Abstract: The flotation behavior of sphalerite at wet grinding conditions with different grinding mediums (steel ball and ceramic ball) was researched when butyl xanthate was used as collector. The results show that the floatability of sphalerite grinding with ceramic ball is higher than those grinding with steel ball under the same pharmaceutical conditions. The optimum flotation pH of sphalerite is maintained between 4 and 6， it is not affected by the grinding medium. The inhibitory effect of zinc sulfate on sphalerite is also unaffected by the grinding medium. Scanning electron microscopy and X-ray photoelectron spectroscopy were used to investigate the influence mechanism of grinding medium on the flotation behavior of sphalerite. The results show that the surface of sphalerite grinding with ceramic ball is relatively flat and the surface is covered with less metal oxide. The surface of sphalerite grinding with steel ball is severely corroded， and the surface is covered with a large amount of white flocculent oxide， which reduces the floatability of the sphalerite. In the wet grinding system of the steel ball， the wear and tear of the steel ball causes a large amount of Fe³⁺ in the slurry. With the increase of grinding time， Fe³⁺ and Zn²⁺ are continuously combined with OH^- in the slurry to form metal oxides covering the surface of minerals， which leads to the continuous decrease of metal ion content in the slurry.

Key words: Grinding medium, Sphalerite, Surface property, Flotation