Characteristics of BiAsO4 precipitate formation in copper electrolyte

The characteristics of BiAsO4 precipitate formation in copper electrolyte were studied. Though BiAsO4 precipitate is theoretically unstable in the copper electrolyte, it can form under the conditions of decreased local acidity. Once BiAsO4 precipitate is formed, it is difficult to redissolve in the copper electrolyte. The formation of BiAsO4 precipitate has exhibits hysteresis. After local acidity was decreased, it was necessary to wait at least 40 min to observe the precipitate beginning to appear in the copper electrolyte. Under normal conditions, the precipitate of BiAsO4 formed in copper electrolyte is α-BiAsO4, while if formed in the copper electrolyte without Sb(III) it is β-BiAsO4 or a mixture of β-BiAsO4 and α-BiAsO4.