1-Hydroxyethylidene-1,1-diphosphonic acid

HEDP is an organophosphoric acid corrosion inhibitor It can chelate with Fe Cu and Zn ions to form stable chelating compounds It can dissolve the oxidized materials on these metals surfaces HEDP shows excellent scale and corrosion inhibition effects under temperatures of 250C HEDP has good chemical stability under high pH values is hard to hydrolyze and is hard to decompose under ordinary light and heat conditions Its acidalkali and chlo rine oxidation tolerance are better than that of other organophosphoric acids salt HEDP can react with metal ions in the water system to form a hexaelement chelating complex with calcium ions in particular Therefore HEDP has good antiscale and visible threshold effects When built together with other water treatment chemicals it shows good synergistic effects Application HEDP is used as scale and corrosion inhibition in circulating cool water system oil field and lowpressure boilers in fields such as electric power chemical industry metallurgy fertilizer etc In light woven industry HEDP is used as detergent for metal and nonmetal In dyeing industry HEDP is used as peroxide stabilizer and dyefixing agent In noncyanide electroplating HEDP is used as chelating agent The dosage of 110mgL is preferred as scale inhibitor 1050mgL as corrosion inhibitor and 10002000mgL as detergent Usually HEDP is used together with polycarboxylic acid