# US 2018/0023168 A1 · Method for recovering scandium

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- Number: US 2018/0023168 A1
- Document ID: US20180023168A1
- Status: Published application
- Kind: A1
- Application number: 15/546,038
- Filed: 2015-12-08
- Published: 2018-01-25
- Earliest claimed: 2015-02-02
- Assignees: Sumitomo Metal Mining Co., Ltd.
- Applicants: Sumitomo Metal Mining Co., Ltd.
- Inventors: Ryoma Yamaguma; Tatsuya Higaki; Hidemasa Nagai; Satoshi Asano; Hiroshi Kobayashi
- Web page: https://patentgrep.com/patent/US20180023168A1

## CPC

- C22B 3/382: {Phosphine chalcogenides, e.g. compounds of the formula R3P=X with X = O, S, Se or Te}
- C22B 3/42: by ion-exchange extraction
- C22B 3/22: by physical processes, e.g. by filtration, by magnetic means {, or by thermal decomposition} (treatment or purification of solutions by liquid-liquid extraction C22B3/26)
- C22B 3/44: by chemical processes (treatment or purification of solutions by liquid-liquid extraction C22B3/26, by ion-exchange extraction C22B3/42)
- C22B 59/00: Obtaining rare earth metals
- Y02P 10/20: Recycling
- C22B: PRODUCTION AND REFINING OF METALS (electrolytic C25); PRETREATMENT OF RAW MATERIALS
- Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS

## Abstract

Provided is a method for recovering scandium with which scandium can be efficiently recovered as high purity scandium oxide from a scandium-containing solution containing impurities such as iron without causing problems such as increased cost and safety problems. According to the method for recovering scandium according to the present invention, the pH of a solution containing scandium and iron (scandium-containing solution) is adjusted within the range of not less than −0.5 and less than 1, then scandium oxalate is obtained by adding the pH adjusted solution to an oxalic acid solution, and the scandium oxalate is roasted into scandium oxide.

## Claims

### Claim 1

A method for recovering scandium, comprising:
adjusting a pH of a solution containing scandium and iron (scandium-containing solution) to a range between −0.5 or more and less than 1;
adding the solution after the pH adjustment to an oxalic acid solution having a pH of between −0.5 and less than 1 to obtain scandium oxalate; and
roasting the scandium oxalate to convert the scandium oxalate into scandium oxide.

### Claim 2 (depends on 1)

The method for recovering scandium according to claim 1, wherein the scandium-containing solution is obtained by subjecting a solution containing scandium to an ion exchange treatment and a solvent extraction treatment.