摘要
以胜利褐煤和昭通褐煤为研究对象,采用H_2O、HCl/CH_3COONH_4及CH_3COONH_4/HCl/HF对褐煤进行逐级脱矿处理,利用XRF、XRD和SEM对褐煤中的矿物质种类、含量及其形貌进行分析,采用热重法对比分析了脱矿前后煤样的燃烧特性及动力学反应过程,分析了矿物质对褐煤燃烧特性的影响。结果表明:两种褐煤中的主要矿物元素为Si、Al、Fe、S及碱/碱土金属元素,主要矿物组成为石英、高岭石、云母、石膏、方解石和黄铁矿;3种脱矿方式的矿物质脱除率分别为:胜利褐煤1.22%、32.49%、97.90%,昭通褐煤0.47%、26.41%、94.79%;原煤及脱矿煤的综合燃烧指数S的大小顺序为:原煤<HCl/CH_3COONH_4脱矿煤<H_2O脱矿煤<CH_3COONH_4/HCl/HF脱矿煤,胜利及昭通褐煤呈现相同的规律。三级脱矿处理显著改善了煤的综合燃烧性能。煤中以羧酸盐形式、配位键形式存在于含氧或含氮官能团上的碱及碱土金属对煤的燃烧存在促进作用。煤中水溶性矿物质对燃烧具有抑制作用。褐煤燃烧从着火温度到燃尽温度这一温度区间满足一级反应方程,且线性相关性系数R均在0.985以上。
In this work,the two typical Chinese low rank coals,Shengli lignite and Zhaotong lignite were demineralized by H_2O,HCl/CH_3COONH_4,CH_3COONH_4/HCl/HF solution step by step. The elemental composition and surface structures were tested using XRF,XRD and SEM,respectively. The combustion characteristics and the kinetics of the reaction process of raw lignite and treated lignite were investigated by thermogravimetry（TG）. The results showed that the coal ash mainly consisted of silicon,aluminium,ferrum,sulphur and the alkali/alkaline earth metal sodium（AAEMs）. There are mainly six types of minerals existing in two lignite,including quartz,kaolinite,muscovite,gypsum,calcite and pyrite. The three removal rates of minerals of Shengli and Zhaotong lignite were as follows：1.22%,32.49%,97.90% and 0.47%,26.41% and 94.79%,respectively. The combustion comprehensive index（S）followed in the order： row ligniteremoved by HCl/CH_3COONH_4 washingremoved by water washingremoved by CH_3COONH_4/HCl/HF washing. Shengli and Zhaotong lignite had the same variation trend. S of treated lignite was significantly improved by third grade demineralization. AAEMs bound in oxygen-containing or nitrogen-containing functional groups and acid exchange carboxylate can promote the coal combustion characteristics to a certain extent. Water soluble mineral matter inhibited the combustion of coal. Lignite combustion reaction zone meet the first order reaction from the ignition temperature to the burn out temperature,and the value of the linear correlation coefficient R was more than 0.985.
作者
侯康
武建军
尚晓玲
张一昕
HOU Kang WU Jianjun SHANG Xiaoling ZHANG Yixin(Key Laboratory of Coal Processing and Efficient Utilization in Ministry of Education, School of Chemical Engineering and Technology, China University of Mining and Technology, China National Engineering Research Center of Coal Preparation and Purification, Xuzhou 221116, Jiangsu, China)
出处
《化工进展》
EI
CAS
CSCD
北大核心
2017年第3期900-908,共9页
Chemical Industry and Engineering Progress
基金
国家重点基础研究发展计划(2012CB214902)
国家重点研发计划(2016YFB0600401-02)项目
关键词
褐煤
矿物质
热重分析法
燃烧特性
动力学分析
lignite
mineral matter
thermogravimetry
combustion characteristics
kinetic analysis
