PROCESS FOR RECOVERING ARGON FROM SMELTING WASTE GAS USING ARGON-OXYGEN MIXTURE

PURPOSE:To permit inexpensive operation with a simple installation and to recover argon having high purity by shielding the waste gas of an argon-oxygen smelting process from external atmosphere, collecting only the waste gas having high argon concn. produced in the final stage of smelting, and introducing the collected gas into an adsorption tower. CONSTITUTION:Smelting waste gas 5 produced in an argon-oxygen smelting process is led through a hood 6 shielded from external atmosphere, cooling tower 7, and a dust collector 8 to a duct 9, and stored in a waste gas holder 11 through a suction fan 10. Only the waste gas having high argon concn. at the final stage of smelting is stored in the gas holder, and the waste gas of low Ar concn. produced at the initial and middle stage is led through a bypath duct 16 and treated separately. The compsn. of the gas stored in the waste gas holder 11 is about 91% Ar, 2% P2, and 7% N2 due to mixing of some external atmosphere. The gas is sent from the waste gas holder 11 to a PS system 12, where it is separated into Ar from O2 and N2 using an adsorbent having adsorptivity for O2 and N2. By this method, gaseous Ar having >=99.8% purity is recovered.