Composite cathode for conducting electrode reaction under rare earth metal fluorine-containing melt system

Abstract

The invention discloses a composite cathode for electrode reaction in a rare earth metal fluorine-containing melting system. The composite cathode includes a U-shaped tungsten sleeve, a filler, an electrical connector, a thermocouple and a cooling pipe. The U-shaped tungsten sleeve is filled with filler The open end of the U-shaped tungsten sleeve is connected with an electrical connector, and the thermocouple extends through the electrical connector to the bottom of the filler. The thermocouple is wrapped with a cooling tube, and the cooling liquid is passed through the cooling tube. The material of the U-shaped tungsten sleeve is Tungsten, the filler material is copper alloy, and the hot electrode material of thermocouple is platinum-rhodium alloy. The composite cathode is light in use, high in strength, and has good thermal conductivity, and is not easy to be oxidized and gasified due to high temperature, which reduces the cost of use, and is also equipped with a temperature measurement function.

Description

technical field [0001] The invention belongs to the field of rare earth metal preparation, and in particular relates to a composite cathode for electrode reaction in a rare earth metal fluorine-containing melting system. Background technique [0002] Rare earth metals, also known as rare earth elements, are the general term for the 17 elements of scandium, yttrium, and lanthanide in group IIIB of the periodic table of elements, and are often represented by R or RE. From the discovery of the first rare earth element yttrium in 1794 to the discovery of the natural rare earth element promethium in 1972, it took 178 years for people to find all 17 rare earth elements in nature. The luster of rare earth metals is between silver and iron, and the chemical activity of rare earth metals is very strong. [0003] Rare earth metals have extremely important uses and are an important part of contemporary high-tech new materials. A series of compound semiconductors, electro-optical mate...

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Problems solved by technology

[0008] For the electrode reaction made of existing rare earth metals, generally only a small amount of metal materials such as molybdenum and tungsten can be used as cathode materials to participate in the electrode reaction, but metals such as molybdenum and tungsten are made of powder metallurgy, and the material has a high melting point and a large specificity. It is easy to break, so it cannot be made into a size that is too large, too small, or too long, which leads to the use of a cathode that is made of this type of material to participate in the electrode reaction. In the electrode reaction of fluorine, tungsten is generally used as the cathode, but when the temperature of tungsten is above 600°C and exposed to oxygen, that is, when the cathode participates in the electrode reaction in a fluorine-containing molten system, it is very easy to be gasified due to high-temperature oxidation, which intensifies This reduces the consumption of cathode materials, thereby affecting the service life of the cathode, resulting in the need to replace the cathode frequently and increasing the operating cost; at the same time, in the atmosphere of the molten system containing fluorine, because the molten salt system contains highly corrosive fluorine and high temperature environment, many conventional temperature measurement materials cannot be used for temperature measurement, so nowadays it is generally measured by infrared rays, but the use of infrared rays for temperature measurement is greatly affected by the environment, the measurement accuracy is low, and the cost is high, which cannot meet the actual needs of production , with the increasing control of rare earth metals in the country today, the refinement requirements for the extraction of rare earth metals in industry are also getting higher and higher, so it is urgent to improve the above problems

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