Processes for the removal and recovery of cadmium from wet-process phosphoric acid

A method for the removal of a cadmium (Cd) impurity or contaminant from a Cd-comprising phosphoric acid solution, or a Cd-comprising phos-acid feedstock, comprising:

• (a) treating a Cd-comprising phosphoric acid solution or a phos-acid feedstock with an activated clay, a bentonite material and/or flocculents thereof, to produce a pretreated acid mix;
• (b) clarifying or settling the pretreated acid mix to substantially remove solids that are in the pretreated acid mix to produce a clarified phos-acid acid mix;
• (c) treating or filtering the clarified phos-acid acid mix to substantially remove an insoluble solid or solids, if present, after the clarifying or settling step of (b), thereby generating a filtered solid or filtered solids, if present;
• (d) feeding or loading a clarified phos-acid solution obtained from the treating or filtering in step (c) onto a strong cation exchange resin or a composition capable of reversibly binding the Cd under conditions wherein the Cd and non-Cd cations remain bound on or reversibly bind to the strong cationic exchange resin or the composition capable of reversibly binding the Cd, and non-Cd cations also remain on or reversibly bind to the strong cationic exchange resin or the composition capable of reversibly binding the Cd;
• and
• (e) washing the strong cation exchange resin or the composition capable of reversibly binding the Cd with a solution or solvent that does not remove substantially all of the Cd or other cations reversibly bound to the strong cation exchange resin or the composition capable of reversibly binding the Cd to remove phos-acid from the strong cation exchange resin prior to eluting the Cd or other ions.