The development of research on pyrite low alkalinity flotation depressants

Pyrite is widely associated with non-ferrous metal minerals such as chalcopyrite, sphalerite and galena. The production practice shows that in the flotation separation of polymetallic sulphide ores, the high alkali process represented by lime can effectively inhibit pyrite. However, the high alkali scheme represented by lime has some disadvantages, such as large amount usage of lime, scaling of pipes, unstable production operation and unfavorable to the recovery of rare and precious metals. The research, development and application of high efficiency, high selectivity and low alkalinity pyrite depressants are of great significance for improving the level of comprehensive utilization of resources, reducing the construction investment and production cost of mining enterprises and environmental protection. Based on the summary of pyrite crystal structure and its floatability, this paper systematically summarizes the types of pyrite low alkalinity inhibitors, the action mechanism of different kinds of inhibitors and the latest research progress. The analysis results show that the inhibition mechanism of inhibitors on pyrite can be divided into two categories: the surface of pyrite is oxidized to form hydrophilic films such as Ca（OH）₂, CaSO₄ and Fe（OH）₃, thus reducing the floatability of pyrite. The surface of pyrite is adsorbed through physical or chemical action, which hinders the adsorption of collectors. In order to meet the national requirements for green, low-carbon and environmental protection of metal mines, the next development direction of pyrite low alkalinity inhibitors is to strengthen the research on the inhibition mechanism of new and combined inhibitors on pyrite, and develop new and efficient inhibitors by means of quantum chemistry and molecular design.