Lower cathode rare earth metal electrolytic tank and electrolysis technique adopting the same

Abstract

The invention provides a cathode rare earth metal electrobath and an electrolysis technique for using the electrobath. The electrobath comprises an anode and a cathode. The cathode is arranged at the bottom part of the electrobath; the electrolyzed single or mixed metals are collected on the cathode; a liquid metal surface is used as the surface of the cathode; the anode arranged above the cathode is connected with a transmission mechanism; the transmission mechanism adjusts the distance between the cathode and the anode. The electrobath is suitable for electrolyzing in a fluoride electrolyzing system to generate the rare earth elements which include generating single rare earth metals of La, Ce, Pr and Nd as well as the mixed rare earth metals between the elements. The distance between the anode and the cathode can be adjusted at any time; the power operating factor and the current efficiency of the electrobath are high; the effective operating factor of an auxiliary material is high; the service life of the electrobath is longer than that of the prior electrobath; the electrobath is suitable for developing on the aspect of large capacity.

Description

Technical field [0001] The invention relates to a lower cathode rare earth metal electrolytic cell and an electrolysis process using the electrolytic cell. technical background [0002] At present, the electrolysis of rare earth metals using oxides as raw materials and fluorides as molten salt systems has an upper cathode electrolytic cell. The characteristic of this type of electrolytic cell is that the anode and cathode are immersed into the electrolyte in parallel from the top of the electrolytic cell. A crucible that is resistant to high temperature and corrosion and does not react with rare earth metals such as tungsten or molybdenum is placed directly below the cathode to receive the electrolyzed metal. At present, the electrolyzers used in industrial production mainly include small-scale electrolyzers from 3000 to 4000A and large-scale electrolyzers above Wanan. [0003] Chinese Patent 99127580.2 discloses an electrolytic cell using block-shaped multiple anodes on a tradit...

AI Technical Summary

Problems solved by technology

The common disadvantage of this type of cell is that with the consumption of the anode during the electrolysis process, the pole distance increases continuously, and the voltage increases accordingly, which brings a part of electric energy loss; When exposed to the air, complex multi-phase reactions and mechanical wear will occur at the gas-liquid interface, which will cause this place to become a vulnerable part and reduce the service life of the cathode; the temperature distribution of the electrolytic cell is uneven, the bottom furnace temperature is low and the upper furnace High temperature causes slagging at the bottom of the furnace, and at the same time, the high-temperature liquid surface makes the electrolyte volatilize seriously, which affects the electrolysis yield; the process of rare earth metal flowing into the crucible after the cathode is precipitated is very long, which makes the secondary re-dissolution probability of the metal in the electrolyte, The reaction probability of metal and carbon is greatly increased. The above factors lead to the low economic and technical indicators of this type of electrolytic cell. The utilization rate of each anode carbon block is below 75%, and the general current efficiency is below 80%. Effective utilization is only about 20%

Images