Soda lime silicate flint glass melts containing sodium sulfate or blast furnace slag were prepared and the sulfur redox equilibrium was studied by square wave voltammetry. Voltammograms at different frequencies ill the temperature range from 1000 degrees C to 1400 degrees C were produced. The melts containing sodium sulfate showed two reduction peaks at high frequency but only one peak at low frequency. Based oil the relation between peak current and pulse time, it was concluded that the second peak was nothing to do with the pure reduction of S(4+) to S(0) but might be related to sulfur adsorbed to in electrode. The peaks observed in the voltammograms of melts containing blast furnace slag with sulfide were located at similar potentials with those of sodium sulfate.

Keywords: sulfate; sulfide; redox reaction; voltammogram