The concept of Chromium Salt Electrolyzer
Chromium Salt Electrolyzer is mostly used to produce low melting point metals. Its characteristic is to operate at high temperature, and should try to prevent the entry of moisture to avoid hydrogen ion reduction on the cathode. For example, when preparing metals, since the cathode reduction potential of ions is very negative, reduction is very difficult. Anhydrous molten salt or molten hydroxide without hydrogen ions must be used to avoid hydrogen precipitation at the cathode. For this reason, the electrolysis process needs to be carried out at a high temperature, for example, when the sodium hydroxide is electrolyzed and melted, the temperature is 310°C. When sodium chloride is contained as a mixed electrolyte, the electrolysis temperature is about 650°C.
The high temperature of the Chromium Salt Electrolyzer can be achieved by changing the electrode spacing to convert the electrical energy consumed by the ohmic voltage drop into thermal energy. When electrolyzing molten sodium hydroxide, the tank body can be iron or nickel. The electrolysis of molten electrolyte containing chloride is often due to the inevitable introduction of a small amount of water in the raw material, which will cause the anode to generate moist chlorine gas, which has a strong corrosive effect on the electrolytic cell. The electrolytic cell for electrolyzing molten chloride generally uses ceramic or phosphate materials, and iron can be used for parts that are not affected by chlorine.
The cathode and anode products in the Chromium Salt Electrolyzer also require proper separation and should be drawn from the tank as soon as possible to prevent the cathode product metal sodium from floating on the surface of the electrolyte for a long time, which will further interact with the anode product or oxygen in the air.