Abstract:The effects of crushing energy, ore hardness and particle size of cassiterite polymetallic sulphide ore and lead-zinc polymetallic sulphide ore on the crushing characteristics during impact crushing were investigated by mineral liberation analyzer (MLA) and drop weight test. The results show that both ores contain pyrrhotite, sphalerite, jamesonite, gangue mica and quartz except cassiterite. Cassiterite is closely associated with sulphide and quartz to form aggregates, which are mixed with each other in the form of intergrowth or symbiotic disseminated fine grains. Cassiterite has a significant impact on ore crushing characteristics. Ore hardness is negatively correlated with the product of crushing parameters of A and b, i.e. A×b, the effect of crushing energy on crushing fineness is related to crushing parameters A and b, and the influence degree increases with the increase of A. The influence degree increases with the increase of b when crushing energy E_CS is less than 1 kW·h/t, and the influence degree decreases with the increase of b when crushing energy E_CS is greater than 1 kW·h/t. The impact of crushing energy on crushing fineness is greater than that of ore particle size when the crushing energy is lower; on the contrary, the impact of ore particle size on crushing fineness is greater than that of crushing energy when crushing energy is higher.

Key words: polymetallic sulfide ore; crushing fineness; crushing parameters; crushing energy; ore particle size