Tungsten cathode for molten salt electrolysis, preparation method of tungsten cathode and application of laser cladding technology

Abstract

The invention discloses a preparation method of a tungsten cathode for molten salt electrolysis, which comprises the following steps: sequentially carrying out laser cladding on the surface to be subjected to laser cladding of a tungsten substrate in copper, stainless steel and an anti-corrosion metal composite material to obtain the tungsten cathode with a copper cladding layer, a stainless steel cladding layer and an anti-corrosion metal cladding layer; wherein the surface to be subjected to laser cladding is the surface of the tungsten substrate in the area between the 1 / 10 position of the length of the tungsten substrate and the 1 / 4 position of the length of the tungsten substrate from the same end part of the tungsten substrate; the anti-corrosion metal composite material is prepared from the following components: 0.02 wt%-0.06 wt% of C, 1.5 wt%-2.5 wt% of Si, 2.5 wt%-3.5 wt% of W, less than or equal to 7 wt% of Fe, 10 wt%-20 wt% of Mo, 20 wt%-30 wt% of Cr, 8 wt%-20 wt% of ZrO, 0.4 wt%-0.8 wt% of B and the balance Ni. According to the method, the service life of a traditional tungsten cathode can be prolonged from about 200 days to 310-320 days.

Description

technical field [0001] The invention relates to a tungsten cathode for molten salt electrolysis and a preparation method thereof, and also relates to an application of laser cladding technology. Background technique [0002] When using the rare earth molten salt electrolysis method to prepare rare earth metals, the molten salt electrolyte mostly uses fluorides and oxides, and the current during electrolysis is as high as thousands of amps, and the temperature of the electrolyte can reach above 1000 ° C. The working conditions are very bad, so it is necessary to use A highly corrosion-resistant, refractory metal serves as the cathode. At present, tungsten cathodes are generally used in production. [0003] In actual production, since the tungsten cathode exposed above the molten salt liquid level (especially the position close to the molten salt liquid level) has been under high temperature conditions of 700°C to 850°C for a long time, and is vulnerable to the impact of vola...

AI Technical Summary

Problems solved by technology

[0003] In actual production, since the tungsten cathode exposed above the molten salt liquid level (especially the position close to the molten salt liquid level) has been under high temperature conditions of 700°C to 850°C for a long time, and is vulnerable to the impact of volatile gas flow, the The parts are easily oxidized, which leads to the corrosion and failure of the tungsten cathode

Since tungsten is a rare metal and is expensive, frequent replacement of tungsten cathodes not only increases production costs, but also affects production efficiency

Images