Recovery of metals from waste printed circuit boards by supercritical water pre-treatment combined with acid leaching process
Recovery of metals from waste printed circuit boards by supercritical water pre-treatment combined with acid leaching process
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超临界水预处理结合酸浸工艺从废旧印刷电路板中回收金属
DOI：
10.1016/j.wasman.2013.01.023
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发表时间：
2013-05-01
期刊：
影响因子：
8.1
通讯作者：
Zhang, Fu-Shen
中科院分区：
文献类型：
--
作者：
Xiu, Fu-Rong;Qi, Yingying;Zhang, Fu-Shen
废印刷电路板（PCB）含有大量的金属，例如Cu、Sn、Pb、Cd、Cr、Zn和Mn。本研究开发了一种高效、环保的超临界水预处理与酸浸相结合的方法从废弃多氯联苯中回收金属。该工艺采用超临界水对废弃多氯联苯进行预处理，分离出的固相产物中富集有金属，再进行酸浸回收金属。研究了超临界水预处理对废多氯联苯中不同金属回收的影响。研究了超临界水预处理的两种方法：超临界水氧化法（SCWO）和超临界水解聚法（SCWD）。实验结果表明，超临界水氧化和超临界水分解预处理对不同金属的回收率有显著影响。超临界水氧化预处理能有效提高铜、铅的回收率，且随着预处理温度的升高，铜、铅的回收率显著提高。420 ℃超临界水氧化预处理的Cu和Pb的回收率分别为99.8%和80%，而大部分的Sn和Cr被固定在残渣中。所有研究的金属回收率提高SCWD预处理和增加沿着与预处理温度。高达90%的Sn、Zn、Cr、Cd和Mn可在440摄氏度（C）下回收用于SCWD预处理2013 Elsevier Ltd.保留所有权利。
Waste printed circuit boards (PCBs) contain a large number of metals such as Cu, Sn, Pb, Cd, Cr, Zn, and Mn. In this work, an efficient and environmentally friendly process for metals recovery from waste PCBs by supercritical water (SCW) pre-treatment combined with acid leaching was developed. In the proposed process, waste PCBs were pre-treated by SCW, then the separated solid phase product with concentrated metals was subjected to an acid leaching process for metals recovery. The effect of SCW pre-treatment on the recovery of different metals from waste PCBs was investigated. Two methods of SCW pre-treatment were studied: supercritical water oxidation (SCWO) and supercritical water depolymerization (SCWD). Experimental results indicated that SCWO and SCWD pre-treatment had significant effect on the recovery of different metals. SCWO pre-treatment was highly efficient for enhancing the recovery of Cu and Pb, and the recovery efficiency increased significantly with increasing pre-treatment temperature. The recovery efficiency of Cu and Pb for SCWO pre-treatment at 420 C was 99.8% and 80%, respectively, whereas most of the Sn and Cr were immobilized in the residue. The recovery of all studied metals was enhanced by SCWD pre-treatment and increased along with pre-treatment temperature. Up to 90% of Sn, Zn, Cr, Cd, and Mn could be recovered for SCWD pre-treatment at 440 degrees C (C) 2013 Elsevier Ltd. All rights reserved.