金刚线切割废料制备铝硅合金的研究

Study on Preparation of Al-Si Alloy from Diamond Wire Cutting Waste

在晶体硅片生产过程中会产生大量的切割废料,不仅造成资源浪费,而且带来环境污染,有效回收该废料已成为亟待解决的问题。以晶体硅金刚线切割废料为硅源制备铝硅合金,引入冰晶石作为熔剂来促进硅的溶解。研究了冰晶石分子比对合金硅含量、切割废料利用率以及铝损失率的影响,得到较优的冰晶石分子比为1.6,此时得到的合金硅含量为11.74%,切割废料利用率为64.75%,铝损失率为4.78%。合金产物的XRD分析及金相表征结果表明制得的铝硅合金组织较为均匀。此外,对熔炼过程的机理也进行了系统的研究,结果表明,熔炼过程可分为两步:第一步,切割废料表面的SiO2被熔解,使得颗粒内部的硅暴露出来;第二步,熔盐中的Si与Al液在界面处接触,生成Al-Si进入铝液。

A large amount of cutting waste is produced during the production process of crystal silicon wafer,which not only causes waste of resources,but also brings about environmental pollution.Thus,recycling cutting waste effectively has become an urgent problem to be solved.In this paper,the crystal silicon diamond wire cutting waste was recycled as raw material to prepare Al-Si alloy and cryolite was introduced as flux to promote the dissolution of Si.The effect of the molecule ratio of cryolite on the silicon content of the alloy,the utilization ratio of cutting waste,and loss ratio of aluminum was investigated.The molecule ratio of the obtained cryolite was 1.6,the silicon content of the alloy reached 11.74%,and the utilization ratio of cutting waste and the loss ratio of aluminum were 64.75%and 4.78%,respectively.The results of XRD and metallographic characterization show that the Al-Si alloy with uniformly distributed microstructure has been successfully prepared.In addition,the mechanism of the smelting process was also systematically studied.The results show that the smelting process can be divided into two steps:firstly,the SiO2 on the surface of cutting waste was dissolved to expose the silicon inside the particles;secondly,the Si in molten salt contacted with Al liquid at the interface and then the Al-Si alloy was produced.