Microwave-ultrasonic assisted zeolitization of coal fly ash(CFA): value-added materials for environmental applications

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Power generation by coal-fired power plants produces millions of tons of coal fly ash (CFA) as a by-product. Currently, worldwide profitable usage of fly ash is varied widely in different countries from a minimum of 3% to a maximum of 57%, with a global average of about 15-20% of the total ash. The primary uses of CFA in Canada are in cement manufacturing, hydraulic mine backfill (cement replacement), liquid waste stabilization, flowable fill (use for backfill, excavation, sub base, road base), and as mineral fillers. The main objective of the current proposal is to convert CFA, as a free source of silicon and aluminum, to zeolitic products that meet or exceed the performance characteristics of current zeolite products in a more energy efficient and greener way using a hybrid technique with microwave (MW) and ultrasonic (UTS) sources of energy. Zeolites are crystalline porous aluminosilicate compounds with unique orderly structural chemistry leading to numerous properties including molecular sieving, selective adsorption, high thermal stability, selective ion exchange, and shape selective catalytic properties. The manufactured porous zeolitic materials will be shaped in the form of granules, pellets and rods to be used as adsorbents (e.g. 4A and 13X zeolites). Furthermore, the synthesized zeolites will be modified using environmentally friendly surfactants to obtain multifunctional adsorbents for removal of heavy metal cations, toxic oxyanion and organic pollutants for contaminated air, water and soil treatment. Success in this project will create technology based products and jobs affecting the manufacturing and environmental sectors in Canada and worldwide. The proposal is of value in addressing the over dependency our society has for landfilling. A portion of the CFA will be converted to a valuable product. The HQP involved in this project will be trained in the areas of CFA solid waste remediation technologies, UTS/MW assisted synthesis processes, characterization and testing of porous materials for ion exchange, adsorption and separation processes, and application of the zeolitic products for air, water and soil pollution control.