( 中南大学 冶金科学与工程学院， 长沙 410083)
摘 要: 研究了碳酸氢铵-氨水热解法制备轻质氧化镁的工艺条件， 考察了原料Mg2+浓度、 反应温度、 Mg2+与NH3t当量比、 NH3与NH4HCO3摩尔比和预氨化pH值对碱式碳酸镁的过滤性能、 沉镁效率和碳酸氢铵消耗量的影响，并探讨了煅烧温度、 煅烧时间、 升温速度对轻质氧化镁视比容的影响。 最佳工艺参数为： 原料Mg2+浓度2.5 mol/L、 反应温度50 ℃、 当量比115%、摩尔比1.35、 预氨化pH值7.8~7.9、 煅烧温度800 ℃、 煅烧时间60 min、 升温速度6 ℃/min。 在最佳工艺条件下， 沉镁效率为82%， 生产1 t轻质氧化镁消耗碳酸氢铵量降到了1.76 t左右， 产品质量优于HG1-324-77特级标准。 该工艺可作为开发盐湖水氯镁石资源的有效途径。
关键字: 水氯镁石； 碳酸氢铵； 氨水； 碱式碳酸镁； 轻质氧化镁
（ College of Metallurgical Sciences and Engineering,Central South University, Changsha 410083, China）
Abstract: The technological parameters of the productive process of light magnesium oxide by ammonium bicarbonate-ammonia pyrogenation technology had been studied. The effects of raw material Mg2+concentration, reaction temperature, equivalent ratio, mol-ratio and aminated pH on the filtration capability of basic magnesium carbonate, yield of Mg2+ and the consumption of NH4HCO3 were investigated, and the effects of calcination temperature, time and rising speed of the temperature on the apparent gravity of light magnesium oxide were also investigated. The optimal technological parameters were: content of Mg2+ in raw material 2.5 mol/L, reaction temperature 50 ℃, equivalent ratio 115%, mol-ratio 1.35, aminated pH 7.8-7.9, calcination temperature 800 ℃, calcination time 60 min, rising speed of temperature 6 ℃/min. Under the optimal technological parameters, the results achieve yield of Mg2+about 82% and the consumption of NH4HCO3 for each ton light magnesium oxide reduces to 1.76 t in the process and the product has met the superfine-class standard of HG1-324-77. This process may be one of the effective routes to exploit the resources of saline bischofite.
Key words: bischofite； ammonium bicarbonate； ammonia； basic magnesium carbonate； light magnesium oxide
