Methods for extracting coal from fly ash
July.26,2024
The methods for extracting coal from fly ash mainly include wet method and dry method. These methods have their own advantages and disadvantages and are suitable for different production conditions and needs.
Wet extraction
Wet extraction is mainly achieved through coal slurry method, and its steps include:
Crushing: The fly ash is crushed with crushing equipment to reduce the particle size for subsequent processing.
Stirring into coal slurry: Put the preliminarily crushed fly ash into a mixing bucket, add appropriate amount of water and agitator, stir and mix to form coal slurry. The purpose of this step is to disperse the coal particles in the fly ash in water for subsequent separation operations.
Gravity separation: The formed coal slurry is separated by gravity separation process using the density difference between different components. Through the action of gravity, coal particles will settle at the bottom due to their higher density, while impurities such as limestone and sand will float on the upper layer due to their lower density. Through this step, coal and impurities can be initially separated.
The advantages of wet extraction are simple process, low cost, convenient operation, and full use of fly ash resources to reduce environmental pollution. However, wet refining also has some problems. For example, the coal slurry may still contain impurities and require further processing. At the same time, this method does not require high purity of coal.
