硅钙摩尔比对准东煤燃烧过程中矿物演变及灰熔融特性的影响  

Influence of molar ratio of silicon to calcium on mineral evolution and ash melting characteristics during the combustion process of Zhundong coal

作　　者：王光绪 金晶[1,2] 张云鹏 刘薄鉴治[1,2] 梁诗雨 翟中媛 WANG Guangxu;JIN Jing;ZHANG Yunpeng;LIU Bojianzhi;LIANG Shiyu;ZHAI Zhongyuan(School of Energy and Power Engineering,University of Shanghai for Science and Technology,Shanghai 200093,China;Shanghai Key Laboratory of Multiphase Flow and Heat Transfer in Power Engineering,Shanghai 200093,China;Shanghai Boiler Works Co.,Ltd.,Shanghai 200245,China)

机构地区：[1]上海理工大学能源与动力工程学院,上海200093 [2]上海市动力工程多相流与传热重点实验室,上海200093 [3]上海锅炉工程有限公司,上海200245

出　　处：《化工进展》2022年第8期4140-4146,共7页Chemical Industry and Engineering Progress

基　　金：国家自然科学基金(51976129)。

摘　　要：选择准东高钙五彩湾(WCW)煤作为研究对象,通过改变煤灰中硅钙摩尔比(M)研究煤灰熔融特性及矿物演变的变化规律,进一步借助FactSage热力学计算软件进行矿物平衡预测。研究表明:在WCW原煤灰中,矿物CaSO_(4)演变生成低熔点矿物Ca_(2)MgSi_(2)O_(7),使得原煤灰借助灰熔融温度(AFTs)预测其结渣、玷污时出现较大偏差。对于混煤灰,当M升高至3时,相比原煤灰,其中矿物CaSO_(4)的分解提前,SiO_(2)优先与CaO反应生成熔点较低的矿物CaMgSi_(2)O_(6),进而引起混煤灰的熔点降低;当混煤灰中M升高至5时,充足的SiO_(2)会与MgO发生反应,生成高熔点矿物Mg_(2)SiO_(4),使得此时混煤灰的AFTs显著提升,改善了煤灰熔融特性。热力学计算矿物平衡结果与X射线衍射分析(XRD)结果吻合较好,吉布斯自由能结果验证了矿物演变过程的合理性。Selecting the Zhundong high-calcium Wucaiwan(WCW)coal as the research object,the coal ash melting characteristics and mineral evolution were studied by changing the molar ratio of silicon to calcium(M)in coal ash,and the mineral balance was predicted by using FactSage thermodynamic calculation software.The results showed that in WCW raw coal ash,mineral CaSO_(4)evolved into mineral Ca_(2)MgSi_(2)O_(7)with low melting point,which made the prediction of slagging and fouling of raw coal ash by ash melting temperatures(AFTs)had a great deviation.For mixed coal ash,when M increased to 3,compared with raw coal ash,CaSO_(4) was decomposed earlier,and SiO_(2)reacted with CaO preferentially to generate CaMgSi_(2)O_(6)mineral with lower melting point,thus causing the melting point of mixed coal ash to decrease.When the M in coal ash increased to 5,sufficient SiO_(2)will react with MgO to generate the high melting point mineral Mg_(2)SiO_(4),which significantly improved the AFTs of mixed coal ash at this moment and improved the coal ash fusion characteristics.The results of thermodynamic calculation of mineral equilibrium agreed well with X-ray diffraction analysis(XRD),and the Gibbs free energy results verified the rationality of mineral evolution process.

关 键 词：准东煤 二氧化硅 矿物演变 灰熔融特性 

分 类 号：TQ536.4[化学工程—煤化学工程]