Characterization of Dry Flue Gas Desulfurization By-Products for Hydraulic Placement in Underground Mines

摘要

In addition to obtaining bulk characteristics of the selected matrices made from coal combustion by-products, TCLP and modified SLP tests were run on the matrix constituents and trial mixtures to ascertain their leachate properties. ASTM column tests were used to determine the persistence of leachate concentration and hydraulic conductivity measurements were made to examine the potential leachate production. Test results indicated relatively few elements of concern with either the selected mixture or the components of the matrices. The most pronounced metals in the leachates were alkali metals such as calcium. Boron was also seen in the leachate but was less pronounced when larger concentrations of scrubber byproduct were used. Calcium leaching was persistent, whereas boron leaching was not. The results obtained for the bulk properties were found suitable for hydraulic placement of the trial composites.