Conversion of Anthropogenic CO₂ and Waste Flue Dust from Cement Factories into Calcium Carbonate and Magnesium Carbonate: A Circular Approach to Carbon Mitigation

Abstract

Industrial flue dust, an abundant byproduct of metallurgical processes, was evaluated as a low-cost CO₂ material for CO2 conversion to calcium carbonate and magnesium carbonate under ambient conditions. Batch system experiments compared CO₂ concentration profiles in a sealed chamber with and without flue dust at 25 °C and 1 atm., using a CO₂ injection rate of 20 mL per 30 s. In the absence of flue dust, CO₂ concentration rose steadily from 407–414 ppm to 1058 ppm at 900 s, reflecting passive accumulation. With flue dust present, CO₂ levels remained near ambient for up to 690 s, with measured concentrations 124–286 ppm lower than the control during 240–690 s. This corresponds to a CO₂ removal capacity of 23.5–41.4%, peaking at 41.4% before declining to 3.5% at 900 s due to reduction of calcium and magnesium oxide.