Grantee Research Project Results
Sustainable Utilization of Coal Combustion Byproducts through the Production Of High Grade Minerals and Cement-less Green ConcreteEPA Grant Number: SU835349
Title: Sustainable Utilization of Coal Combustion Byproducts through the Production Of High Grade Minerals and Cement-less Green Concrete
Investigators: Mohanty, Manoj K.
Institution: Southern Illinois University - Carbondale
EPA Project Officer: Lank, Gregory
Project Period: August 15, 2012 through August 14, 2014
Project Amount: $89,943
RFA: P3 Awards: A National Student Design Competition for Sustainability Focusing on People, Prosperity and the Planet - Phase 2 (2012)
Research Category: Pollution Prevention/Sustainable Development , P3 Challenge Area - Built Environment , P3 Challenge Area - Materials & Chemistry
The main objectives of the proposed study include:
- To develop a novel flowsheet for extracting valuable mineral oxides, such as Iron and Aluminum oxides from high sulfur coal ash and validate it using large-scale process equipment.
- To develop a suitable process to utilize majority of the non-magnetic coal ash in the form of a geopolymer-based concrete which could potentially eliminate the use of Portland cement having a much higher carbon foot print and water need.
- To educate the present and future university students about the challenges behind the continued use of coal-based electricity and the commercialization potential of the holistic approach of dealing with the coal combustion residues proposed in this study.
More than 136 million tons of Coal Combustion Byproducts (CCBs) are being produced annually to satisfy our nation’s need for electricity and energy. However, less than 45% of these CCBs are being successfully used in various applications and the remainder is being dumped as waste materials in the landfills and ash ponds. Many past studies indicate the presence of a variety of metal oxides in CCBs. Some of these metal oxides like Fe2O3 and Fe3O4 are present in much greater proportion if the combustion feed coal contains high amount of pyritic sulfur. Incidentally, these oxides are extracted from the mother-nature in the form of hematite and magnetite ore minerals, respectively in Iron ore mines. Understandably, the amount of mining activity and the associated negative environmental impact can be significantly reduced by extracting various minerals from the CCBs which are abundantly available in numerous ash ponds in the country.
Another wide-scale application envisioned for the CCBs is cement-less geopolymer-based concrete. Usually, concrete is prepared using Portland cement utilizing a high CO2 producing chemical process and thus is responsible for about 5-8% of total CO2 emissions as a green house gas affecting global warming. A local utility company (Southern Illinois Power Cooperative) has shown significant interest in the proposed ideas and has committed significant assistance during this study. Our team will work closely with coal power plants in Southern Illinois area and the research outcomes will be presented on campus as well as national and state community to promote the concepts of high-value utilization of CCBs.Expected Results:
Low cost processing flowsheets to extract various metal oxides (like Iron oxides and Aluminum oxides) from fly ash and bottom ash as well as a suitable procedure for producing cement-less geopolymer-based concrete using fly ash and bottom ash will be the main research deliverables. Poster and product demonstration will also be conducted upon the successful completion of this project.Supplemental Keywords:
waste to value, sustainable construction materials, geopolymer, green concrete, alternative construction material, recycled materials, hazardous waste remediation, environmental education