A system for treating a feedstock for the purposes of waste destruction, energy generation, or the production of useful chemicals is disclosed and includes a reactor vessel. A heating lance is configured to outflow the products of a partial oxidation reaction into a reaction chamber in the vessel. The hot reaction products heat and pyrolyze the feedstock in the chamber generating a process effluent which typically includes gases (e.g. syn-gas) and carbon solids. Glasses and metals in the feedstock accumulate in the chamber in a molten state. The molten materials store thermal energy and provide thermal stability to the treatment system. A recycle loop uses carbon solids from the process effluent as an input to the lance for reaction with an oxidant therein.