Effect of CO on the Desulfurization of Sintering Flue Gas with Hydrated Lime.

The effect of carbon dioxide (CO) on the desulfurization of sintering flue gas with hydrate (Ca(OH)) as an absorbent was investigated, and the formation of calcium carbonate (CaCO) and its effect on the desulfurization was discussed. The competitive relationship between carbon dioxide (CO) and sulfur dioxide (SO) with the deacidification agent in sintering flue gas is discussed thermodynamically, showing that sulfates are more likely to be generated under high oxygen potential conditions and that SO reacts more preferentially than CO under a thermodynamic standard state. The amount of produced CaCO increases under the condition that the CO concentration is absolutely dominant to SO in the sintering flue gas atmosphere. The effect of temperature, humidity and CO concentration on the desulfurization of Ca(OH) are discussed experimentally. The increasing temperature is not conducive to desulfurization, and the humidity can promote desulfurization, while excessive humidity could inhibit desulfurization. The suitable relative humidity is 20%. In situ generated calcium carbonate has a certain desulfurization effect, but the desulfurization effect is not as good as Ca(OH). However, a large proportion of CaCO was produced in the desulfurization ash under the condition that CO concentration was absolutely dominant to SO in the sintering flue gas atmosphere.