Study On The Melting And Fouling Characteristics Of Coal Gasification Slag

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.