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.

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.

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.

The invention relates to a method for treating a residue obtained from the chloride process, wherein the residue comprises the components titanium dioxide, coke, an inert metal oxide, and an iron-containing component. Further, the invention refers to the use of this method to separate the components contained in said residue, and to the use of the separated components in the chloride process for obtaining titanium dioxide.

The invention relates to a method for treating a residue obtained from the chloride process, wherein the residue comprises the components titanium dioxide, coke, an inert metal oxide, and an iron-containing component. Further, the invention refers to the use of this method to separate the components contained in said residue, and to the use of the separated components in the chloride process for obtaining titanium dioxide.

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.