The Utilization Potential of Dry FGD Material in OPC Concrete

Recirculating Dry FGD systems have gained some momentum in recent years due to their flexibility and multi pollutant capabilities. Improvements sorbent utilization efficiency has also increased their acceptance. The later has been brought about through improved humidification and recycling. Depending on the collection and process flow, different types of solids are collected. These range from a FGD material essentially devoid of fly ash to one that is a mix of predominantly fly ash and dry FGD material. In addition the dry FGD material differs from more traditional wet FGD materials, consisting primarily of calcium sulfite instead of calcium sulfate, with calcium hydroxide and minor calcium carbonate also present. The morphology and chemistry of the FGD materials along with the relative amount of fly ash in the final product will affect its character and compatibility with Portland concrete in unknown ways.