A method for recovering metal zinc from a solid metallurgical waste containing zinc and manganese, may include: (a) bringing the solid metallurgical waste into contact with an aqueous leaching solution comprising chloride ions and ammonium ions to produce at least one leachate including zinc ions and manganese ions and at least one insoluble solid residue; (b) cementing the leachate, by adding metal zinc as a precipitating agent, to eliminate at least one metal other than zinc and manganese possibly present in the leachate as ions and producing a purified leachate; (c) subjecting the purified leachate to electrolysis in an electrolytic cell including at least one cathode and at least one anode immersed in the purified leachate to deposit metal zinc on the cathode and producing at least one exhausted leachate, and, before the electrolysis, precipitating manganese ions by oxidation with permanganate ions and subsequently separating a precipitate including MnO.sub.2.

A method for recovering metal zinc from a solid metallurgical waste containing zinc and manganese, may include: (a) bringing the solid metallurgical waste into contact with an aqueous leaching solution comprising chloride ions and ammonium ions to produce at least one leachate including zinc ions and manganese ions and at least one insoluble solid residue; (b) cementing the leachate, by adding metal zinc as a precipitating agent, to eliminate at least one metal other than zinc and manganese possibly present in the leachate as ions and producing a purified leachate; (c) subjecting the purified leachate to electrolysis in an electrolytic cell including at least one cathode and at least one anode immersed in the purified leachate to deposit metal zinc on the cathode and producing at least one exhausted leachate, and, before the electrolysis, precipitating manganese ions by oxidation with permanganate ions and subsequently separating a precipitate including MnO.sub.2.

A method of treating a waste liquid: an aluminum dissolution step of dissolving aluminum in an acidic waste liquid and performing separation into a first treated water and a reduced heavy metal precipitate; a gypsum recovery step of adding a calcium compound to the first treated water at a pH of 4 or less, and performing separation into a second treated water and gypsum; a heavy metal coprecipitation step of adding a ferric compound to the second treated water and performing separation into a third treated water and a heavy metal coprecipitate; an aluminum and fluorine removal step of adding an alkali to the third treated water and performing separation into a fourth treated water and a precipitate containing aluminum and fluorine; and a neutralization step of adding an alkali to the fourth treated water and performing separation into an alkali neutralization treated water and a neutralized heavy metal hydroxide.

Provided is a method for treating an alloy by which nickel and/or cobalt can be selectively isolated from an alloy that contains copper as well as nickel and/or cobalt, in a waste lithium ion battery. The present invention is a method for treating an alloy, by which a solution that contains nickel and/or cobalt is obtained from an alloy that contains copper as well as nickel and/or cobalt, the method including: a leaching step in which a leachate is obtained by subjecting an alloy to an acid-based leaching treatment under conditions in which a sulfurizing agent is also present; a reduction step in which a reduced solution is obtained by subjecting the leachate to a reduction treatment using a reducing agent; and an oxidation/neutralization step in which a solution that contains nickel and/or cobalt is obtained by adding an oxidizing agent and also a neutralizing agent to the reduced solution.

The present invention relates, on one hand, to a metal cementing apparatus (1) formed by a vessel (2) with a liquid phase formed by a solution (3) containing noble metal, and a solid phase formed by a cementing metal or a less noble metal in contact with the solution (3), where one of said phases moves at a high speed with respect to the other one, and the difference in speeds allows the cementation of the noble metal on the solid phase, and the simultaneous detachment and separation thereof, and comprises means for generating the movement of at least the phase with the high speed and removing means for removing the precipitated noble metal. The invention describes, on the other hand, a continuous cementation method consisting of passing a continuous flow of solution in a vessel (2); reacting the solid phase with the liquid phase, where one of said phases moves at a high speed with respect to the other one, causing the fixing of the noble metal and the simultaneous detachment thereof; removing the precipitated noble metal.

The present invention relates, on one hand, to a metal cementing apparatus (1) formed by a vessel (2) with a liquid phase formed by a solution (3) containing noble metal, and a solid phase formed by a cementing metal or a less noble metal in contact with the solution (3), where one of said phases moves at a high speed with respect to the other one, and the difference in speeds allows the cementation of the noble metal on the solid phase, and the simultaneous detachment and separation thereof, and comprises means for generating the movement of at least the phase with the high speed and removing means for removing the precipitated noble metal. The invention describes, on the other hand, a continuous cementation method consisting of passing a continuous flow of solution in a vessel (2); reacting the solid phase with the liquid phase, where one of said phases moves at a high speed with respect to the other one, causing the fixing of the noble metal and the simultaneous detachment thereof; removing the precipitated noble metal.

A method of processing a black mass material feed material can include a) receiving a black mass material feed material; b) acid leaching the black mass material at a pH that is less than 4, thereby producing a pregnant leach solution (PLS) comprising at least 80% the lithium from the black mass feed material, and at least a portion of the iron and the phosphorous from the black mass feed material; providing a first intermediary solution after completing step b); and separating at least 90% of the iron and the phosphorous from the first intermediary solution to provide an output solution.

A method of processing a black mass material feed material can include a) receiving a black mass material feed material; b) acid leaching the black mass material at a pH that is less than 4, thereby producing a pregnant leach solution (PLS) comprising at least 80% the lithium from the black mass feed material, and at least a portion of the iron and the phosphorous from the black mass feed material; providing a first intermediary solution after completing step b); and separating at least 90% of the iron and the phosphorous from the first intermediary solution to provide an output solution.

A method for extracting rare earth elements (REEs) from a REE hyperaccumulator, including: subjecting the REE hyperaccumulator to microwave-assisted digestion to obtain a REE extract; subjecting the REE extract to absorption with a chelating resin and elution to obtain a purified REE solution; and subjecting the purified REE solution to precipitation and calcination to obtain high-purity rare earth compound.

The present application provides a method for recovering metal from metal-containing material by leaching, the method comprising providing aqueous solution containing leaching agent precursor, providing one or more source(s) of external energy comprising a source of electric current connected to one or more non-metallic electrode(s) comprising carbon material(s) selected from graphite, graphene and derivatives thereof, and carbon nanomaterial(s) selected from carbon nanofibers, carbon nanotubes and carbon nanobuds, treating the aqueous solution with the external energy, which is electric current providing electrochemical reactions, to form hydrogen peroxide from oxygen in the aqueous solution, reacting the leaching agent precursor with the formed hydrogen peroxide to form a leaching agent and to obtain a leaching solution, providing metal-containing material, reacting the metal-containing material with the leaching solution to obtain soluble metal complexes, and recovering the soluble metal complexes. The present application also discloses a device for recovering metal from metal-containing material by leaching.