Coal Fired Electrical Production by-products are liberated as Coal is burned to boil water generating steam.  Steam creates positive pressure spinning turbines generating electricity.  Raw Coal contains Carbon, Quartz and trace amounts of elemental impurities released during high temperature combustion.  These impurities are collected as microscopic particles in emission control devices.  

 

Most impurities are highly toxic, highly water soluble substances. The smallest particles left over from Coal combustion are termed Fly Ash, and are commonly used as an additive in Ordinary Portland Cement (OPC) to increase strength, workability, chemical resistance and reduce permeability.  Microscopic Fly Ash particles fill voids between much larger particles of Ordinary Portland Cement.