| Zn is important metal in the development of national economy which is produced mostly from zinc sulfide ores because sulfides are easy to separate from gangue and to concentrate by conventional flotation. Sulfides can be smelted by method of conventional metallurgical techniques. The processing of zinc oxide is becoming more attractive due to the depletion of zinc sulfide ores.There is very abundant zinc oxide ores in China, extensively exists in Yunnan, Guangxi, Gansu, Liaoning, Sichuang, Qinghai, Neimenggu etc province. Zinc oxide ores are difficult to be disposed with beneficiation because of its characteristic, The recovery of zinc is lower(50-60%) by conventional flotation of the zinc oxide ore and with high reagent consumption. Oxided zinc ore can be treated by methods of hydrometallurgy and pyrometallurgy. However, it can not be put into industrial applications due to technical and economical feasibility.Therefore,the reaserch on flotation and recovery of zinc oxide ore focuse on how to change fundamental natur of the zinc oxide ore.Two kinds of zinc oxide ore was treated by method of hydrothermal sulphidation in this paper. Firstly, the mineralogy of zinc oxide ore was investigated by various determination methods:chemical element analysis, chemical phase analysis, scanning electronic microscope, X-ray diffraction.Based on mineralogy.The effect of reaction time,reaction temperature and dosage of sulfur on sulphidation extent was investigated. The experimental results show that the sulphidation extent of silicate hosted zinc oxide ore reachs 78% under the conditions of sulphidization temperature of 200℃, the sulphidization time of 240 min, the dosage of sulfur is 1.5 ratio of theoretical dosage. The sulphidation extent of carbonate hosted zinc oxide ore was above 63% by conditions of reaction time of 240min, sulphidation temperature of 180℃and dosage of sulfur is 1.5 theoritical multiple. Besides,temperature is most important factor, the effect of sulphidation of zinc oxide increased with the increase of temperature.The surface or whole grains of hemimorphite, willemite, smithsonite will be sulphided producing sulfides on the process of hydrothermal sulphidation, and the gangue such as silicon, calcium, magnesium and other gangue mineral not changed and increaseing the nature difference between the useful minerals and gangue composition, then achieves the separation of useful components and gangues. Therefore, the method of hydrothermal sulphidation is effective to zinc oxide ore flotation precured sulphidation. |
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