MAPPING SHALE AND FIRECLAY RESOURCES FOR A POTENTIAL SHALE-FLY ASH BRICK INDUSTRY IN CENTRAL ILLINOIS

Fly ash, a by-product from coal-burning power plants, has recently been demonstrated to be a feasible and attractive raw material for brick manufacture when blended with low-sulfur, non-calcareous shale and fireclay resources. Many shales in the Pennsylvanian Carbondale and Modesto Formations in Illinois have the correct composition and firing properties for brick manufacture. However, high-quality shale and fireclay need to be near the manufacturing site to make the development profitable. With support from the Illinois Clean Coal Institute, we mapped the presence and distribution of suitable shale and fireclay near two power plants along the Illinois River Valley between Peoria and Morgan Counties, Illinois, where a shale-fly ash brick manufacturing plant is under consideration. Suitable shale resources were identified and delineated by reviewing published and unpublished reports and examining more than 2,000 well records within a 15-mile radius of the utility sites. The well record data were used to develop contour maps of the overburden thickness (depth to top of suitable shales) and the shale thickness. Potential shale strata that could serve as raw materials to be blended with fly-ash from coal-fired power plants and used for brick manufacture were identified. Overburden thickness was important for delineating areas with the greatest mining potential. Since mining feasibility is also affected by cultural and environmental restrictions, such as residential and industrial development, parks, etc., these restrictions were delineated for the study area using information available in the Illinois State Geological Survey’s GIS database. The results of this study will be used to assess a potential shale-fly ash brick manufacturing site. The new industry can provide a host of economic benefits including: 1) utilization of significant amounts of fly ash now landfilled or stock-piled in ponds, 2) new business opportunities to commercially produce bricks using fly ash, and 3) new jobs to stimulate the local and state economy.