MMO Anode
Mixed Metal Oxide Anodes (MMO Anodes), also called dimensionally stable anodes, are a type of Impressed Current Protection Anode, consisting of rare earth oxides coated onto a titanium substrate.
Here at TNTI we are able to supply the MMO anode material available in rod, wire, tubular, ribbon or mesh form.
MMO anodes work best in aggressive solutions or other difficult applications and our anodes are performance-tested through DNV accelerated life tests according to latest NACE standards.
MMO anodes have imperceptibly low wear rates and are often referred to as Dimensionally Stable Anodes (DSA) as they do not change geometry over time. MMO anodes are quickly becoming the most popular impressed current anode gaining market share over conventional anodes such as graphite and high silicon cast iron.
MMO Anode Advantages：
Strong resistance in conditions impacted by both oxygen and chlorine
Various product compositions available depending on application
Excellent resistance in acidic media
High current output
Durability
Demonstrated reliability
Exceptionally long life
Available in numerous anode configurations
Low cost
MMO coated titanium anodes are used in a variety of environments such as seawater, brackish water, fresh water, carbon backfill, and concrete. MMO coating amazingly prolongs the life of the anode and provides excellent chemical corrosion resistance, especially in acid conditions. MMO coating has an extremely low consumption rate, with a Faradic wear rate of approximately 0.5 – 1.0 micrograms of coating per Ampere hour. As a result of this low consumption rate, the metal dimensions remain nearly constant during the design life of the anode, which provides a consistently low resistance anode.
MMO coated titanium anodes are lightweight and geometrically flexible, thereby assuring ease of installation, quick replacement and capability for multiple refurbishing in a cost-effective way.
Titanium offers several key advantages as a substrate:
Titanium MMO Anode Advantages
Titanium is readily available in commercially pure form
Excellent adherence properties with proper surface preparation
Lightweight
Outstanding mechanical strength
MMO Anode Manufacturing Process
The typical manufacturing process for MMO anodes starts with surface preparation of the substrate by thoroughly cleaning the commercially pure titanium. This is followed by a chemical etching and in some cases mechanical abrasion of the surface. Once the substrate surface preparation is complete, the coating is applied as a mixture of metal salts and then thermally decomposed at temperatures ranging 400 to 600 °C. This forms an adherent layer of mixed metal oxides. The MMO coatings can be applied in many layers and heat treated after each coat to achieve the desired coating loading to meet the current capacity requirements for the application.
Mixed Metal Oxide Anodes have proven to operate effectively in all types of environments. Including areas with extremely low pH level and high level chloride concentration. While these anodes can be used singularly, their unique configuration makes them ideal for use in strings on offshore platforms or in deep ground beds. In addition, the string anodes can be installed parallel to transmission pipelines, or used for other special application.
With over 10 years experience in manufacturing anodes here at TNTI Anodes we believe that our technical expertise is matched by our production capability, providing our customers with the highest quality products and a first-rate service.