CN113337851A

CN113337851A - Large-size cathode rare earth molten salt electrolytic cell

Info

Publication number: CN113337851A
Application number: CN202110344886.1A
Authority: CN
Inventors: 廉华; 潘燚; 郭海涛; 孔向民; 刘雨; 张志军; 杨培绿; 艾玉忠; 孙致杰; 薛琪; 刘文晶; 侯磊; 李国栋; 赵越
Original assignee: Baotou Rewin Rare Earth Metal Materials Co ltd
Current assignee: Baotou Rewin Rare Earth Metal Materials Co ltd
Priority date: 2021-03-31
Filing date: 2021-03-31
Publication date: 2021-09-03

Abstract

The invention relates to a large-size cathode rare earth fused salt electrolytic cell, which comprises an anode conductive plate, an anode clamp, an anode, a cathode, a receiver, a cell body lining, a cell body leakage-proof layer, an inner protective layer, a heat-insulating layer and an outer protective layer, wherein the cell body lining is arranged on the anode conductive plate; wherein the electrolytic cell is an open test, a single cathode is adopted, and the water-cooled anode conducting plate is used for cooling the upper part of the electrolytic cell, so that the molten salt is crusted on the upper part of the cell body, and the service life of the furnace body is prolonged; a large-size tungsten cathode is manufactured by a high-temperature hot melting compression technology, and the current density of the cathode is ensured; the MATLAB software is utilized to compile a rare earth electrolytic cell electric field numerical model to further optimize the technological parameters of the electrolytic cell, the designed electrolytic cell has high productivity and lower power consumption, the produced metal products have good quality consistency and high yield, the building cost of the electrolytic cell is low, the electrolytic area in the hearth is regular, the electrolytic cell is convenient to stop and start, the consumption of electrolyte is small, and the production change is flexible.

Description

Large-size cathode rare earth molten salt electrolytic cell

Technical Field

The invention relates to the technical field of rare earth molten salt electrolysis, and particularly discloses a technical scheme of a large-size cathode rare earth molten salt electrolytic cell.

Background

The industrial production method of light rare earth metal and its alloy mainly adopts molten salt electrolysis method, and the research of rare earth molten salt electrolysis process technology in China is started in 60 years of 20 th century, and at present, the electrolytic method of rare earth fluoride oxide is mainly adopted. The specifications of domestic electrolytic baths mainly have 6KA-25KA grade and other specifications, wherein electrolytic baths with the scale below 8KA grade adopt upwards inserted single-cathode circular electrolytic baths, and the electrolytic baths have the advantages of low single-furnace productivity, high power consumption, poor quality consistency of metal products and low yield.

Baorui Ruixin rare earth metal materials corporation adopts a 10 KA-grade masonry large-scale electrolytic tank with three inserted cathodes from 2002, and has been developed to the technical popularization and application of a 16 KA-grade graphite integrated tank and a large-size water-cooling anode conducting plate.

The electrolytic cell has the advantages of high single-furnace capacity, low power consumption, long furnace life, good product quality consistency and the like, and is suitable for producing metal neodymium and praseodymium neodymium metal products with large demand and high added value. The multi-cathode electrolytic cell has certain limitations at present, and has the outstanding problems of high construction investment cost of the electrolytic cell, irregular electrolytic area in a hearth, difficult implementation of metal production automation operation, large cell stopping and molten salt starting consumption of the electrolytic cell, large electrolyte consumption and inflexible production change.

An electrolytic cell between the two is urgently needed to be designed, the electrolytic cell has the advantages of higher single-furnace capacity of the electrolytic cell, lower power consumption, better quality consistency of metal products, high yield, reduction of the building cost of the electrolytic cell, regular electrolytic area in a hearth, convenient stopping and starting of the electrolytic cell, small using amount of electrolyte and flexible production conversion.

Disclosure of Invention

In order to overcome the defects of the prior art, the invention provides a large-size cathode rare earth molten salt electrolytic cell.

The invention adopts the following technical scheme.

A large-size cathode rare earth molten salt electrolytic cell comprises an anode conductive plate, an anode, a cathode, a receiver, a cell body lining, a cell body leakage-proof layer, an inner protective layer, a heat-insulating layer and an outer protective layer.

The anode current-conducting plate adopts a water cooling mode, two layers of steel plates are welded in a hollow mode, cooling water is introduced into the anode current-conducting plate, a double-circulation structure is adopted, the water inlet and outlet flow rate and the flow direction are controlled, water with lower temperature enters internal circulation, water with higher temperature enters external circulation, and the anode current-conducting plate is ensured to be uniform in temperature and not to deform; meanwhile, the water-cooling current-conducting plate enables the molten salt to be cooled on the upper part of the lining of the furnace body to form a solid crust, so that the furnace body is prevented from being oxidized by external atmosphere, and the service life of the furnace body is prolonged; the water-cooling current-conducting plate can also reduce the temperature of the anode clamp and the upper part of the anode, reduce the conductor resistance and the anode consumption speed, and reduce the power consumption and the graphite unit consumption.

The anode is made of graphite, and the prior patent technology of Baotouixin rare earth metal material company Limited is utilized, and the patent numbers are as follows: CN102173409B, which is manufactured by a three-dipping two-baking mode, the anode adopts an arc surface to ensure that the power lines are uniformly distributed, and the used anode has high density, high purity, oxidation resistance, strong conductivity, good thermal shock resistance, long service life and low unit consumption.

The cathode is made of metal tungsten, the high-temperature hot melting compression technology is utilized, the density of the cathode is more than 19 g/cm3, and the diameter of the cathode is 100-200 mm; the common metal tungsten is generally forged at high temperature by powder metallurgy, and the density of the manufactured metal tungsten is generally about 18.7 g/cm 3; the tungsten cathode manufactured by adopting the high-temperature hot melting compression technology has the advantages of good compactness, strong oxidation resistance in use, basically no oxidation and long service life.

The slot body inside lining material is high power graphite, integrated into one piece, and inside lining diameter is 800-1000 mm, because the oxidation consumption of slot body inside lining upper portion department near the fire door is very fast, inside lining upper portion adopts bilayer structure, can replace the inside lining inlayer at any time after consuming the certain time to improve the life of slot body inside lining.

The leakage-proof layer of the tank body is made of graphite cold rammed paste and furnace bottom materials, the cold rammed paste is made of adhesive, aggregate and additive by using an air hammer at the temperature of 50 +/-10 ℃, and the main components of the furnace bottom materials are rare earth oxide and rare earth oxyfluoride; at normal electrolysis temperature, sintering to form a compact, oxidation-resistant, sealed leakage-proof layer with a thickness of 50-80 mm.

The receiver is made of tungsten material and is cylindrical, the lower part of the receiver is provided with a bottom, the receiver is formed by one-step die casting, and the receiver can contain 70-100kg of rare earth metal in the receiver, so that the single-furnace capacity is ensured, and the consistency of metal products is improved.

Inner protective layer, outer protective layer adopt the welding of steel material to make, and the inner protective layer mainly prevents that the fused salt from leaking, further consolidates the graphite inside lining, prevents that the graphite inside lining thermal expansion deformation is great, forms the crackle, causes the small opening. The outer protective layer further reinforces the furnace body.

The heat-insulating layer is composed of an asbestos board, heat-insulating bricks and magnesia, the asbestos board and the heat-insulating bricks are stuck on the outer protective layer, and the gaps are compacted by the magnesia.

The method comprises the steps of compiling an electric field numerical model of the rare earth electrolytic cell by using MATLAB software, simulating and calculating three-dimensional electric field distribution in a conductive area in a hearth of the electrolytic cell, designing a large-size cathode rare earth molten salt electrolytic cell according to a calculation result, manufacturing a large-size tungsten cathode by using a high-temperature hot melting compression technology, meeting the technical scheme, and controlling the cathode current density of the electrolytic cell to be 2-5A/cm 2.

Compared with the prior art, the invention has the advantages of improving the single-furnace capacity of the single-cathode electrolytic cell, reducing the building cost of the large rare earth molten salt electrolytic cell, reducing the molten salt consumption of the large rare earth molten salt electrolytic cell during the cell shutdown and the start, improving the yield of the electrolytic cell and the consistency of the quality of metal products, along with small electrolyte consumption and flexible production change. Realizing industrial production and obtaining better economic benefit.

Drawings

FIG. 1 is a schematic structural diagram of a large-size cathode rare earth molten salt electrolytic cell according to the invention.

The reference numerals are explained below:

the device comprises an anode conducting plate 1, an anode 2, a cathode 3, a receiver 4, a tank body lining 5, a tank body leakage-proof layer 6, an inner protective layer 7, a heat-insulating layer 8 and an outer protective layer 9.

Detailed Description

At present, a large-size cathode rare earth molten salt electrolytic cell is put into industrial operation at present, and various economic operation indexes are as follows, the electrolytic current is 9000-12000A, the cell voltage is 8-9V, the direct power consumption is 8-9kwh/kg metal, and the material ratio is 1.1950-1.1960.

Claims

1. A large-size cathode rare earth fused salt electrolytic cell comprises an anode conductive plate, an anode, a cathode, a receiver and a cell body lining, wherein the cell body is provided with a leakage-proof layer, an inner protective layer, a heat-insulating layer and an outer protective layer; wherein the electrolytic cell is an open test, large size cathode.

2. The large-size cathode rare earth molten salt electrolytic cell as claimed in claim 1, wherein the anode conductive plate is cooled by water, the cooling water adopts a double circulation structure, and the temperature of the cooling water is controlled to be 20-80 ℃.

3. A large-size cathode rare earth molten salt electrolysis cell according to claim 1, wherein the anode is made of graphite and has a circular arc surface and a length of 400-600 mm.

4. A large-size cathode rare earth molten salt electrolyzer as claimed in claim 1, characterized in that the cathode is made of metal tungsten, the density of the tungsten cathode is more than 19 g/cm3 by hot melting high-temperature compression technology, and the diameter of the tungsten cathode is 100-200 mm.

5. The large-size cathode rare earth molten salt electrolysis cell of claim 1, wherein the cell body lining is high-power graphite and is integrally formed, and the diameter of the lining is 800-1000 mm.

6. A large size cathode rare earth molten salt electrolyzer as claimed in claim 1, characterized in that the receiver is of tungsten material, cylindrical in shape, and can hold 50-120 kg of rare earth metals inside.

7. The large-size cathode rare earth molten salt electrolysis cell of claim 1, wherein the inner protection layer and the outer protection layer are made of steel materials through welding.

8. The large-size cathode rare earth molten salt electrolyzer of claim 1, wherein the leakage-proof layer of the electrolyzer body is formed by cold ramming paste and ramming furnace bottom materials.

9. The large-size cathode rare earth molten salt electrolysis cell of claim 1, wherein the insulating layer is made of insulating cotton and insulating bricks and is reinforced by magnesia.

10. A large size cathode rare earth molten salt electrolysis cell as claimed in claim 1, wherein cathode current density of said electrolysis cell is 2-5A/cm²。