文献类型：期刊文献

中文题名：低温氧化过程中煤的宏观特性与微观结构变化

英文题名：Macroscopic Characteristics and Microstructure Change of Coal during Low Temperature Oxidation

作者：沈冰洁[1];黄婕[1];曹银平[2];张福行[2]

机构：[1]华东理工大学化工学院,上海200237;[2]宝山钢铁股份有限公司炼铁厂,上海200941

年份：2021

卷号：47

期号：1

起止页码：17

中文期刊名：华东理工大学学报（自然科学版）

外文期刊名：Journal of East China University of Science and Technology

收录：CSTPCD;;Scopus;北大核心:【北大核心2020】；CSCD:【CSCD_E2021_2022】；

语种：中文

中文关键词：炼焦煤;低温氧化;指标气体;孔结构;官能团

外文关键词：coking coal;low temperature oxidation;index gas;pore structure;functional group

摘要：为深入研究炼焦煤的低温氧化行为,以瘦煤、肥煤和气煤为研究对象进行了升温与恒温氧化实验,并采用低温氮气吸附仪、扫描电子显微镜(SEM)、能谱仪(EDS)和傅里叶变换红外光谱仪(FT-IR)对氧化后的样品进行表征。恒温实验结果表明:在3种设定温度(95、130、190℃)下,煤所释放的CO有少量来自煤自身的热分解,大部分来自氧化反应所产生的碳氧络合物的分解。氮气吸附实验和SEM-EDS结果显示,在95℃下氧化对煤结构的破坏作用较小,但在190℃下氧化后,煤表面裂隙增多,粉化程度变高,煤的总孔容、平均孔径增大,由于部分氧化产物堵塞孔洞,因而比表面积下降。煤表面存在Al、Si元素,可以推断附着的颗粒中包含Al_2O_3、SiO_(2)。FT-IR结果显示,在氧化过程中,煤的羟基、甲基、亚甲基与O_(2)反应后生成了羰基、羧基和醚键等碳氧络合物,并进一步被分解为CO、CO_(2)等气体。提出了气体产生机理,经HSC Chemistry 6.0软件计算认为其在热力学上可行。
In this paper,lean coal,fat coal and gas coal were taken as the research objects to deeply study the macroscopic gas release law and microstructural changes of coking coal during low temperature oxidation.The gas release laws were obtained by heating and isothermal oxidation and the structure of coals was characterized by N2 adsorption,scanning electron microscopy equipped with energy dispersive X-ray analysis(SEM-EDS)and infrared spectroscopy(FT-IR).The results of constant temperature experiment showed that a small amount of the CO generated at a certain temperature produced by the thermal decomposition of coal itself,and the majority came from the decomposition of carbon-oxygen complexes produced by oxidation reaction.N2 adsorption and SEM characterization results indicated that at 95℃,the destructive effect on coal structure was minimal,while at 190℃,the cracks on coal surface increased and the degree of pulverization became larger.The total volume and average pore diameter increased,while BET surface area decreased due to the blockage of some oxidation products.Al and Si elements were detected on the surface of coal,therefore it could be inferred that the attached particles contained Al2O3 and SiO2.FT-IR characterization result showed that during the low temperature oxidation process,-OH,-CH3 and-CH2-reacted with oxygen forming unstable carbon-oxygen complexes such as C=O,-COOH and ether bonds,which were further decomposed into CO,CO_(2) and other gases.The thermodynamic feasibility of the proposed gas generation mechanism was verified by HSC Chemistry 6.0.In addition,the higher the volatile content of coal contained,the smaller the proportion of aromatic structures and thus the more developed pore structures,resulting in a more frequency of oxidation and the spontaneous combustion occurred.