MMO titanium anode is more and more used in cathodic protection. It has the advantages of high current density, acid resistance, long service life, etc. It is used in soil, pipeline, and concrete. Cathodic protection refers to the external cathodic polarization of the protected metal to reduce the activity and prevent metal corrosion. Generally, two schemes can be adopted:
1. An impressed current cathodic protection method
Impressed current cathodic protection uses impressed current to make the whole surface of the protected metal structure a cathode. When conducting impressed current cathodic protection for metal equipment, connect the metal with a wire to the negative pole of an external power supply, and connect the other auxiliary anode to the positive pole of the power supply. At this time, the current passing through the auxiliary anode, after flowing through the electrolyte solution, is mainly concentrated on the cathodic protection of the metal, making the metal cathodic polarization. The current flows back to the power supply through the cathode, thus reducing the total potential of the metal. If the applied protective current is large enough, the original anode on the protected structure will no longer be dissolved. At this time, only a cathodic reduction reaction will occur on the metal surface, and the additional current is used to achieve complete protection. When selecting cathode materials, we should constantly develop and improve different use conditions.
MMO-coated titanium anode has good conductivity and small surface output resistance due to the use of titanium metal as the substrate and platinum group metal oxides with high catalytic activity as the coating. It is not eroded by the medium and is easy to process. It can adapt to different environments, such as soil, pipes, and other media
2. Sacrificial anode protection method
Sacrificial anode protection is to connect a metal with more negative potential to the protected metal as the anode, which forms a large battery with the protected metal in the electrolyte. The current flows from the anode to the metal equipment through the electrolyte, and the cathodic polarization of the metal equipment is protected accordingly.
