超声酸洗去除晶体硅切割废料中的杂质铁

Removal of Iron Impurities from Crystalline Silicon Cutting Waste by Ultrasonic Leaching

主要研究了超声场环境下晶体硅切割废料的净化除铁工艺。首先,采用XRF、XRD、SEM、ICP及粒度分析等手段研究了切割废料的物理化学性质。然后,研究了不同浸出剂及配比、酸浸温度、机械搅拌速率以及超声波功率和频率对切割废料中杂质铁的浸出效果。结果表明,较优超声酸浸工艺条件为:浸出剂为盐酸与硫酸的混合酸(HCl∶H2SO4为3∶2)、酸浸温度60℃、浸出时间50min、搅拌速率200r/min、超声波功率270 W、超声波频率45kHz。在此条件下,铁的浸出率可达97.10%。最后,将最优条件下酸浸后的切割废料用于制备碳化硅,XRD分析结果表明,所得产物的物相只有SiC和少量了SiO2,且SiC的纯度可达96.80%。

In this paper,the effect of ultrasound on the purification and iron removal process of crystalline silicon cutting waste were studied.Firstly,the physical and chemical properties of cutting waste were studied by XRF,XRD,SEM,ICP and particle size analysis.Then the effects of different leaching agents and ratios,acid leaching temperature,mechanical stirring rate and ultrasonic power and frequency on the impurities Fe were investigated and optimized i.e.The results showed that the optimal ultrasonic acid leaching process conditions are:leaching agent of mixture of hydrochloric acid and sulfuric acid(HCl∶H2SO4∶3/2);leaching temperature of 60℃;leaching time of 50 min;stirring speed of 200 r/min;ultrasonic power of 270 W and ultrasonic frequency 45 kHz.Under these conditions,the removal rate of Fe reached 97.10%.Ultimately,the cutting waste under optimal conditions after acid leaching was used to prepare SiC.XRD results showed that the product was only contain SiC and a small amount of SiO2 phases,and the purity of SiC was up to 96.80%.