A COAL COMBUSTION BYPRODUCT, FLY ASH, FOR FIRED BUILDING BRICK MAKING―A PRELIMINARY TECHNICAL FEASIBILITY STUDY

摘要

Most of the three million tons (2.7 million metric tons) of class F fly ash produced from burning Illinois bituminous coals is ponded or disposed of in landfills, which represents a continuing solid waste disposal problem. The purpose of this study was to obtain a preliminary assessment of the technical feasibility of making fired bricks with Illinois class F fly ash generated by the Meredosia Power Plant in Illinois. The extrusion method was used to form bricks before firing. The fired test bricks were produced with increasing amounts (20% to 40% by weight) of fly ash as a replacement for conventional raw materials, and were examined for their chemical characteristics and engineering properties. The results indicated that the chemical properties of ash containing test bricks were comparable with those of standard test bricks containing no fly ash (that is, containing only the raw materials-clay and shale). The unbumed carbon in fly ash was not a concern in producing fired bricks. Both the ash containing and the standard test bricks met commercial specifications for fired building bricks. However, some engineering properties of the ash-containing test bricks, such as color, physical consistency, and fired compressive strength are better than those of the standard test bricks.