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.

Provided is a method for obtaining high-purity scandium oxide efficiently from a solution containing scandium. The method for producing high-purity scandium oxide of the present invention has a first firing step S12 for subjecting a solution containing scandium to oxalation treatment using oxalic acid and firing the obtained crystals of scandium oxalate at a temperature of 400 to 600° C., inclusive, a dissolution step S13 for dissolving the scandium compound obtained by firing in one or more solutions selected from hydrochloric acid and nitric acid to obtain a solution, a reprecipitation step S14 for subjecting the solution to oxalation treatment using oxalic acid and generating a reprecipitate of scandium oxalate, and a second firing step S15 for firing the reprecipitate of obtained scandium oxalate to obtain scandium oxide.

Provided is a method for obtaining high-purity scandium oxide efficiently from a solution containing scandium. The method for producing high-purity scandium oxide of the present invention has a first firing step S12 for subjecting a solution containing scandium to oxalation treatment using oxalic acid and firing the obtained crystals of scandium oxalate at a temperature of 400 to 600° C., inclusive, a dissolution step S13 for dissolving the scandium compound obtained by firing in one or more solutions selected from hydrochloric acid and nitric acid to obtain a solution, a reprecipitation step S14 for subjecting the solution to oxalation treatment using oxalic acid and generating a reprecipitate of scandium oxalate, and a second firing step S15 for firing the reprecipitate of obtained scandium oxalate to obtain scandium oxide.

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, from 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 rare earth metals from acid-leaching slurries or solutions.

Provided is a method for obtaining high-purity scandium oxide efficiently from a solution containing scandium. The method for producing high-purity scandium oxide of the present invention has a first firing step S12 for subjecting a solution containing scandium to oxalation treatment using oxalic acid and firing the obtained crystals of scandium oxalate at a temperature of 400 to 600 C., inclusive, a dissolution step S13 for dissolving the scandium compound obtained by firing in one or more solutions selected from hydrochloric acid and nitric acid to obtain a solution, a reprecipitation step S14 for subjecting the solution to oxalation treatment using oxalic acid and generating a reprecipitate of scandium oxalate, and a second firing step S15 for firing the reprecipitate of obtained scandium oxalate to obtain scandium oxide.

Provided is a method for obtaining high-purity scandium oxide efficiently from a solution containing scandium. The method for producing high-purity scandium oxide of the present invention has a first firing step S12 for subjecting a solution containing scandium to oxalation treatment using oxalic acid and firing the obtained crystals of scandium oxalate at a temperature of 400 to 600 C., inclusive, a dissolution step S13 for dissolving the scandium compound obtained by firing in one or more solutions selected from hydrochloric acid and nitric acid to obtain a solution, a reprecipitation step S14 for subjecting the solution to oxalation treatment using oxalic acid and generating a reprecipitate of scandium oxalate, and a second firing step S15 for firing the reprecipitate of obtained scandium oxalate to obtain scandium oxide.

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.

The invention provides a method for recovering scandium from an acidic solution containing scandium. The method having [a] a precipitation step wherein sodium sulfate is added into the acidic solution containing scandium to obtain a precipitate of a scandium double sulfate; [b] a neutralization step wherein pure water is added to the precipitate of a scandium double sulfate to dissolve the precipitate of a scandium double sulfate therein, and scandium hydroxide is obtained by adding a neutralizing agent into the dissolution liquid; and [c] a re-dissolution step wherein an acid is added to the scandium hydroxide obtained in the neutralization step, so that a scandium dissolution after purification, in which the scandium hydroxide is dissolved, is obtained.

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. % (in terms of dry matter), the TiO.sub.2 content not more than 3 wt. % (in terms of dry matter), the ZrO.sub.2 content not more than 15 wt. % (in terms of dry matter), and wherein scandium in the concentrate is in form of a mixture of Sc(OH).sub.3 hydroxide with ScOHCO.sub.34H.sub.2O. Also provided is a method for producing high-purity scandium oxide, with a purity of approximately 99 wt. %.