关键词: 含碳金矿石, 碳抑制剂, 碳酸钠, 氰渣品位

Abstract:

The nature of the ore in Xinhui gold mine is polymetallic sulfide ore which contains many useful elements such as gold，silver，copper，lead and zinc as well as a number of harmful elemental carbon.The content of carbon in ore and concentrate increases with mining depth.Because of the absorption of carbon on gold，higher carbon content of concentrate leads to a poorer leaching and washing effect, higher cyanide slag grade and lower cyaniding recovery rate.Since the beginning of 2011，we have been trying small experiments of adding carbon inhibitors in the leaching progresses in order to reduce the influence of carbon on cyanidation and to improve the recovery rate of gold.The results show that the recovery rate of gold can be improved by adding sodium carbonate in leaching progresses which can suppress the absorption of carbon on gold.The industrial test was carried out since June 2011 that sodium carbonate is added in the actual production of cyanide，and the result shows that cyanide slag grade during June 2011 and December 2011 is reduced by 0.26 g/t than that of 2010，which brings the company an extra economic gain of 1.55 million yuan per year.

Key words: carbonaceous gold ore, carbon inhibitors, sodium carbonate, cyanide slag grade