Abstract: A novel smelting process and furnace for the economical recovery of vanadium, in the form of ferrovanadium alloy, from oil ashes and/or coal ashes while producing non-hazardous slag for safe and inexpensive disposal in landfill areas. A preferred embodiment of the present process involves the steps of (a) mixing the waste ashes with a contained or added carbon source, such as coal, and a binding material, such as cement; (b) pelletizing the mixture; (c) feeding the pellets, optionally together with steel scrap, through a vertical preheater shaft furnace into a slag pool; (d) impinging fuel gas jets upon the surface of the slag layer to heat and circulate the slag and to burn the carbon added to the pellets, generating additional heat, to produce a layer of molten ferrovanadium alloy at the bottom of the molten pool, covered by a protective layer of molten slag, (e) withdrawing the valuable molten ferrovanadium alloy for use, and (f) withdrawing the molten slag for safe disposal in landfill areas.

Abstract: A system for reducing the formation of NO.sub.x pollutants during the combustion of liquid fuel in a gas turbine engine. The system comprises introducing an externally modulated, rapidly-pulsed, oscillated or sinusoidal fuel flow delivery rate (generically referred to as "modulated") to produce a controlled degree of combustor air input flow oscillation and bulk flow oscillation within the combustor which enhances the fuel-air mixing rate and homogeneity within the combustor, decreases the residence time of transition fuel/air mixtures prone to NO.sub.x formation, and substantially decreases the NO.sub.x concentration in the resulting combustion gas product without creating a net pressure gain throughout the combustion chamber.