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.

Processes and methods for refining ferronickel alloy, and producing nickel sulfate or other nickel product, are provided, where the ferronickel alloy is treated with an oxidizing leach. The oxidizing leach may be, for example, a pressure oxidation (POX) leach or a leach with peroxide or copper (II) ions. The treatment may be in the presence of added copper, such as by providing a copper sulfate solution. Producing nickel sulfate may comprise removing copper and iron after the leach, removing impurities, and either crystallizing the nickel sulfate or precipitating/winning another nickel product.

Provided is a method for separating impurities and cobalt without using an electrolysis process from a cobalt chloride solution containing impurities and producing a high purity cobalt sulfate. The production method includes: a first solvent extraction step (S1) of bringing an organic solvent containing an alkyl phosphoric acid-based extractant into contact with a cobalt chloride solution containing impurities, and extracting zinc, manganese, and calcium into the organic solvent to separate to remove zinc, manganese, and calcium; a copper removal step (S2) of adding a sulfurizing agent to a cobalt chloride solution and generating a precipitate of sulfide of copper to separate to remove copper; a second solvent extraction step (S3) of bringing an organic solvent containing a carboxylic acid-based extractant into contact with a cobalt chloride solution and back extracting cobalt with sulfuric acid after extracting cobalt into the organic solvent to obtain cobalt sulfate solution; and a crystallization step (S4) of the cobalt sulfate solution obtained after having undergone through the second solvent extraction step (S3). These steps are sequentially executed. Without using an electrolysis process, a high purity cobalt sulfate is directly produced by separating cobalt and impurities containing manganese.

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.

Provided is a production method and a production apparatus that increase a throughput of nickel sulfate per equipment. A first dissolution step I of introducing a nickel briquette, sulfuric acid, and water to a leaching tank (1) and dissolving the nickel briquette to obtain a primary nickel sulfate solution, and a second dissolution step II of introducing the primary nickel sulfate solution and additionally introducing a nickel briquette to a leaching adjustment tank (2) and dissolving the additionally introduced nickel briquette with free sulfuric acid in the primary nickel sulfate solution to obtain a nickel sulfate solution are executed in this order. With the leaching adjustment tank (2) having a role as a concentration adjustment tank that increases a nickel concentration and decreases a free sulfuric acid concentration, and the leaching tank (1) supplied with the sulfuric acid and the water in addition to the nickel briquette, a continuous dissolution is achievable without increasing a retention time and without unnecessarily enlarging the equipment.

Provided is a hydrometallurgical process of recovering Ni from nickel oxide ore using a high pressure acid leaching, in which abrasion of the facilities caused by an ore slurry is suppressed, the amount of a final neutralized residue is reduced, and impurity components are separated and recovered for recycling. The hydrometallurgical process includes, as steps of the high pressure acid leaching, at least one step selected from step (A): separating and recovering chromite particles in the ore slurry; step (B-1): through leaching step and a solid-liquid separation step, performing neutralization of a leachate obtained after the solid-liquid separation step using a Mg-based alkali such as Mg(OH).sub.2; and step (B-2): through leaching step and a solid-liquid separation step, performing neutralization of a leachate obtained after the solid-liquid separation step using a Mg-based alkali such as Mg(OH).sub.2, and then recovering hematite particles.

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.

A nickel recovery process capable of decreasing nickel remaining in a byproduct by recovering nickel from the byproduct of electrolytic nickel manufacturing process by chlorine-leaching, and also, capable of simplifying a cementation step simultaneously, is provided. In a nickel recovery step S60, a nickel recovery step S70 and a nickel recovery step S80, nickel is recovered in each step from S.sup.0 slurry, residue flaker and chlorine-leached residue, which are byproducts of electrolytic nickel manufacturing process by chlorine-leaching, by using an aqueous solution containing 80 g/L to 390 g/L of chlorine and 30 g/L to 70 g/L of copper.

In an autoclave apparatus for a high-pressure acid leaching process which advances leaching by stirring heated and pressurized material slurry and sulfuric acid by stirrers in compartments in an autoclave main body of a plurality of compartments, transfers slurry from an upstream side compartment to a downstream one to advance leaching, liquid flow ports for slurry transfer that open and close by doors are provided on the partition walls, the liquid flow ports for slurry transfer are installed at positions where the heights from the lowermost portion the autoclave to the center of gravity are 0.1 to 0.3 times an autoclave diameter and distances from the center lines of the partition walls to the center of gravity are 0.05 to 0.25 times the autoclave diameter, and the liquid flow ports for slurry transfer have shapes which do not reach end portions of the partition walls.