用天然石膏制备硫酸钙晶须的研究

Reseach on preparation of calcium sulphate whiskers from natural gypsum

以天然石膏为原料,采用水热法制备硫酸钙晶须。以电镜作为分析硫酸钙晶须直径的手段,得出硫酸钙晶须的最优化工艺条件为：反应温度为130℃、料浆初始pH为10.0、料浆质量分数为5%、原料粒度小于122μm、反应时间为1.5 h。在此条件下,制备出了平均直径为1.32μm、长径比为76-90的硫酸钙晶须产品。中试试验结果显示,以天然石膏为原料制备硫酸钙晶须的长径比和直径与以纯石膏为原料制备的硫酸钙晶须相当。得出的结论对硫酸钙晶须的工业化生产具有重要的指导意义。

Calcium sulfate whiskers were prepared by hydrothermal method with natural gypsum as raw material.Through SEM as the direct analysis method,optimum process conditions of calcium sulfate whiskers were obtianed as follows：reaction temperature was 130 ℃,initial pH of CaSO4 ·2H2O slurry was 10.0,mass fraction of slurry was 5%,material size was lower than 122 μm,and reaction time was 1.5 h.Under these conditions calcium sulphate whisker product with average diameter of 1.32 μm and L/D ratio of 76~90 was obtained.Pilot test results indicated that L/D ratio and diameter of calcium sulfate whiskers with natural gypsum as raw material was equivalent to the products with pure gypsum as raw material.Conclusion drawn from the experiment will play an important guiding role in the industrial production of calcium sulfate whiskers.