College of Chemical and Environmental Engineering, Shandong University of Science and Technology, Qingdao, Shandong 266590, China.
College of Chemical and Environmental Engineering, Shandong University of Science and Technology, Qingdao, Shandong 266590, China.
Waste Manag. 2019 Apr 15;89:21-26. doi: 10.1016/j.wasman.2019.03.061. Epub 2019 Apr 1.
Recycling metal from waste printed circuit boards (WPCBs) through green flotation technology has been concerned in this paper. For the sake of environmentally friendly of flotation process, a renewable collector was prepared from waste oil by saponification reaction. The collector composition was analyzed by GC-MS, and results show that the main compositions are n-Hexadecanoic acid, oleic acid and octadecanoic acid. XRD and XRF results show that copper is the main valuable element for recovery. Effects of collector dosage and pH on flotation behavior were analyzed. In addition, the feasibility of improving copper recovery by multiple sorting test processes was also verified. Flotation results show that the concentrate yield and metal recovery decreases with the increase of collector dosage, accompanied by the increase of copper grade. When the dosage of collector is 3 kg/t, concentrate with 22% yield, 66% copper grade, and 47% copper recovery is obtained. Furthermore, concentrate yield and metal recovery rate first decrease and then increase with the increase of pH, while copper content first increase and then decrease. The suitable pH of the separation process is neutral environment (pH = 6-8). The study provides an alternative process for the recovery of metals in WPCBs.
本文关注通过绿色浮选技术从废印刷电路板 (WPCB) 中回收金属。为了浮选过程的环保性，通过皂化反应从废油中制备了可再生的捕收剂。通过 GC-MS 对捕收剂成分进行了分析，结果表明主要成分是正十六烷酸、油酸和十八烷酸。XRD 和 XRF 结果表明，铜是主要的有价回收元素。分析了捕收剂用量和 pH 值对浮选行为的影响。此外，还通过多次精选试验过程验证了提高铜回收率的可行性。浮选结果表明，随着捕收剂用量的增加，精矿产率和金属回收率降低，同时铜品位升高。当捕收剂用量为 3kg/t 时，可获得产率为 22%、铜品位为 66%、铜回收率为 47%的精矿。此外，精矿产率和金属回收率随 pH 值的增加先降低后升高，而铜含量先升高后降低。分离过程的适宜 pH 值为中性环境 (pH=6-8)。该研究为从 WPCB 中回收金属提供了一种替代工艺。
