测定磷矿石中铁、铝、钙、镁的含量,一般是经过滤、洗涤等分离手续,测定所需时间较长,操作手续烦锁。我们学习了有关资料,经过摸索,对上述四个组份的分析作了改进。改进后,测定所需时间较短,其准确度仍满足普钙生产的要求。方法原理于测定铁后的溶液中,在 pH4时,用氟化钠使 Al—EDTA 中的 EDTA 析出,以PAN 为指示剂,用 CuSO_4溶液滴定 EDTA 而测定铝,在此条件下, Determination of phosphate rock in iron, aluminum, calcium, magnesium content, usually by filtration, washing and other separation procedures, the determination of the longer time required, the operating procedures annoying lock. After learning the relevant information, we have made improvements in the analysis of the above four components. After the improvement, the determination of the required time is shorter, the accuracy is still to meet the requirements of general calcium production. Principle of the method After the determination of iron in the solution, at pH4, with sodium fluoride EDTA in Al-EDTA was precipitated with PAN as an indicator, titration EDTA with CuSO4 solution determination of aluminum, under this condition,