# US 10,246,761 B2 · Method for recovering scandium > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,246,761 B2 - Document ID: US10246761B2 - Status: Granted - Kind: B2 - Application number: 16/061,684 - Filed: 2016-12-13 - Published: 2018-12-27 - Granted: 2019-04-02 - Earliest claimed: 2015-12-16 - Assignees: Sumitomo Metal Mining Co., Ltd. - Applicants: Sumitomo Metal Mining Co., Ltd. - Inventors: Tatsuya Higaki; Hidemasa Nagai; Hiroshi Kobayashi - Web page: https://patentgrep.com/patent/US10246761B2 ## CPC - C22B 59/00: Obtaining rare earth metals - C22B 3/24: by adsorption on solid substances, e.g. by extraction with solid resins - C22B 3/44: by chemical processes (treatment or purification of solutions by liquid-liquid extraction C22B3/26, by ion-exchange extraction C22B3/42) - Y02P 10/234 - 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 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. ## Claims ### 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. ### Claim 2 (depends on 1) 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. ### Claim 3 (depends on 1) 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. ### Claim 4 (depends on 3) The method for recovering scandium according to claim 3, wherein the extractant after backward extraction is repeatedly used as the extractant for solvent extraction. ### Claim 5 (depends on 1) 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. ### Claim 6 (depends on 1) 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. ### Claim 7 (depends on 2) 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. ### Claim 8 (depends on 3) 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. ### Claim 9 (depends on 4) 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. ### Claim 10 (depends on 2) 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. ### Claim 11 (depends on 3) 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. ### Claim 12 (depends on 4) 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.