Degradation of brominated epoxy resin and metal recovery from waste printed circuit boards through batch sub/supercritical water treatments
Degradation of brominated epoxy resin and metal recovery from waste printed circuit boards through batch sub/supercritical water treatments
复制标题
通过批量亚/超临界水处理降解溴化环氧树脂并从废弃印刷电路板中回收金属
DOI：
10.1016/j.cej.2012.12.066
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发表时间：
2013-03-01
影响因子：
15.1
通讯作者：
Zhang, Fu-Shen
中科院分区：
文献类型：
--
作者：
Xing, Mingfei;Zhang, Fu-Shen
废弃印刷电路板中含有大量的溴系阻燃剂和重金属，会带来一系列的环境和健康问题。在本研究中，一个有效的和良性的过程中使用亚/超临界水（sub/SCW），同时降解溴化环氧树脂和回收金属的WPCB。实验在间歇式反应器中进行，温度范围为200 ~ 400 ℃，加水量为10 ~ 40 ml，保温时间为30 ~ 240 min。结果表明，在亚临界水条件下，溴化环氧树脂（BERs）可以快速有效地分解。当反应温度为400 ℃、加水量为40 ml、反应时间为120 min时，脱溴率可达97.8%。大部分溴被转化为HBr，约97.7%富集在水中。同时，得到无溴油，其主要成分为苯酚（58.5%）和4-（1-甲基乙基）-苯酚（21.7%）。经亚/超临界水处理后，残渣中的玻璃纤维和铜箔可以分别容易地释放和回收。在纯度为96.74%（粒度> 2.0mm）和92.74%（粒度0.147- 2.0mm）的条件下，铜的回收率达到98.11%。该研究为废弃印刷线路板的回收利用提供了一种高效、绿色的途径。(C)2013爱思唯尔有限公司版权所有。
Waste printed circuit boards (WPCBs) contain high amount of brominated flame retardants and heavy metals which may bring a series of environmental and health problems. In the present study, an effective and benign process using sub- and supercritical water (sub/SCW) to simultaneously degrade brominated epoxy resin and recover metals from WPCBs was developed. Experiments were performed in a batch-type reactor with temperatures ranging from 200 to 400 degrees C, water adding amounts from 10 to 40 ml and holding times from 30 to 240 min. The results showed that brominated epoxy resins (BERs) could be quickly and efficiently decomposed under sub/SCW condition. The debromination rate was 97.8% by controlling the temperature, water adding amount and holding time at 400 degrees C, 40 ml and 120 min, respectively. Most of the bromine was changed into HBr and around 97.7% was enriched in water. Meanwhile, bromine-free oil was obtained of which the main compositions were phenol (58.5%) and 4-(1-methylethyl)-phenol (21.7%). After the sub/SCW treatments, the glass fibers and copper foils in the residue can be easily liberated and recovered respectively. The copper recovery rate reached 98.11% in the purities of 96.74% (grain size >2.0 mm) and 92.74% (0.147-2.0 mm). This study provides an efficient and green approach for WPCBs recycling. (C) 2013 Elsevier B.V. All rights reserved.