IMPLEMENTATION OF A NOVEL CERAMIC SEALANT ON METALLIC COATINGS IN HEAT EXCHANGERS TO IMPROVE PERFORMANCE IN HIGH TEMPERATURE, EROSIVE AND CORROSIVE ENVIRONMENTS IN WASTE TO ENERGY PLANTS

Abstract

he ceramic coating is a developing technology for the protection of boiler’s heatexchanger materials in Waste-to-Energy power plants. Aluminum phosphate ceramic adhesives is a candidate coating material for ceramic coatings. It has been manufactured with different Al:P molar ratios on steel and Nickel-chromium alloy substrates. The focus of this study was directed on producing the monoaluminium phosphate Al(H2PO4)3 and the aluminum phosphate AlPO4 binder with Al:P molar ratios of 1:3 and 1:1, respectively. The X-ray diffraction (XRD), Differential Scanning Calorimeter (DSC) techniques were applied to determine the chemical compositions of the lab-based manufactured aluminum phosphate binders. The XRD results showed that a monoaluminium phosphate was manufactured in binder K08 and the DSC curve of that binder showed a phase transition at about 119⁰C. Alumina particles Al2O3 was added to the binders to increase their mechanical properties such as wear resistance. Also, potassium silicate was added to some of the compounds to increase their pH values. By deciding to work with two Al:P molar ratios and adding alumina particles and potassium silicate; the manufacturing of several aluminum phosphate products are presented in this thesis with the issues and challenges faced in the process.