THERMAL INTERACTION BETWEEN SOME OXIDES AND ZIRCON AS A MATERIAL FOR DIESEL ENGINES FILTER

This study investigates the high temperature chemical resistance of zircon, ZrSiO4, against Na2O, CaCO3, PbO, ZnO, Fe2O3, V2O5 and CeO2. It was observed that lead and sodium oxides react with zircon only at 700 and 850degreesC respectively, while the others do not react over the temperature range examined. Surprisingly, if V2O5 and PbO are present at the same time, the reaction of PbO is inhibited and zircon does not suffer degradation. On the other hand, the ternary mixture V2O2-PbO-Na2O reacts slightly with zircon, the reaction was confirmed by XRD after thermal treatment of the mixtures at 650degreesC and by FTIR after thermal treatment at 700degreesC revealing the formation of lead silicates and lead zirconates. Not all the reactions between zircon and the other oxides are destructive and suggest that zircon is a suitable material for the production of diesel ceramic filters. (C) 2003 Elsevier Ltd and Techna S.r.l. All rights reserved.