Recovery of silver from tailing dams waste of Eti Silver Mine Company

RECYCLING OF THE SILVER IN THE TRAILING DAMS OF ETİ SILVER MINE ENTERPRISES Selçuk YAMAN Chemistry, M. SC. Thesis, 2019 Thesis Supervisor: Prof. Dr. Yunus ERDOĞAN SUMMARY At the present time, the silver is traditionally produced with cyanide. However, when the ore is processed with cyanide leaching, productivity of the production process decreases. After the cyanide leaching of the ore in the production, the waste solid is sent to the dams. In order to recycle the high grade silver in the tailings dam, either the cyanide leaching or increasing the productivity by reducing the grain size is required. This led us to different studies. This thesis study is based on the recycling the silver with cyanide leaching after the pretreatment of the blended ore obtained from the tailings dam is cleansed from the contaminations. The key question here is "Why acid leaching or smaller grain size is supposed to be effective to increase the efficiency in the tailings dam of Eti Gümüş A.Ş.?". The findings give us the answer. It is found that approximately 30% of the silver in the run-of-mine ore is restrained inside of the silica mineral is supported by experimental research data. Therefore, it is aimed to expand the surface area of the ore thanks to reducing it into smaller sizes. Also, it is aimed to make the silver covered by silica mineral should be in contact with CN-. Metallic rendering of the silver is in the form of zinc oxide in the metallic zinc waste dam used in the Merrill-Crowe process. In Eti Gümüş A.Ş., metallic zinc is used up to five times the silver's quantity in the liquid. Unless zinc oxide is not removed from the environment, the substitution reaction in the last phase of the Merrill-Crowe process is inhibited. Therefore, it is aimed to increase the efficiency by removing zinc oxide and other metal-oxide forms using sulfuric acid leaching pretreatment. In the experiments, it was observed in the ICP-OES results that needless metal forms in the environment were removed. As H2SO4 concentration increases, it is observed in the experimental studies that percentage yield increases as well as a result of cyanide leaching of the decontaminated ore. Keywords: Silver Production, Sulfuric Acid, Atomic Absorption Spectroscopy.