recycling by product recycling by product products made from a variety of materials can be recycled using a number of processes. building and construction waste aggregates and concrete concrete blocks in germany. concrete aggregate collected from demolition sites is put through a crushing machine, often along with asphalt, bricks, dirt, and rocks. smaller pieces of concrete are used as gravel for new construction projects. crushed recycled concrete can also be used as the dry aggregate for new concrete if it is free of contaminants. builder's rubble (like broken down bricks) is also used for railway ballast and gravel paths. this reduces the need for other rocks to be dug up, which in turn saves trees and habitats. asphalt and tarmac asphalt including asphalt shingle can be melted down and in part recycled. tarmac can also recycled and there is now an active market for recycling tarmac in the developed world. this includes tarmac scalpings produced when roads are scarified before a new surface is laid. gypsum, plaster and plasterboard products because up to 17% of gypsum products are wasted during the manufacturing and installation processes. wallboard (australia and others), plasterboard, gyp (new zealand), drywall (usa) or plasterboard (uk and ireland) is frequently not re-used and disposal can become a problem. some landfill sites have banned dumping of gypsum because of the tendency to produce large volumes of hydrogen sulfide gas. some manufacturers take back waste wallboards from construction sites and recycle it into new wallboard. gypsum waste from new construction, demolition and refurbishment activities can be turned into recycled gypsum through mechanical processes, and the recycled gypsum obtained can replace virgin gypsum in the gypsum industry. some of the reasons for recycling this waste are: gypsum is one of the few construction materials for which closed loop recycling is possible. closed loop gypsum recycling saves virgin gypsum resources. according to the european directive 2008/98/ec on waste, recycling should be preferred to recovery and landfill disposal. this directive also establishes that the preparing for re-use, recycling and other material recovery of non-hazardous construction and demolition (c&d) waste (excluding soil and stones other that those containing dangerous substances) have to be increased to a minimum of 70% by weight by 2020. the disposal of gypsum-based materials can become a problem if they are accepted at normal cells in non-hazardous landfills, as the sulphate content of gypsum mixed with organic waste can break down under certain conditions into hydrogen sulfide gas. bricks intact bricks recovered from demolition can be cleaned and re-used. batteries some batteries contain toxic heavy metals, making recycling or proper disposal a high priority. these batteries are dutch; the netherlands openly encourages battery recycling. the large variation in size and type of batteries makes their recycling extremely difficult: they must first be sorted into similar kinds and each kind requires an individual recycling process. additionally, older batteries contain mercury and cadmium, harmful materials that must be handled with care. because of their potential environmental damage, proper disposal of used batteries is required by law in many areas. unfortunately, this mandate has been difficult to enforce. lead-acid batteries, like those used in automobiles, are relatively easy to recycle and many regions have legislation requiring vendors to accept used products. in the united states, the recycling rate is 90%, with new batteries containing up to 80% recycled material. japan, kuwait, the usa, canada, france, the netherlands, germany, austria, belgium, sweden, the uk and ireland all actively encourage battery recycling programs. in 2006, the eu passed the battery directive of which one of the aims is a higher rate of battery recycling. the eu directive said at least 25% of all the eu's used batteries must be collected by 2012, and rising to no less than 45% by 2016, of which, that at least 50% of them must be recycled. biodegradable waste main article: composting kitchen, garden, and other green waste can be recycled into useful material by composting into leaf mold and regular compost. this process allows natural aerobic bacteria to break down the waste into fertile topsoil. much composting is done on a household scale, but municipal green-waste collection programs also exist. these programs can supplement their funding by selling the topsoil produced. electronic waste electronics disassembly and reclamation an abandoned computer monitor in denton, texas. electronic recycling is recycling or reuse of computers or other electronics. it includes both finding another use for materials (such as donation to charity), and having systems dismantled in a manner that allows for the safe extraction of the constituent materials for reuse in other products. the direct disposal of electrical equipment—such as old computers and mobile phones is banned in many areas, such as the uk, parts of the usa, japan, ireland, germany and the netherlands, due to the toxic contents of certain components. the recycling process works by mechanically separating the metals, plastics, and circuit boards contained in the appliance. when this is done on a large scale at an electronic waste recycling plant, component recovery can be achieved cost-effectively. with high lead content in crts, and the rapid diffusion of new flat-panel display technologies, some of which (lcds) use lamps containing mercury, there is growing concern about electronic waste from discarded televisions. related occupational health concerns exist, as well, for disassemblers and scrap dealers removing copper wiring and other materials from crts. further environmental concerns related to television design and use relate to the devices' increasing electrical energy requirements. computers that are termed trashware in north america or totally reconditioned hardware in the uk and ireland are computer equipment that has assembled from old hardware, using cleaned and checked parts from different computers, for use by disadvantaged people to bridge the digital divide. trashware is different from retrocomputing, which has only cultural and recreational purposes. ink jet printer cartridges resetting an epson ink cartridge using a resetter tool. because printer cartridges from the original manufacturer are often expensive, demand exists for cheaper third party options. these include ink sold in bulk, cartridge refill kits, machines in stores that automatically refill cartridges, re-manufactured cartridges, and cartridges made by a corporate entity other than the original manufacturer. consumers can refill ink cartridges themselves with a kit, or they can take the cartridge to a refiller or re-manufacturer where ink is pumped back into the cartridge. pc world reports that refilled cartridges have higher failure rates, print fewer pages than new cartridges, and demonstrate more on-page problems like streaking, curling, and colour bleed. metals a wide range of metals in commercial and domestic use have well developed recycling markets in most developed countries. domestic recycling is commonly available for iron and steel, aluminium and in particular beverage and food cans. in addition, building metals such as copper, zinc and lead are readily recyclable through specialised companies. in the uk, these are usually either specialised scrap dealers or car breakers. other metals present in smaller quantities in the domestic waste stream such as tin and chromium are also extracted from metal put into the recycling system but are rarely recovered from the general waste stream. paint this section is an excerpt from paint recycling. paint is a recyclable item. latex paint is collected at collection facilities in many countries and shipped to paint-recycling facilities. paper and newsprint waste paper collected for recycling in ponte a serraglio, near bagni di lucca, italy. paper and newsprint can be recycled by reducing it to pulp and combining it with pulp from newly harvested wood. as the recycling process causes the paper fibres to break down, each time paper is recycled its quality decreases. this means that either a higher percentage of new fibres must be added, or the paper down-cycled into lower quality products. any writing or colouration of the paper must first be removed by deinking, which also removes fillers, clays, and fibre fragments. almost all paper can be recycled today, but some types are harder to recycle than others. papers coated with plastic or aluminium foil, and papers that are waxed, pasted, or gummed are usually not recycled because the process is too expensive. sometimes recyclers ask for the removal of the glossy paper inserts from newspapers because they are a different type of paper. glossy inserts have a heavy clay coating that some paper mills cannot accept. most of the clay is removed from the recycled pulp as sludge, which must be disposed of. if the coated paper is 20% by weight clay, then each ton of glossy paper produces more than 200 kg of sludge and less than 800 kg of fibre. the price of recycled paper has varied greatly over the last 30 or so years. the german price of €100/£49 per tonne was typical for the year 2003 and it steadily rose over the years. by the september 2008 saw the american price of $235 per ton, which had fallen to just $120 per ton, and in the january 2009, the uk's fell six weeks from about £70.00 per ton, to only £10.00 per ton. the slump was probably due to the economic down turn in east asia leading to market for waste paper drying up in china. 2010 averaged at $120.32 over the start of the year, but saw a rapid rise global prices in may 2010, with the june 2010 resting $217.11 per ton in the usa as china's paper market began to reopen! mexico, america, the eu, russia and japan all recycle paper en masse and there are many state run and private schemes running in those countries. in 2004 the paper recycling rate in europe was 54.6% or 45.5 million short tons (41.3 mt). the recycling rate in europe reached 64.5%3 in 2007, which confirms that the industry is on the path to meeting its voluntary target of 66% by 2010. plastic plastic shipping crates in italian recycling plant. this section is an excerpt from plastic recycling. plastic recyclingclockwise from top left: sorting plastic waste at a single-stream recycling centrebaled colour-sorted used bottlesrecovered hdpe ready for recyclinga watering can made from recycled bottles plastic recycling is the processing of plastic waste into other products. recycling can reduce dependence on landfill, conserve resources and protect the environment from plastic pollution and greenhouse gas emissions. recycling rates lag those of other recoverable materials, such as aluminium, glass and paper. through 2015, the world produced some 6.3 billion tonnes of plastic waste, only 9% of which has been recycled, and only ~1% has been recycled more than once. additionally, 12% was incinerated and the remaining 79% sent to landfill or to the environment including the ocean. almost all plastic is not biodegradable and absent recyling, spreads across the environment where it can cause harm. for example, as of 2015 approximately 8 million tons of waste plastic enter the oceans annually, damaging the ecosystem and forming ocean garbage patches.even the highest quality recycling processes lead to substantial plastic waste during the sorting and cleaning process, releasing large amounts of microplastics in waste water, and dust from the process. almost all recycling is mechanical: melting and reforming plastic into other items. this can cause polymer degradation at a molecular level, and requires that waste be sorted by colour and polymer type before processing, which is complicated and expensive. errors can lead to material with inconsistent properties, rendering it unappealing to industry. in feedstock recycling, waste plastic is converted into its starting chemicals, which can then become fresh plastic. this involves higher energy and capital costs. alternatively, plastic can be burned in place of fossil fuels, in energy recovery facilities or biochemically converted into other useful chemicals for industry. in some countries, burning is the dominant form of plastic waste disposal, particularly where landfill diversion policies are in place. plastic recycling is low in the waste hierarchy. it has been advocated since the early 1970s, but due to economic and technical challenges, did not impact plastic waste to any significant extent until the late 1980s. the plastics industry has been criticised for lobbying for expansion of recycling programs, even while research showed that most plastic could not be economically recycled. rubber tires this section is an excerpt from tire recycling. tyre arm chair tires are among the most problematic sources of waste. progress in recycling has resulted in a major reduction in dumping.