Inhibiting boiler scale formation or metal corrosion - e.g. in sea water evapn. by adding cyclic dimer of hydroxy-di:phosphonic acid

摘要

Formation of deposits, esp. boiler scale, or corrosion of metal surfaces in water conduits or plant is inhibited by adding 500 ppm of a cyclic dimer of a hydroxy-diphosphonic acid. The dimer has formula (I) (where R is a 1-20C alkyl, aryl, aralkyl or aliphatic ether gp., esp. Me). (I) are esp. useful for treating (i) sea-water fed to evaporators for drinking water prodn. on ships, desert coats or islands, partic. chlorinated sea-water and sea-water subjected to continuous chlorination, and (ii) water injected into oil wells during sec. oil recovery, to inhibit the formation of Ba- or Ca-contg. deposits.