Process for maintaining heat protective layers of solidified synthetic slag within a slagging coal gasifier

Claim 1

A process for forming and maintaining heat protective layers of solid slag between metallic materials and the zone of combustion within a slagging coal gasifier in which a combustible mixture of coal and oxygen is injected through at least one burner comprising: injecting into the gasifier, in at least one location which is near the inner face of at least one of said burners but is separate from any conduit through which coal and combustion supporting gas are introduced into the gasifier, a stream of finely divided heat protective and heat-resistant solid synthetic slag particles which are substantially noncorrosive to metallic surfaces, with said synthetic slag particles being introduced at a rate sufficient for forming and replacing erodedaway portions of base layers of solid synthetic slag on which coal-formed slag particles become accreted, so that the layers of slag provide heat protection between said metallic surfaces and the zone of combustion without causing the layers of slag to thicken to an extent at which their volume impedes the outflow of molten slag from the gasifier.