Method of removing copper and copper oxide from a ferrous metal surface
AssigneeHalliburton Company
InventorsLarry D. Martin, Gary W. Bradley
Life of this patent
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Abstract
A method of removing copper and copper oxide from a ferrous metal surface comprising contacting said metal and said copper oxide with an aqueous composition having a pH from about 3.0 to about 6.0 and comprising an oxidizing agent, a compound selected from the group consisting of oxalic acid, the alkali metal, and ammonium salts of oxalic acid and mixtures thereof, and an ingredient selected from the group consisting of citric acid, polyaminocarboxylic acids, the ammonium and alkali metal salts of citric acid and polyaminocarboxylic acids and mixtures thereof.
Claims18
A method of removing copper and copper oxide from a ferrous metal surface comprising:
- contacting said copper and copper oxide with an aqueous composition having a pH of from about 3.0 to about 6.0 said composition consisting essentially of:
- (a) an oxidizing agent which is stable at a pH of about 3.0 to about 6.0;
- (b) a compound selected from the group consisting of oxalic acid, the alkali metal and ammonium salts of oxalic acid and mixtures thereof;
- and,
- (c) an ingredient selected from the group consisting of citric acid, polyaminocarboxylic acids, the ammonium and alkali metal salts of citric acid and polyaminocarboxylic acids, and mixtures thereof.
A method of cleaning a ferrous metal surface whereby copper and copper oxide is removed from said surface without replating of said copper and said copper oxide on said metal surface comprising:
- contacting the surface for a sufficient time to remove the copper and copper oxide with an aqueous composition having a pH of about 3.0 to about 6.0 said composition consisting essentially of:
- (a) an oxidizing agent which is stable at a pH of about 3.0 to about 6.0;
- (b) a compound selected from the group consisting of oxalic acid, the alkali metal and ammonium salts of oxalic acid and mixtures thereof;
- and,
- (c) an ingredient selected from the group consisting of citric acid, polyaminocarboxylic acids, the ammonium and alkali metal salts of citric acid and polyaminocarboxylic acids, and mixtures thereof.
Dependencies are inferred from the claim text.