氯氧化锆生产中废碱液的回收利用

Reuse of Spent Lye in Zirconium Oxychloride Production

建立了以CaO为沉淀剂去除废碱液中SiO_2回收NaOH的工艺,研究了各工艺因素对SiO_2去除效果的影响,实验结果表明,CaO沉淀除去废碱液中SiO_2的最佳工艺条件为:CaO与废碱液中SiO_2摩尔比3.0,反应温度80～95℃,反应时间40～60 min,搅拌转速200 r/min。在此条件下,SiO_2去除率可达95.0%,NaOH回收率为85%。回收的液碱符合GB209—2006《工业用氢氧化钠》的产品质量标准,可应用于锆英砂的烧结生产。

The process for recover NaOH from spent lye by removing SiO2 using CaO as precipitant was developed and the factors affecting SiO2 removal efficiency were studied. The optimum process conditions are as follows ： molar ratio of CaO to SiO2 3.0, reaction temperature 80 - 95℃, reaction time 40 - 60 min, stirring speed 200 r/min. Under these conditions, the SiO2 removal rate and the NaOH recovery rate are 95.0% and 85% respectively. The recovered lye accords with the national standard of GB209 - 2006, and can be used in production of zircon sand by alkaline fusion process.