蛋白土与硫酸铵煅烧反应产物及过程动力学  

Reaction products and kinetic process for the calcination of opoka with ammonium sulfate

作　　者：刘阳钰 贾宏伟 潘永泰[1] 郑水林[1] 孙志明[1] 李铭哲 LIU Yangyu;JIA Hongwei;PAN Yongtai;ZHENG Shuilin;SUN Zhiming;LI Mingzhe(School of Chemical and Environment Engineering,China University of Mining and Technology(Beijing),Beijing 100083,China)

机构地区：[1]中国矿业大学(北京)化学与环境工程学院,北京100083

出　　处：《化工进展》2018年第12期4543-4550,共8页Chemical Industry and Engineering Progress

基　　金：中央高校基本科研业务费项目(2010YH10;2015QH01)

摘　　要：蛋白土具有良好的应用前景,但是其自然白度较低制约了其开发应用。蛋白土硫酸铵煅烧法可去除其中的显色金属氧化物,提高蛋白土的白度,同时提取其中Al2O3。本文采用热重-差示扫描量热(TG-DSC)、同步热分析与红外质谱(TG-FTIR-MS)联用系统,结合X射线衍射对煅烧过程的固相及气相产物进行了表征分析,明析了其化学过程。结果表明,蛋白土中的Al2O3和Fe2O3在200～350℃时反应生成(NH4)3(Al, Fe)(SO4)3,同时逸出NH_3和H_2O;350～450℃时,进一步反应转化为NH4(Al, Fe)(SO4)2,同时逸出NH_3、H_2O、SO_2和O2;450～550℃时,NH4(Al, Fe)(SO4)2分解生成(Al, Fe)2(SO4)3,同时逸出NH_3、H_2O、SO_2和O2;550～750℃时(Al, Fe)2(SO4)3分解生成Al2O3和Fe2O3,同时逸出SO_2和O2。采用Kissinger微分法与Ozawa积分法分别计算出4个阶段表观活化能后取二者平均值,分别为101.74kJ/mol、104.52kJ/mol、201.40kJ/mol、232.51kJ/mol,并获得对应4个热化学反应阶段的频率因子、反应级数和动力学方程。Opoka has a good application prospect,but its natural whiteness is low,which restricts its development and application.The opoka ammonium sulfate calcining method can remove the coloured metal oxide,improve the whiteness of opoka,and extract the Al2O3.The solid phase and gaseous products of calcining process were characterized by X-ray diffractometry,TG-DSC and simultaneous thermogravimetry analyzer-Fourier transform infrared spectroscopy-mass spectrometer(TG-FTIR-MS),and the chemical process was clearly analyzed.The results showed that,at 200-350℃,the Al2O3 and Fe2O3 in opoka react to form(NH4)3(Al,Fe)(SO4)3 and release NH3 and H2O;at 350-450℃,the further reaction to form NH4(Al,Fe)(SO4)2 and release NH3,H2O,SO2 and O2;at 450-550℃,NH4(Al,Fe)(SO4)2 decomposes to form(Al,Fe)2(SO4)3 and release NH3,H2O,SO2 and O2;at 550-750℃(Al,Fe)2(SO4)3 decomposes to form Al2O3 and Fe2O3 and release SO2 and O2.By Kissinger and Ozawa methods,the values of apparent activation energy for the four steps are 101.74kJ/mol,104.52kJ/mol,201.40kJ/mol and 232.51kJ/mol,respectively.The frequency factor,reaction order and kinetic equations corresponding to the four thermo-chemical reaction stages in the calcination process were established.

关 键 词：蛋白土 硫酸铵煅烧 化学过程 反应 动力学 

分 类 号：X754[环境科学与工程—环境工程]