Stationary phase for preparative High Pressure Liquid Chromatography (HPLC) for preparative separation of Rare Earth Elements (REEs), the stationary phase comprising porous particles suitable for HPLC having a non-polar surface being impregnated with ligands binding REEs, wherein the porous particles has a pore size of 300 Å or higher, is described.

A method for recovering lithium from lithium ion battery scrap according to this invention comprises subjecting lithium ion battery scrap to a calcination step, a crushing step, and a sieving step sequentially carried out, wherein the method comprises, between the calcination step and the crushing step, between the crushing step and the sieving step, or after the sieving step, a lithium dissolution step of bringing the lithium ion battery scrap into contact with water and dissolving lithium contained in the lithium ion battery scrap in the water to obtain a lithium-dissolved solution; a lithium concentration step of solvent-extracting lithium ions contained in the lithium-dissolved solution and stripping them to concentrate the lithium ions to obtain a lithium concentrate; and a carbonation step of carbonating the lithium ions in the lithium concentrate to obtain lithium carbonate.

The present disclosure relates to a method for lithium recovery by extraction-stripping separation and purification, including: (1) performing an extraction on a lithium-containing solution using an extraction system including a composite extractant at a pH in a range of 10-13 and separating to obtain a lithium-loaded organic phase; (2) subjecting the lithium-loaded organic phase obtained in step (1) to a gas-liquid-liquid three-phase stripping to obtain a lithium-loaded stripping solution; and (3) subjecting the stripping solution obtained in step (2) to a thermal treatment and separating to obtain a lithium product and a separated mother liquor.

A new system in which a forward extraction part, a scrubbing part, and a backward extraction part operate together and synchronously to produce specific substances by extraction and separation in a liquid-liquid system. The aqueous phase is circulated independently only in the forward extraction part one or more times, and the organic phase is circulated from the forward extraction part through the scrubbing part and the backward extraction part to the forward extraction part again in synchronization with the liquid circulation of the aqueous phase.

Provided is a method for producing lithium hydroxide, which can obtain lithium hydroxide from lithium sulfate with a relatively low cost. A method for producing lithium hydroxide from lithium sulfate includes: a hydroxylation step of allowing the lithium sulfate to react with barium hydroxide in a liquid to provide a lithium hydroxide solution; a barium removal step of removing barium ions in the lithium hydroxide solution using a cation exchange resin and/or a chelate resin; and a crystallization step of precipitating lithium hydroxide in the lithium hydroxide solution that has undergone the barium removal step.

Methods and systems for the extraction of metals from an aqueous feed solution containing the metal ions. The aqueous feed solution is contacted with one side of a hydrophilic membrane support while an organic liquid is contacted with an opposite side of the hydrophilic membrane support. Metal ions migrate from the aqueous feed solution through the membrane support and into the organic liquid. The metal ions may be re-extracted from the organic liquid using a strip solution. The steps of extraction and reextraction may be carried out in a system including two hollow fiber membrane modules that each include a plurality of hydrophilic polymer hollow fibers.

An extractant which makes it possible to extract both light rare earths and heavy rare earths from an aqueous phosphoric acid solution, likely to be present in this solution, and which is characterised in that it comprises: a compound of formula (I) below: ##STR00001##
wherein R1 and R2, identical or different, are a hydrocarbon group, saturated or unsaturated, linear or branched, in C6 to C12; R3 is a hydrocarbon group, in C1 to C6, or a hydrocarbon group, saturated or unsaturated, monocyclic, in C3 to C8; R4 and R5, identical or different, are a hydrogen atom or a hydrocarbonate group, saturated or unsaturated, linear or branched, in C2 to C8; and a surfactant. Applications of this extractant include treatment of aqueous solutions from the leaching of natural phosphates by sulphuric acid and aqueous solutions from the leaching of urban minerals by phosphoric acid, in view of making profitable use of the rare earths present in these solutions.

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.

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.

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.