化工进展2024，Vol.43Issue(8)：4694-4703,10.DOI:10.16085/j.issn.1000-6613.2023-1118
脱硫石膏转化α-半水石膏的特征及机理:实验与模拟
Characteristics and mechanism of desulfurization gypsum to α-hemihydrate gypsum:Experiments and simulations
摘要
Abstract
The efficient utilization of desulfurized gypsum can effectively alleviate a series of environmental problems and turn waste into treasure.This paper used dihydrate gypsum to prepare α-hemihydrate gypsum in ethylene glycol aqueous solution containing trace anhydrous sodium sulfate,and explored the effects of temperature(94-98℃),ethylene glycol volume fraction(25%—35%),sodium sulfate concentration(0.1-0.3mol/L)on the mole fraction of α-hemihydrate gypsum and kinetic parameters in the dehydration conversion process from dihydrate gypsum to α-hemihydrate gypsum.The results showed that in ethylene glycol aqueous solution,the dehydration conversion process of dihydrate gypsum to α-hemihydrate gypsum conformed to the dispersion kinetic model.With the increase of temperature and ethylene glycol concentration,the kinetic parameter α remained basically unchanged,while the parameter β increased significantly,leading to an increase in the activation entropy(∆S*),which in turn led to a decrease in the energy barrier(Ea)and promoted the dehydration of dihydrate gypsum to α-hemihydrate gypsum.The addition of a small amount of anhydrous sodium sulfate significantly shortened the nucleation induction time of α-hemihydrate gypsum.Through molecular dynamics simulation,with increasing the concentration of sodium sulfate,the coordination number of Na+and SO42-increased,and the absolute difference of diffusion coefficient ∆D decreased,resulting in the increase of coordination ability and the decrease of decoupling ability.This study was of great significance for efficient utilization of desulfurized gypsum and mastering its conversion characteristics to α-hemihydrate gypsum.关键词
二水石膏/α-半水石膏/乙二醇/结晶/动力学模型/分子模拟Key words
dihydrate gypsum/α-hemihydrate gypsum/ethylene glycol/crystallization/kinetic model/molecular simulation分类
化学化工引用本文复制引用
怀立业,仲兆平,杨宇轩..脱硫石膏转化α-半水石膏的特征及机理:实验与模拟[J].化工进展,2024,43(8):4694-4703,10.基金项目
清洁高效燃煤发电与污染控制国家重点实验室开放基金(D20227K076). （D20227K076）
