Mixtures of phosphonic acid / phosphate to control the corrosion of metal and inhibit the precipitation of the calcium salt in aqueous systems.

摘要

A method of controlling the corrosion of a metal surface in contact with an aqueous system while at the same time preventing the precipitation of potentially scale-forming calcium salts such as calcium phosphate, comprises treating the system with a source of orthophosphate ion and a mixture of methylene phosphonic acid derivatives of C6 diamines, or the salts thereof.