Coal Feeder is a device that regulates the amount of coal to be supplied into the Coal Mill. The amount of coal is regulated according to the needs in the boiler combustion chamber (furnace). Feed coal is premixed with anhydrous sodium hydroxide or mixed sodium and potassium hydroxides, and then fed to a rotary kiln reactor where the mixture is heated to reaction temperatures of 325–415°C, causing the caustic to melt and become sorbed in the coal matrix, it reacts with the coal sulphur and mineral matter, and dissolve the reaction products containing sulphur and inorganic components.