Abstract: A refractory tile system includes a barrier layer coating applied to the wall (membrane and waterwall or tube wall) of a boiler of an incinerator or heat exchanger. Refractory tiles are then fastened to the tube wall utilizing a floating attachment mechanism to provide a relatively high degree of freedom of movement relative to the tube wall to accommodate micro-scale bowing of the tile generated by the relatively large temperature gradient and mean temperature typically experienced by such tiles. Each tile is also effectively isolated from adjacent tiles by providing a predetermined gap therebetween of sufficient size to effectively prevent macro-scale bowing generated by networking thereof. Moreover, a compressible fibrous mortar is preferably disposed in the gap or channel between each adjacent tile to substantially prevent ash or other contaminants from passing therethrough.

Abstract: A ceramic body comprising at least about 80 w/o silicon nitride and having a mean tensile strength of at least about 800 MPa.

Abstract: A silicon nitride ceramic comprising:a) inclusions no greater than 25 microns in length,b) agglomerates no greater than 20 microns in diameter, andc) a surface finish of less than about 8 microinches, said ceramic having a four-point flexural strength of at least about 900 MPa.