A method for reusing a positive electrode active material includes dry-milling a positive electrode scrap comprising an active material layer on a current collector to convert the active material layer into a powdered state and to separate the active material layer from the current collector. The active material layer is a lithium composite transition metal oxide positive material active material layer. The method further includes adding a lithium precursor to a the active material layer. The method further includes thermally treating the active material layer in the powdered state to collect an active material. The method further includes obtaining a reusable active material by washing the collected active material with a basic lithium compound aqueous solution and drying the collected active material.

A comprehensive utilization method for valuable elements in hydrometallurgical slag of laterite nickel ore, comprising the following steps: S1. placing an iron-aluminum slag produced by laterite nickel ore hydrometallurgy in a tube furnace, and introducing an HCl gas stream for a one-stage distillation at 185-290 C. to obtain a one-stage distillation tail gas and a one-stage distillation residue; and condensing the one-stage distillation tail gas to obtain anhydrous AlCl.sub.3; S2. introducing an HCl gas stream to the one-stage distillation residue for a two-stage distillation at 320-500 C. to obtain a two-stage distillation tail gas and a two-stage distillation residue; and condensing the two-stage distillation tail gas to obtain anhydrous FeCl.sub.3; S3. subjecting the two-stage distillation residue to a leaching treatment by using a leaching solution to obtain a leaching residue and a leaching solution; subjecting the leaching solution to a scandium precipitation treatment to obtain a scandium precipitate and a de-scandiumed liquid; S4. adjusting the pH value of the de-scandiumed liquid to obtain an MHP. The obtained aluminum, iron, and scandium products have high purity and high recovery.

In a method for recovering an active metal of a lithium secondary battery, a sulfuric acid solution is added to a lithium metal composite oxide so as to prepare a sulfated active material solution. A transition metal is extracted from the sulfated active material solution. A lithium precursor is recovered by adding a lithium extracting agent to the solution remaining after the transition metal has been extracted from the sulfated active material solution. In the method, the amount of impurities is reduced, and sulfuric acid and the neutralizing agent can be recycled so that a high-yield lithium precursor recovery is enabled.

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.

To provide a method of recovering, at low cost, valuable metals from waste lithium-ion batteries by a dry smelting process. The present invention is a method of recovering valuable metals from waste lithium-ion batteries, the method comprising: an oxidation roasting step S3 in which oxidation roasting is implemented on a raw material containing waste lithium-ion batteries; and a reduction step S4 in which the obtained oxidation-roasted matter is reduced in the presence of carbon. In the oxidation roasting step S3, an oxidant of 1.5 times or more the chemical equivalent of carbon within the raw material to be treated is introduced, and the oxidation roasting is carried out at a processing temperature selected in a range of 600 C. to 900 C., so that the carbon grade of the obtained oxidation-roasted matter will be less than 1.0 mass %.

Provided are a conformable polymer coated lithium metal electrode, a solid electrolyte, and an inorganic molten salt electrolyte for a rechargeable lithium metal battery. Systems and methods are also provided for controlling the electroplating of lithium metal onto negative electrodes to allow for more rapid recharging of lithium metal batteries while minimizing dendrite formation.

The invention relates to a method of recovering rare-earth in cerium-based rare-earth polishing powder waste by two-step acid leaching gradient separation, characterized by: firstly, using a one-step acid leaching treatment on cerium-based rare-earth polishing powder waste to obtain a rare-earth leaching liquor which is rich in La; secondly, the leaching residue is then processed through alkali activation and transformation process, water washing and impurity removal process, secondary acid leaching process, filtration, and recovery to obtain high purity CeO.sub.2 products; thirdly, the acid leaching liquor obtained through first acid leaching and second acid leaching process is finally precipitated by oxalic acid, filtered and calcined at high temperature to obtain rare-earth oxide mixed products, which achieves the gradient separation and recovery of rare-earths from cerium-based rare-earth polishing powder waste. The total recovery efficiency of rare-earth of this invention reaches 97% or higher, with high efficiency of rare-earth recovery, wide process applicability, and low environmental pollution.

Provided is a method for cost-effectively recovering valuable metals from waste lithium-ion batteries through a pyrometallurgical process. The present invention pertains to a method for recovering valuable metals from waste lithium-ion batteries, the method comprising: an oxidation roasting step S3 in which raw materials including waste lithium-ion batteries are subjected to an oxidation roasting treatment; and a reduction step S4 in which the obtained oxidation roasted product is reduced in the presence of carbon. In the oxidation roasting step S3, calcium carbonate is charged into a furnace together with the raw materials including waste lithium-ion batteries to control the treatment temperature of the oxidation roasting treatment.

Provided is a method which makes it possible to suppress wear of a treatment furnace, and to safely and efficiently collect valuable metals from raw materials including waste lithium-ion batteries and the like. This method is for producing a valuable metal from a raw material including the valuable metal and comprises: a preparation step for preparing a raw material including at least lithium (Li), aluminum (Al), and a valuable metal; a reduction melting step for subjecting the raw material to a reduction melting treatment to obtain a reduced product including a slag and an alloy containing the valuable metal; and a slag separation step for separating the slag from the reduced product to collect the alloy. The preparation step and/or the reduction melting step include adding, to the raw material, a flux containing calcium (Ca), and also adding thereto magnesia (MgO).

A method for recovering rare earth metals uses organic acids. The method for recovering the rare earth metals using the organic acids is eco-friendly without using inorganic acids and has an effect of high selectivity for rare earth metals. In addition, impurities generated during the process may be removed only by adjusting the pH of the solvent, thereby significantly reducing the process time compared to conventional methods.