Preparation of phosphorous acid from industrial waste material containing phosphites

摘要

A process for the preparation of phosphorous acid from phosphites contained in industrial wastes, wherein the waste material is dissolved in an aqueous solution of phosphorous acid and reacted with a strong mineral acid that will remove the cation of the phosphite producing phosphorus acid. An alternative method for preparation is the passage of the solution of phosphite in phosphorus acid through a cation ion exchange resin to produce phosphorous acid. A typical industrial waste containing phosphites is the waste that occurs from the process of manufacturing sodium hypophosphite.