Corrosion of High Alumina Castables by Liquid Ashes during the Gasification of Sewage Sludge
CNRS, CEMHTI UPR3079, Univ. Orléans 45071 Orléans/France
Revision 31.05.2014, 23.09.2014
Volume 7, Issue 1, Pages 69 - 72
The overall objective of this work is to understand the thermo chemical interactions between different high alumina refractory materials and slag during the gasification of biomass (sewage sludge). The slag behaviour and the corrosion between different high alumina-based castables and the liquid ashes are studied. Corrosion tests were carried out using static and dynamic tests. The loss of thickness of the initial interface was used to evaluate the amount of corrosion and impregnation, whereas the dynamic test was performed out in order to quantify the erosion phenomenon. Quantitative and qualitative analysis were carried out using SEM and DRX. These techniques were also used to determine the liquidus temperature of sewage sludge ashes after quench at high temperature. Results shows the presence iron oxide, lime, and iron/lime phosphate crystals (Ca9Fe(PO4)7). The liquidus temperature of slag is located between 1250 °C and 1300 °C. Trials of corrosion indicate a higher impregnation and corrosion for rich alumina castables (tabular/alumina and alumina/spinel). Chrome alumina refractory presents a very limited corrosion and andalusite-based refractory exhibits limited penetration.
gasification, sewage sludge, inorganics, refractories
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