The rapid growth of global energy demand has paved the way for the development of natural resources alternatives.However,coal still plays an important role in the world’s main energy source.Coal accounted for 29%of global energy supply in 2015,and it is estimated that by 2035,coal will still account for 24%of the energy.As an industrial by-product of coal-fired power plants,the amount of coal fly ash will remain high for a long time.Coal fly ash has become the focus of environmental concern due to its complex composition and unreasonable treatment.At the same time,coal fly ash is a potential resource,which urgently needs to be utilized reasonably.At present,the resource utilization of coal fly ash involves a wide range of fields,but the high-value utilization rate is low.The premise of high-value utilization is to study the properties of coal fly ash.Coal fly ash is composed of solid or hollow amorphous spherical particles,irregular unburned carbon particles and mineral particles such as mullite,quartz,hematite,etc.There are some differences in the physical properties,chemical composition and mineral composition of coal fly ash in different producing areas.Its utilization way and purpose also are not identical.The complex composition of coal fly ash is a major obstacle to high-value utilization.However,the useful components,such as hollow microspheres,unburned carbon,magnetic materials,etccan be separated from complex components by reasonable separation techniques.The chemical composition and mineral composition of fly ash are low-priced raw materials for high value-added products such as geopolymers,glass-ceramics and zeolites.The chemical composition and original particle size of coal fly ash have a great influence on the strength of geopolymers.The optimal technical conditions should be determined on the basis of fully considering the basic properties of coal fly ash when preparing geopolymers.According to the chemical composition of coal fly ash,the glass-ceramics prepared from coal fly ash mainly consist of two systems:CaO-Al2O3-SiO2 and MgO-Al2O3-SiO2,but the energy consumption of the preparation method is relatively high.The direct sintering method with low energy consumption still needs to be further studied and popularized.There are many application experiments of zeolite synthesized from coal fly ash,but few industrial experiments are carried out.The theoretical research on the preparation of mesoporous silica and silica aerosol experiments is not thorough enough,the conditions are difficult to control,and there is still a long way before industrial production.