Method for recovering scandium

Patent metadata

Field	Value
Publication number	US-2018371579-A1
Application number	US-201616061684-A
Country	US
Kind code	A1
Filing date	Dec 13, 2016
Priority date	Dec 16, 2015
Publication date	Dec 27, 2018
Grant date	—

Abstract

A method for recovering scandium is provided, which is capable of recovering highly-pure scandium from nickel oxide ore in a simple and efficient manner. The method for recovering scandium according to the present invention includes a scandium elution step S2 of passing a solution containing scandium through an ion exchange resin to obtain an eluted liquid containing scandium from the ion exchange resin, a neutralization step S3 of adding for neutralization a neutralizing agent to the eluted liquid, a solvent extraction step S4 of solvent-extracting the neutralized eluted liquid using an amine-based extracting agent, and a scandium recovering step S5 of obtaining a scandium precipitate from residual liquid separated by the solvent extraction, and then roasting the precipitate to obtain scandium oxide.

First claim

1 . A method for recovering scandium, comprising:
a scandium elution step of allowing a solution containing scandium to pass through an ion exchange resin and obtaining an eluate containing scandium from the ion exchange resin; a neutralization step of neutralizing the eluate by adding a neutralizing agent to the eluate; a solvent extraction step of subjecting a post-neutralization eluate to solvent extraction using an amine-based extractant; and a scandium recovering step of obtaining a precipitate of scandium from a raffinate liquid separated by solvent extraction and obtaining scandium oxide by roasting the precipitate.

2 . The method for recovering scandium according to claim 1 , wherein scrubbing to mix a sulfuric acid solution having a concentration of 1.0 mol/L or more and 3.0 mol/L or less as a washing liquid with an extractant after solvent extraction and to separate scandium contained in the extractant into the washing liquid is performed in the solvent extraction step and
a precipitate of scandium is obtained from the washing liquid after scrubbing along with the raffinate liquid in the scandium recovering step.

3 . The method for recovering scandium according to claim 1 , wherein a carbonate is added to an extractant after solvent extraction and backward extraction is performed to obtain an extractant after backward extraction and a backward extraction liquid in the solvent extraction step.

4 . The method for recovering scandium according to claim 3 , wherein the extractant after backward extraction is repeatedly used as the extractant for solvent extraction.

5 . The method for recovering scandium according to claim 1 , wherein a neutralizing agent is added to the eluate to adjust a pH to a range of 5 to 6, a neutralized precipitate and a neutralized filtrate are generated by solid-liquid separation, and an acid is added to the neutralized precipitate to obtain a redissolved liquid in the neutralization step and
the redissolved liquid obtained is subjected to solvent extraction as the post-neutralization eluate in the solvent extraction step.

6 . The method for recovering scandium according to claim 1 , wherein in the neutralization step,
a neutralizing agent is added to the eluate to adjust a pH to a range of 3.5 to 4.5, a primary neutralized precipitate and a primary neutralized filtrate are generated by solid-liquid separation, subsequently a neutralizing agent is further added to the primary neutralized filtrate to adjust a pH to a range of 5.5 to 6.5, a secondary neutralized precipitate and a secondary neutralized filtrate are generated by solid-liquid separation, and an acid is added to the secondary neutralized precipitate to obtain a redissolved liquid and the redissolved liquid obtained is subjected to solvent extraction as the post-neutralization eluate in the solvent extraction step.

7 . The method for recovering scandium according to claim 2 , wherein a neutralizing agent is added to the eluate to adjust a pH to a range of 5 to 6, a neutralized precipitate and a neutralized filtrate are generated by solid-liquid separation, and an acid is added to the neutralized precipitate to obtain a redissolved liquid in the neutralization step and
the redissolved liquid obtained is subjected to solvent extraction as the post-neutralization eluate in the solvent extraction step.

8 . The method for recovering scandium according to claim 3 , wherein a neutralizing agent is added to the eluate to adjust a pH to a range of 5 to 6, a neutralized precipitate and a neutralized filtrate are generated by solid-liquid separation, and an acid is added to the neutralized precipitate to obtain a redissolved liquid in the neutralization step and
the redissolved liquid obtained is subjected to solvent extraction as the post-neutralization eluate in the solvent extraction step.

9 . The method for recovering scandium according to claim 4 , wherein a neutralizing agent is added to the eluate to adjust a pH to a range of 5 to 6, a neutralized precipitate and a neutralized filtrate are generated by solid-liquid separation, and an acid is added to the neutralized precipitate to obtain a redissolved liquid in the neutralization step and
the redissolved liquid obtained is subjected to solvent extraction as the post-neutralization eluate in the solvent extraction step.

10 . The method for recovering scandium according to claim 2 , wherein in the neutralization step,
a neutralizing agent is added to the eluate to adjust a pH to a range of 3.5 to 4.5, a primary neutralized precipitate and a primary neutralized filtrate are generated by solid-liquid separation, subsequently a neutralizing agent is further added to the primary neutralized filtrate to adjust a pH to a range of 5.5 to 6.5, a secondary neutralized precipitate and a secondary neutralized filtrate are generated by solid-liquid separation, and an acid is added to the secondary neutralized precipitate to obtain a redissolved liquid and the redissolved liquid obtained is subjected to solvent extraction as the post-neutralization eluate in the solvent extraction step.

11 . The method for recovering scandium according to claim 3 , wherein in the neutralization step,
a neutralizing agent is added to the eluate to adjust a pH to a range of 3.5 to 4.5, a primary neutralized precipitate and a primary neutralized filtrate are generated by solid-liquid separation, subsequently a neutralizing agent is further added to the primary neutralized filtrate to adjust a pH to a range of 5.5 to 6.5, a secondary neutralized precipitate and a secondary neutralized filtrate are generated by solid-liquid separation, and an acid is added to the secondary neutralized precipitate to obtain a redissolved liquid and the redissolved liquid obtained is subjected to solvent extraction as the post-neutralization eluate in the solvent extraction step.

12 . The method for recovering scandium according to claim 4 , wherein in the neutralization step,
a neutralizing agent is added to the eluate to adjust a pH to a range of 3.5 to 4.5, a primary neutralized precipitate and a primary neutralized filtrate are generated by solid-liquid separation, subsequently a neutralizing agent is further added to the primary neutralized filtrate to adjust a pH to a range of 5.5 to 6.5, a secondary neutralized precipitate and a secondary neutralized filtrate are generated by solid-liquid separation, and an acid is added to the secondary neutralized precipitate to obtain a redissolved liquid and the redissolved liquid obtained is subjected to solvent extraction as the post-neutralization eluate in the solvent extraction step.

Assignees

• Sumitomo Metal Mining Co

Inventors

• Higaki Tatsuya
• Nagai Hidemasa
• Kobayashi Hiroshi

Classifications

• C22B59/00 Primary

  Obtaining rare earth metals · CPC title

• C22B3/44

  by chemical processes (treatment or purification of solutions by liquid-liquid extraction C22B3/26, by ion-exchange extraction C22B3/42) · CPC title

• Y02P10/20

  Recycling · CPC title

• C22B3/42

  by ion-exchange extraction · CPC title

• C22B3/28

  Amines · CPC title