低浓度硫酸下盐石膏相转变机制及石膏晶须制备研究  

Study on Phase Transformation Mechanism of Salt Gypsum and Preparation of Gypsum Whisker under Low Concentration Sulfuric Acid

作　　者：彭建波 罗兴国 刘烨 杨丽梅 PENG Jian-bo;LUO Xing-guo;LIU Ye;YANG Li-mei(Yunnan Salt Industry Co.,Ltd.,Kunming 650000,China)

机构地区：[1]云南省盐业有限公司,云南昆明650000

出　　处：《盐科学与化工》2022年第4期26-33,共8页Journal of Salt Science and Chemical Industry

摘　　要：文章以盐石膏为原料,采用常压酸化法开展了石膏提纯和石膏晶须制备的工艺技术研究,考察硫酸浓度、酸化反应温度、反应时间对盐石膏溶解行为以及镁、钠、氯杂质离子脱除效果的影响;同时,考察降温结晶时间、结晶温度对石膏晶须形貌和长径比的影响。实验结果表明,在酸化硫酸浓度40 g/L、酸化反应时间2 h、酸化反应温度95℃、降温结晶温度25℃、降温结晶时间7 h条件下制备得到的高纯石膏符合GB/T 21371-2019规定的限定值,可作为水泥等建筑原料;降温结晶制备得到的石膏晶须长度为180μm,长径比达79%。此外,表面致密且光滑,有利于石膏晶须的后续使用。In this article, the purification of gypsum and the preparation of gypsum whisker were carried out by atmospheric acidification with salt gypsum as raw material. The effects of sulfuric acid concentration, acidification reaction temperature and reaction time on the dissolution behavior of salt gypsum and the removal effect of magnesium, sodium and chlorine impurities were investigated. Meanwhile, the effects of cooling crystallization time and crystallization temperature on the morphology and aspect ratio of gypsum whisker were investigated. The experimental results showed that under the conditions of acidizing sulfuric acid concentration of 40 g/L, acidizing reaction time of 2 h, acidizing reaction temperature of 95 ℃, cooling crystallization temperature of 25℃, cooling crystallization time of 7 h, the high purity gypsum prepared meets the limit value specified in GB/T 21371-2019 and can be used as cement and other building materials. The length of gypsum whisker prepared by cooling crystallization is 180 μm and the aspect ratio is 79%. In addition, it shows that the gypsum whisker is compact and smooth, which is beneficial to the subsequent use of gypsum whisker.

关 键 词：盐石膏 常压酸化法 高纯石膏 石膏晶须 

分 类 号：TQ132.32[化学工程—无机化工]