METHOD OF SEPARATION OF HEAVY REM (YTTRIUM, YTTERBIUM, ERBIUM AND DYSPROSIUM) DURING EXTRACTION THEREOF FROM PHOSPHATIC SOLUTIONS Russian patent published in 2021 - IPC C22B59/00 C22B3/26 

FIELD: metallurgy.

SUBSTANCE: invention relates to the area of hydrometallurgy of rare and rare earth metals, namely the methods of extraction separation and synthesis of individual compound of REM. Separation of heavy rare earth metals (REM), including yttrium, ytterbium, erbium and dysprosium, from phosphatic solutions includes extraction with di-2-ethylhexilphosphorous acid (D2EHPA) solution in kerosene and gradual separation of heavy REM in a cascade of contra-flow reactors. The resulting extraction is treated from iron (III) by oxalic acid. Separation of heavy REM is conducted from the treated extraction in the cascade of reactors comprised of three series containing 5 to 10 stages resulting in individual compounds of REM. First dysprosium is separated under the temperature between 21 and 23 °C using 1 to 2 M of sulphuric acid solution. Then yttrium and erbium are separated by 2 to 4.5 M sulphuric acid solution under the temperature between 21 and 23 °C. Ytterbium is separated under the temperature between 50 and 60 °C using 5 to 6 M of sulphuric acid solution. The resulting aqueous solutions from each series are directed for precipitation by sodium carbonate, rinsing and filtration resulting in insoluble REM carbonates.

EFFECT: method enables collateral synthesis of individual REM compounds with no less than 90% purity from extraction phosphorous acid with extraction rate of heavy REM no less than 90%.

1 cl, 2 dwg