Study On Gold Leaching From Refractory Concentrate Ore Bearing Gold, Sulfur And Arsenic By Roasting-iodine Process

Gold is a rare metal and the exploration and metallurgy of gold deposit isimportant to the development and stability of world economic.Gold resources are becoming scarce with the development of economy and moreand more development and utilization of mineral resources.The reserves of gold ore are small and the grade of is low and the exploration ofgold ore deposit need a lot of time. It is not realistic that increasing the output of goldby exploring new gold deposits,but also is inconsistent with the rational use ofresources and the requirements of sustainable development.Refractory gold ores is widely distributed in our country, and the reserves isabout1000tons, accounting for about1/3of China’s gold reserves. How to use theserefractory gold ore and improve the utilization rate of the refractory gold ore is anefficient means to improve China’s gold output, also conforms to the requirements ofsustainable development of mineral resource. Researchers have made great efforts anda lot of experiments have been done in the process of the development and utilizationof refractory gold resources.A lot of process that can effectively improve the goldleaching rate of refractory is developed and it made a huge contribution to improvethe utilization rate of gold resources.This paper introduced the pretreatmentexperiment with microwave and conventional roasting.The pretreated ore is leachedwith iodide and the leaching rate is greatly improved compared with direct oreleaching. The main results were as follows:1. The results show that the concentrate ore bearing gold, sulfur and arsenic is akind of refractory concentrate ore bearing gold, sulfur and arsenic with the analysis ofprocess mineralogy of ore and the test of direct ore leaching.The refractoryconcentrate ore bearing gold, sulfur and arsenic contain more than40%S and Fe elements and the main mineral compositions in the ore is FeS2through the XRDtesting.2. Microwave roasting pretreatment can increase the temperature of sulfide tohigher temperature in a short period of time and the sulfide react with the oxygen inthe air and the lattice structure of sulfides is destroyed, but the microwave roastingpretreatment takes a long time and large power.3. The conventional oxidation roasting can effectively improve the leaching rateof gold of refractory concentrate ore bearing gold, sulfur and arsenic.4. The iodide can effectively extract the gold in ore and the leaching rate of goldcan reach over78%after ore is pretreated.The results has important reference value to the process design of the refractoryconcentrate ore bearing gold, sulfur and arsenic and microwave roasting.