Abstract:The procedure of removal calcium (calcium sulfate) from copper electrolyte at purification system of copper electrolysis was determined, by combining theoretical analysis with production practice. Crystallization mother liquor of copper sulfate was maintained room temperature adequately, then pumped to flow through pressure filter naturally, calcium and part of arsenic, antimony, bismuth, etc, was removed from the solution. The ratio of removal calcium was achieved for 90%, and calcium concentration in copper electrolyte was controlled effectively.