The present invention related to generally to a process to recover metals from waste electronics, and more particularly a process to recover gold from waste electronics. The gold is first delaminated in a first step using a solution containing a weak acid in combination with an oxidizer. The second step isolates and purifies the delaminated gold from the chip debris using solvents, water and a wetting agent/surfactant. The proposed two step method of gold recovery from electronic waste is effective without the need for strong or costly chemicals or leaching.

A method for extracting and enriching gold with a selenide includes: mixing an isocyanate and a selenium-containing compound of a formula of HO—R—Se—R—OH in a solvent to obtain a mixture system, where R is selected from linear or branched C.sub.2 to C.sub.11 alkylene groups; adding a tin-based catalyst into the mixture system to activate a reaction, drying the mixture system after the reaction, and obtaining a powdery selenium-containing polymer by grinding; immersing the selenium-containing polymer in an aqueous solution containing gold ions to allow gold to be extracted from the aqueous solution; and removing the selenium-containing polymer attached to a surface of extracted gold, thereby obtaining an extracted and enriched gold.

The invention relates to the field of comprehensive recovery of valuable elements such as bromine, base metal and precious metal from incineration ash, especially relates to a method for enriching precious metals from printed circuit board incineration ash by bath smelting-chlorination circulation process. The process mainly comprises pretreatment of the printed circuit board Incineration ash and circulation-chlorination enrichment process for precious metals. The crude copper, crude zinc sulfate, bromine, lead chloride and precious metal enriched slag are obtained. Compared with the traditional process, it realizes the cycle enrichment of precious metals as well as avoids the loss of valuable metals and secondary pollution caused by tail liquid discharge.

To recover materials forming a fuel cell stack by an easy method.

Provided is a method of recovering, from a fuel cell stack having a stack structure including a plurality of fuel cells stacked, materials forming the fuel cell stack, the fuel cells each including a membrane electrode assembly and two separators holding the membrane electrode assembly therebetween, the separators each being provided with a gas flow channel configured to supply a raw material gas to the membrane electrode assembly, the method including: a first step of supplying a solvent or a solvent and a reagent to the fuel cell stack through the gas flow channel, collecting the solvent which contains a material, and recovering the material from the collected solvent; and a second step of subjecting the fuel cell stack after the first step to a heat treatment to obtain a molten liquid or gas and recovering a material from the molten liquid or gas, the materials recovered including materials forming the membrane electrode assembly and the separators.

A method for supercritical fluid extraction of metal from a source, the method comprising: providing a reactor chamber; providing a source comprising a target metal; optionally, providing a chelating agent; providing a solvent; adding the source comprising the target metal, the chelating agent and the solvent into the reactor chamber; adjusting the temperature and pressure in the reactor chamber so that the solvent is heated and compressed above its critical temperature and pressure; optionally, providing mechanical agitation to the reactor chamber; recovering a chelate comprising the target metal.

A recycling process that facilitates separation of materials from metallic substrates by cryogenically cooling the recyclable items to induce embrittlement of the metals. Embrittled metals may be shattered more efficiently and with a higher yield of materials bound to the metallic substrates. Metal embrittlement may be induced by mixing the source stream with liquid nitrogen, and cooling the stream to approximately minus 200° F. Multiple recovery stages may be employed to maximize the yield of the target materials. Embodiments may enable recovery of platinum group metals (PGMs) from catalytic converters with metallic foil substrates. Yield of PGMs may be enhanced by employing a primary recovery stage and a secondary recovery stage, by cryogenically cooling input materials for each stage, by mixing the pulverized material in secondary recovery with an aqueous solution to dissipate attractive charges, and by wet screening the pulverized material slurry to obtain the PGM particles.

A method for removing metal and/or precious metal-containing depositions from substrates, wherein said substrate is subjected to treatment with an organo amine protectant component P and an inorganic active component A. Component P may be formed in situ by reaction with component R. Component P is an organic amine and/or organic amine hydrohalide and/or organic ammonium halide (preferably diisopropylamine hydrochloride), component A is an inorganic compound (preferably inorganic acid or a mixture thereof) and component R is an organic compound that can be split along the C—N bond by the component A into an organic amine (preferably dimethylformamide or N-methyl pyrrolidone). The metals in the form of organo-metallic complexes and/or metalorganic compounds are isolated and/or separated by means of different chemical reactions (preferably reduction reactions) and/or biosorption (preferably with seaweed or yeast). The isolated and/or separated organo-metallic complexes and/or metalorganic compounds are subjected to refinement process to form pure metals and/or pure precious metals. The substrates remain intact after the treatment.

A method of recovering metals from electronic waste comprises providing a powder comprising electronic waste in at least a first reactor and a second reactor and providing an electrolyte comprising at least ferric ions in an electrochemical cell in fluid communication with the first reactor and the second reactor. The method further includes contacting the powders within the first reactor and the second reactor with the electrolyte to dissolve at least one base metal from each reactor into the electrolyte and reduce at least some of the ferric ions to ferrous ions. The ferrous ions are oxidized at an anode of the electrochemical cell to regenerate the ferric ions. The powder within the second reactor comprises a higher weight percent of the at least one base metal than the powder in the first reactor. Additional methods of recovering metals from electronic waste are also described, as well as an apparatus of recovering metals from electronic waste.

A method for extracting and enriching gold with a selenide includes: mixing an isocyanate and a selenium-containing compound of a formula of HO—R—Se—R—OH in a solvent to obtain a mixture system, where R is selected from linear or branched C.sub.2 to C.sub.11 alkylene groups; adding a tin-based catalyst into the mixture system to activate a reaction, drying the mixture system after the reaction, and obtaining a powdery selenium-containing polymer by grinding; immersing the selenium-containing polymer in an aqueous solution containing gold ions to allow gold to be extracted from the aqueous solution; and removing the selenium-containing polymer attached to a surface of extracted gold, thereby obtaining an extracted and enriched gold.

The present invention relates to a method for recovering metals using an adsorbent, which comprises preparing a leachate comprising metal ions and cyanides, wherein the metal ions comprise gold ions and copper ions; and in a state where the leachate has a cyanide (CN) concentration of 0.1 ppm or greater, adding to the leachate an adsorbent, which has an open circuit potential value between the open circuit potential value of the gold ions and that of the copper ions; and selectively adsorbing the copper ions to the adsorbent.