| Resourceful zinc ores are found in southwest of China, most of which are complicated sulphide and intractable oxide, that' s difficult to recover valuable metals economically by traditional flotation or metallurgy. With the decreasing grade of the ores and incresing attention of environmental protection, new technology with short process and low cost and no pollution is required and inevitalbe in the futher development of mineral processing engineering.Experiments on leaching, extraction, and electrowinning are studied according to the mineralogical analyses of low-grade zinc oxide ores from Wenshan, Yunnan province. Thermodynamic and kinetic researches into hydrometallurgical mechanism are engaged to this kind of ores, besides, extraction equilibrium and kinetics to the leaching solution. A new technology of direct leaching and solvent extraction and electrowinning (L-SX-EW) to produce high purity zinc from zinc oxide ores is presented.Leaching conditions such as method of acid adding, pH value, temperature and particle size are optimized to achieve a leaching rate at 90%. Results of single factor analysis show that pH value and temperature are the most important influences, which accord to the outcomes of thermodynamics. Also, the results provide elemental data for kinetic study, and here are the equations:090min, 1-(1-α)1/3 =4.3014×l0-4d-1[H+]0.4896 exp(-9676/RT)t + C1;120240min, 1-(1-α)1/3 = 2.3435×l0-4d-1[H+]0.4896 exp(-1888/RT)t + C2。 P204 is testified as a fitable extractant. With variables of 30%P204, pH2. 0 and extracting time 3 minutes, qualified solution can be obtained through the serial processing of extracting, washing and stripping.Closed circuit and industry-scale examinations are carried out, and the ultimate productions indicate that such a kind of technology (L-SX-EW) is feasible to deal with low-grade zinc oxide ores with the advantages of shorter flowage, easier operating and less pollution.
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