摘要
The effects of leaching temperature(60−105°C),NH4Cl concentration(3−7 mol/L),liquid/solid ratio(4:1−12:1 mL/g),stirring speed(150−750 r/min),and leaching time(5−90 min)on the leaching rates of Zn and Pb were investigated.The leaching kinetics of Zn-and Pb-rich fuming dust with a NH4Cl solution was also studied.The leaching rates of Zn and Pb respectively reached 98.2%and 75.6%at leaching temperature of 100°C,an NH4Cl concentration of 7.0 mol/L,a liquid/solid ratio of 10:1 mL/g,a stirring speed of 450 r/min and leaching time of 60 min.The kinetics results indicate that the leaching of Zn and Pb conforms to the shrinking unreacted core model and is controlled by the internal diffusion of NH4Cl through the reacted fuming dust layer and external diffusion of NH4Cl through the leaching solution boundary layer,respectively.The apparent activation energies of Zn and Pb are 23.922 and 19.139 kJ/mol,respectively.This study demonstrates that the use of NH4Cl solution,without ammonia,is an environmentally friendly method for simultaneous extracting Zn and Pb from the fuming dust of lead blast furnace slag.
考察了浸出温度(60~105℃)、NH4Cl浓度(3~7 mol/L)、液固比(4:1-12:1 mL/g)、搅拌速度(150~750 r/min)和浸出时间(5~90 min)对锌和铅浸出率的影响。研究了NH4Cl溶液浸出含铅、锌烟化烟灰的浸出动力学。在反应温度为100℃、NH4Cl浓度为7.0 mol/L、液固比为10:1 mL/g、搅拌速度为450 r/min和反应时间为60 min的最佳工艺条件下,锌和铅的浸出率分别为98.2%和75.6%。动力学结果表明,锌和铅的浸出符合未反应收缩核模型,分别受NH4Cl通过反应后烟化烟灰层的内扩散和NH4Cl穿过浸出液边界层的外扩散控制。锌和铅的表观活化能分别为23.922和19.139 kJ/mol。本研究证明了使用不含氨的NH4Cl溶液从铅鼓风炉渣的烟化烟灰中同步提取锌和铅是一种环境友好的方法。
基金
financial supports from the National Natural Science Foundation of China(No.51704107)
the Department of Education Scientific Research of Hunan Province,China(No.22A0401)
the Natural Science Foundation of Hunan Province,China(No.2024JJ7160).
