Research on Using Carbide Slag to Mineralize the Carbon Dioxide in Electrolytic Aluminum Waste Gas

This study proposes the technology of using waste carbide slag to treat carbon dioxide in the tail gas of electrolytic aluminumAluminum and innovatively designs a VenturiVenturi gas–liquid–solid three-stage reactor. The ability of Ca(OH)2 slurry to absorb CO2 under operating conditions was studied. The results show that the residual proportion of CO2 in the waste gas is below 0.08% through the absorption of the stage reactor. The particle size of calcium carbonateCalcium carbonate obtained from the third-stage reactor can reach 5.9 um, significantly smaller than the mixing tanks and industrial products. When the gas velocity is greater than 21.231 m/s, the gas holdup and bubbles rising velocity increases rapidly, so the superficial gas velocity should not exceed 21.231 m/s. As the superficial liquid velocity increases, the bubble rising velocity and gas holdup first increase and then decrease. The superficial liquid velocity should exceed 1.504 m/s. As the inlet gas pressure increases, the bubbles rising velocity first increases and then decreases, and the gas holdup first decreases and then increases. Therefore, the gas pressure should be greater than 0.15 MPa.