氢氧化镁和氧化镁中酸不溶物的研究

Study on acid insoluble substance of magnesium hydroxide and magnesium oxide

产硝后的高镁卤水和硫氢化钡溶液进行反应，生成氢氧化镁，酸不溶物在0．3％（质量分数）左右，但将其煅烧成氧化镁后，酸不溶物高达1．2％-2．5％（质量分数），二者酸不溶物远不成比例关系。通过对样品在分析中穿滤对比、硫酸法测定酸不溶物、碘量法测定硫化物试验，确定在生产过程中，硫氢化钡被氢氧化镁吸附，经过高温煅烧，硫氢化钡被氧化成硫酸钡，成为氧化镁中的酸不溶物，这就是氧化镁和氢氧化镁中酸不溶物不成比例的主要原因。

After Glauber＇s salt formed,the bittern containing high content magnesium reacts with barium hydrosulfide to produce magnesium hydroxide,in which the acid insolubles content is about 0.3% （mass）. But when the magnesium hydroxide is calcined into magnesium oxide, the acid insolubles content will reach 1.2% -2.5% （mass）. Through determination of acid insolubles content in sample by sulfuric acid method and determination of sulfur content in sample by combustion iodometric method,it is indicated that HS^- is absorbed by magnesium hydroxide during the process of producing Magnesium hydroxide, then the adsorbed HS- is oxidized into barium sulfate, which is acid insolubles, after magnesium hydroxide calcined in high temperature. This is why acid insolubles content in magnesium oxide doesn＇t match that in magnesium hydroxide.