Method for separating, reclaiming and recycling CO2 in gas of blast furnace and converter

The invention relates to a method for separating, reclaiming and recycling CO2 in gas of a blast furnace and a converter respectively, belongs to the fields of ferrous metallurgy and greenhouse gas discharge reduction, and provides an energy-saving technique for improving the mass energy of the gas and reducing the discharge of CO2. The method integrates and optimizes the reclamation and recycle of the gas of the blast furnace and the converter; the reclamation and separation of the CO2 in the gas are executed by a gas treatment system, an absorption tower and a regeneration tower with a built-in boiler, and a chemical absorption system is additionally provided; and the reclaimed CO2 and partial external CO2 can be used for blasting in a hot-blast stove of the blast furnace and carrying gas for injection fuel, and the reclaimed CO2 also can be used for replacing N2 to carry out slag splashing protection for the converter. The method realizes the recycle of the CO2 during iron making in the blast furnace and steel making in the converter, also can use the external CO2 reclaimed from the industrial waste gas in the industries of power, chemical engineering and the like, reduces the discharge of the CO2, realizes an environment-friendly steel production process, and has remarkable social and environmental benefits.