Improved spinel-containing refractory castables for slagging gasifiers

In gasifiers the reaction of a carbon feedstock with oxygen and water takes place to produce synthetic gas. The decrease of the operation temperature at the refractory lining by an innovative gasification technology permits the development of new chrome oxide free materials fulfilling economical as well as ecological aspects. Considering this aspect, spinel-containing refractory castables with increasing spinel content have been investigated according to their thermomechanical properties, phase formation as well as their resistance against corrosion attack by molten coal slag under gasification-similar conditions. In order to determine the influence of spinel and cement in the alumina-spinel castables, increasing spinel amounts and cement types has been added to alumina. In particular, MA-spinel cement has been applied. It has been shown, that the addition of MA-spinel cement to spinel-rich alumina improves the corrosion resistance against molten slag remarkably.