METHOD OF PRODUCING BISMUTH NITRATE BASIC Russian patent published in 2018 - IPC C01G29/00 C22B30/06 C22B3/44 

FIELD: metallurgy.

SUBSTANCE: invention relates to the hydrometallurgy of rare metals, in particular, to methods for processing bismuth-containing materials to produce bismuth nitrate base. Producing of bismuth nitrate basic is carried out by treatment of bismuth-containing material with nitric acid. Then, hydrolytic purification of bismuth from the impurities is carried out by adding a solution of bismuth nitrate to the heated bismuth to 50–80 °C water at a volume ratio of water and bismuth-containing solution (7–9):1 followed by adjusting the pH of the mixture with an aqueous solution of ammonia to 0.5–1.4. Precipitate is washed with water at a temperature of 15–40 °C and dried at 80–120 °C. Technical result is increasing in recovery rate of bismuth into the product to 96.8 %, as well as increasing in the specific surface area of the product to 1.08 m²/g.

EFFECT: increase in bismuth recovery rate and increase in the specific surface area of the product.

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