Abstract: The invention provides a method and apparatus for creating a stable combustion flame from natural gas and an oxygen containing gas which is useful for the pyrometallurgical treatment of finely divided materials such as metal ores. In particular, natural gas and the oxygen containing gas are injected in a manner which forms recirculation zones between the natural gas and oxygen containing gas thereby maintaining the stability of the combustion flame. The apparatus of the invention encourages the formation of the recirculation zones by using a bluff body orifice plate to provide a dead space between the injections of the oxygen containing gas and natural gas. Additional gas injection is used downstream in the combustor to create turbulence and further stabilize the combustion flame.

Abstract: Process and apparatus for pyrometallurgically treating finely divided ores, concentrates, residues, slags and like materials. The process utilizes a reactor having two co-axially extending, vertical reaction chambers. The process comprises forming within the upper chamber of the reactor hot fuel-rich reaction gases; passing the hot fuel-rich reaction gases by dump flow into a second vertically extending chamber; introducing into the second chamber the finely divided materials to be treated; and reacting the finely divided materials with the hot fuel-rich reaction gases. The dump flow of hot fuel-rich reaction gases passing into the second chamber is produced by providing a zone of sudden expansion in the flow passage between the first and second chambers.