Abstract: In order to reduce the nitrogen content of the whole scrap quantum electric arc furnace, optimize the smelting performance of the EAF and reduce the carbon emission of the EAF, the CO₂ injection process was used to replace the original injection process to achieve the above goals. A large number of CO₂ injection process tests were carried out on a 150 t quantum EAF, and the trends of nitrogen content, smelting power consumption, smelting cycle, carbon emission and other performance indexes of the electric arc furnace before and after the improvement process were compared. The test results show that after the CO₂ injection process, the nitrogen mass fraction of the electric arc furnace is reduced by 30.6×10^-6, the smelting power consumption is reduced by 5.6 kWh/t, the smelting cycle is shortened by 3.2 min, the average carbon and oxygen equilibrium is reduced by 4.4×10^-4, the mass fraction of FeO in slag  is reduced by 4.5 %, and the carbon emission is reduced by 8.4 %. By combining the CO₂ carrier gas injection carbon powder process with the Ar+CO₂ dynamic mixed bottom blowing process, it can effectively reduce the nitrogen content of molten steel, smelting power consumption, carbon emissions and other performance indicators, and optimize the quantum electric arc furnace injection process.

Key words: nitrogen content, smelting power consumption, smelting cycle, CO₂ injection process, carbon emission