventually vaporize
Vaporization (or vaporisation) of an element or compound is a phase transition from the liquid phase to vapor. There are two types of vaporization: evaporation and boiling. Evaporation is a surface phenomenon, whereas boiling is a bulk phenomeno ...
and exit from the reactor. These vapors can be burned directly to produce power or condensed into an oily type liquid, generally used as a fuel
A fuel is any material that can be made to react with other substances so that it releases energy as thermal energy or to be used for work. The concept was originally applied solely to those materials capable of releasing chemical energy but ...
. Some molecules are too small to condense. They remain as a gas which can be burned as fuel. The minerals that were part of the tire, about 40% by weight, are removed as solid ash
Ash or ashes are the solid remnants of fires. Specifically, ''ash'' refers to all non-aqueous, non- gaseous residues that remain after something burns. In analytical chemistry, to analyse the mineral and metal content of chemical samples, ash ...
es. When performed properly, the ''tire pyrolysis'' process is a clean operation and produces little emissions or waste; however, concerns about air pollution
Air pollution is the contamination of air due to the presence of substances in the atmosphere that are harmful to the health of humans and other living beings, or cause damage to the climate or to materials. There are many different types ...
due to incomplete combustion
Combustion, or burning, is a high-temperature exothermic redox chemical reaction between a fuel (the reductant) and an oxidant, usually atmospheric oxygen, that produces oxidized, often gaseous products, in a mixture termed as smoke. Combusti ...
as is the case with tire fire
Tire fires are events that involve the combustion of large quantities of tires, usually waste tires, typically in locations where they are stored, dumped, or processed. They exist in two forms: as fast-burning events, leading to almost immediat ...
s has been documented.
The properties of the gas, liquid, and solid output are determined by the type of feed-stock used and the process conditions. For instance whole tires contain fibers and steel. Shredded tires have most of the steel and sometimes most of the fiber removed. Processes can be either batch or continuous. The energy required to drive the decomposition
Decomposition or rot is the process by which dead organic substances are broken down into simpler organic or inorganic matter such as carbon dioxide, water, simple sugars and mineral salts. The process is a part of the nutrient cycle and is e ...
of the rubber include using directly fired fuel (like a gas oven
A gas stove is a stove that is fuelled by combustible gas such as syngas, natural gas, propane, butane, liquefied petroleum gas or other flammable gas. Before the advent of gas, cooking stoves relied on solid fuels such as coal or wood. The ...
), electrical induction (like an electrically heated oven) or by microwaves
Microwave is a form of electromagnetic radiation with wavelengths ranging from about one meter to one millimeter corresponding to frequencies between 300 MHz and 300 GHz respectively. Different sources define different frequency rang ...
(like a microwave oven). Sometimes a catalyst
Catalysis () is the process of increasing the rate of a chemical reaction by adding a substance known as a catalyst (). Catalysts are not consumed in the reaction and remain unchanged after it. If the reaction is rapid and the catalyst recyc ...
is used to accelerate the decomposition. The choice of feed-stock and process can affect the value of the finished products.
The historical issue of tire pyrolysis has been the solid mineral stream, which accounts for about 40% of the output. The steel
Steel is an alloy made up of iron with added carbon to improve its strength and fracture resistance compared to other forms of iron. Many other elements may be present or added. Stainless steels that are corrosion- and oxidation-resistant ty ...
can be removed from the solid stream with magnets for recycling. The remaining solid material, often referred to as "char
Char may refer to:
People
*Char Fontane, American actress
*Char Margolis, American spiritualist
* René Char (1907–1988), French poet
*The Char family of Colombia:
** Fuad Char, Colombian senator
** Alejandro Char Chaljub, mayor of Barranquilla ...
", has had little or no value other than possibly as a low grade carbon fuel. Char is the destroyed remains of the original carbon black
Carbon black (subtypes are acetylene black, channel black, furnace black, lamp black and thermal black) is a material produced by the incomplete combustion of coal and coal tar, vegetable matter, or petroleum products, including fuel oil, fluid ...
used to reinforce and provide abrasion resistance to the tire. The solid stream also includes the minerals used in rubber
Rubber, also called India rubber, latex, Amazonian rubber, ''caucho'', or ''caoutchouc'', as initially produced, consists of polymers of the organic compound isoprene, with minor impurities of other organic compounds. Thailand, Malaysia, and ...
manufacturing. This high volume component of tire pyrolysis is a major impediment, although this theme continues to be a source of innovation.
Cryogenic recycling
Tires can be frozen using cryogens, or super-cold fluids, then broken down and made into a material called "crumb," which can be used in asphalt road beds, agricultural hoses, and truck bed liners.
Repurposing
Aside from recycling old tires, the old tire can be put to a new use.
Old tires are sometimes converted into a swing for play. The innovative use allows for an easy way to find a purpose for an existing old tire not suitable for road use.
Used tires are also employed as exercise equipment for athletic programs such as American football
American football (referred to simply as football in the United States and Canada), also known as gridiron, is a team sport played by two teams of eleven players on a rectangular field with goalposts at each end. The offense, the team with ...
. One classic conditioning drill that hones players' speed and agility is the "Tire Run" where tires are laid out side by side, with each tire on the left a few inches ahead of the tire on the right in a zigzag pattern. Athletes then run through the tire pattern by stepping in the center of each tire. The drill forces athletes to lift their feet above the ground higher than normal to avoid tripping. Other athletic uses include tire flipping (tractor or large truck tires typically used) or for upper cardio conditioning by hitting a tire repetitively with a sledge hammer.
Re-purposed tires can also be harnessed as an affordable alternative building material used in the framework of rammed Earth thermal mass dwellings. This is beneficial across scales of production such as individually sustainable housing.
Rows of stacks of tyres are often used as barriers in motor racing circuits as a method of dissipating kinetic energy over a longer period of time during a crash, comparatively to striking a less malleable material such as a concrete or steel wall.
Many cattle farmers re-purpose old tractor tires as water troughs for their cattle by placing them over natural springs or by piping stream water into them. These tires contain the water and allow it to pool for the cattle without any additional interaction from the farmer. Most farmers also include a drainage pipe near the top or in the center of the tire so excess water can drain off to prevent overflow and erosion around the outside of the tire where the cattle would be.
Environmental concerns
Due to their heavy metal and other pollutant content, tires pose a risk for the leaching
Leaching is the loss or extraction of certain materials from a carrier into a liquid (usually, but not always a solvent). and may refer to:
* Leaching (agriculture), the loss of water-soluble plant nutrients from the soil; or applying a small amou ...
of toxins into the groundwater
Groundwater is the water present beneath Earth's surface in rock and soil pore spaces and in the fractures of rock formations. About 30 percent of all readily available freshwater in the world is groundwater. A unit of rock or an unconsolidate ...
when placed in wet soils. Research has shown that very little leaching occurs when shredded tires are used as light fill material; however, limitations have been put on use of this material; each site should be individually assessed determining if this product is appropriate for given conditions.
For both above and below water table applications, the preponderance of evidence shows that TDA (tire derived aggregate, or shredded tires) will not cause primary drinking water standards to be exceeded for metals. Moreover, TDA is unlikely to increase levels of metals with primary drinking water standards above naturally occurring background levels.
See also
*Artificial turf
Artificial turf is a surface of synthetic fibers made to look like natural grass. It is most often used in arenas for sports that were originally or are normally played on grass. However, it is now being used on residential lawns and commer ...
*Plastic recycling
Plastic recycling is the reprocessing of plastic waste into new products. When performed correctly, this can reduce dependence on landfill, conserve resources and protect the environment from plastic pollution and greenhouse gas emissions.
A ...
*Rubber mulch Rubber mulch is a type of mulch used in gardens and landscaping that is made from recycled rubber, most often crumb rubber sourced from waste tires.
Composition
Rubber mulch generally consists of either waste tire bits or nuggets of synthetic ru ...
*Rubberized asphalt
Rubberized asphalt concrete (RAC), also known as asphalt rubber or just rubberized asphalt, is noise reducing pavement material that consists of regular asphalt concrete mixed with crumb rubber made from recycled tires. Asphalt rubber is the la ...
* Technoflex
*Tire fire
Tire fires are events that involve the combustion of large quantities of tires, usually waste tires, typically in locations where they are stored, dumped, or processed. They exist in two forms: as fast-burning events, leading to almost immediat ...
*Vulcanization
Vulcanization (British: Vulcanisation) is a range of processes for hardening rubbers. The term originally referred exclusively to the treatment of natural rubber with sulfur, which remains the most common practice. It has also grown to include ...
*Waste management
Waste management or waste disposal includes the processes and actions required to manage waste from its inception to its final disposal.
This includes the collection, transport, treatment and disposal of waste, together with monitoring ...
References
External links
*
Giant microwave turns plastic back to oil
New Scientist
''New Scientist'' is a magazine covering all aspects of science and technology. Based in London, it publishes weekly English-language editions in the United Kingdom, the United States and Australia. An editorially separate organisation publishe ...
, 2007-06-26
{{Recycling, state=collapsed
Tires
Vehicle recycling
Recycling by product