Gm Global Technolgoy Operations, Inc.

Richard P Tison

Su-Chee Simon Wang

Dexter Dean Snyder

Process for the efficient, electrolytic scavenging and depositing of metal from dilute aqueous solutions thereof by performing such process in a packed bed of strongly acidic, cation exchange resin particles flooded with the solution. The particles contact the cathode in a quiescent layer of the solution contiguous the cathode.

Electrolytic demetallization of dilute solutions using ion exchange

Anodic formation of amorphous iron phosphate films in a dialkyl hydrogen phosphate electrolytic medium containing hydrogen-rich cation exchange resin particles having a free moisture content between about 9% and about 33% by weight.

Phosphate coating complex metal surfaces

In a preferred embodiment, plating chemicals are recovered from contaminated rinse water using an electrodialysis recovery unit immersed directly in an electroplating bath between a cathode intended to be plated and an anode. Electrodialysis is driven parasitically by the electroplating currents, thereby eliminating the cost of additional equipment dedicated solely for electrodialysis. The unit is sized and positioned so that only a relatively minor portion of the total plating current is employed for electrodialysis, thereby permitting a sufficiently high current density at the cathode to electrodeposit a dense, commercially acceptable metal plate.

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Pontiac, MI, United States of America

Richard P Tison