Some Results of the Wetting and Adherence of Synthetic Coal Ash Droplets on Steel

Abstract

As part of a study of slagging in boiler furnaces the sticking temperature, strength of adhesion and contact angle of molten mineral glass drops on various oxidized steel substrates have been investigated. The freezing of the interface between the drop and the metal substrate occurs in milliseconds and in this time a bond is formed between the glass and the oxide coating on the steel. Mineral compositions of low melting point which have reduced liquidus temperatures when iron is dissolved from the surface appear to give the lowest sticking temperatures. Stainless steels which were not heavily oxidized gave low strengths of adhesion. Pyrrhotite formed from melting of pyrite wetted the oxidized surfaces well and gave low sticking temperatures.