Provided is a method for producing, from scandium oxalate crystals obtained through an oxalate conversion process, a readily-soluble scandium compound that dissolves easily in an aqueous solution such as an acid. This method for producing a scandium compound involves carrying out an oxalate conversion process using oxalic acid in a solution containing scandium, separating the product obtained through the oxalate conversion process into a liquid and scandium oxalate crystals, and obtaining a scandium compound by roasting the obtained scandium oxalate crystals at a temperature of 400° C. to 800° C., preferably 400° C. to 600° C.

Provided is a method for recovering scandium as scandium oxide that contains high-quality scandium and in which coarse particles having good handling properties are formed. This method for recovering scandium includes a step for carrying out an oxalate conversion process wherein oxalic acid is used in a solution containing scandium (scandium-containing solution) to generate a reaction in which the scandium is converted into an oxalate form, the method characterized in that the temperature of the reaction solution during the oxalate conversion process is 50° C. to 80° C.

Provided is a method for recovering scandium as scandium oxide that contains high-quality scandium and in which coarse particles having good handling properties are formed. This method for recovering scandium includes a step for carrying out an oxalate conversion process wherein oxalic acid is used in a solution containing scandium (scandium-containing solution) to generate a reaction in which the scandium is converted into an oxalate form, the method characterized in that the temperature of the reaction solution during the oxalate conversion process is 50° C. to 80° C.

A method for recovering scandium, by which scandium is able to be recovered from nickel oxide ore. The present invention comprises: a leaching step S1 for obtaining a leachate by leaching a nickel oxide ore containing scandium with use of sulfuric acid; a neutralization step by adding a neutralizing agent thereto; a sulfurization step by adding a sulfurizing agent to the post-neutralization solution; an ion exchange step by bringing the post-sulfurization solution into contact with a chelating resin; a dissolution step by obtaining a precipitate of scandium hydroxide by adding an alkali into the scandium eluent, and subsequently adding an acid solution to the scandium hydroxide; a solvent extraction step by bringing the scandium acid dissolution liquid into contact with a neutral extractant; and a scandium recovery step by adding oxalic acid to the extraction residue and subsequently roasting the salt of scandium oxalate.

A method for recovering scandium, by which scandium is able to be recovered from nickel oxide ore. The present invention comprises: a leaching step S1 for obtaining a leachate by leaching a nickel oxide ore containing scandium with use of sulfuric acid; a neutralization step by adding a neutralizing agent thereto; a sulfurization step by adding a sulfurizing agent to the post-neutralization solution; an ion exchange step by bringing the post-sulfurization solution into contact with a chelating resin; a dissolution step by obtaining a precipitate of scandium hydroxide by adding an alkali into the scandium eluent, and subsequently adding an acid solution to the scandium hydroxide; a solvent extraction step by bringing the scandium acid dissolution liquid into contact with a neutral extractant; and a scandium recovery step by adding oxalic acid to the extraction residue and subsequently roasting the salt of scandium oxalate.

A method of separating actinium and/or radium from proton-irradiated thorium metal. The thorium metal is irradiated to produce isotopes including thorium, actinium and/or radium. The resultant product is dissolved in solution and a selective precipitant is used to precipitate a bulk portion of the thorium. The precipitated thorium can be recovered. Chromatography is carried out on the remaining solution to remove residual thorium and to separate the actinium from the radium.

A method of separating actinium and/or radium from proton-irradiated thorium metal. The thorium metal is irradiated to produce isotopes including thorium, actinium and/or radium. The resultant product is dissolved in solution and a selective precipitant is used to precipitate a bulk portion of the thorium. The precipitated thorium can be recovered. Chromatography is carried out on the remaining solution to remove residual thorium and to separate the actinium from the radium.

A composite extractant-enhanced polymer resin comprising an extractant and a polymer resin for direct extraction of valuable metals such as rare earth metals, and more specifically, scandium, front an acid-leaching slurry and/or acid-leaching solution in which ferric ions are not required to be reduced into ferrous ions. The extractant may be cationic, non-ionic, or anionic. More specifically, the extractant di(2-ethylhexyl)phosphoric acid may be used. The polymer resin may be non-functional or have functional groups of sulfonic acid, carboxylic acid, iminodiacetic acid, phosphoric acid, or amines. The composite extractant-enhanced polymer resin may be used for extraction of ran earth metals from acid-leaching slurries or solutions.

The invention relates to a method for producing a scandium-containing concentrate from the wastes of alumina production and extracting high-purity scandium oxide from the same. Provided is a method for producing a scandium-containing concentrate from a red mud, wherein the Sc.sub.2O.sub.3 content therein is least of 15 wt. %, the TiO.sub.2 content not more than 3 wt. %, the ZrO.sub.2 content not more than 15 wt. %, and wherein scandium in the concentrate is in form of a mixture of Sc(OH).sub.3 hydroxide with ScOHCO.sub.3.4H.sub.2O. Also provided is a method for producing high-purity scandium oxide, with a purity of approximately 99 wt. %.

The present disclosure provides a process for polishing at least one metal contaminant from a stock solution comprising Sc comprising the steps of a) contacting the stock solution with an ion exchange resin capturing Sc and the at least one metal contaminate so as to produce a metal ion exchange resin complex, and b) scrubbing the metal resin complex with a scrubbing solution comprising a carboxylate ion, so as to produce a Sc ion exchange resin complex and a spent carboxylate solution, which can be treated by electrodialysis to regenerate the carboxylate ion required for scrubbing.