Study On The Characteristics Of Glass Microspheres Formed By Combustion Of Various Coals And Modified Combustion Of Silicon And Aluminum

In the context of environmental protection and efficient resource utilizatio,.the resource utilization of solid waste has become an urgent need for ecological civilization construction.The fly ash generated by coal-fired power plants is a type of solid waste,and glass microspheres in fly ash are widely used as high value-added products.The properties of glass microspheres generated by different coal combustion vary,affecting their utilization in various fields.This paper is based on the differences in coal types and uses a dropper furnace experimental platform to study the effects of typical coal,blended coal,and silicon aluminum ratio on the morphology,particle size,and yield of glass microspheres.And analyzed the mineral composition,ash melting point,and droplet viscosity changes in fly ash.aiming to provide reference for the production and resource utilization of glass microspheres in coal-fired power plants.The effects of combustion of Shengli lignite(SL).Jinjie bituminous coal(JJ)and Russian anthracite(RU)on the formation of glass microspheres were studied.The results show that the fly ash minerals of the three coals are mainly composed of mullite,quartz and hematite.Compared to Shengli fly ash,Jinjie fly ash has more calcium containing phases,while Russian fly ash has more mullite phases.With the increase of temperature,the mullite diffraction peaks of XRD of three kinds of fly ash increase,while other diffraction peaks such as quartz and hematite decrease;The ash flow temperatures of SL,JJ,and RU are 1245℃,1152℃,and 1398℃,respectively;The viscosity of the melt is negatively correlated with temperature.ranging from high to low as RU.SL,and JJ;The increase in temperature promotes the increase in particle size of solid and hollow microspheres,as well as the increase in spherical particles.At the same temperature,the spherical particles in fly ash are sorted from most to least as JJ,SL,and RU;The yield of hollow glass microspheres increases with increasing temperature.At 1400℃,the yield of hollow glass microspheres for SL,JJ,and RU is 8.98%,5.05%,and 18.08%.respectively.The effect of blended coal combustion on the formation of glass microspheres was studied.The results showed that adding B coal to A coal promoted the conversion of fly ash minerals from A to B;The ash melting point of blended coal is between the melting points of two single ash,but it does not change nonlinearly;With the increase of Jinjie bituminous coal in Shengli lignite,the viscosity of the ash melt gradually decreases.When Russian anthracite was added to Shengli lignite or Jinjie bituminous coal,the ash melt viscosity first increased and then decreased,reaching the maximum at RU:SL=3:1 and RU:JJ=3:1,respectively;The fly ash generated by the combustion of each blended coal is mainly spherical particles,and the particle size of the microspheres produced by the blended coal is mostly between two single coal;Adding Jinjie bituminous coal to Shengli lignite reduces the yield of hollow glass microspheres.However,when Russian anthracite was added to Shengli lignite or Jinjie bituminous coal,the yield of hollow glass microspheres increased.The effect of adding different proportions of SiO2 and Al2O3 to Jinjie bituminous coal on the formation of glass microspheres during combustion was studied.The results show that when 40%Al2O3 is added,the diffraction peak of mullite in XRD is enhanced.As the silicon aluminum ratio increases,the diffraction peak intensity of mullite gradually decreases,while the diffraction peak of quartz gradually increases;The ash melting point after adding SiO2 and Al2O3 is higher than that of Jinjie ash.By increasing the silicon aluminum ratio,the ash melting point first decreases and then increases,reaching its lowest point at SiO2/Al2O3=30:10;The viscosity of the melt increases with the increase of silicon aluminum ratio;Fly ash is mostly presented as spherical particles,and a small amount of solid "hemispherical" particles are also found;The average particle size of hollow and solid microspheres decreases with an increase in silicon aluminum ratio,and the yield of hollow glass microspheres decreases with an increase in silicon aluminum ratio.When 40%SiO2 is added,the yield of hollow glass microspheres decreases to 2.40%.