APPARATUS FOR REFINING MOLTEN ALUMINUM

• US 3,743,263 A
• Filed: 12/27/1971
• Issued: 07/03/1973
• Est. Priority Date: 12/27/1971
• Status: Expired due to Term

• Current Assignee: Union Carbide Industrial Gases Technology Corporation
• Original Assignee: Andrew Geza Szekely
• Inventors: Szekely, Andrew Geza
• Primary Examiner(s): Dost, Gerald A.
• Application Number:
  US05/211,950
• Time in Patent Office: 554 Days
• Field of Search: 266/34A,34T,38 75/59,60,93
• US Class Current: 266/225
• CPC Class Codes: B01F 23/2331 characterised by the introduction of the gas along the axis of the stirrer or along the stirrer elements
• CPC Class Codes: B01F 23/23311 through a hollow stirrer axis
• CPC Class Codes: B01F 23/23314 through a hollow stirrer element
• CPC Class Codes: B01F 23/2368 Mixing receptacles, e.g. tanks, vessels or reactors, being completely closed, e.g. hermetically closed
• CPC Class Codes: C22B 21/066 Treatment of circulating aluminium, e.g. by filtration C22B21/068 takes precedence
• CPC Class Codes: C22B 9/00 General processes of refining or remelting of metals; Apparatus for electroslag or arc remelting of metals

Abstract

The apparatus of the invention is capable of injecting gas in the form of small discrete bubbles into a mass of molten metal. The apparatus comprises a rotatable shaft coupled to drive means at its upper end and a vaned rotor at its lower end. Gas under sufficient pressure to be injected into the melt is fed into a passageway extending axially through the device whereby upon rotation of the rotor the gas is injected into the molten metal and subdivided into discrete gas bubbles. The process of the invention utilizes the above described gas injection apparatus for refining molten aluminum by introducing an inert gas into the metal beneath the surface of the melt.

Claims

2. The device of claim 1 wherein the induced circulation pattern is such as to transport the injected gas bubbles in a direction extending radially outward from the axis of said device with a downward component relative to said axis.

3. an axially extending passageway for conveying and discharging said gas into said mass of metal, formed by the inner surfaces of said sleeve and stator and the outer surface of said shaft, and

4. means for providing gas to the upper end of said passageway under sufficient pressure to be injected into the melt, whereby upon rotation of said rotor and provision of said gas flow, the gas is injected into said molten metal and subdivided into discrete gas bubbles, and a circulation pattern of said molten metal is induced, which causes intensive stirring such that substantially the entire mass of molten metal in said enclosure comes into intimate contact with the gas bubbles.

5. Apparatus for refining molten aluminum, comprising in combination:

(1) a gas injection device as set forth in claim 1, (2) an insulated vessel provided with entrance and exit means for the continuous flow of molten metal through said vessel, means for the discharging of gas from said vessel and (3) a vessel cover which seals said vessel to prevent infusion of air and moisture into said vessel, which enables said vessel to be operated under positive pressure and which has an opening therein into which said gas injection device is inserted in a sealed manner.

6. The apparatus of claim 5 wherein said vessel contains a plurality of refining zones each of which is provided with a gas injection device as set forth in claim 1.