Claims
- 1. A process for removing corrosive deposits from a metal surface exposed to an aqueous system where said process comprises:
- contacting an effective amount of a metal cleaner to a metal surface exposed to an aqueous system where the pH of said metal cleaner is 50 to 75 and said metal cleaner comprises:
- (a) from about 1 to about 40 parts by weight of citric acid;
- (b) from about 15 to about 25 parts by weight of an alkanolamine;
- (c) from about 1 to about 20 parts by weight of EDTA, alkali metal salts thereof, and ammonium salts thereof, and
- (d) water,
- where said parts by weight are based upon 100 parts of metal cleaner, and whereby corrosive deposits are removed from said metal surface.
- 2. The process of claim 1 where the process is carried out a temperature of 20.degree. C. to 100.degree. C.
- 3. The process of claim 1 where the metal cleaned is selected from the group consisting of iron and steel.
- 4. The process of claim 3 where the corrosive deposit removed from the metal is iron oxide or rust.
- 5. The process of claim 1 where the process is carried out on-line.
- 6. The process of claim 1 where the process is carried out off-line.
- 7. The process of claim 1 which additionally contains a sulfur-containing polymer.
- 8. The process of claim 1 where the alkanolamine is triethanolamine.
- 9. The process of claim 1 wherein the metal cleaner comprises:
- (a) from about 10 to about 20 parts by weight of a citric acid;
- (b) from about 15 to about 20 parts by weight of triethanolamine;
- (c) from about 1 to about 20 parts by weight of ethylenediaminetetraacetic acid;
- (d) from about 0.5 to about 15 parts by weight of a sulfonated polymer; and
- (e) a surfactant.
CROSS REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of application Ser. No. 08/747,872 filed on Nov. 13, 1996, now abandoned.
US Referenced Citations (2)
Number |
Name |
Date |
Kind |
4965019 |
Schmid et al. |
Oct 1990 |
|
5507971 |
Ouzounis et al. |
Apr 1996 |
|
Continuation in Parts (1)
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Number |
Date |
Country |
Parent |
747872 |
Nov 1996 |
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