METHOD OF EXTRACTING HAFNIUM AND ZIRCONIUM FROM FLUORIDE SECONDARY MATERIAL CONTAINING HAFNIUM AND ZIRCONIUM Russian patent published in 2020 - IPC C22B34/14 C22B3/06 

FIELD: chemistry.

SUBSTANCE: invention relates to extraction of hafnium and zirconium from secondary raw materials, and also can be used for extraction of zirconium and hafnium from fluoride secondary raw material. Method involves aqueous washing of the material to obtain a precipitate, dissolving the precipitate in an acid, followed by separation of hafnium and zirconium in the form of salts. Water washing is carried out at temperature of 60 ± 5 °C and phase ratio S:L = 1:3–5, followed by alkaline treatment of the precipitate with potassium hydroxide solution with mass concentration from 120 to 250 g/dm³ at temperature of 55 ± 5 °C and phase ratio S:L = 1:3–5, filtration and subsequent washing of the residue. Dissolving the obtained precipitate is carried out in hydrofluoric acid, then potassium chloride is added, pH is adjusted to pH = 4–5 and filtered in hot form. Obtained filtrate is cooled for crystallization of potassium fluorhydrate and potassium fluorozirconate.

EFFECT: method enables complex extraction of hafnium and zirconium with minimization of losses of hafnium and zirconium with residue.

1 cl, 3 ex