太阳能电池硅片线锯砂浆中硅屑的回收技术研究

Development of Technology for Recovery of Silicon Saw Dusts from Wire Saw Slurry

多线切割是当前硅太阳能电池片生产的主要工艺。在线切割过程中约有1/2的晶体硅成为锯屑进入到切割砂浆。砂浆中的各种污染物并未进入高纯硅屑晶体内部,因此可以期望通过物理分离、清洗等技术来提取获得高纯硅粉,而不需要通过高耗能的高温化学或相变过程。综述了硅片线切割过程、硅屑形成及废砂浆特性,评述了从线切割废砂浆中回收高纯硅粉的研究现状和进展,包括本研究组近期的研究结果。

Multi-wire-saw cutting is the current major process for the production of silicon wafers for solar cells. About half of high purity silicon becomes saw dusts and are mixed into the wire saw slurry. As the system is well cooled and no significant thermal diffusion occurs, the contamination to the silicon dusts is limited to its surface, and therefore can be removed without the need for high-temperature energy-consuming chemical or phase transformation processes. The wire-cutting process, formation of the silicon dusts and characteristics of the slurry are introduced. Researches and patents for processing and recovery of the wire saw slurry waste,with emphasis on recovery of high purlty silicon powders,are reviewed,including the latest results of the authors＇ group.