基于穆斯堡尔谱的煤气化渣中铁的析出机理  

Iron Precipitation Mechanism in Coal Gasification Slag Based on Mössbauer Spectroscopy

作　　者：熊金钰[1] 刘铭[1] 李寒旭[1] XIONG Jinyu;LIU Ming;LI Hanxu(School of Chemical Engineering, Anhui University of Science and Technology, 232001 Huainan, China)

机构地区：[1]安徽理工大学化学工程学院,安徽淮南232001

出　　处：《煤炭转化》2021年第2期43-50,共8页Coal Conversion

基　　金：安徽省高等学校自然科学研究项目(KJ2018A0091);安徽理工大学硕博基金资助项目.

摘　　要：气化条件下,煤中含铁矿物被还原,气化渣中析出单质铁,影响熔渣的黏度。以铁含量较高的煤样为研究对象,借助XRD和穆斯堡尔谱分析煤中矿物尤其是含铁矿物的组成。利用高温管式炉模拟气化条件,制备不同温度不同气氛下的熔渣,采用穆斯堡尔谱定性和定量分析熔渣中的含铁物相,研究熔渣中含铁物相的生成与温度和气氛的关系,探讨单质铁的析出机理。结果表明:气氛对含铁物相的种类和含量均有显著影响;气氛中CO体积分数为60%时,熔渣中含铁物相的组成显现“拐点”特征;在φ(CO)∶φ(N2)=3∶2气氛中,温度升高,含铁物相种类减少,其质量分数变化较复杂;还原性气氛中,煤中含铁矿物以不同途径转化成单质铁;铝硅酸盐矿物中掺杂的Fe3+直接或间接地被还原,黄铁矿转化成一系列铁硫化物,断键、熔化、分解,产生单质铁;综合实验结果,建立了高温熔渣中单质铁的析出模式。Under gasification condition,the iron-bearing minerals in coal are reduced to metallic iron precipitated in slag,which can affect slag viscosity.The constituent of iron-bearing minerals in the coal with high content ferrum was analyzed by XRD and Mössbauer spectroscopy.The coal slag samples were collected through the high-temperature tube furnace experiments in reducing atmosphere at different temperatures.The iron phases in slag samples were analyzed qualitatively and quantitatively by means of Mössbauer spectroscopy to investigate the influences of temperature and atmosphere on iron-bearing components and to reveal iron precipitation mechanism.The experimental results show that the atmosphere has remarkable effect on the types and relative contents of the iron phases.The constituent of the iron phases shows an inflection point in the atmosphere ofφ(CO)∶φ(N2)=3∶2.It is found that the types of the iron phases formed decrease and the relative amounts of the iron phases has complex changes with temperature increase in the certain atmosphere ofφ(CO)∶φ(N2)=3∶2.In reducing atmosphere the iron-bearing minerals may be transformed into metallic iron through different reaction paths.The ferric ion doped in aluminosilicate minerals is exposed in gasification atmosphere and reduced directly or indirectly.Pyrite in coal transforms into a serial of iron sulfide,becomes liquid and decomposes to metallic iron.In gasification atmosphere the metallic iron is precipitated in high-temperature slag and the proposed precipitation pattern is established.

关 键 词：还原性气氛 煤气化 高温熔渣 穆斯堡尔谱 析铁 

分 类 号：TQ533.1[化学工程—煤化学工程]