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

燃煤发电厂的发电会产生数百万吨的副产品飞灰(CFA)。目前，全球范围内对飞灰的有利可图的使用在不同的国家差别很大，从最低的3%到最高的57%，全球平均约占总灰分的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、流动填充(用于回填、挖掘、底基层、道路基层)以及用作矿物填料。 当前提议的主要目标是利用微波(MW)和超声波(UTS)能源的混合技术，以更节能、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性能特征的沸石产品。沸石是具有独特有序结构的多孔铝硅酸盐化合物，具有分子筛分、选择性吸附、高热稳定性、选择性离子交换和择形催化等性能。制成的多孔沸石材料将被塑造成颗粒、小球和棒状物的形式，用作吸附剂(例如4A和13X沸石)。此外，还将利用环境友好型表面活性剂对合成的沸石进行改性，以获得多功能吸附剂，用于去除重金属离子、有毒氧阴离子和有机污染物，用于污染空气、水和土壤的处理。 该项目的成功将创造以技术为基础的产品和就业机会，影响加拿大和世界各地的制造业和环境部门。这项建议对解决我们的社会对堆填区的过度依赖是有价值的。CFA的一部分将被转换为有价值的产品。参与该项目的HQP将在CFA固体废物修复技术、UTS/MW辅助合成工艺、用于离子交换的多孔材料的表征和测试、吸附和分离工艺以及沸石产品在空气、水和土壤污染控制中的应用等领域进行培训。

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.