Abstract: A metal refining method particularly useful with a basic oxygen steelmaking process, wherein during an initial period, refining oxygen is provided into the furnace headspace surrounded by a shroud comprising oxygen and inert gas, and during a subsequent period refining oxygen is provided into the furnace headspace surrounded by a flame shroud.

Abstract: A system for providing gases into an injection volume in one or more coherent gas jets proximate to one or more turbulent gas jets wherein a coherent gas jet is formed in a forming volume with a flame envelope prior to passage into the injection volume into which the turbulent gas jets are directly passed.

Abstract: A method for providing main gas into a pool of molten metal, which is particularly useful for use in an electric arc furnace. The method employs combustion of secondary oxygen with fuel to form a flame envelope around a main gas stream which protects the main gas from entrainment of ambient gases as it passes through the headspace of the furnace. This enables the gas to retain to a substantial degree its original force upon injection into the headspace and thus may be injected into the furnace at a safe distance from the molten metal surface while still achieving substantially complete penetration into the molten metal.

Abstract: A lance which may be used to establish a long coherent gas jet which includes a primary passageway having a converging/diverging nozzle, and two radially spaced secondary passageways for establishing a flame barrier, each of the passageways communicating with an injection space defined by a protective jacket.

Abstract: A method for providing main gas into a pool of molten metal, which is particularly useful for use in an electric arc furnace. The method employs combustion of secondary oxygen with fuel to form a flame envelope around a main gas stream which protects the main gas from entrainment of ambient gases as it passes through the headspace of the furnace. This enables the gas to retain to a substantial degree its original force upon injection into the headspace and thus may be injected into the furnace at a safe distance from the molten metal surface while still achieving substantially complete penetration into the molten metal.

Abstract: A method for introducing gas into a liquid wherein a gas stream is ejected from a lance spaced above the liquid surface and directed from the lance onto the liquid surface. The gas retains substantially all its original jet axis velocity when it contacts the liquid surface, and substantially all of the gas penetrates the liquid surface and is introduced into the liquid. Preferably the gas stream is surrounded by a flame envelope running from the lance to the liquid surface, which shields the gas from ambient gas entrainment. The gas stream preferably forms a gas cavity within the liquid having a diameter substantially the same as the diameter of the gas stream as it is ejected from the lance.