老卤-碳铵法制备高纯氧化镁研究

以山东海化集团有限公司老卤（主要组分为氯化镁）和纯碱煅烧冷凝液（富含碳酸铵和碳酸氢铵）为原料制备高纯氧化镁。通过实验确定了老卤净化精制工艺条件：向老卤中加入氯化钙溶液生成硫酸钙沉淀以脱除老卤中的硫酸根,控制钙离子与硫酸根物质的量比为0.9~1.0时硫酸根的脱除效果较好。以净化精制后的老卤和纯碱煅烧冷凝液为原料,在反应温度为65 ℃、搅拌转速为70 r/min、老卤镁离子质量浓度为15 g/L条件下反应,再经热解、陈化合成碱式碳酸镁;碱式碳酸镁经过滤、洗涤、干燥,在900 ℃煅烧2 h,得到合格的高纯氧化镁。研究表明,以山东海化老卤和纯碱煅烧冷凝液为原料可制得高纯氧化镁。

Study on the preparation of high purity magnesium oxide from residual brine and ammonium bicarbonate

High purity magnesium oxide was prepared by using residual brine（main component of magnesium chloride） from Shandong Haihua Group Co.and condensate（rich in ammonium bicarbonate and ammonium carbonate） from calcination unit of sodium carbonate plant as raw materials.The purification and refining process condition of residual brine was determined through experiments：calcium chloride solution was added to residual brine to form calcium sulfate precipitation to remove sulfate from residual brine.When the amount-of-substance ratio of Ca²⁺ to SO₄^2- was controlled to be 0.9~1.0,the sulfate removal effect was better.The purified residual brine and calcined condensate of sodium carbonate were used as raw materials.The reaction was carried out at the reaction temperature of 65 ℃,the stirring speed of 70 r/min and the mass concentration of residual brine magnesium ion of 15 g/L,and then the basic magnesium carbonate was synthesized by pyrolysis and aging.Basic magnesium carbonate was filtered,washed,dried and calcined at 900 ℃ for 2 h to obtain qualified high-purity magnesium oxide.The research results showed that it was feasible to manufacture high purity magnesium oxide from residual brine from Shandong Haihua Group Co.and condensate from calcination unit of sodium carbonate plant.