Composition and method for removing sulfide-containing scale from metal surfaces
AssigneeThe Dow Chemical Company
InventorsWayne W. Frenier, Michael D. Coffey, James D. Huffines, Donald C. Smith
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Abstract
Sulfide-containing scale is removed from metal surfaces by contacting the encrusted surface with an aqueous acid cleaning solution having an aldehyde (e.g., formaldehyde) dissolved or dispersed in the acid in an amount sufficient to prevent the evolution of hydrogen sulfide gas.
Claims21
A method of chemically cleaning acid-soluble, sulfide-containing scale from a metal surface comprising contacting said scale with an aqueous acid cleaning composition comprising an aqueous non-oxidizing acid having at least one aldehyde dissolved or dispersed therein, which aldehyde is present in an amount at least sufficient to prevent or substantially prevent the evolution of hydrogen sulfide gas.
An aqueous acid composition comprising an aqueous acid having dissolved or dispersed therein at least one aldehyde;
- said composition having, as one of its chemical properties, the capability of dissolving acid-soluble, sulfide-containing scale from a metal surface without the evolution of hydrogen sulfide gas, provided that the aldehyde is present in excess of the acid required to dissolve the sulfide containing scale.
Dependencies are inferred from the claim text.