NOVEL PAPERLESS STRUCTURAL COMPOSITES FROM WET FGD SCRUBBER SLUDGE

摘要

The environmentally conducive disposal of and the economically friendly management of wet flue gas desulfurization (FGD) scrubber sludge are of considerable importance to coal-burning electric utilities. To mitigate these concerns, our research has focused on developing marketable but recyclable paperless structural materials from a sulfate-rich wet scrubber sludge. The wet sludge was extensively characterized by X-ray diffraction, scanning electron microscopy (SEM), dynamic mechanical analyzer (DMA), thermal analyses (DSC and DTA), and Fourier transform infrared (FTIR) techniques for ascertaining how its crystal growth and crystal interlocking behavior changed under high pressures at mildly elevated temperatures. The knowledge acquired from the characterization results was combined with the fact that the enhanced interlocking of the sludge crystallites could be achieved by the incorporation of natural proteins and macro-fibrils derived from straw. Under appropriate processing conditions, a paperless wallboard composite resulted from wet scrubber sludge whose mechanical properties were much better than those of conventional papered wallboard material. Additionally, our composites, besides being recyclable materials, could be directly painted, could be mounted with seamless finish, and could be repaired in-situ.