Thermodynamic Analysis of Pyrolusite for Dry Flue Gas Desulfurization

Various approaches to flue gas desulfurization by low-grade manganese and high efficiency desulfurization in sintering enterprises were investigated, and the predominance areas of the Mn/Fe-S-O system were constructed in this paper. Additionally, the areas in different temperatures were established based on the thermodynamic properties achieved from manuals. From the view of thermodynamics, manganese oxides were suitable and feasible for desulfurization at an appropriate temperature range from 393 K to 453 K (120 ̋C to 180 ̋C), which means that the SO2 of sintering flue gas could be removed directly without further cooling or heating. The analysis often showed that there was an overlap area of the Mn-S-O and Fe-S-O system, indicating that it would be a coexistence stability region of MnSO4 and Fe2O3, which provided a possibility of desulfurization by selective salvation without the sulfate and sulfide of iron forming. More importantly, the predominance areas of Mn/Fe-S-O would offer an attractive way of determining optimum experimental conditions for dry desulfurization by low-grade manganese resources.