Summary
As coal fired power plants are forced to limit mercury emissions, the fly ash produced will have greater amounts this element, making it unusable for cement kilns who will also have to meet the new standards.
Analysis
Reducing mercury emissions is a great goal. However, the recent plans by the EPA may have some unforeseen consequences.
Fly ash produced as a waste product of coal fired power plants is often used as kiln feed in the manufacture of cement. This is a great way to dispose of this waste product, as the alternative is to pond fly ash. (Recently, TVA experienced a break in one of their huge fly ash ponds that led to the contamination of a large tract of farmland and homes.)
The issue at hand is that by trapping the mercury prior to it going up the smokestack, it will tend to reside in the fly ash produced.
Because cement kilns will also be expected to meet the new mercury emission standards, they may not be able to use fly ash, and will have to return to using clay and slate/ shale as a source of aluminum silicates.
Bad news for the power plants who will see an increase in fly ash disposal costs. Bad news for cement makers, who will see their raw material costs increases. Good news for clay and shale/ slate producers who may see an increase in demand from the cement industry.
Good news for all of us that there will be less mercury discharged into the environment.
