METHOD OF PROCESSING OF THE TANTALONE-BIOBASE CONCENTRATE Russian patent published in 2017 - IPC C22B34/24 C22B30/06 C22B3/06 

FIELD: chemistry.

SUBSTANCE: tantalone-biobase concentrate containing 39.6-43.0 wt % of bismuth is treated at an initial room temperature with a mixture of hydrofluoric acid with a concentration of 270-330 g/l of HF and sulfuric acid with a concentration of 400-500 g/l of H₂SO₄ at T:H=1:(1.9-3.0) with transfer of bismuth in the form of fluoride to the precipitate, which is separated from the filtrate containing tantalum and niobium. The fluoride bismuth-containing precipitate is treated with a solution of 92-94% sulfuric acid at a temperature of 95-105°C. The resulting bismuth sulfate precipitate is treated with nitric acid at a concentration of 200-300 g/l HNO₃ at T:H=1:(6.6-10.0) to obtain a nitrate-bismuth-containing solution.

EFFECT: method makes it possible to increase the extraction of tantalum and niobium from the concentrate into a solution, extracting bismuth from the sulfate precipitate into a nitric acid solution, while reducing the energy intensity of the process and reducing the consumption of reagents.

4 cl, 5 ex