Cleaning aluminum at low temperatures

Abstract

Acid cleaning of aluminum surfaces is accomplished employing a composition comprising hydrofluoric acid and sulfuric acid. More specifically, this invention relates to a composition and method for treating aluminum containers at low temperatures.

I claim: .[.1. An aqueous cleaning composition for removing and dissolving aluminum fines and cleaning lubricating oils from aluminum surfaces comprising of from about 1 to about 10 grams/liter of sulfuric acid and from about 0.005 to about 0.1 grams/liter of hydrofluoric acid..]. .[.2. The composition of claim 1, wherein the pH is from about 1.0 to about 1.8..]. .[.3. The composition of claim 1, further comprising a surfactant in an amount from about 0.1 to about 10 grams/liter..]. .[.4. The composition of claim 3, wherein the surfactant is selected from the group consisting of nonionic and anionic surfactants..]. .[.5. The composition of claim 4, wherein the surfactant is selected from the group consisting of sodium 2-ethyl hexyl sulfate and an alkyl polyethoxylated ether..]. .[.6. An aqueous cleaning composition for removing and dissolving aluminum fines and cleaning lubricating oils from aluminum surfaces consisting essentially of about 3 to about 5 grams/liter of sulfuric acid, from about 0.01 to about 0.03 grams/liter of hydrofluoric acid, and from about 0.1 to about 10 grams/liter of an alkyl polyethoxylated ether nonionic 
     
        surfactant..]. .Iadd.7.  An acidic aqueous cleaning solution having a pH of less than 2.0 and consisting essentially of about 1 to about 10 g/l of sulfuric acid, about 0.005 to about 0.1 g/l of hydrofluoric acid, and about 0.1 to about 10 g/l of a surfactant selected from the group consisting of nonionic and anionic surfactants, wherein the sources of said acids are respectively sulfuric acid and hydrofluoric acid, wherein said solution is free of a corrosion inhibitor in a corrosion-inhibiting amount and of a sludge-forming material, and wherein said solution is effective in removing and dissolving aluminum fines and in cleaning lubricating oils from the surfaces of drawn and ironed aluminum cans of 3004 alloy at a temperature within the range of about 110° F. to about 135° F., said cleaned surfaces being water-break-free. 
     
     
        .Iaddend. .Iadd.8.  A cleaning solution according to claim 7 wherein the concentration of said sulfuric acid is about 3 to about 5 g/l. .Iaddend. .Iadd.9. A cleaning solution according to claim 7 wherein the concentration of said hydrofluoric acid is about 0.01 to about 0.03 g/l. .Iaddend. .Iadd.10. A cleaning solution according to claim 7 wherein the concentrations of said sulfuric and said hydrofluoric acid are respectively about 3 to about 5 g/l and about 0.01 to about 0.03 g/l. .Iaddend. .Iadd.11. A cleaning solution according to claim 7, 8, 9 or 10 wherein said pH is about 1.0 to about 1.8. .Iaddend. .Iadd.12. A cleaning solution according to claim 7, 8, 9 or 10 wherein said pH is about 1.2 to about 1.5. .Iaddend. .Iadd.13. A cleaning solution according to claim 7, 8, 9 or 10 wherein said surfactant is a nonionic surfactant. .Iaddend. .Iadd.14. A cleaning solution according to claim 13 wherein said pH is about 1.0 to about 1.8. .Iaddend. .Iadd.15. A cleaning solution according to claim 13 wherein said pH is about 1.2 to about 1.5. .Iaddend.