湿法磷酸副产物氟硅酸制白炭黑连续工艺研究

以湿法磷加工过程的氟硅酸为原料,和氨水发生连续氨化反应,生成白炭黑和氟化铵。白炭黑作为一种性能优越的补强材料,有着广阔的市场;氟化铵可与强酸反应生产氢氟酸。连续氨化反应的优化条件为:氟硅酸质量分数为10%、氨水质量分数为10%、反应温度为20℃、搅拌转速为700 r/min、平均停留时间为15 min,在此条件下开展连续氨化反应,生成的白炭黑比表面积可达到350 m2/g,其他化学指标均达到HG/T 3061—1999质量标准。因此,此路线是氟硅酸综合利用较为有效的方法。

Study on continuous technology of silica white using by-product fluosilicic acid from wet-process phosphoric acid

Silica white and ammonium fluoride were prepared by using ammonia continually react with fluosilicic acid which is a by-product of wet-process phosphoric acid.As a reinforcing material with superior performance,silica white has a broad market;ammonium fluoride can be reacted with strong acid to form hydrofluoric acid.Optimized technologic conditions were as follows:the mass fraction of fluosilicic acid was 10%,the mass fraction of ammonia was 10%,the reaction temperature was 20 ℃,the stirring speed was 700 r/min,and average residence time was 15 min.Specific surface area of silica white produced under these technological conditions could reach 350 m2/g,and other chemistry indexes met with the quality requirements of HG/T 3061—1999.So this route is relatively effective for the integrated utilization of fluosilicic acid.