Soluble anode and insoluble anode
The soluble anode functions to supplement metal ions and conduct electricity during the electrolysis process, and the insoluble anode only serves to conduct electricity. The earliest insoluble anodes were graphite and lead-based anodes. In the 1970s, titanium anodes began to be used in the electrolysis and electroplating industries as new technologies. At present, insoluble anodes can be divided into two major categories: chlorine evolution anodes and oxygen evolution anodes. The chlorine evolution anode is mainly used in the chloride electrolyte system. During the electroplating process, the anode has chlorine gas released, so it is called the chlorine evolution anode; the oxygen evolution anode is mainly used for the electrolyte system such as sulfate, nitrate, hydrocyanate, etc. During the process, the anode has oxygen released, so it is called an oxygen evolution anode. The lead alloy anode anodic oxygen evolution anode and the titanium anode have the functions of oxygen evolution, chlorine evolution or both, depending on the surface catalytic coating.
Titanium anode for chlor-alkali industry
Compared with the graphite electrode, the diaphragm method produces caustic soda, and the working voltage of the graphite anode is 8A/DM2, and the coated anode can be multiplied by up to 17A/DM2. In this way, the product can be multiplied in the same electrolytic environment, and the quality of the produced product is high, and the purity of the chlorine gas is high.
Titanium anode for electroplating
The insoluble anode for electroplating is coated with a noble metal oxide coating having high electrochemical catalytic properties on a titanium substrate (mesh, plate, ribbon, tube, etc.) containing a highly stable valve metal oxide. The new insoluble titanium anode has high electrochemical catalytic energy, and the oxygen evolution overpotential is about 0.5 V lower than the lead alloy insoluble anode. The energy saving is remarkable, the stability is high, the plating solution is not polluted, the weight is light, and the replacement is easy. The oxygen evolution overpotential of the new insoluble titanium anode is also lower than that of the platinized insoluble anode, but the lifetime is more than doubled. Widely used in various electroplating as anode or auxiliary anode, can replace conventional lead-based alloy anode, under the same conditions, can reduce the tank voltage and save power consumption; insoluble titanium anode has good stability in electroplating process (Chemical, electrochemical), long service life. This anode is widely used in nickel plating gold plating, chrome plating, galvanizing, copper plating and other non-ferrous metals industries.
Lead and lead alloy anode
The lead alloy anode belongs to the oxygen evolution anode, and the electrolyte for oxygen evolution reaction is sulfuric acid and sulfate, which is mainly used for electrolytic metallurgy. This anode has the drawback that the geometry will change during the electrolysis process. In the electrolysis process, the lead anode matrix is first converted to lead sulfate and then converted to lead oxide. Lead sulphate is an intermediate layer that acts as an insulator and acts as a chemical barrier to protect the inner lead matrix in a sulphuric acid environment. Lead oxide is an electrode in the actual sense, and an oxygen evolution reaction occurs. The oxygen evolution potential of lead oxide is high and increases rapidly with the increase of current density. This characteristic of lead alloy anode is oxidized by its outer layer. The inherent characteristic of lead - lead oxide is determined by the poor conductor of electricity. In addition, in the electrolysis process, the electrochemical performance of the lead oxide anode structure is continuously attenuated, and the internal stress causes the oxide layer to fall off. In addition, the formation of lead oxide causes the oxide to continuously dissolve, and the sulfuric acid as the intermediate layer Lead is once again converted into lead oxide, which becomes a new outer oxide electrocatalytic active material, and the inner lead matrix is oxidized to form a new intermediate layer of lead sulfate. Therefore, during the electrolysis process, lead and its alloying elements are continuously dissolved into the electrolyte and precipitate to cause solution contamination (chemical precipitation in solution) and contamination of the cathode product (electrodeposition of contaminants on the cathode surface, the purity of the copper to the copper cannot be very high. Good to get guaranteed).
Coated titanium anode
Coated titanium anode, commonly known as DSA (Dimensionally Stable Anode), also known as DSE (Dimensionally Stable Electrode), is a new type of insoluble anode material developed in the late 1960s. DSA coated titanium anodes are mainly used in two major departments of electrochemistry and electrometallurgy.
The fields of DSA coated titanium anodes are: chlor-alkali industry, chlorate production, hypochlorite production, perchlorate production, persulfate electrolysis, electrolytic organic synthesis, electrolytic extraction of non-ferrous metals, production of electrolytic silver catalysts, Electrolytic method for manufacturing copper foil, electrolytic oxidation for mercury recovery, water electrolysis, chlorine dioxide production, hospital sewage treatment, cyanide-containing wastewater treatment in electroplating plants, disinfection of domestic water and food utensils, treatment of power plant cooling circulating water, wool spinning Treatment of dyeing and finishing wastewater, treatment of industrial water, preparation of acid-base ionized water by electrolysis, galvanization of copper plate, rhodium plating, palladium plating, gold plating, lead plating, electrodialysis to desalinate seawater, electrodialysis to prepare tetramethyl hydroxide Ammonium, molten salt electrolysis, battery production, cathodic protection, production of negative electrode foil, anodization of aluminum foil, etc. Applications include chemical, metallurgical, water treatment, environmental protection, electroplating, electrolytic organic synthesis and other fields.