Effect of Protective Alkali and pH on Gold Extraction in Cyanide Leaching Process of Two Stage Roasting Calcine of Arsenic Bearing Gold Concentrate

The effect of protective alkali and pH on gold extraction in cyanide leaching process of two stage roasting calcine of arsenic bearing gold concentrate was investigated. The results showed that the gold extraction was independent of protective alkali such as caustic soda, sodium carbonate and lime, and the effect of pH on gold extraction was obvious. If the pH of pulp is high, the arsenic concentration of cyanide leaching solution is increased to decrease gold extraction. The effect of arsenic concentration of solution on gold extraction was also investigated. When the leaching solution has no lead ion, the arsenic has no effect on gold extraction, but when the arsenic and lead exist in solution simultaneously, the effect of arsenic on gold extraction is high.