Investigations on desulphurisation of some high-sulphur Indian coals by γ-ray-induced chlorinolysis

Results of investigations on desulphurisation of high-sulphur (2–8 wt%) coals of Meghalaya by radiation chlorinolysis, effected in different media of chlorination (CCl4, CCl4/H2O, and CCl4/CH3OH) via radiolysis of CCl4, for the removal of both the inorganic (pyritic and sulphate) and the organic forms of sulphur as well as mineral matter are reported. In general, maximum removal of total sulphur (up to 37%) and mineral matter (up to 10%) takes place in CCl4/CH3OH medium, which is attributed to the CH3OH acting as a better wetting agent for coal. It is found that while pyritic and sulphate sulphur are removed almost quantitatively, there is variation in the removal of organic sulphur from the coals. Furthermore, the coal matrix is not affected/degraded to any appreciable extent and the caking property of the coals is either improved or slightly degraded after desulphurisation. Mechanism of desulphurisation of coal via radiation chlorination is proposed.