Abstract: This invention relates to a process of dissolving and removing silicate scale and particularly magnesium silicate scale and sludge from various aqueous systems, particularly boiler water and desalination systems by adding to the water effective amounts of at least one water-soluble phosphinocarboxylic acid. These polyphosphinocarboxylic acids and the salts thereof are added to the water in the aqueous system in amounts ranging up to about 50 thousand parts by weight per million and preferably in amounts ranging up to about 2000 parts by weight per million parts by weight of water either alone or in combination with at least one organic dispersant selected from the group consisting of nonionic and anionic dispersants.

Abstract: Corrosion inhibiting compositions for inhibiting corrosion and the deposition of mineral scale on metal in aqueous systems contain sequestrants such as carboxylic acids, phosphates, or optionally sulfur containing lignosulfonates, as well as carboxylated phosphonic acids of the formula ##STR1## wherein m is from 1 to about 6, wherein n is from 0 to about 6, wherein R is --H, -alkyl, -alkenyl, -alkynyl, -aryl, -alkyl substituted aryl, -cycloalkyl, -methylene phosphonic acid, or -methylene carboxylic acid, and wherein R.sup.1, R.sup.2, R.sup.3 and R.sup.4 independently is --H, -alkyl, -aryl, -alkyl substituted aryl, --OH, --SH, --NH.sub.2, --PO.sub.3 H.sub.2, --CH.sub.2 PO.sub.3 H.sub.2, --CO.sub.2 H, --CH.sub.2 CO.sub.2 H, halogen, or --SO.sub.3 H. The composition can also contain other corrosion inhibiting compounds such as azoles, molybdates, and the like.

Abstract: This invention is directed to a corrosion inhibiting composition and to a process for inhibiting corrosion and the deposition of mineral scale on metal in aqueous systems which comprises adding to the water effective amounts of a water soluble polymer comprising acrylic acid characterized by molecular weights ranging up to about 2500. The polymer comprises vinyl monomer in excess of about 90%, i.e. acrylic acid, in combination with minor amounts of phosphorous acid and derivatives thereof.

Abstract: This invention is directed to corrosion inhibiting compositions and to a process for inhibiting corrosion and the deposition of mineral scale on metal in aqueous systems. The invention comprises adding to a water system effective amounts of an inhibiting composition comprising a water-soluble carboxylic acid and/or the salt thereof containing at least one hydroxyl group per molecule, an amino alkylene phosphonic acid or its derivative, a dispersing amount of a water-soluble polymeric dispersing agent and other inhibitors such as the molybdates, azoles and various inorganic metal compounds.

Abstract: This invention relates to a corrosion inhibiting composition and to the process for inhibiting corrosion and the deposition of mineral scale on metal in aqueous systems. The process comprises adding to water a novel composition containing an azole, molybdates and effective amounts of at least one aminomethylene phosphonic acid and the derivatives thereof.

Abstract: This invention is directed to a corrosion inhibiting composition and to a process for inhibiting corrosion and the deposition of mineral scale on metal in aqueous systems which comprises adding to the water effective amounts of citric acid and/or the alkali metal salts thereof or combinations of a metal molybdate with citric acid and/or an alkali metal salt thereof and at least one amino methylene phosphonic acid or a derivative thereof.