MATRIX EFFECTS OF DEHYDRODITHIZONE MODIFIED POLYMERS ON THE SORPTION AND DESORPTION OF PRECIOUS METALS

This investigation carries on previous studies on a low crosslinked gel-type resin, denoted as P-TD. This sorbent with incorporated sulphur-bonded tetrazolium groups extracts primarily platinum group metals and gold selectively and reversibly, so that it can be utilized successfully for analytical separation procedures. Further attempts were made to functionalize different chloromethylated polystyrene-DVB copolymers by dehydrodithizone to attain optimum properties for hydrometallurgical applications. The conditions of synthesis as well as the basic sorption and desorption properties of the modified polymers depend strongly on the morphology (gel-types with different crosslinkages, macroporous type) and size of the various resin beads. As indicated by X-ray microprobe analysis, the macroporous network of the P-TDm sorbent causes a relatively stronger retention of some precious metals due to metal coordination. The predominating ion pair formation assumed for a fine grain, low crosslinked gel resin (P-TD4) allows a fast sorption and facile elution of selectively bonded metal ions. Column tests performed with synthetic and real process solutions point to a more profitable use of the P-TD4 resin for the recovery of precious metals. © 1990.