Coated Titanium Anodes for Trivalent Chrome

Sulfate-based trivalent chrome is best produced with the use of mixed-metal oxide (MMO)-coated titanium anodes. Lead anodes, commonly used in toxic hard chrome plating, generate environmentally hazardous sludge that requires careful disposal, attracting increased scrutiny from government regulators and increased costs. Similarly, the lead anodes themselves are a hazardous material which must be properly disposed at the end of use. Lead anodes also are large and heavy, creating a safety issue when lifting. Lead’s higher oxygen overpotential also means higher electrical usage and operational costs.

MMO-coated anodes, being insoluble and dimensionally stable, ensure a consistent surface finish for years of use, even in complex geometries or recessed areas. This dimensional stability means there is no cleanup of toxic sludge, reducing scrutiny from government regulators and decreasing operational expenses. MMO-coated anodes can be repeatedly recoated and reused.

Beyond their environmental benefits, MMO-coated anodes also offer lower oxygen overpotential, resulting in reduced energy consumption, operational costs and longer bath life from lower oxidation rate of additives. The risk of poisoning the expensive chemistry in the bath with lead sludge is eliminated, and insoluble MMO-coated anodes don’t require draining the bath to recover broken pieces as lead anodes often do.

Insoluble MMO-coated anodes have been used for over 50 years in a variety of industries and applications such as chrome plating, automotive, electrochlorination, electrowinning, and metal recovery.