Concrete-FriendlyTM C-PAC sorbent from Sorbent Technologies Corporation offers a dual benefit to generating stations selling their fly ash to the ready mix concrete industry. Based on Sorbent Technologies’ patented B-PAC technology, C-PAC offers exceptional performance as a mercury control sorbent and does not affect the air-entrainment properties of the resultant fly ash. The result is lower mercury emissions and continued fly ash sales revenue.
All concrete mixes include a certain level of air entrainment to act as a physical buffer against cracking from freeze/thaw cycles. To achieve the desired level of air entrainment a chemical additive is employed, matching the dosage level with the desired level of air entrainment. When carbon is introduced to the formulation (as LOI in the fly ash) the active sites on the carbon compete with the air for the active sites on the entrainment chemical, resulting in insufficient or inconsistent air entrainment. Introduction of traditional activated carbons into the fly ash greatly amplifies this condition, generally making the fly ash unusable in concrete.
Laboratory testing of C-PAC sorbent revealed mercury capture levels in excess of 90% while maintaining, or reducing, the foam index of the resultant ash. In fact, with C-PAC levels as high as 3%WT no meaningful change in foam index was observed. Additionally, C-PAC has no effect on short (24 hour), or long term (30 day) compressive strength of concrete manufactured with C-PAC inclusive fly ash.
For more information on the advantages of C-PAC see the options buttons to the left. For more information on the fundamentals of Sorbent-based mercury control please follow this link to our mercury control tutorial.
