Provided herein is a nickel recovering method, comprising: (A-i) a reduction heat treatment process for thermally treating a first raw material containing nickel and lithium; (B) a first leaching process for leaching the heat-treated product produced by the reduction heat treatment process; (A-ii) a roasting process for thermally treating a second raw material containing nickel and sulfur; (C) a second leaching process for leaching the first leaching residue produced by the first leaching process and calcine produced by the roasting process; (D) a neutralization process for neutralizing the second leachate produced by the second leaching process; (E) a purification process for removing impurities contained in the neutralized solution produced by the neutralization process; and (F) a precipitation process of performing a precipitation method to recover nickel from the purified solution produced by the purification process, and a nickel hydroxide is recovered by the precipitation process.

A method of separating and recovering a cobalt salt and a nickel salt includes a separation step of separating, by using a nanofiltration membrane, a cobalt salt and a nickel salt from a rare metal-containing aqueous solution containing at least both the cobalt salt and the nickel salt as rare metals, in which the nanofiltration membrane has a glucose permeability of 3 times or more a sucrose permeability, the sucrose permeability of 10% or less, and an isopropyl alcohol permeability of 50% or more when a 1,000 mg/L glucose aqueous solution, a 1,000 mg/L sucrose aqueous solution, and a 1,000 mg/L isopropyl alcohol aqueous solution, each having a pH of 6.5 and a temperature of 25 C., individually permeate through the nanofiltration membrane at an operating pressure of 0.5 MPa.

A method for reducing waste by recovering transition metal of a lithium secondary battery of the present invention includes preparing a cathode active material from a cathode of the lithium secondary battery, producing a first leachate by treating the cathode active material with a first acidic solution containing a reducing agent in an amount smaller than an amount corresponding to a reaction equivalent of the cathode active material, and producing a second leachate by treating the remaining cathode active material, which excludes a fraction contained in the first leachate, with a second acidic solution containing a reducing agent. Accordingly, extraction rate of manganese and purity of cobalt may be improved.

Methods are provided for removing impurities from recycled battery black mass. The method includes mixing a delithiated black mass with a first solution to form a pre-leached delithiated black mass and a pre-leach solution, separating the pre-leached delithiated black mass from the pre-leach solution, mixing the separated pre-leached delithiated black mass and a second aqueous solution to form a mixture comprising graphite and a leachate solution, and separating the graphite and the leachate solution. The pre-leach solution is comprised of a first group of impurity ions while the leachate solution is comprised of a second group of impurity ions and cathode metal ions.

Disclosed is a combined treatment method for laterite nickel ore hydrometallurgical slag and phosphating slag, the combined treatment method includes uniformly mixing a laterite nickel ore hydrometallurgical slag, a phosphating slag, and a sodium alkaline salt to obtain a mixed material; subjecting the mixed material to sodium reduction roasting to obtain a roasted material; leaching the roasted material with water and filtering to obtain a water leaching solution and a water leaching slag; subjecting the water leaching slag to magnetic separation to obtain an iron concentrate. In the disclosure, by mixing a laterite nickel ore hydrometallurgical slag and a phosphating slag and then performing sodium reduction roasting, the iron exists in the form of Fe.sub.3O.sub.4 and elements such as manganese and zinc exist in the slag in the form of oxides, and during the roasting process, aluminum oxides react with alkali to be converted into sodium aluminate.

A nickel recovering method includes: (A-i) a reduction heat treatment process for thermally treating a first raw material containing nickel and lithium; (B) a first leaching process for leaching the heat-treated product produced by the reduction heat treatment process; (A-ii) a first roasting process for thermally treating a second raw material containing nickel and sulfur; (C) a second leaching process for leaching the first leaching residue produced by the first leaching process and calcine produced by the first roasting process; (D) a neutralization process for neutralizing the second leachate produced by the second leaching process; (E) a purification process for removing impurities contained in the neutralized solution produced by the neutralization process; (F) a precipitation process for performing precipitation on the purified solution produced by the purification process; and (G) a second roasting process for roasting the precipitated residue produced by the precipitation process to recover nickel.

Processes are described for extracting metals from a combination derived from spent lithium-ion batteries and comprising such metals, a liquid, an acid, and other components.

Processes are described for extracting metals from a combination derived from spent lithium-ion batteries and comprising such metals, a liquid, an acid, and other components.

A hydrophobic deep eutectic solvent includes a combination of at least two of (a) a hydrophobic component. (b) an acidic component, and (c) a reducing agent. The solvent is useful in a method of recovering critical metals from lithium-ion batteries. That method includes steps of: shredding the lithium-ion batteries to separate metal container and shell components from a black mass including graphite, copper, cathode, anode and electrolyte battery materials, leaching the black mass with a hydrophobic deep eutectic solvent to extract critical metals, including lithium, cobalt, nickel and manganese, and generate a pregnant hydrophobic deep eutectic solvent, and recovering the critical metals from the pregnant hydrophobic deep eutectic solvent.

In a method for recovering an active metal of a lithium secondary battery, a preliminary cathode active material mixture is prepared from a cathode of a waste lithium secondary battery, the preliminary cathode active material mixture is fluidized through oxygen-containing gas within a fluidized bed reactor to form a cathode active material mixture, reductive gas is injected into the fluidized bed reactor to form a preliminary precursor mixture from the cathode active material mixture, and a lithium precursor is recovered from the preliminary precursor mixture.