Large-grained anhydrite(VI) γ-CaO₄ was prepared in autoclave method by using flue-gas desulfurization gypsum as materials. The influence of slurry concentration, succinic acid and sodium chloride content, reaction temperature, reaction time, pH value, 1,4-butanediol was investigated. The research shows that large-grained anhydrite(VI) γ-CaSO₄ with length of 120 μm and length–diameter ratio of 1, dry compressive strength of which is similar to α40 grade, was obtained at slurry concentration of 18 wt%, succinic acid of 0.02 wt%, NaCl content of 3.0 wt%, 1,4-butanediol of 0.712 wt% after three times washing under 120°C without change of pH value. After five times circulation of mother liquid, the morphology and performance of product had no significant difference with initial product.

大晶粒硬石膏（VI）γ-的CaO ₄在高压釜方法通过使用烟道气脱硫石膏为原料制备。研究了浆料浓度，琥珀酸和氯化钠含量，反应温度，反应时间，pH值，1，4-丁二醇的影响。研究表明，大粒度硬石膏（VI）γ-的CaSO ₄与1为120μm和长度直径比的长度，干燥压缩强度类似于α40级中，在18重量％的浆料浓度得到，琥珀酸在120℃下洗涤3次后，在不改变pH值的情况下，可得到0.02重量％的硫酸，3.0重量％的氯化钠，0.712重量％的1，4-丁二醇。在母液循环五次后，产物的形态和性能与初始产物无明显差异。