Process for purifying an aqueous solution of alkaline phosphate, produced from the phosphoric acid of the wet process and wherein said process includes a step of partial purification to reduce the iron content of the alkaline phosphate solution to less than 10,000 ppm over a base of 75% phosphoric acid, characterized in that it comprises further treating said aqueous alkaline phosphate solution containing less than 10,000 ppm of iron, on a base of 75 phosphoric acid with a sulfide reagent, selected from the group consisting of a alkali sulfide and hydrogen sulfide, at a ph between 6.5 and 9, to form insolubles; and removing said insolubles to substantially lower the iron content of said aqueous alkaline phosphate solution to a value below 50 ppm on a 75% phosphoric acid base. (Machine-translation by Google Translate, not legally binding)
展开▼
