“…1 However, coal is an impure fossil fuel which contains a number of impurities such as minerals, sulphur (S), nitrogen (N) and ash. 2 Among the periodic table elements, S is known as one of the most dominating contaminants in coal and it is usually present in four forms (mode of occurrence). The sulphur forms include sulphate minerals, sulphide minerals (predominantly pyrite), elemental sulphur and organosulphur compounds within the organic framework of coal.…”