DOWEX Resins for Separation of Platinum and Palladium from Liquid Media

 
Platinum - Pt Palladium - Pd
Platinum and Palladium are rare, chemically-resistant metals, valued for their usefulness in applications ranging from organic reaction catalysts, to fine jewelry, to micro electronics.

Applications

Acidic Halogen Leach: Many mining projects are underway in which ores are leached under oxidizing and acidic conditions. Under these conditions, DOWEX™ anion exchange resins have proven to be tough, steady performers. Downloadable information is available in Recovery of Precious Metals from Acidic Halogen Leach Solutions (364KB PDF).

Catalyst Recovery: When precious metals are used as heterogeneous or homogeneous catalysts, part of the metal can be lost to the process resulting in further uncontrolled reaction, quality issues, and higher costs due to the lost metal value. These metals can be recovered with an ion exchange resin scavenger. In many cases DOWEX M-43  resin does an excellent job of loading platinum and palladium. The resin is effective under basic to acidic conditions. The ion exchange resins can be regenerated or sacrificed to recover the metal. DOWEX M-43 resin is also effective in recovering precious metals from organic solvent-based streams, but the resin should be used dry. Non-aqueous exchange kinetics are slower so adequate contact time must available. For more information on resin preparation see Processing Organic Solvents. Precious metal loaded resins can be processed by catalyst suppliers to recover lost metals.

Plating Baths: DOWEX anion exchange resins are commonly used in the recovery of platinum and palladium from spent plating bath solutions. Generally, the loaded resin will absorb up to 60 oz of metal per cubic foot (60g/l) and the metal is recovered by thermal decomposition (fuming). Downloadable information is available on fuming in Recovery of Precious Metals from Acidic Halogen Leach Solutions (364KB PDF).

Selective Platinum Resin: Dow offers a Thiouronium functionalized designated XUS 43600.00. This product is patterned after the PAZ type resin developed by Gloria Schmuchler. It is highly selective for PGMs. The resin is a macroporous, uniform particle size bead so it has good exchange kinetics. It is a tough and rugged product for resin in pulp applications. Note that the Thiouronium group is subject to base hydrolysis so the product should be used under acid to neutral pH conditions.

DOWEX Ion Exchange Resins

Product Description Type Matrix Total
Exchange
Capacity*
eq/l (kgr/ft3)		 Available
Forms
XUS 43600.00 Uniform particle size, highly selective resin for platinum group metals. Chelating Resin Styrene-DVB, Macroporous 0.7 Cl-
DOWEX 21K XLT Uniform particle size, high capacity, strong base anion exchange resin for mineral processing applications. Type I Strong Base Anion Styrene-DVB, Gel 1.4 Cl-
DOWEX 21K 16/20 High efficiency, strong base anion exchange resin for mineral processing applications. Type I Strong Base Anion Styrene-DVB, Gel 1.2 Cl-
DOWEX 21K 16/30 High efficiency, strong base anion exchange resin for mineral processing applications. Type I Strong Base Anion Styrene-DVB, Gel 1.2 Cl-
DOWEX M-43 Corrosion control with DOWEX M-43 ion exchange resin. Weak Base Anion Styrene-DVB, Macroporous 1.55 FB (Free Base) form


®™* Trademark of The Dow Chemical Company ("Dow") or an affiliated company of Dow