Abstract: Using the sintering dust containing Ag from iron and steel metallurgical process as raw material, on the basis of phase analysis, an efficient leaching process of silver with thiourea from the dust was proposed. The effects of particle size, temperature, concentration of thiourea, leaching time and stirring speed on leaching rate of silver were examined. The results showed that silver leaching rate from water washed sintering dust could reach 90% under the conditions of ratio of liquid volume to solid mass 8 mL/g, 22 g/L thiourea and stirring speed at 400 r/min for 120 min. The leaching of silver conformed well to the shrinking core model with internal diffusion control. The apparent activation energy of silver reaction was calculated as 29.7 kJ/mol and the reaction order in acidic thiourea solution was approximately 1.

Key words: sintering dust, silver, thiourea, leaching, kinetics

摘要： 以炼铁烧结灰水浸渣为原料，在物相分析的基础上，用硫脲选择性浸取其中的银，考察了物料粒径、浸出温度、硫脲浓度、浸出时间、搅拌速度对银浸出率的影响. 结果表明，在液固体积质量比8 mL/g、原料粒径96~80 mm、浸出温度50℃、硫脲浓度22 g/L、浸出时间120 min、搅拌速度400 r/min的条件下，银浸出率接近90%. 硫脲浸出水浸渣中的银符合收缩未反应核模型，反应表观活化能为29.7 kJ/mol，反应级数近似为1，动力学限制环节为通过固体产物层的内扩散控制.

关键词: 烧结灰, 银, 硫脲, 浸出, 动力学