High Arsenic Gold Sulfur Concentrate Resources And Efficient Use Of The Pilot Study

Gold-bearing pyrite with high arsenic of Hengyang, Hunan Province is a complex pyrite concentrate of fine-grained arsenic-polymetallic minerals, with gold content of 5.00g/t, siliver 47.90g/t, sulfur 45.59%, iron 39.10%,lead 0.58%,zinc 0.89%,arsenic 1.20%. A large amount of research has been done at home and abroad to find an efficient way of extracting gold, sulfur, iron and other minerals. However, little breakthrough has been achieved in this long standing problem.Considering the characteristics of concentrate associated with sulfur, a new efficient process of united technology of beneficiation and metallurgy was presented in this paper:depth concentrate-- oxidizing roasting-- chloridizing volatilization at high temperature, which means, in the premise of full use of existing equipment and technical staff, grafting the process of chloridizing volatilization at high temperature of precious metals such as gold, silver and non-ferrous metals lead, zinc, between the link of the industrial production of sulfuric acid and smelting iron, to achieve the comprehensive recycling of the resources above farthest.As gold is wrapped by pyrite and arsenopyrite in the form of microscopic native gold, it is difficult to recycle the gold-bearing pyrite with high arsenic effectively by traditional leaching gold extraction process. Thus, depth concentrate was applied, and the corresponding experimental studies were conducted. By testing the effects of grinding fineness, sulfuric acid dosage and xanthate dosage on depth cleaning of sulfur concentrate, we obtained the depth cleaning concentrate with high level of surfur(50.18%), iron(43.97%)and low level of calcium, magnesium, aluminum, silica, gangue(the grade content of iron and sulfur reached more than 94%, belonging to high purity of gold-bearing sulfur concentrate, and the recovery rate of both gold and sulfur was more than 91%).Theoretical analysis and experimental study were introduced on the oxidation process of sulfur concentrate with high quality attained from depth cleaning. The results showed that:oxidation of arsenopyrite required relatively weak oxidation atmospHere, with temperature above 550℃, in which arsenic could be removed effectively; while pyrite needed rich oxidation atmospHere, with temperature above 750℃, where desulfurization could be complete. Therefore, two roasting processes can be used to remove arsenic and sulfur, which brought about arsenic removal rate of 92%, desulfurization rate of 99.3%. Then calcine with high level of iron(63.53%), low content of arsenic(0.13%), sulfur(0.45%)and gold up to 9.30g/t. was acquired, which provided good conditions for next oxidation to produce high quality iron pellets.In the experiment of chloridizing volatilization of gold-bearing calcine at high temperatur and low chlorine conditions, the effects of chlorinating agent types, chloride dosage, roasting time and temperature on this experiment were tested, and statistical product and service solutions software was used to analyze statistics. Results suggested that:the chlorinating agent types have a significant impact on the experiment from a statistical perspective. Under the optimum condition with the production practice and economic factors considered, evaporation rate of gold was up to 96.3% and pellets containing 59.5% iron,0.02%lead,0.012%sulfur,0.059%arsenic were acquired, which belonged to secondary sinter standards and could be directly put into the blast furnace to smelt pig iron.