电镀污泥中铜的浸出和溶剂萃取回收研究

Leaching and Solvent Extraction of Copper from Electroplating Sludge

采用硫酸浸出-萃取-反萃工艺流程回收电镀污泥中的铜。运用MATLAB拟合了1 mol/L硫酸体系中铜的浸出动力学模型,表明该浸出过程为扩散和表面反应共同控制。在硫酸浓度1 mol/L、液固比15:1条件下浸出10 min,铜浸出率达到90%。采用萃取-反萃取的方式回收浸出液中的Cu^2+,以Mextral■984H为萃取剂、Mextral■DT100为稀释剂,在溶液pH=2、萃取时间30 min、O/L相比1:1、萃取剂浓度10%条件下萃取,铜萃取率可达99%;O/L相比1:1、反萃取时间30 min,用25%的硫酸溶液进行反萃取,铜反萃取率可达95%。此工艺流程铜总回收率可达85%,实现了铜的高效回收。

Copper in electroplating sludge was recovered by adopting a process consisting of sulfuric acid leaching, extraction and stripping in an experiment. The leaching kinetic model data of copper in 1 mol/L H2SO4 system was fitted using MATLAB, indicating that the leaching process was controlled by both diffusion and surface reaction. The copper leaching rate reached 90% from the test under the conditions including the liquid-solid ratio of 15:1, H2SO4 concentration of 1 mol/L and leaching time of 10 min. Then, Cu2+ in leaching solution was extracted by a process of extractive-reverse extraction under the following conditions: with Mextral■984 H as an extractant, Mextral■DT100 as a diluent, solution pH of 2, the extraction time of 30 min, O/L ratio of 1:1 and the extractant concentration of 10%, resulting in the extraction rate of 99%;then with 25% sulfuric acid solution as a stripping agent, with O/L ratio of 1:1 and the reverse extraction time of 30 min, the reverse extraction rate of copper reached 95%. The total copper recovery rate reached 85%, indicating copper in the electroplating sludge was efficiently recovered using this process technique.