Large volumes of fly ash and other coal combustion products (CCPs) are produced every year by coal-fired power plants. About 50% of the CCPs produced in the U.S. is buried in impoundment lagoons or dry landfills. Fly ash is generally enriched in several potentially hazardous trace elements, such as As, B, Cd, Co, Cr, Mo, Se, Sr, and V, which can leach from older, unlined disposal sites. Therefo...

On-line nuclear meters have been in use in the coal industry for many years. They have been utilised for coal quality monitoring, in the control systems for coal blending, or for separating coals in the heavy media separation process. Their operation is based on the scattering or the absorption of incident gamma radiation, and the derived density or ash value is the result of a time-averaged me...

Pulverized Wyoming subbituminous coal was beneficiated by low-pH oil agglomerationat CONSOL to prepare the coal for direct liquefaction. Conventional cleaning is not veryeffective in cleaning this coal; for example, conventional oil agglomeration only givesabout 20% ash rejection. To improve ash rejection, the coal-water slurry was acidifiedto a pH of about 0.5. Oil agglomeratio...

America’s electricity generation industry has historically been almost entirely dependent on the burning of coal. This necessity to burn coal so as to provide vital energy for our nation will likely continue for several decades into the future. Due to the large volumes of ash generated by the burning of coal and the toxins associated with coal ash, the Environmental Protection Agency (EPA) has ...

ERDA's companion government group, the Environmental Proportion­ ment Administration, cautioned the new energy source may be danger­ ous to the environment. A spokesman said emissions from the combustion contained unknown compounds which are likely to be dirty and toxic. Besides, the fuel contains bacteria which are known to reproduce. In reply, ERDA countered that many components of the new fu...

The combustion of pulverised coal in power stations results in slagging and fouling in the boiler section and this can be a more severe problem when co-fired with biomass, especially straw. Prediction of the effects of different combination of biomass and coal are helpful to the plant operators. Predictive software gives information about the onset and nature of the slag formed but often the re...

In this paper the possibility of using the pyrolysis oil derived from waste tyres as a collector in flotation of coal was evaluated. The pyrolysis oil was obtained at the initial and final pyrolysis temperatures of 400 and 700 C, respectively, and the heat holding time of 30 min. Flotation results indicated that the pyrolysis oil emulsion showed stronger collecting ability than diesel and the c...

Potentially harmful elements (PHE) occur both naturally from geogenic sources and from anthropogenic derived pollution. Anthropogenic sources can be further categorised into those derived from point sources. A point source is a single identifiable source which is confined to a very small area such as that arising from disposal of waste material or from an industrial plant. Diffuse pollution ari...

What is fly ash? Fly ash consists of the lighter particles that travel up from the coal furnaces during combustion. Bottom ash is the heavier particles that cling to the sides of the furnace and do not escape during the burning of coal. Fly ash particles range in size from 1 to 100 micrometers in diameter (EPRI, 2009) and are comprised of silica, alumina, calcium oxides and iron oxides (EPRI, 2...

Fig. 1. Relationship between waste and raw materials in the production and use of building materials; the lines illustrating areas of interest for Waste Management are emphasized. An ever-increasing number of papers focusing on the use of waste as an alternative material in the production of building materials is being submitted to Waste Management. Indeed, the wide variety of waste components ...