线切割废砂浆资源化利用研究技术

研究了从单晶硅或多晶硅线切割加工硅晶片产生的废砂浆中回收碳化硅,同时生产白炭黑的工艺方法。该工艺包括对废砂浆进行预处理,酸洗除去其中的铁及金属杂质;然后,向其中加入高浓度氢氧化钠溶液,使其与砂浆中的硅反应生成硅酸钠,过滤得到纯的碳化硅,对硅酸钠溶液进行酸处理,得到絮凝状沉淀,干燥后即得白炭黑产品;最后,向酸洗液中加入一定量10%的石灰乳溶液,得到红褐色沉淀,干燥得到氢氧化铁产品。本工艺操作简单,可有效回收废砂浆中的碳化硅,同时利用处理后的废液副产白炭黑,进一步降低碳化硅的回收成本,减少污水的排放量,具有较好的经济效益、社会效益和环保效益。

Line cutting waste mortar resource utilization technology research

This paper studied from single crystal silicon or polysilicon line cutting silicon wafer produced waste recycling carbide mortar,while the production of white carbon black process.The process includes the mortar pretreatment,acid washing to remove the iron and metal impurities;then,added to the high concentration of sodium hydroxide solution,and the mortar in the silicon reaction of sodium silicate,filtering to obtain pure silicon carbide on the sodium silicate solution to form acid treatment,flocculation precipitation,drying to obtain silica products;and finally,to the acid solution by adding a certain amount of 10% lime solution,red and brown precipitate,and drying to obtain ferric hydroxide products.The process has simple operation,can effectively recover waste slurry in silicon carbide,while the use of treated waste by-product silica,further reducing the silicon carbide cost recovery,reduce sewage emissions,good economic benefit,social benefit and environmental benefit.