Patent ID: 8900539

Claim:
A method for reducing or preventing scale in a wet-process phosphoric acid production process, the method comprising: adding to at least one stage of the wet-process phosphoric acid production process a scale inhibiting amount of a reagent selected from the group consisting of i) a polysaccharide comprising a sulfate, sulfonic acid or carboxylic acid functional group; ii) a polymer or copolymer having a low critical solution temperature phase transition from 30° C. to 100° C., wherein said polymer or copolymer is selected from the group consisting of ethyleneglycol-propyleneglycol-ethyleneglycol copolymers; poly-(n-isopropyl acrylamide); copolymers of acrylic acid and n-isopropyl acrylamide; and mixtures thereof; iii) a reagent blend comprising an organic acid, a polyamine, and a sugar acid; and (iv) mixtures of (i)-(iii), thereby reducing or preventing scale in said process.