Fly ash is one of the materials produced during the coal combustion process that is carried up in the flue gases and can be collected before exiting the stack using pollution control equipment including electrostatic precipitators or baghouses. In an effort to protect the environment, the importance of keeping fly ash out of landfills, or ash ponds, continues to increase. An alternative to dumping, or storing, fly ash is to reuse it for other purposes with the primary usage being a replacement for cement in producing concrete.
In order for fly ash to be sold by coal-fired power plants for alternative uses, the fly ash needs to be processed to a specific micron size. To consistently control the fineness of fly ash particles, producers can rely on air classification technology to separate out larger and smaller sized particles. Air classifiers offer a screen-less option for separating fine and coarse particles from a material such as fly ash using the physical principles of centrifugal force, drag force, and gravity to classify particles according to size or density. Fly ash, to be used in concrete, needs to be specified to a size of 45 microns (325 mesh) so the air classifier utilized would need to be able to separate fly ash particles to that range.
The Side Draft Air Classifier is a versatile, energy-efficient air classifier that can separate particles in the 100- to 400- mesh (150-38 micron) range. Through vigorous testing at our full-service laboratory, the Side Draft Air Classifier proved capable of separating fly ash according to specifications for use in producing concrete and as a result aiding in the reduction of accumulation of fly ash in landfills and other dumping sites while also reducing the need for alternatives that need to be quarried and are energy intensive to create.
Read more on how Sturtevant can assist with fly ash beneficiation through air classification.