EXTRACTION OF SOLUBLE PHOSPHATES FROM NATURAL ORIGINAL IRON AND ALUMINUM PHOSPHATES USING SOLUTIONS OF ALKALINE HYDROXIDES AND CARBONATE

摘要

A process for production of alkali metal phosphates from material containing iron and aluminium phosphates comprises leaching the said material with alkali metal carbonate solution to produce a leachate containing dissolved phosphates, and recovering alkali metal phosphates from the leachate. In a preferred embodiment, the carbonate leach is followed by further leaching wth alkali metal hydroxide to effect further dissolution of phosphates from the material, before recovering alkali metal phosphates from the leachate.