氮气气氛下FeS对二水石膏热分解特性的影响

采用TG-DSC方法分析FeS做还原剂时化学纯石膏的热分解特性,并利用Coats-Redfern模型计算还原剂掺量不同时石膏分解的活化能值。为防止还原剂被氧化选择氮气作为载气流。结果表明,焦炭与石膏摩尔比从1∶2增加到2∶1时,石膏分解所需的活化能从327kJ/mol降低到210kJ/mol,起始温度从1350℃降到956℃;FeS与石膏的摩尔比从1∶22增加到3∶22时,石膏分解所需的活化能值从327kJ/mol降低到214 kJ/mol,起始分解温度从1350℃降低到998℃,同时生成的产物Fe2O3对石膏的分解有促进作用。

The Influence of FeS on the Thermal Decomposition Characteristics of Gypsum in the Nitrogen Atmosphere

To study the influence of FeS,as reducing agent,on thermal decomposition characteristics of gypsum and to calculate the active energy required for gypsum decomposition with different proportion of reducing agent,the method of TG-DSC and the model of Coats-Redfern were adopted respectively.The study used Nitrogen as carrier gas to prevent reducing agent from oxidation.Results showed that when the ration of molar mass between FeS and gypsum was increased from 1∶22 to 3∶22,the activation energy value decreased from 327 kJ/mol to 214 kJ/ mol;accordingly,the initial decomposition temperature fell from 1350 ℃ to 998 ℃.The decomposition characteristics of gypsum represented similar tendency when the molar mass ratio of coke and gypsum increased from 1∶2 to 2∶1 apart from a slump in the initial decomposition temperature from 1350 ℃ to 956 ℃.Besides,the product Fe2O3has positive effects on the sequential decomposition of gypsum.