Effect Of Different Shape Grinding Media On Reactivity And Flotation Behavior Of Galena And Sphalerite Milled Particles

Grinding is a significant stage in mineral dressing for producing satisfactory particles,and directly affects the subsequent process,in that the grinding media especially the shapes of grinding media play the important roles.Therefore,in this study galena and sphalerite were selected as the research objects,and self-made mill and grinding media called short cylinder and ball were designed for the grinding tests.The conclusions are as follows.The grinding effect,efficiency and particle size distribution characteristics of short cylinder and ball grinding media were varied.The results of grinding tests and particle size distribution indicated that the grinding efficiency of the short cylinder grinding media was higher,however,and the content of coarse and over-grinding particles in the grindng products was lower.While for ball grinding products,the results of grinding effect,efficiency and the content of coarse and over-grinidng particles were opposite.The shape parameters,wettability and floatability of short cylinder and ball grinding products were different.The collision probability between the short cylinders and the particles was lager,so that the values irregularity(D_PA)and roundness were small,and with obvious edges and lager surface roughness;while for balls,the collision between meida and minerals was random,and the values of D_PA,roundness and surface roughness were opposite.The results surface tension and single mineral flotation tests showed that ball milled products were more easily wetted,and the short cylinder milled products were more hydrophobic,so that the pulp potential and flotation recovery of short cylinder grinding products were higher.There are certain differences in the exposure and electrochemical reactivity of short cylinder and ball grinding particles.For galena,more（200）surfaces with lower surface broken bond density and surface energy were exposed,and（200）surface owned higher electrostatic potential and electrochemical reactivity,and the surface cooperates to form the oxidation peaks of sulfur and lead xanthate,effectively avoid excessive oxidation of sulfur.For sphalerite,more（220）surface with low surface broken bond density and surface energy were exposed,and held higher electrostatic potential,and exhibited higher electrochemical activity with the addition of xanthate.The mixed ore grinding and flotation test showed that short cylinder grinding media could promote the separation of galena and sphalerite.Therefore,it is an effective way to improve the recovery and grade of mineral resources by using different shapes of grinding media to control the particle properties and characteristics.