MgO-based desulfurizer for SO2 removal of sintering flue gas: Performance and mechanism

Low-temperature desulfurization products of sintering flue gas are difficult to be treated, and the wastewater increases the cost of desulfurization; to solve these problems, the MgO-based dry desulfurization technology was studied. Application of sintering flue gas indicated that the desulfurization efficiency reached 97% steadily under the dry condition of 60°C. The absorption mechanism of SO2 with the desulfurizer was investigated by the means of scanning electron microscopy and X-ray photoelectron spectroscopy; it was found that the absorption of SO2 by a MgO-based desulfurizer belonged to chemical absorption, and the product was sulfate. The desulfurization process was as follows: first, SO2 diffused to the MgO-based desulfurizer surface, then it was oxidized to sulfite by the oxygen defect site (O2−), and finally, the sulfite was oxidized to the sulfate by the oxygen in the sintering flue gas.