【摘要】 以磷肥生产过程中的副产物氟硅酸为原料制备高纯二氧化硅。氟硅酸与氨水反应,得到氟硅酸铵溶液,加入铵盐沉淀钙镁离子,再加入钙盐沉淀铝铁离子,静置后过滤得到净化的氟硅酸铵溶液;将净化液氟硅酸铵与氨水反应生成二氧化硅沉淀,经过滤、热洗、干燥、煅烧,得到高纯二氧化硅。样品SiO₂符合国标要求。实验表明,以氟硅酸制备高纯二氧化硅工艺可行。工艺特点是将低附加值的氟硅酸转化为高附加值的高纯SiO₂,铵盐钙盐除杂适宜,反应步骤少、过程简单、操作条件温和。更多还原

【Abstract】 High purity SiO₂ was prepared with Fluosilicic acid as the raw material,which is the byproduct of the production of phosphate fertilizer. Fluosilicic acid reacts with ammonia to obtain Ammonium fluosilicate solution,and add ammonium salt in it to precipitate calcium and magnesium ions,and calcium salt to precipitate iron and aluminum ions,after standing for a while,filter it to obtain purified ammonium fluorosilicate solution. It reacts with ammonia to form SiO₂ precipitate. High purity SiO₂ will be obtained after filtration,hot washing,drying and calcination. The SiO₂ precipitate meets the national standard. The experiment result shows that it is feasible to use Fluosilicic acid to get high-purity silicon dioxide. The characteristics of this process are as follows,first it can convert low value-added fluorine acid to high value-added high-purity SiO₂,then it is appropriate to remove impurities by ammonium salt and calcium salt; at last,there are just few steps,simple process and mild reaction condition.更多还原