Slag removal apparatus

In coal-gasification apparatus, slag particles received in free-fall by a water bath at the bottom of the reactor, or of a waste heat boiler associated therewith, are wetted with oil, or another additive agent. As a result they become bonded together. This prevents floating and facilitates sinking of the slag for removal from below the water bath. An annular duct having nozzles at different angles is used to spray the slag particles with oil near the surface of the water bath. The nozzles create a turbulence at the surface, thereby increasing the effect on the slag particles. A lock hopper fluidly communicates with the water bath right below, and collects the slag particles. The removed slag is classified before being used or recycled by feedback into the reactor together with coal dust, water and oxygen as components for the reactive process.