METHOD OF PRODUCING HIGHLY PURE TANTALUM OXIDE FROM TANTALUM-CONTAINING SOLUTIONS Russian patent published in 2017 - IPC C01G35/00 

FIELD: chemistry.

SUBSTANCE: method for producing highly pure tantalum oxide from the tantalum-containing solutions comprises tantalum hydroxide preparation for the cleansing extraction. Precipitating of tantalum hydroxide, ageing and filtration of pulp, washing of precipitate are carried out consecutively. Then, tantalum hydroxide is dissolved in a mixture of sulfuric and hydrofluoric acids to obtain the base solution for the cleansing extraction. The mentioned base solution has the following composition: tantalum oxide 140-160 g/l, total fluoride-ion is 80-97 g/l, sulfuric acid 200-300 g/l. The cleansing extraction of the resulting solution by an extracting agent, followed by washing of saturated extract andre-extraction are carried out. Octanol-1 is used as an extracting agent. Washing of the saturated extract is carried out in two steps: The resulting tantalum re-extract is diluted, tantalum hydroxide is precipitated. Filtration and washing of the precipitate, followed by its repulping are carried out. Then, tantalum hydroxide is dried and calcined to obtain tantalum oxide.

EFFECT: invention reduces costs during production of tantalum oxide, increases its purity.

4 cl, 3 dwg, 9 tbl