设计和研究了一种由高杂质氟硅酸制备氟化铵联产氟化镁的高效利用工艺。根据高杂质氟硅酸和氟化铵母液的特点,深入研究了工艺过程中的关键影响因素,包括pH、反应温度、游离氨、加料方式、放热曲线、浓缩曲线及物料平衡等,弥补了相关研究的不足,得到了最佳工艺条件。在该条件下,氟化铵一次结晶收率约为25%,符合GB/T 28653—2012中一等品的要求;氟化镁收率达到95%以上,符合YS/T 691—2009中MF-2的要求。浓缩研究表明,氟化铵质量分数与密度呈现出良好的线性关系,关系式为y=3.977 8x-4.001 7（y为质量分数,x为密度）,浓缩结晶的临界密度为1.14 g/cm³。物料平衡研究显示,该工艺路线原料利用率高,具有重要的工业应用价值。

An Efficient utilization process of high impurity fluosilicic acid was designed and researched to produce NH₄F with co-production of MgF₂.On the basis of characteristics of high impurity fluosilicic acid and mother liquor of NH₄F,a series of key factors were deeply studied to make up for the lack of related researches,including pH,reaction temperature,free ammonia,feeding method,exothermic curve,concentration curve and material balance,etc..Optimized process conditions were obtained,under which,the yield of primary crystallization of NH₄F was about 25%,which meet the requirements of first-class products in GB/T 28653—2012;the yield of MgF₂ reached more than 95%,which meet the MF-2 requirements of YS/T 691—2009.Research on concentration revealed that there was a good linear relationship between the concentration and density of NH₄F（y=3.9778x-4.0017;y：the concentration;x：the density）,and the critical crystallization density was 1.14 g/cm³.Material balance research showed that the studied process had a high raw material utilization and important industrial application value.