There is provided a melting device including a melting cylinder that is heated to a predetermined temperature, melts a molding material supplied from a material supply port, and generates a molten material; an inert gas supply device configured to supply an inert gas onto a melting surface of the molten material and form an inert gas layer; and a low specific gravity gas supply device configured to supply a low specific gravity gas which is a gas having a different type from the inert gas and form a low specific gravity gas layer on the inert gas layer, wherein the low specific gravity gas layer has a lower specific gravity than the inert gas layer.

There is provided a melting device including a melting cylinder that is heated to a predetermined temperature, melts a molding material supplied from a material supply port, and generates a molten material; an inert gas supply device configured to supply an inert gas onto a melting surface of the molten material and form an inert gas layer; and a low specific gravity gas supply device configured to supply a low specific gravity gas which is a gas having a different type from the inert gas and form a low specific gravity gas layer on the inert gas layer, wherein the low specific gravity gas layer has a lower specific gravity than the inert gas layer.

Disclosed are degassers, couplings, impeller shafts and impellers for use in molten metal. One such coupling transfers gas into an impeller shaft, the coupling having a smooth, tapered internal surface to align with a corresponding surface on the impeller shaft and help prevent gas leakage and to assist in preventing damage to the impeller shaft. Improved impellers for shearing and mixing gas are also disclosed, as is a degasser including one or more of these components.

Disclosed are degassers, couplings, impeller shafts and impellers for use in molten metal. One such coupling transfers gas into an impeller shaft, the coupling having a smooth, tapered internal surface to align with a corresponding surface on the impeller shaft and help prevent gas leakage and to assist in preventing damage to the impeller shaft. Improved impellers for shearing and mixing gas are also disclosed, as is a degasser including one or more of these components.

A burner-lance unit (1) includes at least two gas connections (2a, 2b, 2c), a burner tube (3), and a lance tube (4) that is placed concentrically in the burner tube (3). The burner tube (3) and the lance tube (4) both have a gas inlet end and a gas outlet end (15). The lance tube (4) has a de Laval nozzle (4a) at the gas outlet end thereof. The de Laval nozzle (4a) is releasably connected to the lance tube (4). The burner tube (3) has a burner nozzle (3a) which is releasably connected to the burner tube (3).

A burner-lance unit (1) includes at least two gas connections (2a, 2b, 2c), a burner tube (3), and a lance tube (4) that is placed concentrically in the burner tube (3). The burner tube (3) and the lance tube (4) both have a gas inlet end and a gas outlet end (15). The lance tube (4) has a de Laval nozzle (4a) at the gas outlet end thereof. The de Laval nozzle (4a) is releasably connected to the lance tube (4). The burner tube (3) has a burner nozzle (3a) which is releasably connected to the burner tube (3).

A molten iron refining method having, an auxiliary material, and an oxidizing gas supplied through a top-blowing lance, to a cold iron source and molten pig iron that are contained/fed in a converter-type vessel, and molten iron is subjected to a refining process. A pre-charged cold iron source is charged into the converter-type vessel at an amount not larger than 0.15 times. A furnace-top-added cold iron source that's part or all of the cold iron source and added from a furnace top is fed during the refining process. A burner at a leading end of the top-blowing lance that spray holes through which a fuel and a combustion-supporting gas are ejected. During the refining process, a powdery auxiliary material processed into powder that's part of the auxiliary material is blown in, to pass through a flame formed by the burner.

Furnace operation includes consecutive cycles of a heating step, a stopping step and a restarting step. The fuel and/or the oxidizing agent is preheated upstream of the furnace by indirect exchange with the discharged fumes through a medium passing through a chamber. A first wall separates the fumes from the medium in the chamber. The fuel and/or oxidizing agent is separated from the medium in the chamber by second wall. During restarting, the medium's flow rate Dm is regulated to limit the heating rate of the first wall until it reaches the operational temperature at an end thereof.

In an aspect, a method of manufacturing a high purity copper-based alloy comprises providing in a melting furnace a feedstock and melting the feedstock. The method additionally includes bubbling an inert gas into the molten copper-based alloy to form the high purity copper-based alloy. Aspects are also directed to an apparatus and a method of fabricating an apparatus for manufacturing the high purity copper-based alloy.

In an aspect, a method of manufacturing a high purity copper-based alloy comprises providing in a melting furnace a feedstock and melting the feedstock. The method additionally includes bubbling an inert gas into the molten copper-based alloy to form the high purity copper-based alloy. Aspects are also directed to an apparatus and a method of fabricating an apparatus for manufacturing the high purity copper-based alloy.