Gold Leaching of a Residue Containing Elemental Sulfur with Lime Added under Pressurized Oxygen
难处理金精矿含元素硫的酸浸渣加石灰氧压浸金

A gold leaching process for an acid leached residue from an arsenic refractory gold concentrate in lime slurry under pressurized oxygen is investigated. The residue contains 17.4% of elemental sulfur. The experimental results show that the optimum quantity of lime added to the leaching solution should ensure the mole ratio of elemental sulfur to OH in the range of 0.8 to 1.1. In 3 to 5 h, 90% of gold is leached at 85C under 0.1 to 0.3 MPa oxygen pressure with the optimum lime addition in the solution. The thiosulphate produced from elemental sulfur in lime solution during oxygen leaching might be the major complexing agency for gold leaching.