Separation of scandium and thorium from rare earth minerals

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61389021%3A_____%2F24%3A00616852" target="_blank" >RIV/61389021:_____/24:00616852 - isvavai.cz</a>

Result on the web

<a href="https://webadmin.icct.cz/Amca-ICCT/media/content/2024/documents/Book_of_abstracts_-ICCT2024.pdf" target="_blank" >https://webadmin.icct.cz/Amca-ICCT/media/content/2024/documents/Book_of_abstracts_-ICCT2024.pdf</a>

DOI - Digital Object Identifier

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Result language

angličtina

Original language name

Separation of scandium and thorium from rare earth minerals

Original language description

Both uranium ores and the thorium-bearing phosphate mineral monazite contain significant amounts of lanthanides, including scandium and yttrium. Similar variations have been identified following the recent announcement of the discovery of new lanthanoid deposits in the Kiruna region of Sweden. The processing of raw materials to extract REEs and scandium primarily requires the removal/isolation of radioactive thorium. This can be achieved by, inter alia, carbidation of the raw material, with subsequent conversion of the hydrolyzable carbides into soluble compounds suitable for ion-exchange separation. The possibility of formation of thorium carbide by reaction with carbon at temperatures of 2000 - 2200°C by Spark plasma sintering (SPS) was verified on raw material from the Czech uranium deposit Jáchymov, containing oxides and silicates of scandium and thorium, with high radioactivity caused by thorium content. At a maximum temperature of 2200°C in the FCT SYSTEME HP-D10 apparatus, hydrolyzable carbides Sc2OC and Sc4C3 were formed, and carbidation of the present ThO2 did not occur, even when using the more reactive carbon form of graphene. A thermodynamic calculation of the reaction ThO2 + xC = ThC, ThC2 + yCO indicated the possibility of this reaction above 2500°C. The reaction at higher temperatures was therefore verified in an Acheson-type micropiece with a tungsten heating core with the possibility of reaching temperatures up to 3400°C. After hydrolysis of this product, allylene, a typical hydrolysis product of scandium carbides, was identified in the gas phase. After subsequent dissolution of the sample in hydrochloric acid and filtering of the solution, only the radioactive monocarbide ThC (type B1) was identified in the insoluble residue. The radioactivity value of the eachate after removal of the thorium, suitable for further safe processing, was at the limit of the exemption level according to the SÚJB standard.

Czech name

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Czech description

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Type

O - Miscellaneous

CEP classification

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OECD FORD branch

20506 - Coating and films

Project

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Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2024

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů