Influence Of Mineral Occurrence And Thermal Transformation On Viscosity-temperature Characteristics Of Shendong Coal

The minerals in coal significantly affect the viscosity temperature characteristics of coal ash,resulting in slag plugging and other problems,which restrict the gasification production.Taking the minerals in coal and coal ash viscosity-temperature characteristics as the main research object,this paper analyzes the basic properties of coal in Shendong mining area by means of float and sink analysis,industrial analysis,coal ash composition and fusibility analysis.The composition of the main minerals in Shendong coal was quantitatively analyzed by optical microscope and SEM.The viscosity-temperature curve of coal ash is measured by the high-temperature viscosity tester of coal ash.Fact Sage7.3 is used to simulate the viscosity-temperature characteristics of coal ash based on its composition.The main factors affecting the viscosity-temperature characteristics of coal ash are discussed,especially the influence mechanism of the type and content of minerals in coal on the coal ash viscositytemperature characteristics.Based on the Urbain modified model,the viscositytemperature prediction model is formed by considering six modified components.The results show that the mineral composition of the coal in the Shendong mining area mainly includes illite-type clay minerals,calcite,pyrite,siderite,etc.There are some detrital quartz and illite symbiosis.Illite-type clay minerals are high in content and some associated quartz which results in high silicon-aluminum content and Si / Al ratio in coal ash and increases the viscosity of coal ash.Calcite is the main calcium-containing mineral,and excessive calcium content will cause crystal slag to appear and increase viscosity.Iron series minerals are mainly pyrite and In siderite and the relatively high iron content results in a loose network structure and reduces the coal ash viscosity.In addition,higher sulfur content may lead to increased coal ash viscosity.The results of the viscosity-temperature characteristics of the simulated blending coal show that the coal sample ratio between 4.1:5.9 and 8.3:1.7 can better meet the operating temperature and viscosity range of the liquid slagging gasifier.For calculating with the viscosity temperature prediction model,the calculation results of crystalline slag type coal ash have larger deviation,but the calculation results of glass slag type and plastic slag type coal ash are better.