Coal, Trace Elements

With ever-increasing demand of solid fossil fuel, distribution of trace elements in coal has become a great concern as it is a big environmental constraint. Two aspects – mode of occurrence and distribution of trace elements – are significant. Trace elements may either be due to primary biogenic concentration in the plants or precipitation/sorption during the formation of coal.

The depositional environment during peatification and diagenesis plays an important role in the formation of trace elements in coal. Trace elements associated with plant materials undergo chemical changes causing alteration in organic combinations. The formation of insoluble metal sulfides is a result of the reduction of sulfate to sulfide due to bacterial action.

Syngenetic elements are likely to be derivatives of organic matter, However, such elements are unlikely to remain in its original form during coalification process which involves change in hydrogen ion concentration (pH), oxidation reduction potential...