PROCESS FOR PRODUCING PHOSPHOROUS ACID

摘要

PW691 PROCESS FOR PRODUCING PHOSPHORUS ACID Phosphorous acid is made by a continuous recycling process from a mixture of phosphorous and hydrochloric acids, comprising: (i) continuously recycling the mixture in a loop apparatus; (ii) adding water to and passing phosphorus trichloride into said recycling mixture so as to generate a condition of turbulent flow at the point of contact of the phosphorus trichloride and the recycling mixture, whereby a reaction product, comprising an aqueous solution of phosphorous and hydrochloric acids as a continuous liquid phase and gaseous hydrogen chloride as gas bubbles of disperse phase, is produced; (iii) separating said gaseous hydrogen chloride; (iv) cooling said reaction product; and (v) recycling at least a portion of said reaction product and repeating steps (ii), (iii) and (iv) thereon to produce a more highly concentrated solution of phosphorus acid.