Possible Design of Chromeoxide-free Refractory Castables for Use in Slagging Gasifiers
Institute of Ceramics, Glass and Construction Materials, TU Bergakademie Freiberg, 09599 Freiberg/Germany
Revision 05.06.2012, 17.09.2012
Volume 5, Issue 1, Pages 99 - 104
Abstract
Gasifiers are containment vessels used to react carbon feedstocks with oxygen and water in order to produce synthetic gas. Raising the profitability by extending the service life of gasifiers on the one hand and the replacement of high chrome oxide materials by environmentally friendly, recyclable and economic refractories on the other hand, allows the reduction of CO2 emission in more than one way. The development of a new gasification technique reduces the peak temperature at the liner wall from 1600 °C to about 1400 °C, which allows the development of new chrome oxide free materials. In these contribution three different approaches has been pursued to improve pure alumina refractory castable by enhancing the mechanical and chemical properties in order to reduce the wear by molten coal slag. Compared to pure alumina castable, the mechanical properties as well as corrosion resistance of MgAl2O4 (spinel) mixed with MAspinel cement, alumina mixed with brown coal ash and alumina with titania and zirconia addition have been investigated. The resistance against an intermediate molten coal slag has been evaluated by applying the cup test at 1450 °C in gasification similar CO atmosphere. It has been shown that the developed environmentally friendly refractories are promising to replace chrome oxide based liner materials for gasification processes up to 1450 °C.
Keywords
refractories, corrosion, alumina, gasification
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