含白云石萤石矿中氟化钙含量的准确测定

Accurate Determination of Calcium Fluoride in Fluorite Ore Containing Dolomite

萤石矿中氟化钙的测定方法一般根据氟化钙的含量来选择,过滤分离后的残渣,用盐酸-硼酸-硫酸的混合溶液(ω_(CaF2)>60%)浸取,或者用三氯化铝溶液(ω_(CaF2)<60%)浸取。这两种方法均是使用稀乙酸(1+9)使氟化钙与碳酸钙分离,但是对于含白云石的萤石矿,稀乙酸并不能完全使白云石中的碳酸钙与氟化钙实现分离,造成检测结果高于该类矿物中氟化钙的真实含量。文章通过测定样品中的总镁含量,及氟化钙常规分析方法中过滤所留下的滤液中的镁含量,最终计算出含白云石萤石矿中氟化钙的真实含量。

The determination method of calcium fluoride in fluorite ore is generally selected according to the content of calcium fluoride.The residue after filtration and separation is leached with the mixed solution of hydrochloric acid boric acid sulfuric acid(ω_(CaF_(2)) >60%),or aluminum trichloride solution(ω_(CaF_(2))< 60%).Both methods use dilute acetic acid(1+9)to separate calcium fluoride and calcium carbonate, but for fluorite ore containing dolomite, dilute acetic acid can not completely separate calcium carbonate and calcium fluoride in dolomite, resulting in the detection result higher than the true content of calcium fluoride in this kind of mineral.In this paper, through the determination of the magnesium content in the sample and the magnesium content in the filtrate left by the conventional analysis method of calcium fluoride, the real content of calcium fluoride in dolomite bearing fluorite ore is finally calculated.