Indoor Emissions from Household Combustion of Coal

Coal is a highly variable fuel, which ranges from high heating-value anthracite through various forms of bituminous coal to intermediates in coal formation, viz. lignite and peat. Each of these types of fuel can contain different levels of moisture, non-combustible inorganic material (ash), sulfur, and sometimes significant levels of other impurities, e.g. arsenic, fluorine, lead and mercury. Raw coal may be used in many forms, from lumps and briquettes to fine powders. Processing of coal may be as simple as forming coal balls or cakes by hand followed by sun-drying, or it may be a sophisticated procedure, blending coal into a uniform mixture with binders to reduce sulfur and particulate emissions and formed into briquettes designed to burn efficiently and cleanly in special stoves. 1.1.2 Constituents of coal emissions