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

燃煤发电厂的发电产生数百万吨的粉煤灰（CFA）作为副产品。目前，全世界粉煤灰的可盈利使用在不同国家中变化很大，从最小3%到最大57%，全球平均约为总灰的15-20%。CFA在加拿大的主要用途是水泥制造、水力矿山回填（水泥替代）、液体废物稳定、可流动填料（用于回填、挖掘、底基层、道路基层）以及矿物填料。 本提案的主要目的是使用微波（MW）和超声波（UTS）能源的混合技术，以更节能和更环保的方式将CFA作为硅和铝的自由来源转化为满足或超过当前沸石产品的性能特征的沸石产品。沸石是结晶多孔铝硅酸盐化合物，具有独特的有序结构化学，导致许多性质，包括分子筛分、选择性吸附、高热稳定性、选择性离子交换和形状选择性催化性质。所制造的多孔沸石材料将成形为颗粒、丸粒和棒的形式以用作吸附剂（例如4A和13 X沸石）。此外，合成的沸石将使用环境友好的表面活性剂进行改性，以获得多功能吸附剂，用于去除重金属阳离子，有毒的含氧阴离子和有机污染物，用于污染的空气，水和土壤处理。 该项目的成功将创造基于技术的产品和就业机会，影响加拿大和全球的制造业和环境部门。这项建议对于解决本港社会对堆填区的过度依赖，是有价值的。 CFA的一部分将转化为有价值的产品。参与该项目的HQP将接受CFA固体废物补救技术、UTS/MW辅助合成工艺、离子交换、吸附和分离工艺用多孔材料的表征和测试以及沸石产品在空气、水和土壤污染控制中的应用等领域的培训。

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.