A Tin Ore Process Mineralogy And Washability

There are plenty of tin ores in China, and the reserves and outputs of the said tin ores take the lead of the world. The methods of processing tin ores are decided by their characteristics, including traditional gravity concentration and flotation technology due to the finely diseminaterd particle size of cassiterite. There are many oxides existing in the tin ores, such as magnetite, hematite, limonite etc. And these ores can be hardly separated from the tin ores, so the method of magnetic separation can be found in the concentration of such kind of ores.Being consigned by Sichuan Huili Zinc Mine Co., Ltd, we conducted some researches on following aspects. The research of process mineralogy shows that this kind of ore contains some metallic ores such as pyrrhonist, arsenopyrite, iron pyrites, cassiterite, chalcopurite, etc. The main gangues (invaluable minerals) contain quartz, pyroxene, actinolite, chlorite, mica, etc. The valuable mineral which can be recovered is cassiterite. Moreover, the content of Cu in run of mine ore is 0.41%, and it can get concentrated too. The impurities which need to be removed or reduced are S Fe As SiO₂ MgO CaO Al₂O₃ ,etc. The laboratory tests mainly cover two aspects: Gravity Concentration-Flotation and Floatation-Gravity Concentration.The results of the experiments show that the mesh of grinding is 63 % -0.074mm for the closed circuit grinding of the first stage, then we use bulk-floatation to concentrate the Cu and S, and then we conduct the separation of copper sulfide and pyrite by means of further grinding to 95%-0.074mm to produce the copper concentrate and tailing. Tailings from the separation of copper sulfide and pyrite and bulk separation enter into the next stage to obtain the tin rough concentrate and rich middlings by means of stage grinding and stage separation for three times on the shaking tables.The obtained products in the research consist of rough tin concentrate, rich middlings and copper concentrate. Tin concentrate with a grade greater than 30% can be obtained by further maganic separation on the obtained tin rough concentrate with a grade about 20-30%. And the magnic product can be sold as medium product rich middlings. The practical production indicates that the reducation of tin grade of the concentrate helps to get a higher recovery of tin. Therefore, the production of tin rough concentrate with a grade of 20-25% is recommended for future production, which can be transferred to the smelter as a raw material.This research deals with not only the process mineralogy aspect, but also the mineral processing technology too. The obtained results can be used for the concentrators which process the same kinds of ores in China. These methods of stage grinding and stage flotation give us some new ideas on processing tin ores with different disseminated particle sizes.