Immobilization of metal contaminants from a liquid to a solid medium

摘要

PCT No. PCT/GB92/02086 Sec. 371 Date May 4, 1994 Sec. 102(e) Date May 4, 1994 PCT Filed Nov. 11, 1992 PCT Pub. No. WO93/09849 PCT Pub. Date May 27, 1994.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.