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Abstract: Solid waste management is gaining significant importance with the ever-increasing quantities of industrial by-products and wastes. With the environmental awareness and scarcity of space for landfilling, wastes/by-product utilization has become an attractive alternative to disposal. Several industrial by-products are produced from manufacturing processes, service industries and municipal solid wastes. Some of these industrial by-products/waste materials could possibility be used in cement-based materials. Coal combustion by-products (CCBs) represent incombustible materials left after combustion of coal in conventional and/or advanced clean-coal technology combustors. These include fly ash, bottom ash, boiler slag, and flue gas desulfurization (FGD) by-products from advanced clean-coal technology combustors. This paper briefly describes various coal combustion products produced, as well as current best recycling use options for these materials. Materials, productions, properties, potential applications in manufacture of emerging materials for sustainable construction, as well as environmental impact are also briefly discussed. [ABSTRACT FROM AUTHOR]

Reducing the potential leaching of Mo and Ni from the fly ash (FA) of petroleum coke is an increasingly important issue as Asia and Europe's demand is expected to drastically intensify as continuing urbanisation and technological innovation demands ever more electricity. In the present study, we investigated coal combustion products (CCP) from a large coal-fired power station fed with a 56:44 coal/petroleum coke blend. Results revealed that leachable concentrations of Mo and Ni from FA were in the upper non-hazardous limit and in the inert limit, respectively (2003/33/EC). Whilst common prevention measures for Mo and Ni based on the adsorption capacity of boiler slag (BS), a mixture of BS: goethite, and jarosite, were considered insufficient to reduce the potential leaching of Mo into FA leachates, a novel chemical stabilisation method based on an aggregate product of portlandite and FA immobilised both Mo and Ni such that the resulting concentrations were below the limits established in the abovementioned 2003 EC Decision. Precipitation may be responsible for the fixation of Mo and Ni in the FA: portlandite aggregates as Ca(MoO 4) and NiMoO 4 , respectively. The findings of this novel study support the use of this aggregate to reduce FA pollutants, which will be of particular interest to nations that remain largely coal/petroleum coke-dependant. • Coal combustion products from a large coal-petcoke fired power station were studied. • Leachable concentrations of Mo in FA were in the upper non-hazardous limit (2003/33/EC). • Leachable concentrations of Ni in FA were in the inert limit (2003/33/EC). • A novel portlandite and FA aggregate product immobilised Mo and Ni below the EC Decision limits. • Ca(MoO 4) and NiMoO 4 precipitation may be responsible for the fixation of Mo and Ni. [ABSTRACT FROM AUTHOR]