This application pertains to methods of recovering metals from metal sulfides that involve contacting the metal sulfide with an acidic sulfate solution containing ferric sulfate and a reagent that has a thiocarbonyl functional group, wherein the concentration of reagent in the acidic sulfate solution is sufficient to increase the rate of metal ion extraction relative to an acidic sulfate solution that does not contain the reagent, to produce a pregnant solution containing the metal ions.

A method for producing a nickel sulfate solution includes a leaching step of leaching a nickel cathode in sulfuric acid under a high temperature and a high pressure to produce a leachate, a neutralization step of neutralizing the leachate produced in the leaching step to produce a neutralized solution, and a filtration step of filtering the neutralized solution produced in the neutralization step to produce a filtrate.

A method for producing a nickel sulfate solution includes a leaching step of leaching a nickel cathode in sulfuric acid under a high temperature and a high pressure to produce a leachate, a neutralization step of neutralizing the leachate produced in the leaching step to produce a neutralized solution, and a filtration step of filtering the neutralized solution produced in the neutralization step to produce a filtrate.

A process recovers metals from a black mass. The process includes the following steps in the following order: step (a) providing the black mass, which comprises Li; step (b) adding water to the black mass and creating a suspension of the black mass in the water; step (c) dosing ozone as an oxidant to the suspension while stirring the suspension; and step (d) filtering and separating a filtrate containing LiOH dissolved in water from a Li depleted residue of the black mass. In step (c), the suspension is stirred with a shear rate greater than 11000 s.sup.?1 within the suspension.

A process recovers metals from a black mass. The process includes the following steps in the following order: step (a) providing the black mass, which comprises Li; step (b) adding water to the black mass and creating a suspension of the black mass in the water; step (c) dosing ozone as an oxidant to the suspension while stirring the suspension; and step (d) filtering and separating a filtrate containing LiOH dissolved in water from a Li depleted residue of the black mass. In step (c), the suspension is stirred with a shear rate greater than 11000 s.sup.?1 within the suspension.

Disclosed is a process for the selective separation and recovery of metal values from process liquors, in particular for the selective recovery of mixed metal sulfates, such as a mixed cobalt-nickel sulfate, from a metal sulfate process liquor.

A process for generating a metal sulfate that involves crystallizing a metal sulfate from an aqueous solution to form a crystallized metal sulfate in a mother liquor with uncrystallized metal sulfate remaining in the mother liquor; separating the crystallized metal sulfate from the mother liquor; basifying a portion of the mother liquor to convert the uncrystallized metal sulfate to a basic metal salt; and using the basic metal salt upstream of crystallizing the metal sulfate. So crystallized, the generated metal sulfate may be battery-grade or electroplating-grade.

A process for generating a metal sulfate that involves crystallizing a metal sulfate from an aqueous solution to form a crystallized metal sulfate in a mother liquor with uncrystallized metal sulfate remaining in the mother liquor; separating the crystallized metal sulfate from the mother liquor; basifying a portion of the mother liquor to convert the uncrystallized metal sulfate to a basic metal salt; and using the basic metal salt upstream of crystallizing the metal sulfate. So crystallized, the generated metal sulfate may be battery-grade or electroplating-grade.

The present invention is to provide a process for removing magnesium contained as an impurity from nickel sulfate and producing high-purity nickel sulfate.

The process for producing an aqueous nickel sulfate solution from which magnesium is removed from nickel sulfate, comprises the following steps (1) to (3): (1) a carbonation step obtaining a slurry comprising nickel carbonate as a solid content by mixing a nickel sulfate aqueous solution and lithium carbonate, (2) a solid-liquid separation step of separating the slurry obtained in the carbonation step into a solid content and liquid component, and (3) a dissolution step dissolving the solid content obtained in said solid-liquid separation step with a solution containing sulfuric acid.

The present invention is to provide a process for removing magnesium contained as an impurity from nickel sulfate and producing high-purity nickel sulfate.

The process for producing an aqueous nickel sulfate solution from which magnesium is removed from nickel sulfate, comprises the following steps (1) to (3): (1) a carbonation step obtaining a slurry comprising nickel carbonate as a solid content by mixing a nickel sulfate aqueous solution and lithium carbonate, (2) a solid-liquid separation step of separating the slurry obtained in the carbonation step into a solid content and liquid component, and (3) a dissolution step dissolving the solid content obtained in said solid-liquid separation step with a solution containing sulfuric acid.