Abstract: The present invention relates to processes for controlling the formation and deposition of scale and sludge and in particular calcium phosphate which would otherwise occur in aqueous mediums containing sludge and the ions capable of forming scale. The invention, more particularly, relates to the control, reduction and/or prevention of scale and sludge deposits in cooling water, scrubber and steam generating systems, evaporators, economizers, and the like by the introduction of a copolymer comprising sulfonated styrene and maleic anhydride moieties to the water used therein. The copolymers discovered to be particularly effective for the purpose are those having a mole ratio of sulfonated styrene moieties to moieties derived from maleic anhydride of from about 2:1 to about 4:1 and preferably 2:1 to 3:1 with certain type deposits.

Abstract: The present invention relates to processes for controlling the formation and deposition of scale and/or suspended solid matter which otherwise would occur in aqueous mediums containing scale imparting ions and dispersed particles. The invention, more particularly, relates to the control of the formation of, the reduction and/or the prevention of the deposition of calcium phosphate, magnesium silicate and/or iron oxide, clay and mixtures thereof in cooling water, scrubber and steam generating systems, evaporators, economisers and the like by the introduction of an effective amount for the purpose of a water soluble polymer composed primarily of moieties derived from acrylic acid or water soluble salt thereof and hydroxy lower alkyl acrylate moieties or water soluble salt thereof to the water used therein. The polymers discovered to be effective for the purpose are those preferably having a mole ratio of from about 34 : 1 to about 1 : 4 of acrylic acid to hydroxylated lower alkyl acrylate moieties.