A continuous process for preventing the build-up of metals from the hydrocarbonaceous fuel feed in a partial oxidation system in which about 80-100 wt. % of the carbon-soot produced is recycled to the gas generator. By the subject process a significantly large portion of the metals and metal compounds i.e. ash in the soot-water feed stream to the decanter become concentrated in the grey water that separates out in the decanter in the carbon recovery section. The concentration of ash suspended in the grey water may be then easily reduced in a solids-liquid separator with or without the addition of a flocculant and prior to recycling a portion of the grey water to the gas quench tank and/or gas scrubber. Further, the ash suspended in the carbon-soot-liquid hydrocarbonaceous fuel stream from the bottom of the liquid organic extractant still may be optionally reduced in another solids-liquid separator prior to recycling a portion of said stream to the gas generator as part of the hydrocarbonaceous reactant fuel feed.