There are many kinds of electronic waste, which can be roughly divided into two categories: one is waste electronic products with relatively simple materials and less harm to the environment.
Such as refrigerators, washing machines, air conditioners and other household appliances, as well as medical and scientific research appliances. The disassembly and handling of this product is relatively simple; The other is waste electronic products, which are made of complex materials and harmful to the environment, such as lead in computer and TV picture tubes, arsenic and mercury in computer components. A variety of persistent and bioaccumulative toxic substances such as arsenic, cadmium and lead in mobile phone raw materials.
Through manual disassembly and mechanical disassembly and sorting, electronic waste is comprehensively treated, which not only protects the natural environment, but also recycles some resources, thus achieving the purpose of reducing the manufacturing cost of components.
[Edit this paragraph] Classification of electronic waste
In fact, electronic appliances include electrical appliances and electronic products, among which household appliances, as the main source of electronic waste, are the unity of the above two parts. At present, there are hundreds and tens of thousands of styles and specifications of household appliances in the world, but their classification has not been unified in the world.
For example, in the United States, household appliances are basically classified according to complexity and size; Germany and France are also classified by size; Japan is classified by using bundles. China is basically classified according to use, generally divided into the following 14 categories.
(1) refrigerators, freezers, cold drinks machines, ice makers, ice cream machines and other refrigeration appliances.
(2) Air conditioning appliances such as air conditioners, electric fans, dehumidifiers, humidifiers, and constant temperature and humidity machines.
(3) Heating appliances, such as space heaters, plate electric heaters, far infrared electric heaters, electric blankets, foot warmers, etc.
(4) Kitchen utensils such as electric cooker, electric frying pan, electric frying pan, electric chafing dish, electric steamer, electric cooker, electric oven, sandwich oven, toaster, household magnetic water purifier, oil smoke filter, can opener, electric kettle, electric coffee pot, electric cooker, microwave oven, induction cooker and electric cutting machine.
(5) Washing machines, dryers, vacuum cleaners, floor polishers, waxing polishers, window cleaners, showers and other cleaning appliances.
(6) Beauty appliances, such as hair dryer, electric clipper, electric shaver, multifunctional hair trimmer, hair dryer, shaver, etc.
(seven) ordinary electric irons, temperature regulating electric irons, spray electric irons, jet electric irons, ironing machines, ironing machines and other ironing appliances.
(8) electroacoustic appliances, such as radios, tape recorders, record players, loudspeakers, walkie-talkies, digital records, record players, speakers and stereo combination devices.
(9) Television sets, video recorders, video cameras, CDs, VCDs, DVDs and other video appliances.
(10) Electronic toys, electric toys, electronic game machines, electronic musical instruments, fishing devices, musical doorbells and other entertainment appliances.
(1 1) Air negative ion generator, alkali ion decomposer, massager, hypnotist, pulse therapeutic instrument, magnetic therapy instrument, far infrared health care instrument, electric toothbrush, oral cleaner, hearing aid, electric moxibustion instrument, hot compress instrument and other health care appliances.
(12) Lighting appliances such as chandeliers, ceiling lamps, wall lamps, floor lamps, table lamps and spotlights.
(13) timers, program controllers, electronic sewing machines, electric bicycles, electronic watches, electronic clocks, electronic door locks, calculators, translators, multimeters, watt-hour meters, rubber appliances and other electrical appliances.
(14) home computers, various mobile phones, pagers, telephones and other computers and communication appliances.
[Edit this paragraph] Hazards and profit highlights of e-waste
With the advent of the information age, the electronic industry has developed rapidly. With the rapid development of electronic industry, electronic waste pollution is inevitably in front of us. Electronic waste, commonly known as "electronic waste", mainly includes all kinds of discarded computers, communication equipment, televisions, refrigerators, washing machines and other electronic and electrical products.
The electronic information technology industry has become one of the fastest growing industries in China, and the resulting electronic waste is also growing rapidly. The next 10 ~ 20 years will be the new peak of e-waste growth. The disposal and recycling of waste computer motherboards (PBC) and circuit boards (PWC) has become an urgent research topic.
Electronic and electrical products are one of the fastest developing products in the 20th century. According to statistics, the number of TV sets in China has reached 350 million, and the number of refrigerators and washing machines has reached 654.38+0.3 billion and 654.38+0.7 billion respectively. Moreover, with the development and innovation of science and technology, the update speed of electronic products is faster and faster, and the service life of electronic products will be shortened accordingly, which makes the amount of electronic waste increase linearly.
According to relevant data, at least 5 million TV sets, 4 million refrigerators and 5 million washing machines are scrapped every year in China, and 5 million computers and tens of millions of mobile phones enter the elimination period every year. In 2002 alone, China eliminated more than 4 million televisions, 5 million washing machines, 5 million refrigerators, 6 million computers and 30 million mobile phones.
There are 654.38 billion old computers in the United States, and it is estimated that 654.38 billion computers will be eliminated in the next decade. A survey on the market sales of electronic products in western Europe shows that in 2002, the total consumption of various electronic products was about 7 million tons, and the total amount of electronic waste was about 4 million tons, accounting for 2% ~ 3% of the whole European waste logistics. Newsweek also reported that at present, the discarded computer floppy disks all over the world can be added together to form a 100-storey "skyscraper" every 20 minutes.
At present, e-waste increases by 16% ~ 28% every five years, which is three times faster than the total amount of waste. Electronic waste is becoming a new source of hazardous waste pollution.
E-waste is the owner of poison. For example, 1 15 inch CRT computer monitors contain harmful substances such as cadmium, mercury, hexavalent chromium, PVC plastics and brominated flame retardants, computer batteries and switches contain chromium compounds and mercury, and computer components also contain various harmful substances such as arsenic and mercury. Electronic products such as televisions, refrigerators and mobile phones also contain heavy metals such as lead, chromium and mercury. Laser printers and copiers contain toner, etc. If discarded electronic products are discarded as general garbage in the wilderness or landfill, heavy metals such as lead will permeate and pollute the soil and water quality, circulate through the food chain of plants, animals and people, and eventually lead to poisoning incidents; If burned, it will release a lot of harmful gases such as dioxins, which will threaten human health. "Guiyu Phenomenon" is a living example.
The physical method of crushing-sorting-sorting municipal solid waste has the characteristics of less investment and less environmental pollution, which is the development trend of electronic waste treatment at present.
In fact, e-waste contains many recyclable materials such as nonferrous metals, ferrous metals and glass. Strictly speaking. These electronic wastes should not be called electronic wastes, but electronic second-hand goods. The results show that 286lb of copper, 1 1b of gold and 44 1b of tin can be separated from the electronic boards randomly collected by 1t, and the value of llb gold alone is 6000 USD (1lb=0.45359kg). It can be said that "electronic waste" contains huge business opportunities. If the precious metals such as gold, silver, copper, tin, chromium, platinum and palladium contained in "electronic waste" are dismantled, it will be an immeasurable wealth. . For example, CPU, radiator, hard disk drive and other components in waste computers are rich in precious metals such as copper, silver, gold and aluminum; Computer shell, power cord, keyboard and mouse are also rich in copper and plastic; The shells of air conditioners, refrigerators and refrigeration systems contain relatively simple iron, aluminum, copper and plastic. Other heating appliances, cleaning appliances, kitchen appliances, cosmetic appliances and ironing appliances are also rich in iron and plastic. The composition of scrapped mobile phones was analyzed by Yokohama Metal Company of Japan, and it was found that the average mobile phone body contained copper 14g, silver 0. 19g, gold 0.03g and palladium 0.01g.. In addition, metallic lithium can be recycled from the lithium battery of mobile phones. The company has obtained considerable economic benefits by recovering a variety of precious metals from scrapped mobile phones.
The grade of metals, especially precious metals, contained in e-waste is dozens or even hundreds of times that of natural mineral deposits, and the recovery cost is generally lower than that of mining natural mineral deposits.
For example, 1t old mobile phone waste batteries can extract 100g of gold, while ordinary gold-bearing ores can only extract 6g per ton, and most of them are only tens of grams. It can be said that the old mobile phone is a kind of high-grade gold mine. In printed circuit boards, the most common metal is copper, in addition to gold, aluminum, nickel, lead, silicon and other metals, including many rare metals. Statistics show that the gold content of each ton of waste circuit board reaches about1000g. With the improvement of technology, 300g gold can be extracted from each ton of waste circuit board, and the market price is about 30,000 yuan. The United States Environmental Protection Agency has confirmed that replacing new steel products obtained through mining, transportation and smelting with scrap steel recovered from waste household appliances can reduce 97% of mine waste, 86% of air pollution and 76% of water pollution. Water consumption is reduced by 40%, raw materials are saved by 90%, and energy is saved by 74%. The performance of scrap steel is basically the same as that of Xingang.