Förfarande för extrahering och koncentrering av små och medelstora kadmiummängder ur avfallsvatten innehållande koncentrerad svavelsyra

摘要

Process for the extraction and concentration of cadmium contained in low and intermediate concentrations in concentrated sulphuric effluents. The objective of the invention is to concentrate the cadmium in order to enable it to be subsequently reclaimed or stored in the form of waste. This objective is met with the aid of a process including four successive extraction steps carried out with the aid of monothiophosphinic acid, hydrochloric acid, trialkyl phosphate and water, respectively. This process applies especially to the treatment of the raffinates originating from the purification of phosphoric acid.