STUDY ON PLASMA VITRIFICATION AND REUSE OF NON-COMBUSTIBLE FISHERY WASTES

摘要

The fishery industry is very active in coastal Taiwan. Most fishing boats are made of FRP (fiberglass reinforced plastic) for the hulls. These are made in Taiwan. In addition, there are many yachts produced in Taiwan using FRP hulls, decks and accessories. Therefore, large amounts of FRP wastes are produced and need proper treatment. Because the FRP resins used include fire retardant additives and the glass fiber is not combustible, the wastes cannot be treated using conventional thermal incineration. Oyster shells are also produced by the fishery industry and are not combustible, presenting a challenging disposal problem. In previous work, we have demonstrated that plasma vitrification is a viable technology for combustible and non-combustible wastes when large volume reduction occurs and when the end product is in the form of an inert and non-leachable slag which can be safely disposed of. For vitrification processing, we have employed plasma arc technology as a heating source to treat FRP and oyster shell wastes containing metals and organic complexes at temperatures in the range of 1100 to 1400°C. The vitrified slag was characterized using energy dispersive spectroscopy for X-ray chemical microanalysis, scanning electron microscopy for microstructure/morphology observations, and X-ray diffractometry for crystal structure determination. The leachability of the slag was then evaluated using toxicity characteristic leaching procedure (TCLP). Two-stage heating was used and the wollastonite products were formed using a suitable nucleating agent. The resultant wollastonite products exhibit greater hardness, bending strength, and compressive strength than those of commercial products, and they are more chemically resistant.