Desulphurization process using ammonium hydroxide to remove sulfur contaminants from coal

摘要

A method of processing coal to remove contaminants is disclosed, which comprises the steps of:providing a solution of aqueous ammonia (NH4OH ammonium hydroxide) in a selected concentration range of ammonia in a reaction vessel; adding coal into the reaction vessel;agitating the coal inside the reaction vessel to mix the coal and solution to cause the solution to be brought into contact with the surfaces and pores of the coal;discharging the processed coal from the vessel; monitoring the process to detect when the concentration of aqueous ammonia in the reaction vessel has fallen below the selected range; and feeding aqueous ammonia solution with an ammonia concentration in or above the selected range to the reaction vessel to return the solution to within the selected range.