The full name of titanium anode is called titanium-based metal oxide coated anode (MMO). Also called DSA anode, size and shape stable anode. It uses titanium as the base material (wire, rod, tube, plate, net), and brushes a precious metal coating on the titanium substrate to make it have good electrocatalytic activity, conductivity, and oxidation resistance. Compared with the original graphite anode and lead anode, the titanium electrode has the following advantages:
1. The electrode size is relatively stable, and the distance between the electrodes will not change during the electrolysis process, ensuring that the electrolysis operation is carried out under the condition that the cell voltage is stable;
2. High catalytic activity and low working voltage;
3. The working voltage is low, so the power consumption is small, and the DC power consumption can be reduced by 10%-20%;
4. The working life of the titanium anode is long. The metal anode in the chlor-alkali industry produced by the diaphragm method is resistant to chlorine and alkali corrosion. The life of the anode has reached more than 5 to 7 years, while the graphite anode is only 8 months;
5. It can overcome the dissolution problem of graphite anode and lead anode, avoiding the pollution of electrolyte and cathode products, thus greatly improving the purity of metal products;
6. It can increase the current density and increase the electrolysis efficiency;
7. The noble metal iridium and ruthenium oxides have oxidation resistance, so the corrosion resistance of titanium electrodes is strong;
8. The short-circuit problem after the deformation of the lead anode can be avoided, thereby improving work efficiency;
9. Titanium electrode is light in weight, which can reduce labor intensity compared with graphite anode and lead anode;
10. The shape and manufacture of the titanium substrate are relatively easy, and the precision can be increased;
11. The substrate can be used repeatedly without being damaged;
1. Titanium anode classification
1. Ruthenium-coated titanium electrode
This type of electrode has low chlorine evolution overpotential and high oxygen evolution overpotential, and is mainly used in various chlorine evolution occasions, such as chlor-alkali industry, cathodic protection, etc. This type of electrode coating includes the original ruthenium titanium coating (Ru-Ti) and Ru-Ir-Ti, Ru-Co-Ti, Ru-Co-Sn-Ti, Ru-Sn-Ti, Ru-Si-Ti, Ru-Ti-Zr, Ru-Ti-La, Ru-Ti-Ce and other coatings.
2. Iridium-coated titanium electrode
In certain electrolysis processes, such as electrolytic extraction of non-ferrous metals, electroplating industry, electrochemical reduction to produce organics, etc., the anode design reaction is oxygen evolution reaction, so it is hoped to develop an anode material with low oxygen evolution overpotential, iridium coating The layered titanium electrode was developed under this background. Such electrode coatings include Ir-Co, Ir-Ta, Ir-Sn, Ir-Ta-Co, Ir-Ru-Pd-Ti and other coatings. Among them, Ir-Ta coated titanium electrode is the most successful oxygen evolution electrode.
3. Platinum-plated anode: Titanium is the base material. The surface is coated with precious metal platinum, and the thickness of the coating is generally 1-5um.
2. Process flow
1. Purchase GR1 titanium substrate and make sure that the surface of the board is smooth and smooth without deep scratches and defects.
2. Mechanically process the selected titanium substrate to the size required by the customer.
3. Annealing and leveling the titanium substrate at a temperature >500°C. (To eliminate stress and ensure flatness.)
4. During the annealing and leveling process, a dense titanium oxide layer will be formed on the surface of the titanium substrate, and it will be polished mechanically or manually to make the surface appear to have the metallic luster of titanium.
5. The titanium substrate is pickled and corroded with oxalic acid at a concentration of 10%, and the surface oxide layer is etched into a titanium hydride surface in a slightly boiling state for several hours.
6. Reasonable qualitative and quantitative configuration of precious metal solutions according to the anode environment applied by customers.
7. The pickled titanium substrate is qualified, that is, the surface is gray and uniform, and then manually coated, sintered according to the set appropriate temperature, sintered naturally after the furnace is sintered, and cooled to room temperature for the second coating Follow, and so on, until the coating solution has been applied for more than 17 to 20 times.
8. After the sintering of the above processed parts is completed, the life test is carried out with the test piece of the furnace, and the qualified packaging is shipped.
3. Application fields
1. Electrolysis production of chlor-alkali industry chlorate industry sodium hypochlorite
The chemical industry that produces chlorine gas, hydrogen gas, and caustic soda by electrolyzing common salt solution is called chlor-alkali industry. It is the largest field in the modern electrochemical industry and occupies an important position in the national economy.
In addition to the above, downstream products such as hydrogen chloride (aqueous solution is hydrochloric acid), sodium hypochlorite, chlorinated stone, polyvinyl chloride (referred to as PVC Polyvinyl chloride polymer = PVC molecular structure), hydrogen peroxide, etc. can also be produced.
In the production of chlor-alkali, pure saturated saline is used as the electrolytic solution, the titanium electrode is used as the anode, and the iron mesh is attached to asbestos as the cathode. The anode chamber produces chlorine gas, and the cathode chamber produces hydrogen gas and sodium hydroxide. After purification, it is widely used in various industries. in production.
The application of titanium anode has greatly promoted the development of the chlor-alkali industry and is an epoch-making contribution to the field of electrochemistry. The electrode has high catalytic activity for chlorine evolution, and has good electrocatalytic activity, mechanical stability and chemical stability for the chlorine evolution reaction. Today, it is an irreplaceable electrode material in the chlor-alkali industry, with a service life of more than five years.
2. Electrolytic functional water electrolytic functional water tank
Functional water is defined as water obtained by man-made treatment to obtain various useful functions. Electrolyzed water is popular as a sterilization treatment technology with good sterilization effect, strong practicability and no secondary pollution. Functional water is produced by electrolyzing drinking water or a small amount of brackish water through titanium electrodes, which is widely used in electrolyzed water machines.
1) The use of electrolysis to produce hypochlorous radicals, new ecological oxygen, hydroxyl radicals and other strong oxidizing substances to kill microorganisms.
2) The electrolysis electrode is used to directly act on the microorganisms to kill them.
3) Alkaline ionized water can directly treat a variety of diseases, effectively improve the body's metabolic function, eliminate harmful acidic metabolites free radicals, and enhance physical fitness to prevent and improve disease resistance.
4) Acidic ionized water has the effect of inhibiting the growth of bacteria, the effect is the same as that of beauty astringent water, and it should be sterilized and disinfected with strong oxidation; alkaline ionized water is used to regulate the physiological functions of the human body.
Our company's YC-90 ionized water electrolyzer has the characteristics of reasonable structure, low energy consumption, wide range of water quality, reliable performance, long life and easy cleaning. The tank body is made of ABS plastic and has good thermal stability; the electrode is made of titanium-based sintered platinum Group metal alloy, high conductivity, non-toxic, good oxidation resistance, good reversal performance, long service life, in line with national drinking water safety standards.
Installation size: 185 X 44 X 70mm / Model: YC-90 / Water output: 90 ~ 120 l/h / Plate material: TA1 / Housing material: ABS plastic / Overcurrent density: 5000A / Voltage ≤ 24V / ORP value : Less than -250 mV / Service life: 5-10 years (depending on water quality) / PH value alkaline 7.5-10 acidic 6.5-3.5 / tank structure: five poles and four tanks / precipitation of heavy metals and toxic substances: none.
Instructions for use: This electrode can be used as a pole, that is, any terminal of the DC power connection is positive, and the other end is negative. Use a tee to connect one side for the water inlet, and the other end for the acidic and alkaline water outlets. The water quality varies from place to place, and the resistivity of the water varies, so gradually increase the voltage (between 24 and 30 volts) or current until the outlet is a suitable acid or alkaline water. If there are further requirements for PH value, add 0.3% saline solution to continue the measurement.
3. Manufacture of sodium hypochlorite generator and chlorine dioxide generator electrodes. (84 disinfectant)
Sodium hypochlorite is a kind of strong oxidant. It is a truly efficient, broad-spectrum and safe powerful sterilization and virus killing agent. It has a strong bactericidal effect and can replace oxidants such as bleaching powder.
According to chemical measurements, ppm hypochlorite is almost completely hydrolyzed into hypochlorous acid in water, and its efficiency is higher than 99.99%. In the process of sterilization and virus killing, hypochlorous acid can not only act on the cell wall and the virus shell, but also because the hypochlorous acid molecule is small and has no charge, it can also penetrate into the bacteria (virus) body, and the bacteria (virus) body protein, Organic polymers such as nucleic acids and enzymes undergo oxidation reactions to kill pathogenic microorganisms.
Product appearance: plate, mesh, tube, etc., our company provides long-term supply for Hengyang, Beijing, Yixing, Chongqing, Weifang and other companies, current density 30 ~ 60A, voltage 24V.
4. Cathodic protection
In the environment of the use of steel materials such as oceans, ships, bridges, etc., due to the impurities in the steel and the corrosive effect of micro-batteries, combined with the complex natural environment, although corrosion-resistant alloy steel is selected and the thickness of the material is increased, excellent corrosion-resistant paint is applied, but these The corrosion of the structure is still very serious, which greatly threatens the safety of production, and cathodic protection is a convenient and important measure for the effective protection of permanent steel structures in the ocean.
1) Use the applied current to make the entire surface of the protected metal structure into a cathode, which is called applied current cathodic protection.
2) Connect a metal or alloy with a more negative potential to the metal equipment to be protected, called sacrificial anode protection.
Used in the following fields:
1) In fresh water and sea water, prevent corrosion of ships, docks, platforms, gates and cooling equipment.
2) In alkali and salt solutions, prevent corrosion of storage tanks, evaporation tanks, caustic soda boilers, etc.
3) Prevent corrosion of pipelines and cables in soil and sea mud.
5. Gold plating, steel plate zinc plating and tin plating
Titanium electrode has excellent conductivity and corrosion resistance, the service life is much higher than that of lead anode, it can work stably for more than 4000 hours, and the cost is low. It will be an inevitable trend for the development of electroplating zinc and tin production at home and abroad.
Titanium electrodes are currently used in Japan, the United States, Germany, and China, which not only greatly saves the energy consumption of electroplating, but also creates conditions for the production of thick galvanized and tin steel plates because of the increased electroplating current density.
6. Extraction of non-ferrous metals
Electrolytic metallurgy occupies a large proportion in the hydrometallurgical industry. Non-ferrous metals produced by electrolytic metallurgy include Zn, Cd, Cu, Mn, Co, Ni, Cr, etc.
The advantage of electrolytic metallurgy is that it has high selectivity, high purity metals can be obtained, and useful metals can be recovered. Therefore, it can process low-grade minerals and polymetallic ores with complex components, which is conducive to the comprehensive utilization of resources. In addition, the pollution to the environment is small, and production is easier to be continuous and automated.
In recent years, the field of electrolytic metal extraction has widely used coated titanium electrodes, and has become the second industrial field using titanium electrodes on a large scale.
7. Electrolytic copper foil
With the development of science and technology, the degree of automation is increasing, which has promoted the rapid development of the electronics industry. The application of large-scale integrated circuits has increased the demand for copper foil in the electronics and instrument industry, and the quality requirements for copper foil are becoming higher and higher.
According to the thickness, it can be divided into 105µm, 70µm, 35µm, 18µm, 12µm, 9µm and 5µm. Among them, copper foil under 12µm is generally called ultra-thin copper foil.
The electrolytic copper foil uses a metal roller partly immersed in a copper sulfate solution as a cathode, which is continuously electrolyzed to produce foil. The production of copper foil in the world is mainly controlled by Japan. There are about 15 domestic manufacturers with a production capacity of about 35,000 tons.
8. Sewage treatment
With the rapid development of industry and agriculture and population growth, the amount of sewage discharged by humans has increased sharply, causing many water areas to suffer from different degrees of pollution. Electrochemical treatment of sewage is divided into direct electrolysis and indirect electrolysis.
1) Direct electrolysis means that pollutants are directly oxidized or reduced on the electrode and removed from the wastewater. Direct electrolysis can be divided into cathode process and anode process. The anode process refers to the oxidation of pollutants on the surface of the anode to convert into less toxic substances or easily biodegradable substances, and even the inorganics of organic substances occur, so as to achieve the purpose of reducing pollution. The cathode process refers to the reduction and removal of pollutants on the cathode surface. It is mainly used for the dehalogenation of halogenated hydrocarbons and the recovery of heavy metals.
2) Indirect electrolysis refers to the use of electrochemically generated redox substances as reactants or catalysts to convert pollutants into less toxic substances. Indirect electrolysis can be divided into reversible and irreversible processes. The reversible process refers to the redox substances that can be electrochemically regenerated and recycled in the electrolysis process; the irreversible process refers to the use of substances produced by irreversible electrochemical reactions to oxidize organic matter.
Used in printing and dyeing wastewater treatment, landfill leachate treatment, fecal sewage treatment, cyanide-containing wastewater treatment, pharmaceutical wastewater treatment, hospital wastewater treatment, organic wastewater treatment.
9. Etching waste liquid recycling in PCB electronic circuit board factory
Etching is an important process in the production of printed circuit boards. As the etching progresses, the waste etching solution contains a large amount of copper ions or other metal ions, which can be recycled by electrolysis. Through this recycling link, enterprises not only increase economic benefits by recycling copper and other metals, but more importantly, they achieve emission standards and resource recycling, which has long-term social benefits.
The waste liquid includes: acidic etching waste liquid, alkaline etching waste liquid, low copper content waste liquid, waste fixing liquid, waste frame material, nickel-containing waste liquid, gold and palladium-containing waste liquid, and waste tin water.
4. Enterprise advantages
1. The company's own titanium base material and original precious metals ruthenium trichloride and chloroiridium acid ensure the reliability of raw material quality from the source.
2. The company is located in Baoji, a titanium resource base, and has its own CNC lathes and other machining equipment to effectively guarantee the production schedule and precision control.
3. The company continuously improves the sintering device, improves the operating environment, and ensures the stability of production.
4. The company has accumulated many years of anode production experience, and has a group of skilled operating technical workers, and on the basis of this, it continuously optimizes the process and makes the products more competitive in the market.
5. In order to ensure the production and application of customers and terminal manufacturers, the company increased the amount of precious metals on the basis of the original enterprise standards, so the thickness of the coating of the titanium electrode can reach more than 30 microns, effectively enhancing the conductivity, oxidation resistance and catalytic activity of the anode.
V. Precautions for use
1. After the oxidation and sintering of the titanium electrode, it is the black surface of ruthenium dioxide and iridium dioxide or iridium dioxide and tantalum pentoxide. The black side corresponds to the cathode; the uncoated surface is blue or gray titanium dioxide surface. The surface has no electrode performance.
2. Once the pickling of the titanium electrode substrate is completed, all subsequent production and processing procedures and use procedures must be carried out with great care. Wear clean gloves to clamp the ends or edges of the anode during transportation, installation and disassembly. Any scratches on the coated surface and the surface of the coating are strictly prohibited.
Note: The titanium substrate itself is not conductive, and its outer layer is coated with precious metal oxide coating to have electrocatalytic activity, conductivity, and oxidation resistance, but its thickness is only about 20 microns. If it is scratched or damaged, it is electrolyzed. In the process, the electrode will not only corrode from the damage, which will affect the quality and effect of the entire electrode, but also the titanium anode will greatly reduce the service life due to the instantaneous strong current loading.
3. The electrolyte maintains stability, especially cannot contain cyanide ion and fluoride ion, these impurities will seriously corrode the titanium substrate;
4. Add a filter device before the electrolyte enters the electrolytic cell. It must not contain metal particles with a diameter greater than 0.1 mm to prevent excessive accumulation and short circuit of the cathode and anode.
5. When electrolytically recovering metals such as copper, nickel, gold, silver, cobalt, etc., the cathode attachments should not be too thick. When the titanium electrode is initially used, it has the best conductive activity and high copper extraction efficiency, so special attention should be paid to the timing of copper stripping at the beginning. , In order to prevent the electrode spacing is too small or the metal thorns generate the cathode and anode short-circuit breakdown.
6. The distance between cathode and anode can be set according to the actual production, generally 3-25mm. Generally speaking, the pole distance will increase the voltage drop, but it should not be too small, otherwise the cathode scale generated on the cathode surface will easily cause the short circuit of the electrode plate, thus causing the honeycomb electrical corrosion on the anode and cathode surface;
7. Avoid the use of inverted poles. Once the noble metal oxide coating is used as a cathode, a reduction reaction occurs on the surface, which is easily converted into a metal element, and it cannot be effectively combined with the titanium base.
