矿物和岩石中钙和镁的含量及其相互的比例变化很大,目前尚没有一种化学分析方法能适应各种矿物中钙镁的分析。现将我单位对于不同矿种中采用的不司方法,归纳以下几种情况。一粘土、铝土、岩石中低含量钙镁(10~(-1)～10~(-2)%)的测定。用光度法测定,能应用于氧化镁,氧化钙低于1%的矿种,绝对误差不大于±0.05%。二镁砂、菱镁矿中钙镁的测定。为了克服在强碱介质中 EDTA 滴定钙时,大量 The contents of calcium and magnesium in minerals and rocks and their mutual proportions vary greatly. At present, there is no chemical analysis method that can adapt to the analysis of calcium and magnesium in various minerals. Now my unit for different types of minerals used in the Division approach, summed up the following situations. A clay, bauxite, rock low calcium and magnesium content (10 ~ (-1) ~ 10 ~ (-2)%) Determination. Measured by spectrophotometry, can be applied to magnesia, calcium oxide less than 1% of the minerals, the absolute error of not more than ± 0.05%. Two magnesia, magnesite in the determination of calcium and magnesium. In order to overcome the EDTA titration of calcium in a strong alkaline medium, a large amount