Method for extracting valuable metals from electronic waste

An electronic waste and valuable metal technology, applied in the field of environmental engineering, can solve the problems of strong corrosiveness, strong oxidation, and long immersion time.

Inactive Publication Date: 2009-11-11
CENT SOUTH UNIV +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Aqua regia has strong oxidizing and corrosive properties, and nitrogen oxides are formed during the gold-dissolving process, which is easy to cause secondary pollution; and cyanide is highly toxic, and the cyanide method takes a long time to leaching gold, and releases more when nitric acid dissolves metals nitrogen oxides that pollute the environment

Method used

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  • Method for extracting valuable metals from electronic waste

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0053] A waste circuit board is broken to 0.1mm~1.0mm, the main metal components are Cu26.8%, Ni0.47%, Zn1.5%, Sn1.0%, Fe5.3%, Al4.7%, Ag3300g / t , Au80g / t, non-metal components about 51.4%.

[0054] Using NH 4 Cl-NH 3 -H 2 O system leaching, leaching agent composition: [NH 4 + ]=4.5mol / L, [NH 3 ]=2.5mol / L, measure 2L of leaching agent, weigh 500g of the above-mentioned crushed material, leaching time for 2 hours, leaching temperature 50°C, slowly add 30% H 2 o 2 85ml into the leaching system, after 120min the reaction was terminated and left to stand for 30min. Afterwards, the organic components floating on top of the solution were separated by scraping. Dry to obtain polymer raw materials that can be used for further utilization. The remaining leaching solution is filtered and separated, and the leaching residue is further used as a raw material for extracting Sn, Fe, Al and other metals. Add about 5 g of sponge copper powder into the leach solution, stir for 30 mi...

Embodiment 2

[0056] A waste printing plate was broken to 0.05mm~1.0mm, the main metal components were Cu32.1%, Ni0.12%, Zn2.1%, Sn1.3%, Pb0.92%, Fe6.9%, Al6.7 %, Ag2800g / t, Au110g / t, Pd45g / t, non-metal components about 47.2%.

[0057] Using NH 3 -(NH 4 ) 2 SO 4 -H 2 O system leaching, leaching agent composition: [NH 4 + ]=6.0mol / L, [NH 3 ]=4.0mol / L, measure 2L of leaching agent, weigh 500g of the above-mentioned crushed material, leaching time for 3 hours, leaching temperature 40°C, slowly add 75gNaClO 3Into the leaching system, finish the reaction after 120min and let stand for 30min. Afterwards, the organic components floating on top of the solution are separated by the overturning method. Dry to obtain polymer raw materials that can be used for further utilization. The remaining leaching solution is filtered and separated, and the leaching residue is further used as a raw material for extracting Sn, Fe, Al, Pb and other metals. Add about 5 g of sponge copper powder into the l...

Embodiment 3

[0058] Example 3 A certain electronic waste is crushed to 0.04mm~1.0mm, the main metal components are Cu20%, Fe8%, Sn4%, Ni2%, Al2%, Pb2%, Zn1%, Sb0.4%, Ag1000g / t, Au500g / t, Pd50g / g, organic component about 30%.

[0059] Using NH 3 -(NH 4 ) 2 SO 4 -NH 4 Cl-H 2 O system leaching, leaching agent composition: [NH 4 + ]=4.0mol / L, [NH 3 ]=2.0mol / L, measure 10L of leaching agent, weigh 2kg of the above-mentioned crushed material, leaching time for 3 hours, leaching temperature 45°C, slowly add 550g of bleaching powder into the leaching system, finish the reaction after 180min and let stand for 50min. Afterwards, the organic components floating on the upper layer of the solution are separated by an overturning method, the overturned organic components are filtered and dried, and the filtrate is incorporated into the leaching solution. The filter residue is dried to obtain polymer raw materials that can be used for further utilization. The leaching solution is filtered and s...

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Abstract

The invention discloses a method for extracting valuable metals from electronic waste. The method comprises the following concrete steps: smashing; oxidant ammoniac leaching; separating organic components; purifying leaching solution and electrodepositing to obtain the final products of organic granules, gold/silver/palladium powder and cathode copper, more concretely, the method comprises the following steps: carrying out the selective leaching on the smashed electronic waste by an oxidant ammoniac system; separating the organic granules on the basis of the characteristic that the organic components in the smashed electronic waste float on the surface layer of the leaching solution, for the density of the organic components is lower, whereas the valuable metals, such as Au, Ag, Pd, Cu, Ni, Cd, Zn and Pb, enter the solution; then, extracting the valuable metals of Au, Ag and Pd from the leaching solution by replacement; and finally obtaining the electrodeposit copper by the electro-deposition method, and extracting the metals of Ni, Pb, Zn and Cd from the electrolyte by the open-circuit method after the enrichment of the electrolyte. The invention has the outstanding advantages of high material adaptability, high metal recovery rate and low environmental pollution, and achieves the balance between the environmental benefit and the economic benefit.

Description

technical field [0001] The invention belongs to the field of environmental engineering, and relates to a method for extracting valuable metals from electronic waste, so as to realize harmless and resourceful utilization of electronic waste. Background technique [0002] Electronic waste, commonly known as electronic waste, includes all kinds of waste computers, communication equipment, household appliances, and obsolete precision electronic instruments and meters. E-waste usually contains a large amount of toxic and harmful components. If there is no special agency to collect and process it with technologies and equipment that meet environmental protection requirements, it will pose serious harm to the environment and human health. At the same time, in addition to a large number of recyclable non-metals such as plastics, resins and other organic components, electronic waste also contains precious or valuable metals such as gold, silver, copper and nickel. E-waste therefore ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C25C1/12C22B7/00C22B3/14C22B3/46
CPCY02P10/20
Inventor 杨建广唐朝波何静杨声海唐谟堂
Owner CENT SOUTH UNIV
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