Title: CCP – Waste or Resource- Breaking the Regulatory Paradigms

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Publication: CIA

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Date: 2/13/2011

Abstract:
Although regulations have classified the solid products of coal combustion in pulverised fuel power stations including fly ash and furnace bottom ash – generally referred to as coal combustions products (CCP) – as wastes, CCP are increasingly being recognised as a useful mineral resource in Australia. Proven and established applications of CCP occur in the cement and concrete industries, the stabilisation of engineered soils for construction purposes, and the production of synthetic aggregates and zeolites. Applications having increased potential include the improvement of soils for agriculture and horticulture and mine site rehabilitation. This paper discusses CCP applications with the greatest potential in the Australian context, namely: (1) backfill in mining operations, and the resultant benefits to the mine through rehabilitation, subsidence control and other mechanisms; and (2) improving poor structural or weathered soils through amendment with CCP, leading to increased agricultural yields. The mineralogical, geotechnical and geochemical characteristics of individual ashes may vary, depending on the coal feedstock and combustion conditions. The mobility of particular elements may also vary, depending in part on the environmental conditions and soil types onto which CCP are applied. Site-specific studies of the chemical interactions between CCP, soils, rock and water may be significant in establishing the environmental risks, if any, associated with use.