Effect of Mg^(2+) content in ion-exchanged Shengli lignite on its equilibrium adsorption water content and its mechanism  

Mg^(2+)在胜利褐煤中的负载量对其平衡复吸水含量的影响及其机理分析(英文)

作　　者：刘祥春 冯莉 王新华 张营 汤海燕 

机构地区：[1]Key Laboratory of Coal Processing and Efficient Utilization of Ministry of Education, School of Chemical Engineering and Technology, China University of Mining & Technology

出　　处：《Chinese Journal of Chemical Engineering》2015年第2期456-460,共5页中国化学工程学报（英文版）

基　　金：Supported by the National Basic Research Program of China(2012CB214900);the National Natural Science Foundation of China(51274197);the 111 Project(B12030);the Fundamental Research Funds for the Central Universities(2014XT05)

摘　　要：Mg ion-exchanged samples were prepared with acid-washed Shengli lignite.The chemical composition of the ash of the raw sample was determined by X-ray fluorescence.The equilibrium adsorption water contents of samples were determined in a range of relative humidity.The ion-exchange process was characterized by FT-IR,ash content,and p H value.A possible mechanism is proposed for equilibrium adsorption water of ion-exchanged samples at different humidities.The extent of ion-exchange reaction between Mg2+and lignite is controlled by the concentration of Mg2+in Mg SO4solution.The effect of Mg2+on equilibrium adsorption water content varies with relative humidity and content of Mg2+.The factor that controls equilibrium adsorption water content at low relative humidity is water interactions with sorption sites,which are Mg2+–carboxyl group complex.At middle relative humidity capillary force between Mg2+–water clusters Mg+(H2O)nand capillary is more important.At high relative humidity,free water–free water interactions are more significant.Mg ion-exchanged samples were prepared with acid-washed Shengli lignite.The chemical composition of the ash of the raw sample was determined by X-ray fluorescence.The equilibrium adsorption water contents of samples were determined in a range of relative humidity.The ion-exchange process was characterized by FT-IR,ash content,and p H value.A possible mechanism is proposed for equilibrium adsorption water of ion-exchanged samples at different humidities.The extent of ion-exchange reaction between Mg2＋and lignite is controlled by the concentration of Mg2＋in Mg SO4solution.The effect of Mg2＋on equilibrium adsorption water content varies with relative humidity and content of Mg2＋.The factor that controls equilibrium adsorption water content at low relative humidity is water interactions with sorption sites,which are Mg2＋–carboxyl group complex.At middle relative humidity capillary force between Mg2＋–water clusters Mg＋（H2O）nand capillary is more important.At high relative humidity,free water–free water interactions are more significant.

关 键 词：Ion-exchange FT-IR Equilibrium adsorption water content SURFACE 

分 类 号：TQ530[化学工程—煤化学工程]