The gold minerals in a high sulfur gold deposit are closely associated with pyrite, and the average particle sizes of gold ore and pyrite are 3.58 and 32.80 μm, respectively. The embedded particle size is fine. The concentrate grade and recovery are not satisfactory in actual production. In order to further improve the concentrate grade and recovery rate, pyrite was determined as the flotation target mineral in this experimental study according to the characteristics of the mine, The optimal flotation process and parameters were obtained through the system condition test and beneficiation test, and then the open circuit test and closed-circuit test were carried out. But the flotation indexes resulted from the tests were not ideal. Based on the judgment that pyrite in middling ore is mostly conjoined, the flotation middling was reground, and the satisfactory indexes of a concentrate gold grade of 17.4 g/t and a gold recovery of 80.66% were achieved. Combined with the processes of "ultra-fine grinding" and "alkali leaching pretreatment", the leaching test of flotation concentrate yielded a satisfactory index of gold leaching rate of 77%, providing a valuable reference for the production sites. |