Behavior of Arsenic in Refractory Gold Ore Processing-A Case Study of PT Newmont Minahasa Raya

摘要

PT Newmont Minahasa Raya operates a 700,000 tonne per annum gold ore treatment plant in North Sulawesi, Indonesia. The deposit is predominately refractory in nature. The gold is finely disseminated and associated with fine-grained pyrite enriched in arsenic. Extensive studies were performed to develop a process for gold recovery, as well as detoxification. Gold recovery is accomplished by dry grinding and whole ore roasting, followed by conventional cyanidation and carbon adsorption. The tailings are treated to remove arsenic and other deleterious elements before disposing by submarine tailings placement on the sea floor. The arsenic concentration in the feed is normally in the range 0.1 to 0.2