基于298/77 K循环处理回收PCB中非金属组分

Recycling of non-metallic components in PCB based on 298/77 K cycle treatment

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CaF_(2)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。

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,CaF_(2)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%.