METHOD OF BISMUTH-POTASSIUM-AMMONIUM CITRATE PRODUCING Russian patent published in 2002 - IPC

FIELD: chemical technology. SUBSTANCE: invention relates to methods of processing bismuth-containing materials to obtain bismuth as solid compounds or solutions. Bismuth basic nitrate is precipitated from nitrate solutions at pH = 0.5-1.2 and temperature 15-35C and then converted to bismuth citrate at pH = 0.4-1.0 and initial temperature 15-40 C with the following its increase to 50-90 C. Bismuth citrate is dissolved in potassium hydroxide an aqueous solution in the presence of citric acid and ammonia at pH = 7-10 and temperature 50-90 C. The prepared solution is diluted with water and subjected for spraying drying. EFFECT: simplified process, decreased cost of product. 3 ex