Preparation of FeMnAlSiC Powder by CO₂-Steel Slag Cooperative Electro Deoxidation

The resource utilization of CO₂ and steel slag is an urgent problem that needs to be solved. In order to solve the problem of high added value utilization of CO₂-steel slag, thermodynamic calculations were carried out for the preparation of FeMnAlSiC by molten salt electrolysis. Results showed that during 800–1000 °C, the voltage range of −2.51 to −2.39 V could ensure the reduction of slag, and the reduction order was Fe, Mn, Si, and Al. CO₂ was continuously introduced into NaCl–CaCl_2, existed in the form of CO₃²⁻. C will appear under the voltage of −2.77 to −2.51 V, and then reacted with Fe, Mn, Al, Si in the cathode to synthesize FeMnAlSiC powder. In conclusion, considering energy consumption, thermodynamic conditions for the synthesis of metal elements in the cathode and ensuring that molten salt was not electrolyzed, the electrolysis temperature and voltage were 900 °C and −3 V respectively. Under this condition, FeMnAlSiC powder could be prepared theoretically, and the order of alloying in theory was Mn–Si, Fe–Si, Si–C, Mn–C, Al–Si–C, Fe–C.