氟化铵脱除石墨中二氧化硅试验研究

以湖南某地石墨为原料,先加入王水脱除金属杂质,过滤、洗涤再加入氟化铵溶液脱除二氧化硅。试验采用单因素变量法,得到最佳试验条件为,石墨20 g,氟化铵添加量11 g,反应温度80℃,时间3 h,添加水量40 m L,搅拌速率360 r/min,硅去除率达到99.3%,石墨纯度99.92%,能达到与氟化氢除硅相当的效果。并对除硅后的浸出液循环利用,进行二次除硅,除硅率和石墨固定碳含量均较高。试验对降低石墨除硅成本,减少含氟废水排放有一定实践意义。

Study on Silica Remove from Graphite with Ammonium Fluoride

Graphite from Hunan Province was adopted as the material to remove silica dioxide with ammonium fluoride after leaching with aquaregia , filtering and washing. The single factor variable method was explored, and the optimized addition was graphite 20 g, ammonium fluoride added amount of 11 g, reaction temperature 80 ℃, time 3 h, add water 40 mL, stirring rate 360 r/min respectively. And the silicon removal rate is 99.3%, 99.92% purity graphite, which is equal to silicon removal with hydrogen fluoride. After removing silicon, the leaching solution was recycling once, and the rate of removing silicon and carbon content were both relatively high. The test has some practical significance for reducing the cost of removing silicon from graphite and reducing the discharge of fluoride containing wastewater.