METHOD FOR REMOVING HYDROGEN SULFATE AND AMMONIA, AND RECOVERING AMMONIUM THIOCYANATE IN COKE GAS REFINING

摘要

PURPOSE: A method for removing hydrogen sulfate and ammonia, and recovering ammonium thiocyanate in coke gas refining is provided which uses the recovered cyanide compounds as a useful chemical material by separately recovering cyanide compounds which can be problematic in wastewater generated from the coke gas refining process. CONSTITUTION: The method comprises the processes of producing ammonium poly sulfides by passing the air (8) through a solution containing ammonia and hydrogen sulfide absorbed from coke gas by absorption columns (12,13); recovering hydrogen cyanide by collecting hydrogen cyanide in an ammonium thiocyanate (16) form by using the produced ammonium polysulfides; infusing ammonia vapor (22) discharged from an ammonia distilling column (5) into an ammonia and hydrogen sulfide absorption column (13), and containing a large amount of ammonia in the absorption solution so that hydrogen sulfide existing in the coke gas is collected by ammonia, and a high hydrogen sulfide removing ratio is maintained; and preparing a high concentration ammonia solution by absorbing ammonia vapor (22) generated from the ammonia distilling column (5) in an ammonium polysulfide producer (18), and absorbing hydrogen sulfide and hydrogen cyanide using the ammonia solution so that hydrogen cyanide is combined with ammonium polycyanides for producing ammonium thiocyanide (16), and a high absorption ratio of hydrogen sulfide is maintained, wherein the air (8) supplied to the ammonium polysulfide producer (18) is infused into Clause process (15) and used as an oxidizer after having been used in the production of ammonium polysulfides.