REDUCTIVE DECOMPOSITION OF CALCIUM-SULFATE WITH CARBON-MONOXIDE - REACTION-MECHANISM

When CaSO4was treated with a mixture of CO, CO2, SO2, and N2at 1150 °C in thermogravimetric analysis equipment, various reaction stages were identified, and the final product distribution was found to depend on the reducing potential (PCO/PCO2°f the gases. At low reducing potentials (≤0.10), the CaSO4was completely converted to CaO. At moderate reducing potentials (i.e., 0.20), CaSO4was converted rapidly to CaO, which was then converted more slowly to CaS. The rate-controlling mechanisms seemed to differ markedly for the earlier and final reaction stages. © 1990, American Chemical Society. All rights reserved.