Production Practice to Improve the Flotation Process Index of Shuiyindong Gold Mine in Guizhou Province

The gold ore of Shuiyindong Gold Mine in Guizhou province is a micro-fine disseminated refractory gold ore, which contains gold-bearing minerals such as pyrite and arsenopyrite with fine particle size and a large number of gangue minerals that are easy to be argillated. For the process of floating these raw materials, fineness should be α -74 µm 90%. The gold bearing minerals can be fully dissociated, but in the grinding process it is easy to"over-grind". The whole process of rough and cleaning operations in flotation plant were explored in details through sampling, concentration, fineness inspection, screening analysis and laboratory analysis. It was found that there were problems such as "slime", complex flotation reagents, low concentration of cleaning flotation and poor recovery effect of gold in tailings at coarse and fine particle fraction. For those problems, on the basis of experimental study of the reagents optimization system in laboratory, through methods such as adjusting the ball mill with reduce " over-grinding ",adjusting the concentration of pulp in processing, optimizing the reagents system and reducing the number of cleaning flotation we started to have better results. After all that we managed to increase the rate of fine mineral, reduce the cycle of middlings, strengthen the rough and cleaning flotaion of operation efficiency, reduce the tailings grade and raise the index of flotation. Finally, the recovery of gold is increased from 5.76% to over 91%.