【作者】 王凤；

【导师】 李平； 刘水刚；

【作者基本信息】 宁夏大学 ， 工程硕士（专业学位）， 2020， 硕士

【摘要】 在能源转型的大背景下,煤炭的清洁高效利用受到了多方关注。宁东能源化工基地依托丰富的煤炭资源,积极发展粉煤气化等煤炭清洁转化技术。但由于煤质不稳定,气化炉运行过程中仍存在排渣不顺畅、挂渣厚度不理想等问题。本文针对这一现状,对宁东气化用煤进行熔融及沉积特性研究。本文以煤气化渣和原煤为研究对象,借助于马弗炉、XRD、SEM和XRF仪器设备,对取得的煤气化渣进行理化性质分析,主要探究其在相应国标要求下的物相、样品形貌、成分和工业数据的差异。结果表明:渣样的灰分大、水分少,细渣固定碳含量高;细渣样貌为球状颗粒,粗渣样貌为不规则块状,灰样样貌是未熔融块状;成分中SiO2含量最多,Al2O3和CaO的含量次之;粗渣和细渣的残碳量分别为0.499%和12.065%。运用马弗炉、X-射线衍射仪、扫描电子显微镜等实验设备和FactSage热力学计算软件,对工业渣和人工渣进行熔融特性的探究。其中通过相关测试仪器对煤气化渣样进行形貌和矿物质种类的分析,运用FactSage计算软件的相图和平衡模块计算,得到煤气化渣的矿物质含量和相区域变化。通过探究工业渣在高温条件下矿物质种类、含量、相区域和样品形貌的变化,最终得到相关结论:在升温过程中,样品中Fe2O3、SiO2、钠长石、钙长石含量逐渐减少,液相的含量逐渐增多。样品中刚玉含量越少,样品越易熔融。钠长石和钙长石含量越小,样貌越不易存在蜂窝状结构。配制不同Al2O3/CaO 比例的人工煤样,经过高温预熔得到人工渣,进而探究Al2O3/CaO对人工渣熔融特性的影响。结果显示:当Al2O3/CaO=1.23,熔融温度最低。随着Al2O3/CaO的增加,液相的含量降低。钙长石、钠长石和刚玉的含量先增加后下降,莫来石的含量逐渐增加。当CaO的含量增加时,熔融温度逐渐上升,结晶相由长石到Ca(Al,Fe)6O10,莫来石和一氧化物区域。随着Al2O3的增加,熔融温度最高增大到2000 ℃,结晶区域由长石到Ca(Al,Fe)12019和刚玉。基于一维沉降炉和给样设备,对煤气化渣的沉积特性进行研究,得到相关的沉积速率、沉积厚度和在沉积过程中的矿物质变化趋势。具体的结果为:Fe元素的矿物质是造成沉积的主要原因。同一沉积温度,随着沉积时间的增加,粉煤灰沉积速率增加;在同一时间内,随着沉积温度的升高,沉积速率先升高后下降并在1100℃达到最小。更多还原

【Abstract】 In the context of the energy transition,the clean and efficient use of coal has attracted much attention.The Ningdong Energy and Chemical Base relies on rich coal resources and develops actively clean conversion technologies,such as coal gasification.However,due to the unstable coal quality.There are many problems during the operation of the gasifier,such as unsmooth slag discharge and unsatisfactory slag layer thickness.The melting characteristics and deposition characteristics of coal for gasification are studied.This paper takes coal gasification slag and raw coal as research objects.There are many instruments and equipments are used,including muffle furnace,XRD,SEM and XRF.The physical and chemical properties of the coal gasification slag,and explores mainly its phases and samples under the corresponding national standards.The shape results show that the slag has large ash content,low moisture,and high slag fixed carbon conten.The fina slag appearance is spherical particles,the coarse slag sample appearance is irregular block shape and the ash sample appearance is unmelted block shape.The residual carbon content of coarse slag and fine slag is 0.499%and 12.065%respectively.Muffle furnace,X-ray diffractometer,scanning electron microscope and other experimental equipment and FactSage thermodynamic calculation software are used to explore the melting characteristics of industrial slag and artificial slag.Among them,the morphology and mineral types of coal gasification slag samples are analyzed by relevant test instruments,and the phase diagram and balance module calculation of FactSage calculation software are used to obtain the mineral content and phase area change of coal gasification slag.By exploring the changes in mineral species,content,phase area and sample morphology of industrial slag under high temperature conditions,the relevant conclusions were finally obtained:during the heating process,the content of Fe2O3,SiO2,albite and anorthite in the sample gradually decreased The content of the liquid phase gradually increases.The lower the corundum content in the sample,the easier the sample will melt.The smaller the content of albite and anorthite,the less likely the appearance is to have a honeycomb structure.Artificial coal samples with different Al2O3/CaO ratios were prepared,and artificial slag was obtained through high-temperature premelting,and then the effect of Al2O3/CaO on the melting characteristics of artificial slag was investigated.The results can be obtained that albite and anorthite have the lowest melting temperature when Al2O3/CaO is 1.23.The content of the liquid phase decreases and anorthite,albite and corundum firstly increases and decreases with Al2O3/CaO rise.When the CaO content increases,the melting temperature gradually increases and the crystalline phase from feldspar to Ca(Al,Fe)6O10,mullite and monoxide.The content of mullite gradually increases and the melting temperature increases to 2000℃,the crystallization area ranges from feldspar to Ca(Al,Fe)12O19 and corundum as the content of Al2O3 increase.According to the one-dimensional sintering furnace and sample feeding equipment to study the deposition characteristics.The corresponding deposition rate,thickness and mineral changes during the deposition process can be obtained.The specific result is the minerals of Fe caused deposition.At the same deposition temperature,the deposition time increases,and the amount of fly ash deposition increases.At the same deposition time,the transfer deposition temperature increases,and the deposition rate first increases and then decreases.更多还原