CARBON DEPOSITION FROM A GAMMA-IRRADIATED CO2 CO/CH4/C2H6 GAS-MIXTUREON THE MANGANESE OXIDES MNO, MN3O4 AND MN2O3/

The composition of oxides formed on steel surfaces within power reacto rs may influence heat transfer efficiency. Previous studies have indic ated that carbon is deposited on spinal-type oxides containing mangane se, iron, cobalt, nickel and chromium. In this investigation, characte rised manganese oxides have been subjected to gamma-irradiation under conditions similar to those experienced in reactors in an effort to un derstand the catalytic processes involved in deposit initiation and gr owth. Mn3O4 and Mn2O3, under the conditions present in the gamma-cell, were reduced to MnO during the time of exposure. Relative carbon depo sition rates were observed to follow the trend MnO > Mn3O4 approximate to Mn3O4. (C) 1997 Elsevier Science B.V.