Abstract: A method for the immobilization of heavy metal contaminant from a liquid medium containing sulfuric acid and one or more acids of phosphorus, for example in the treatment of acid raffinates generated during the purification of phosphoric acid. The method includes the steps of (i) neutralizing the liquid medium with a stoichiometric excess of an alkaline earth metal oxide to form agglomerates, and (ii) treating the agglomerates with water to form a solid cementitious material wherein the heavy metal contaminants are substantially chemically isolated.

Abstract: Uranium is extracted from wet process phosphoric acid by extraction with a mixture of a diorganophosphate and a neutral phosphorus compound, which is preferably a triorgano phosphine oxide, in the presence of nitrate to form an organic extract layer containing uranium and an aqueous acid layer, which are separated.