电镀污泥中铜的浸出工艺及其动力学

以硫酸为浸出剂,对某表面处理工业园电镀废水处理污泥中的铜做了浸出试验研究.将污泥干燥、研磨,X射线衍射和X射线能谱仪分析表明污泥中含铜19.03%.采用单因素优化试验探讨了固液比、反应时间、浸出温度、硫酸质量分数、搅拌速度对铜浸出率的影响.结果表明:当硫酸质量分数为20%,固液比为1∶10,搅拌速率为700r/min时,在20℃下反应40min,铜的浸出率可达97%以上;根据未反应核收缩模型,对硫酸浸铜过程的动力学机理进行了研究,结果表明:硫酸浸铜过程的控制步骤为固体膜扩散控制,其反应级数为0.828 2,浸出活化能为11.809kJ/mol.研究为含铜电镀污泥安全处置提供理论依据.

Leaching process and kinetics of copper electroplating sludge

The experiment was carried out for leaching copper from sludge of electroplating wastewater in a surface treatment industrial park using sulfuric acid as the leaching agent .The sludge was dried and grinded and it＇s main components were analyzed by using X‐ray diffraction and X‐ray energy spectrome‐ter .Result shows that the sludge contains 19 .03% copper .The effects of sulfuric acid concentration , solid‐to‐liquid ratio ,reaction time ,temperature and stirring speed on the leaching rate of copper were discussed .The results show that the leaching rate of copper is 97% under the conditions of sulfuric acid mass fraction of 20% ,solid‐to‐liquid ratio of 1：10 ,stirring speed of 700 r/min ,reaction time of 40 min and temperature of 20 ℃ .The kinetics of the copper‐leaching process was studied according to the un‐reaction shrinking core model .T he results indicate that the leaching rate of copper is mainly controlled by the solid membrane diffusion rate ,in w hich reaction order is 0 .828 2 and leaching activation energy is 11 .809 kJ/mol . T he study provides a theoretical basis for a safe disposal of copper electroplating sludge .