METHOD FOR PROCESSING EUDIALYTE CONCENTRATE Russian patent published in 2021 - IPC C22B59/00 C22B34/14 C22B3/06 C22B3/26 

FIELD: technological processes.

SUBSTANCE: invention relates to processing of eudialyte concentrate and can be used for production of pure compounds of zirconium, hafnium and rare-earth elements. Eudialyte concentrate is decomposed by nitric acid to obtain gel, drying gel, water leaching gel with conversion of rare-earth elements into solution, and in insoluble residue of zirconium compound, as well as separation of solution from precipitate, followed by separation of zirconium compounds. Drying of gel is carried out at temperature from 180 to 200°C. In order to extract zirconium compounds, the residue after aqueous washing is subjected to nitrogen leaching in the presence of fluorine-containing compounds in amount of 4.0 to 4.5 mol of fluorine per 1 mol of zirconium. Obtained pulp is filtered and the precipitate is washed on the filter. Combined solution after nitric leaching and washing of the residue is neutralized in two steps at first to pH = 5-6 to separate the zirconium compounds precipitate, and then to pH = 9-11 to separate manganese hydroxide. Precipitate of zirconium compounds is dissolved in nitric acid and directed into a cycle for extraction separation of zirconium and hafnium using a solution of tributyl phosphate in a hydrocarbon diluent to obtain highly pure compounds of zirconium and hafnium.

EFFECT: method provides both high degree of recovery of REE and zirconium in form suitable for obtaining especially pure compounds of zirconium and hafnium.

1 cl, 2 ex