芒硝石膏是溶浸钙芒硝矿过程中产生的溶浸尾矿，因其纯度低、不溶性杂质含量高，应用途径极少。针对以上问题，采用晶相重构法对芒硝石膏进行提纯，通过将芒硝石膏中的二水石膏（CaSO₄·2H₂O）转化为大颗粒的钙芒硝晶体（Na₂SO₄·CaSO₄），利用钙芒硝晶体与芒硝石膏中不溶性杂质的粒度差异进行分离提纯，然后控制水化浸取条件，使钙芒硝重新转化为二水硫酸钙，得到高纯度的二水石膏产品。探究反应硫酸钠浓度、温度、加料时间、液固质量比对钙芒硝晶体粒径和CaO收率的影响。研究结果表明，当反应硫酸钠质量分数为20%、反应温度为85 ℃、加料时间为3.0 h、液固质量比为6∶1时，生成颗粒粒度较大的钙芒硝晶体。在此条件下，钙芒硝晶体可通过筛分、旋流等物理方法有效分离不溶性杂质，此时CaO收率为79.60%，后经水化浸取，可获得质量分数为89%的提纯石膏。

Glauberite gypsum is the leaching tailings produced during the dissolved leaching of calcium glauberite ore.Due to the low purity and high content of insoluble impurities，there are very few application avenues.In response to the above problems，utilizing a crystalline phase transition method，dihydrate calcium sulfate from glauberite gypsum was successfully transformed into large glauberite crystals.These were then separated from smaller insoluble impurities based on particle size differences.Controlled hydration leaching conditions facilitated the conversion of glauberite back into dihydrate gypsum to obtain high-purity dihydrate gypsum.The impact of variables such as sodium sulfate mass concentration，temperature，leaching duration，and liquid-to-solid mass ratio on the size of the glauberite crystals and the yield of CaO were analyzed meticulously.Optimal conditions were identified：sodium sulfate mass concentration of 20%，temperature of 85 ℃，leaching duration of 3.0 h，and liquid-to-solid mass ratio of 6∶1.These conditions resulted in the formation of large-sized glauberite crystals and enabled effective separation of impurities by physical means such as sieving and cyclone，achieving a CaO yield of 79.60% and producing gypsum with a mass fraction of 89% after leaching.