Research on the Process of Comprehensive Recovery of Gold from Old Tailings Resources

1. Brief Introduction：
It is a national project, “Technology Research on Development and Utilization of Refractory Gold Resources (in Mining, Mineral Processing and Metallurgy)” under the “Ninth Five Year Plan”, and the achievement was made with the joint effort of Changchun Gold Research Institute and Xiangxi Gold Mine.

Old tailings of Xiangxi Gold Mine is of extra-fine and with occluded gold which are rarely seen home and abroad, and its composition is complicated, containing a kind of gold bearing material with stibium content which is harmful for cyanidation. According to the features of technical mineralogy of this tailing, thorough test and studies were conducted, and a flowsheet of “Flotation for Gold and Stibium + Tailings Cyanidation” was decided. According to the dumping conditions of the tailings dam and the features of the tailings, combining with the requirements of the concentration plant for feed materials, a combined mining method of dredger + water jet mining was selected. The waste water from this process was treated by the sulphur dioxide from the smelter（INCO method, realizing the purpose to treat waste by waste. This achievement passed the technical appraisal of experts of Hunan Provincial Science Committee in Dec. 2000.

2.Main Techno-economic Indices：
Using this achievement, a gold extraction plant for the old tailings with a capacity of 100 tons/day was built in Xiangxi Gold Mine. Through commissioning and pre-commercial production, the actual production capacity reached up to 120 tons/day. The recovery for gold and stibium reached 73.18% and 30% repectively when the grade of gold is 4.18g/t and stibium is 0.71% in the tailings, and the final recovery for gold is 69.9% and for stibium 24%, produciing 105kg gold and 62 tons of stibium concentrate for the mine as an extra.

3. Industrial Application of the Achievements：
Because of the overall gap between China and other developed countries in the metallurgical technology of gold, the gold contents in the tailings of most of the current tailings dams are still high. In the past, the content in flotation tailings was mostly about 1g/t. For example in Zhangjiakou Gold Mine, there is 1 million tons of them, and in Wulong Gold Mine and Xiangxi Gold Mine, 2 million tons of them with a gold content of 0.8~1.0g/t, in Henan Qinling and Wenyu, there are also large amount of this tailings. So, the process achieved by this research in mining and mineral processing has a great application potential, especially for recovering those complex gold contained tailings resources dominated by superfine and disseminated structurs.