Research status and development trend of ultra-low ash coal preparation technology

Coal is the main source of energy in our country, and its role in the economic development is extremely important. However, with the development of economy, the dependence on coal is becoming stronger and stronger. As coal is a nonrenewable resource and caters to the sustainable development policy, the use of coal with low ash, low sulfur and high value is a major trend of coal development in the future. Finally, based on the advantages and disadvantages of the aforementioned preparation technology, the future development direction for Ultra-low ash coal preparation is proposed. This review provides insights for the clean utilization and high-value utilization of coal.