A green chemistry hydrometallurgical process for recovering one or more metals from a metal-containing material includes leaching the metal-containing material with formic acid, obtaining a leachate comprising the one or more metals as one or more metal formates, and precipitating at least one of the one or more metal formates. The metal-containing material may be a lithium-ion battery cathode material, resulting in Li formate remaining in solution and precipitation of salts including one or more of Ni, Co, and Mn formates. Steps may include filtration of the leachate, sulphurization of retained metal formate salts to produce metal sulphate salts, purification of filtered leachate by adding lithium carbonate and filtering, dewatering of the purified leachate, and thermal decomposition of resulting lithium salts to produce battery grade lithium carbonate. Carbon dioxide, water, and formic acid may be recovered and reused, without liquid or solid waste produced.

A process for removal of aluminium and iron in the recycling of rechargeable batteries comprising providing a leachate from black mass, adding phosphoric acid (H.sub.3PO.sub.4) to said leachate and adjusting the pH to form iron phosphate (FePO.sub.4) and aluminium phosphate (AlPO.sub.4), precipitating and removing the formed FePO.sub.4 and AlPO.sub.4, and forming a filtrate for further recovery of cathode metals, mainly NMC-metals and lithium.

The invention discloses a cost-effective method for recovering precious metals in circuit board components, and belongs to the area of waste resource recovery. The method mainly solves the problem of selective recovery of precious metals in chlorination leachate, utilizes the basic principle of oxidation-reduction reaction, adopts a mixed solution of sulfuric acid and hydrogen peroxide and a mixed solution of hydrochloric acid, sodium chloride and sodium chlorate, and also adopts ammonia water and formaldehyde to reduce silver. According to the characteristic that the redox potential of gold and palladium ions is higher, the gold and palladium ions in the chlorination leaching solution are selectively reduced into elements by using a reducing agent which is low in price and moderate in reducibility, then the elements are separated through filtration to realize resource recycling. The whole recycling process is greatly shortened, combined with the lower price of reducing agents, leading to the low cost of process. The method is commercially viable and is beneficial to industrialization. Meanwhile, a large amount of tail liquid is prevented from being generated to pollute the environment in the recycling process.

A method of leaching a precious metal contained in decopperized anode slime includes, agitating and circulating a slurry at the same time, in carrying out hydrochloric acid oxidation leaching of the precious metal contained in the decopperized anode slime by adding a hydrochloric acid and an oxidant to the slurry of the decopperized anode slime, wherein in the circulating, the slurry is extracted from a lower portion of a tank and supplied again into an upper portion of the tank.

Cathode material from exhausted lithium ion batteries are dissolved in a solution for extracting the useful elements Co (cobalt), Ni (nickel), Al (Aluminum) and Mn (manganese) to produce active cathode materials for new batteries. The solution includes compounds of desirable materials such as cobalt, nickel, aluminum and manganese dissolved as compounds from the exhausted cathode material of spent cells. Depending on a desired proportion, or ratio, of the desired materials, raw materials are added to the solution to achieve the desired ratio of the commingled compounds for the recycled cathode material for new cells. The desired materials precipitate out of solution without extensive heating or separation of the desired materials into individual compounds or elements. The resulting active cathode material has the predetermined ratio for use in new cells, and avoids high heat typically required to separate the useful elements because the desired materials remain commingled in solution.

An alloy treatment method is provided, in which a solution containing nickel and/or cobalt is obtained from an alloy containing nickel and/or cobalt and also containing copper and zinc, the method comprising: a leaching step for subjecting the alloy to a leaching treatment with an acid under the condition where a sulfating agent is present to produce a leachate; a reduction step for subjecting the leachate to a reduction treatment using a reducing agent to produce a reduced solution; an oxidation/neutralization step for adding an oxidizing agent and a neutralizing agent to the reduced solution to produce a neutralized solution containing nickel and/or cobalt and also containing zinc; and a solvent extraction step for subjecting the neutralized solution to a solvent extraction procedure using an acidic phosphorus compound-based extractant to produce a solution containing nickel and/or cobalt.

The invention relates to a system for neutralizing asbestos, said system comprising a mobile neutralization unit (200) comprising: an asbestos waste sorting module (225), an asbestos grinder (255) and a hot acid bath (250) for rendering asbestos inert.

Preferably, the asbestos waste sorting module comprises: a window with glove boxes; and a conveyor for transporting the asbestos waste in front of the window.

In embodiments, the system comprises a means for containing the atmosphere within the mobile neutralization unit and/or the hot acid bath (250) of the mobile neutralization unit (200) comprises sulfuric acid.

A method for preparing gold metal nanoparticles, e.g., nanospheres and nanoprisms, includes combining an extract of red algae with chloroauric acid (HAuCl.sub.4). The red algae can be Laurencia papillosa. The extract can include a water solvent extract. The chloroauric acid (HAuCl.sub.4) can be in an aqueous solution. The method can include providing chloroauric acid

(HAuCl.sub.4), providing a red algae extract, and combining the chloroauric acid (HAuCl.sub.4) and the red algae extract to produce gold nanoparticles.

The invention relates to a hydrometallurgical process which makes it possible to selectively recover at least one “heavy” rare earth metal, i.e. a rare earth metal with an atomic number at least equal to 62, that is in an acidic aqueous phase resulting from the treatment of spent or scrapped permanent magnets. It also relates to a hydrometallurgical process which makes it possible to selectively recover, on the one hand, at least one heavy rare earth metal present in an acidic aqueous phase resulting from the treatment of spent or scrapped permanent magnets and, on the other hand, at least one “light” rare earth metal, i.e. a rare earth metal with an atomic number at most equal to 61, that is also in this acidic aqueous phase. The invention has in particular an application in the recycling of rare earth metals present in spent or scrapped permanent magnets of the type Neodymium-Iron-Boron (or NdFeB) and, in particular, dysprosium, praseodymium and neodymium, and also in the recycling of samarium present in spent or scrapped permanent magnets of the type samarium-cobalt (or SmCo).

A method is provided for leaching the metals while granulating molten matte, comprising the steps of feeding a molten matte as a falling stream into a granulation chamber, spraying a liquid jet on the stream of molten matte to atomize the matte, and cooling the matte particles thus formed. The liquid jet comprises an acid solution containing water and sulfuric acid so that the acid solution starts leaching metals from the molten matte when the liquid jet contacts the molten matte. Part of product solution from granulation can be circulated to liquid jets to increase the metal content in the solution and to reduce its acid con-tent.