摘要
以氨水-铵盐缓冲溶液作为浸出试剂,氧气作为氧化剂,在高压釜中通过加压氨浸法回收废弃印刷线路板中的铜、锌和镍,分别研究了浸出时间、氨水浓度、铵盐浓度、搅拌速率、氧气压力、温度和不同种类铵盐对浸出效果的影响,并得到浸出的最优工艺条件:铵盐选择碳酸铵浸出效果最佳,浓度为1 mol/L,氨水浓度为4 mol/L,搅拌速率为700 r/min,氧气压力为0.2MPa,温度为55℃,浸出时间为150 min.在最优工艺条件下对实际废弃线路板进行加压氨浸实验,锌完全浸出,铜的浸出率>99%,镍的浸出率>64%,锡、铅和铁基本不浸出,达到了选择性浸出铜、镍和锌的要求.为配合工艺分析,对铜的加压浸出进行了动力学分析,表明铜的浸出过程遵循不生成固体产物层的"收缩核动力学模型",其表观活化能为14.68 kJ/mol,浸出过程为扩散控制.
The ammonia/ammonium leaching process using oxygen as oxidant in autoclave was studied to extract copper,zinc and nickel from printed circuit board.Parameters such as leaching time,concentration of leaching reagents,stirring speed,oxygen pressure and temperature were optimized.The best results were achieved when the leaching was carried out at 55℃ for 150 minutes,using 4 mol/L NH4 OH and 1 mol/L（NH4）2 CO3 as leaching solution,with 700 r/min stirring speed and 0.2 MPa oxygen.With this method,Zn,Cu and Ni could be effectively recovered from printed circuit boards by 100%,more than 99% and more than 64%,respectively.The kinetics of Cu leaching behavior was studied and it was found that the shrinking core model described it well.It was a diffusion control process and the apparent activation energy was 14.68 kJ/mol.
出处
《环境科学》
EI
CAS
CSCD
北大核心
2011年第2期596-602,共7页
Environmental Science
基金
中国科学院知识创新重要方向性项目(KZCX2-YW-412)
关键词
加压氨浸
废线路板
碳酸铵
动力学
ammonia leaching under pressure
printed circuit boards
ammonium carbonate
kinetics
