Recycling of non-metallic components in PCB based on 298/77 K cycle treatment
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摘要:
为解决废印制电路板(PCB)中非金属组分回收难且二次污染率大的问题,引入298/77 K循环处理技术,首先分析温度改变对PCB内部结构所造成的影响及PCB内部力学性能的变化,测试静电分选和离心分选对PCB非金属组分回收率的实际影响,之后引入CaF2作为精炼过程中的强氧化剂,测试PCB内部结构发生改变后的硅组分回收率,最后测定回收后硅元素的实际纯度。结果表明:PCB在经过298/77 K循环处理后,内部结构受温度循环影响发生明显变化;各项力学性能均实现明显下降;PCB非金属组分实际产出量和硅组分回收率,相比于传统处理方式实现了明显提升,且对原PCB中各项杂质有较好的去除效果,硅元素占比在97%以上。
Abstract:In order to solve the problems of difficult recovery of non-metallic components and high secondary pollution rate in waste printed circuit board (PCB), 298/77 K cycling treatment technology was introduced. First, the effect of temperature change on the internal structure of PCB and the change of mechanical properties in PCB were analyzed, and the actual effect of static and centrifugal separation on the recovery rate of non-metallic components in PCB was tested. Then, CaF2 was introduced as strong oxidant in the refining process. The recovery of silicon components after the change of internal structure of PCB was tested and the actual purity of silicon elements after recovery was determined. The results showed that after 298/77 K cycle treatment, the internal structure of PCB changed significantly under the influence of temperature cycle. The mechanical properties were significantly reduced. The actual output of PCB non-metallic components and the recovery of silicon components had been significantly improved compared with the traditional treatment, and the impurities in the original PCB had been well removed. The mass fraction of silicon element accounted for more than 97%.
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表 1 主要试验仪器名称
Table 1. Name of main experimental instruments
试验仪器 型号 生产厂家 破碎机 SS-1022 武义海纳电器有限公司 高能球磨机 SPEX Sample
Prep 8000M青岛佳鼎分析仪器有限公司 高压电选机 XDF250×200 石城县国邦矿山机械有限公司 离心机 MC-15K 上海精胜科学仪器有限公司 环境试验箱 FT-DW系列 苏州菲唐检测设备有限公司 电子万能试验机 E44型 美国MTS公司 扫描电镜 Apreo 2C 赛默飞世尔科技(中国)有限公司 简支梁冲击试验机 JBW-750H 济南普业机电技术有限公司 光谱仪 ARL3460 赛默飞世尔科技(中国)有限公司 表 2 PCB的实际产出量
Table 2. Actual output of PCB
项目 粒径/mm 实际产出量/g 静电分选 离心分选 >0.147 2.006 2 2.229 5 非金属 0.074~0.147 2.070 5 2.282 4 <0.074 2.101 9 2.312 0 >0.147 2.323 3 2.455 1 金属 0.074~0.147 2.358 6 2.545 2 <0.074 2.401 8 2.577 0 -
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