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废弃挠性PCB是资源化价值高的电子废弃物之一,正需环境友好的方法回收其所含的多种有价金属。采用显微镜对破碎后的挠性PCB粉样进行解离情况观察,发现破碎法难以将挠性PCB中的金属与非金属解离。通过设计单因素实验,研究挠性PCB粉末粒度大小、添加量、培养液初始p H、菌接种量、活化时间以及Fe SO4·7H2O添加量6个因素对氧化亚铁硫杆菌(Acidithiobacillus ferrooxidans,简称A.f菌)浸出挠性PCB中金属过程的影响。结果表明,A.f菌不能浸出挠性PCB中Au,但Cu、Ni可以有效浸出且最优化条件为:10 g·L-1挠性PCB、粒度0.25~0.42 mm、培养基初始p H 2.5、菌接种量5%、菌活化时间5 d、Fe SO4·7H2O添加量30 g·L-1,金属Cu的浸出率达到90.1%,比未接种处理高出42.4%;金属Ni的浸出率达到了85.9%,比未接种处理高出了32.9%。因此,采用生物法可环境友好地回收挠性PCB中Cu、Ni,有利于废弃挠性PCB的资源化处理。
Abandonable flexible PCBs are one of the most cost-effective electronic wastes that require an environmentally friendly method of recovering the various types of valuable metals they contain. Using a microscope to observe the dissociation of the broken flexible PCB powder sample, it was found that it was difficult to break the metal and the nonmetal in the flexible PCB by the breaking method. Through the design of single-factor experiments, the factors affecting the particle size of flexible PCB powder, the amount of addition, the initial pH of the culture medium, inoculation amount, activation time and the amount of FeSO 4 · 7H 2 O addition were studied. Af bacteria) leaching of flexible PCB in the metal process. The results showed that Af bacteria could not leach Au from the flexible PCB, but Cu and Ni could be effectively leached and the optimized conditions were: 10 g · L -1 flexible PCB, particle size 0.25-0.42 mm, medium initial pH 2.5, Inoculation 5%, bacterial activation time 5 d, Fe SO4 · 7H2O dosage 30 g · L-1, the leaching rate of metal Cu reached 90.1%, 42.4% higher than the non-inoculation; the leaching rate of metal Ni reached 85.9 %, 32.9% higher than the non-vaccinated treatment. Therefore, bio-method can be environmentally friendly recovery of flexible PCB Cu, Ni, is conducive to the waste of flexible PCB resource processing.