Detailed explanation of titanium anode
What is titanium anode? The full name of titanium anode is titanium base metal oxide coated titanium anode (MMO).Also known as KSA anode.(Size and shape stable anode). It takes titanium as the substrate and brushes noble metal coating on the titanium substrate to make it have good electrocatalytic activity and conductivity.Classification of titanium anodes: according to the gas evolved from the anode in the electrochemical reaction, the chlorine evolved is called chlorine evolved anode, such as ruthenium-coated titanium electrode; the oxidation evolved is called oxygen evolved anode, such as iridium-coated titanium electrode and platinum-titanium mesh/plate.Chlorine evolution anode (ruthenium coated titanium electrode): the content of chloride ion in the electrolyte is high: generally in hydrochloric acid environment, electrolytic seawater, electrolytic salt water environment.Such as ruthenium iridium titanium anode,ruthenium iridium tin titanium anode.Oxygen evolution anode (iridium coated titanium electrode):The electrolyte is generally sulfuric acid environment.Our products are iridium tantalum anode, iridium tantalum tin anode and high iridium anode.
Platinum-plated anode (platinum titanium mesh/platinum titanium plate): titanium is the base material.The surface is plated with precious metal platinum,and the coating thickness is generally 1-5um (micron).The specification of platinum titanium mesh mesh is generally 12.7 * 4.5mm or 6 * 3.5mm.
At present, domestic titanium anode is mainly brushed. Such electrode has a very wide range of applications.Titanium anode is also known as DSA anode because of its lightweight and flexible manufacturing process.Compared with similar anode titanium anode, it has the following advantages:;
1.The anode size is stable, and the distance between electrodes does not change during electrolysis, which can ensure electrolysis
The operation shall be carried out under the condition that the slot voltage is stable
2.Low working voltage, low power consumption, DC power consumption can be reduced by 10-20%.
3.Titanium anode has long service life and strong corrosion resistance.
4. It can overcome the dissolution of graphite anode and lead anode, avoid the pollution of electrolyte and cathode products, and thus improve the purity of metal products.
5.High current density, low over-potential, high electrode catalytic activity, which can effectively capture high production
6.It can avoid short circuit after lead anode deformation and improve current efficiency.
7.The shape is easy to make and can be high-precision.
8.The titanium matrix can be reused.
9.With low over-potential characteristics, bubbles on the surface between electrodes and electrodes can be easily removed, which can effectively reduce the voltage of the electrolytic cell.Electrowinning extraction of metal is a method of making pure metal by cathodic reduction of metal ions to be extracted from the leached and purified electrolyte, which is composed of Ti matrix and the electrochemical active layer of noble metal and/or noble metal oxide coated on it
What is the role of metal oxide coating on titanium anode?
By covering different coatings, the conductivity and electrocatalytic activity will be enhanced, the electrolytic reaction process will be promoted, and the service life of the anode will be extended under different service conditions, so as to achieve the expected service effect.Thickness of metal oxide coating on titanium anode:The electrochemical catalytic reaction is mainly caused by the noble metal in the coating.Only when the noble metal content meets the use requirements can the normal operation of the anode product be guaranteed.The thickness is only a representation, which is mainly determined by the number of times of brushing and the concentration of solvent, and has no direct connection with the amount of noble metal content.On the contrary, the thick coating is easier to fall off
1.Requirements for anode in the installation of titanium electrode electrolyzer;
2.Titanium electrode process conditions, such as electrolyte (liquid) composition, temperature, current density, service life, etc;
3.Mechanical load of titanium electrode;
4.Conductivity of titanium electrode base material.
5.What are the main factors affecting the service life of anode:
1.Current density: current density is inversely proportional to anode life.The higher the current, the shorter the service life of the anode
2.Titanium base material: The base material of the anode is generally pure titanium, which is required to be above TA1.If the purity of the base material used is not enough, the corrosion resistance will be greatly reduced, which has a great impact on the service life of the anode.
3.Electrolyte: It is forbidden to contain fluorine ion, cyano ion and sulfur ion in the electrolyte. If any, it will also have a great impact on the life of the anode.
4.Inversion: Inversion is a method often used in anode repair, which can make the old coating that has been passivated fall off from the substrate surface. So it is forbidden to reach the extreme in use.
5.Frequent power failure: under the condition of no current passing through, the coating will be greatly damaged if it is soaked in the solution for a long time.
6.Artificial damage: the anode surface shall be free of hard damage.If part of the coating is damaged, even a small scratch will cause the anode to be rapidly corroded/passivated, and finally lead to failure
7.Short circuit: It is forbidden to contact the anode and cathode when the power is on.The instantaneous current caused by short circuit is very large, which can burn the plate.