AbstractThe absorption of dilute SO2into aqueous double slurries containing CaCO3and Mg(OH)2was carried out using a stirred tank with a plane gas‐liquid interface. The absorption rate increased and finally reached that under the completely gas‐film controlled conditions as the absorption process proceeded. The desulfurization process using the double slurry was formulated by a two‐reaction‐plane model in which there are no particles suspended in‐between the interface and the primary reaction plane. It was suggested from comparison of the experimental absorption rates with the theoretical predictions that 40 to 60% of the absorbed sulfur dioxide may be present as an effective magnesium sulfite