A process for recovering non-ferrous metals from a solid matrix may include: (a) leaching the solid matrix with an aqueous-based solution containing chloride ions, ammonium ions, and Cu.sup.2+ ions, having a pH of 6.5-8.5, in a presence of oxygen, at a temperature of 100 C.-160 C. and a pressure of 150 kPa-800 kPa, so as to obtain an extraction solution comprising leached metals and solid leaching residue; (b) separating the solid leaching residue from the extraction solution; and/or (c) subjecting the extraction solution to at least one cementation so as to recover the leached metals in elemental state. The pH may be greater than or equal to 6.5 and less than or equal to 8.5. Temperature may be greater than or equal to 100 C. and less than or equal to 160 C. Pressure may be greater than or equal to 150 kPa and less than or equal to 800 kPa.

A process for recovering non-ferrous metals from a solid matrix may include: (a) leaching the solid matrix with an aqueous-based solution containing chloride ions, ammonium ions, and Cu.sup.2+ ions, having a pH of 6.5-8.5, in a presence of oxygen, at a temperature of 100 C.-160 C. and a pressure of 150 kPa-800 kPa, so as to obtain an extraction solution comprising leached metals and solid leaching residue; (b) separating the solid leaching residue from the extraction solution; and/or (c) subjecting the extraction solution to at least one cementation so as to recover the leached metals in elemental state. The pH may be greater than or equal to 6.5 and less than or equal to 8.5. Temperature may be greater than or equal to 100 C. and less than or equal to 160 C. Pressure may be greater than or equal to 150 kPa and less than or equal to 800 kPa.

A method for in situ solution mining of a mineral from an underground evaporite stratum using a set of wells in fluid communication with at least one mineral cavity with some wells operated in solvent injection mode and other wells operated in brine production mode and optionally with some inactive wells, comprising switching the operation mode of one or more wells. The evaporite mineral preferably comprises trona. The at least one cavity may be formed by directionally drilled uncased boreholes or by lithological displacement of the evaporite stratum at a weak interface with an underlying insoluble stratum by application of a lifting hydraulic pressure to create an interfacial gap. The extracted brine can be processed to make valuable products such as soda ash and/or any derivatives thereof. This method can provide more uniform dissolution of mineral in the cavity, minimize flow channeling, minimize sodium bicarbonate blinding for solution mining of incongruent trona ore, and/or may avoid uneven deposit of insolubles.

A method for in situ solution mining of a mineral from an underground evaporite stratum using a set of wells in fluid communication with at least one mineral cavity with some wells operated in solvent injection mode and other wells operated in brine production mode and optionally with some inactive wells, comprising switching the operation mode of one or more wells. The evaporite mineral preferably comprises trona. The at least one cavity may be formed by directionally drilled uncased boreholes or by lithological displacement of the evaporite stratum at a weak interface with an underlying insoluble stratum by application of a lifting hydraulic pressure to create an interfacial gap. The extracted brine can be processed to make valuable products such as soda ash and/or any derivatives thereof. This method can provide more uniform dissolution of mineral in the cavity, minimize flow channeling, minimize sodium bicarbonate blinding for solution mining of incongruent trona ore, and/or may avoid uneven deposit of insolubles.

The present disclosure discloses a method for extracting lithium from waste lithium batteries, which comprises: leaching positive electrode powder of the waste lithium battery in hydrochloric acid, and obtaining leaching solution by filtering; removing copper and iron from the leaching solution, and then introducing hydrogen sulfide gas for reaction, and performing solid-liquid separation to obtain first filter residue and first filtrate; adding potassium permanganate to the first filtrate, and performing solid-liquid separation to obtain second filter residue and second filtrate; performing spray pyrolysis on the second filtrate to obtain solid particles and tail gas, washing the solid particles with water to obtain a lotion, washing and collecting the tail gas and then mixing the tail gas with the lotion to obtain lithium salt solution. In the present disclosure, the positive electrode powder is leached with hydrochloric acid to obtain the hydrochloric acid leaching solution, and hydrogen sulfide is used to precipitate nickel and cobalt after removing the copper and iron impurities in the leaching solution in turn, and potassium permanganate is added to precipitate manganese ions to generate manganese dioxide. Spray pyrolysis converts the aluminum and magnesium in the solution into oxides and lithium salt is separated. The entire reaction process does not require organic solvent extraction and reduces the loss of lithium.

A method of treating a leaching solution derived from a black mass from spent lithium-ion batteries comprising setting pH of the leaching solution to about pH 1.2 to 2.5, adding iron powder to induce copper cementation, adding lime after copper cementation, and after adding lime, transiting pH of the leaching solution to about pH 6 to extract calcium fluoride, titanium hydroxide, aluminium hydroxide, iron hydroxide, and iron phosphate. A black mass recycling system comprising an impurity removal reactor configured to receive a sodium hydroxide feed, an iron powder feed, and a lime feed.

An aqueous cobalt chloride solution refinement method, in which metallic nickel is washed with an acidic liquid having a pH of not more than 2.5 before the metallic nickel is brought into contact with the aqueous solution containing cobalt chloride. Since the metallic nickel is washed with the acidic liquid having a pH of not more than 2.5, a passive film on a surface of the metallic nickel is removed and therefore, when the metallic nickel comes in contact with the aqueous solution containing cobalt chloride, an impurity more noble than the metallic nickel can be precipitated by a cementation reaction. In addition, since the metallic nickel is only washed with acid to be brought into contact with the aqueous solution containing cobalt chloride, impurities can be easily removed from the aqueous solution containing cobalt chloride.

An aqueous cobalt chloride solution refinement method, in which metallic nickel is washed with an acidic liquid having a pH of not more than 2.5 before the metallic nickel is brought into contact with the aqueous solution containing cobalt chloride. Since the metallic nickel is washed with the acidic liquid having a pH of not more than 2.5, a passive film on a surface of the metallic nickel is removed and therefore, when the metallic nickel comes in contact with the aqueous solution containing cobalt chloride, an impurity more noble than the metallic nickel can be precipitated by a cementation reaction. In addition, since the metallic nickel is only washed with acid to be brought into contact with the aqueous solution containing cobalt chloride, impurities can be easily removed from the aqueous solution containing cobalt chloride.

The present invention relates to a method for the biological recovery of metals in electric and electronic waste, which comprises a) inoculating a series of iron-oxidizing microorganisms and a mineral medium or fertilizers into an immobilized biomass column; b) performing a stage of biological oxidation of the iron II ions present in said mineral medium or fertilizers to iron III ions; c) irrigating a liquid phase into leaching columns that house an electrical material or one or more printed circuit boards from which metals are to be recovered, the iron III ions being reduced to iron II oxidizing the metals, and separating the metals by means of the dissolution thereof; and d) extracting the metals from the solution. The invention operates under a cyclic process that allows the iron II solution being re-circulated to the biomass column.

The present invention relates to a method for the biological recovery of metals in electric and electronic waste, which comprises a) inoculating a series of iron-oxidizing microorganisms and a mineral medium or fertilizers into an immobilized biomass column; b) performing a stage of biological oxidation of the iron II ions present in said mineral medium or fertilizers to iron III ions; c) irrigating a liquid phase into leaching columns that house an electrical material or one or more printed circuit boards from which metals are to be recovered, the iron III ions being reduced to iron II oxidizing the metals, and separating the metals by means of the dissolution thereof; and d) extracting the metals from the solution. The invention operates under a cyclic process that allows the iron II solution being re-circulated to the biomass column.