Trace elements in coal: Associations with coal and minerals and their behavior during coal utilization – A review

• Published in: Fuel (Guildford) Vol. 89; no. 4; pp. 904 - 911
• Main Authors: Vejahati, Farshid, Xu, Zhenghe, Gupta, Rajender
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Kidlington Elsevier Ltd 01.04.2010; Elsevier
• Subjects: Applied sciences; Ash formation; Ashes; Coal; Coal and derived products; Coal combustion; Coal mines; Condensing; Emission; Energy; Energy. Thermal use of fuels; Evaporation; Exact sciences and technology; Fuels; Installations for energy generation and conversion: thermal and electrical energy; Minerals; Structure, chemical and physical properties; Thermal power plants; Trace element; Trace elements; Coal combustion; Emission; Trace element; Ash formation; Arsenic; Combustion; Review; Evaporation; Condensation; Pollutant emission; Fly ash; Fine particle; Coal; Coal power plant; Selenium; Mercury
• ISSN: 0016-2361; 1873-7153
• DOI: 10.1016/j.fuel.2009.06.013

Trace elements such as mercury, arsenic and selenium present in coal are known to be of concern for public health. Coal-fired power plants have resulted in emission of several tons of TEs in environment. These elements mostly evaporate during combustion and condense either homogeneously as sub-micron ash or heterogeneously onto already existing fine ash. The coal–mineral and mineral–mineral associations play an important role in the formation of fine particles and in subsequent condensation of trace elements in various phases. Any retention of these elements in fly ash particles is strongly influenced by their association with other minerals in individual coal and mineral grains. Clean coal technology development is, therefore, a priority area for research and needs continuous improvements in increased efficiency and decreased pollutant emission. The paper will include trace elements in different coals from around the world. It will consider different modes of occurrences present in coals, the ash formation and evaporation of trace elements and emissions. The typical emissions from typical power stations will be presented. The paper will also review different approaches adopted in estimating the deportment of these elements. The paper at the end would discuss control strategies for reducing emissions and future directions.