Blast furnace—converter steel production method based on carbon cycling

A method for steel production in a blast furnace and a converter based on carbon cycling, characterised by the following steps:

• a) smelting iron in a blast furnace to obtain molten iron;
• b) introducing said molten iron into a converter for steel refining to obtain molten steel and untreated converter gas;
• c) subjecting the untreated converter gas to pressurisation, desulphurisation, deoxygenation, dehydration, decarbonisation, and denitrification sequentially to obtain synthesis gas and treated converter gas;
• d) recycling the treated converter gas back into the blast furnace to regulate the ratio of reductive gases within the furnace atmosphere;
• wherein the untreated converter gas contains a CO concentration of 40% or higher;
• wherein step c) further comprises pressurising said untreated converter gas to 0.50 MPa~0.65 MPa via a gas pressurisation unit;
• wherein in step c), prior to the desulphurisation process, the temperature of the pressurised converter gas is controlled between 60° C.~90° C. through a cooling unit;
• wherein in step c), the desulphurisation and denitrification include reducing the sulphur content to less than 10 ppm through a desulphurisation unit, and achieving a denitrification efficiency of 90% or higher through a denitrification unit;
• wherein in step c), the desulphurisation and denitrification include reducing the sulphur content to less than 10 ppm through a desulphurisation unit;
• wherein in step c), the desulphurisation and denitrification include achieving a denitrification efficiency of 90% or higher through a denitrification unit;
• wherein in step d), the recycling of treated converter gas back into the blast furnace includes heating the treated converter gas to 850° C.~950° C. through a gas heating unit;
• the heated converter gas is blown back into the blast furnace so that the fuel ratio is 433 kg/t.