BISMUTH CLEANING METHOD Russian patent published in 2014 - IPC C22B30/06 C25C1/22 C25C5/02 

FIELD: metallurgy.

SUBSTANCE: bismuth cleaning method involves bismuth electrorefining by using a hydrochloric acid bismuth solution as an electrolyte so that a bismuth sponge is obtained. Then, fusion of the obtained bismuth sponge and bubbling of the melt by inert gas is performed. Prior to electrorefining the hydrochloric acid bismuth solution is brought into contact with fine grained bismuth sponge obtained by bismuth electrorefining using hydrochloric acid bismuth solution as an electrolyte containing an additional surface active substance. As surface active substance there used is service mixture of oxyethylated alkyl phenols with Neonol trade mark of AF 9-6 type in concentration of 0.01-0.1 wt %.

EFFECT: obtaining high-purity bismuth with reduced content of Ag, Te, Po.

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