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 process for manufacturing nickel sulphate by leaching metal particles comprising nickel in an aqueous sulphuric acid solution, said process comprising the steps of: introducing the metal particles in the aqueous sulphuric acid solution introducing an aqueous hydrogen peroxide solution in the aqueous sulphuric acid solution containing the metal particles wherein the aqueous hydrogen peroxide solution is introduced progressively into the aqueous sulphuric acid solution containing the metal particles.

A process for manufacturing nickel sulphate by leaching metal particles comprising nickel in an aqueous sulphuric acid solution, said process comprising the steps of: introducing the metal particles in the aqueous sulphuric acid solution introducing an aqueous hydrogen peroxide solution in the aqueous sulphuric acid solution containing the metal particles wherein the aqueous hydrogen peroxide solution is introduced progressively into the aqueous sulphuric acid solution containing the metal particles.

In a method for recovering an active metal of a lithium secondary battery according to an embodiment, a waste cathode active material mixture is prepared from a waste cathode of a lithium secondary battery. A preliminary precursor mixture is formed by reacting the waste cathode active material mixture with a reactive gas in a fluidized bed reactor. The preliminary precursor mixture is cooled by spraying different first and second refrigerants to the preliminary precursor mixture. A lithium precursor is recovered from the cooled preliminary precursor mixture.

A fluidized bed reactor according to an embodiment of the present disclosure includes a reactor body, and a dispersion plate coupled to a bottom portion of the reactor body. The dispersion plate may include a base plate and injection columns protruding from a top surface of the base plate. The injection columns include first injection columns arranged at a central portion of the dispersion plate, and second injection columns arranged at a peripheral portion of the dispersion plate. The second injection column has a greater height than a height of the first injection column. A reactive gas is uniformly injected to a wall surface of the reactor through the dispersion plate, thereby increasing a recovery ratio for an active metal of a lithium secondary battery.

A preparation method for a high nickel ternary precursor capable of preferential growth of crystal planes by adjusting and controlling the addition amount of seed crystals. The method comprises the following steps: 1) feeding a ternary metal solution into a reaction kettle containing a first base liquid for reaction, and when the particle size reaches 1.5 to 3.0 μm, stopping the feeding, so as to obtain a seed crystal slurry; 2) simultaneously adding the ternary metal solution, a liquid alkali solution, and an ammonia solution in cocurrent flow into a growth kettle containing a second base solution for reaction, when the particle size reaches 6 to 8 μm, adding the seed crystal slurry into the reaction system, and controlling the particle size to be 9.0 to 11.0 μm by adjusting the feed rate of the seed crystal, so as to obtain the target object. In the preparation method, by adding seed crystals continuously, the crystal plane parameters of 001 peak in the prepared ternary precursor material is lower than the crystal plane parameters of 101 peak, facilitating the embedding of Li ions, and effectively improving the performance of a battery prepared by using the material.

A preparation method for a high nickel ternary precursor capable of preferential growth of crystal planes by adjusting and controlling the addition amount of seed crystals. The method comprises the following steps: 1) feeding a ternary metal solution into a reaction kettle containing a first base liquid for reaction, and when the particle size reaches 1.5 to 3.0 μm, stopping the feeding, so as to obtain a seed crystal slurry; 2) simultaneously adding the ternary metal solution, a liquid alkali solution, and an ammonia solution in cocurrent flow into a growth kettle containing a second base solution for reaction, when the particle size reaches 6 to 8 μm, adding the seed crystal slurry into the reaction system, and controlling the particle size to be 9.0 to 11.0 μm by adjusting the feed rate of the seed crystal, so as to obtain the target object. In the preparation method, by adding seed crystals continuously, the crystal plane parameters of 001 peak in the prepared ternary precursor material is lower than the crystal plane parameters of 101 peak, facilitating the embedding of Li ions, and effectively improving the performance of a battery prepared by using the material.

Provided is a novel method of producing nickel sulfate from nickel oxide. The method of producing nickel sulfate herein disclosed includes a step of feeding nickel oxide particles and an acid aqueous solution into a pressure resistant container, a step of heating the pressure resistant container in a sealed state to a temperature exceeding 100° C. to obtain a mixed liquid in which nickel oxide is dissolved, and a step of forming nickel sulfate, using the mixed liquid.

Provided is a novel method of producing nickel sulfate from nickel oxide. The method of producing nickel sulfate herein disclosed includes a step of feeding nickel oxide particles and an acid aqueous solution into a pressure resistant container, a step of heating the pressure resistant container in a sealed state to a temperature exceeding 100° C. to obtain a mixed liquid in which nickel oxide is dissolved, and a step of forming nickel sulfate, using the mixed liquid.

The present invention relates to a method of preparing a precursor material of a positive electrode active material from a waste lithium secondary battery, to a method of preparing a lithium secondary battery positive electrode active material including a precursor material prepared by the same precursor preparation method, and to a lithium secondary battery positive electrode active material prepared by the same positive electrode active material preparation method.