A Novel Electrochemical Process for Desulfurization in the CaO-SiO(2)-Al(2)O(3) System

The effect of electric potential on the sulfide capacity of the CaO-SiO(2)-Al(2)O(3) system was evaluated by applying voltages in the range of −1.5 to 1.5 V at 1823 K in a C/CO gas equilibrium. When the cathodic potential (−1.5 to 0 V) was applied, it was confirmed that the sulfur partition ratio increased based on the electrochemical reaction of sulfur (S + 2e(−) = S(2−)). However, the reversibility of the electrochemical resulfurization reaction (S(2−) = S + 2e(−)) in slag was not established in the reverse (anodic) potential region (0–1.5 V), yet the sulfur partition ratio increased. In particular, sulfur evaporation was observed in the anodic potential region. Therefore, in the present study, potential anodic electro-desulfurization mechanisms based on sulfur evaporation are proposed. To verify these mechanisms, sulfur evaporation is discussed in detail as a function of the thermodynamic stability of sulfur in the slag.