RU93805U1 - INSTALLATION FOR ELECTROCHEMICAL PRODUCTION OF POWDERS OF REFROOMING METALS - Google Patents

Abstract

 1. Installation for the electrochemical production of refractory metal powders, including an electrolyzer with a molten electrolyte bath, a cathode, a consumable anode mounted vertically in the center of the electrolyzer, a current supply system to the anode and a cathode containing a power source, a powder-containing product unloading unit, an output system gas, characterized in that it further comprises an electrolyte preparation unit, a lock chamber placed on the supporting frame, on the housing of which guiding racks of the anode group, the anode rod on which the anode or the scraper type device is installed for cleaning the walls of the electrolyzer is provided with a rotation drive, the lock chamber is in communication with the electrolyzer with a lock channel for supplying electrolyte and the passage of the anode rod on which the slide gate is installed, while the electrolyzer is made in the form of a crucible with a sealed lid and a conical bottom and is equipped with a valve for the release of a powder-containing product, the unit for unloading a powder-containing product is equipped with a cooling system deposition and is made in the form of a sealed crucible, the electrolyte preparation unit is made in the form of a crucible, in the bottom of which there is an electrolyte discharge valve, and the electrolyzer and the units for preparing the electrolyte and unloading the powder-containing product to ensure the tightness of the installation and maintain a given atmosphere are connected to each other by heat-insulated pipelines gas supply and exhaust valves. ! 2. Installation for the electrochemical production of powders of refractory metals according to claim 1, characterized in that the airlock

Description

The utility model relates to non-ferrous metallurgy, in particular to devices for producing nanocrystalline powders of a capacitor grade using an electrochemical process.

A known installation for producing tantalum powder by electrolysis, including an electrolyzer with an electrolyte bath made of nickel or nichrome, a cathode installed in the center of the bath, a graphite anode, devices for supplying inert gas and loading raw materials (V.I. Konstantinov, Electrolytic production of tantalum, niobium and their alloys. M. Mysl, Metallurgy, 1977, p.134-137).

The disadvantage of the installation is the short life of the electrolyzer, due to the destruction of the walls of the bath due to their corrosion under the influence of the melt, and the low productivity of the installation, due to the frequency of the electrolysis process - the need to stop the cell to withdraw the cathode with the formed powder layer.

A known installation for producing refractory metals or non-metals in molten salt electrolytes, including a sealed electrolyzer with a housing closed by a sealed cover, a liquid metal cathode in the form of a low-melting metal melt, with at least one anode placed above the surface of the electrolyte layer immersed in the electrolyte layer , means for supplying a molten salt, a working gas to the electrolyte layer, means for withdrawing the anode gas, means for continuously draining the liquid cathode and electrolyte (Patent RF №2264482, IPC 7 C25C 7/00, 5/04, 3/26, publ. 2005.11.20).

The proposed design of the installation increases the efficiency by eliminating the process of stopping the cell during continuous output of the finished product, but does not protect the walls of the cell body from destruction under the influence of the electrolyte.

A known electrolyzer for producing hafnium from molten salts, consisting of a sealed water-cooled case forming a working chamber with a water-cooled plate mounted on it having a cavity in which a cathode deposit receiver is arranged, made in the form of a bucket with a replaceable mold and installed with the possibility of horizontal movement inside cavity of the plate, two anodes introduced into the working chamber, a water-cooled cathode placed between the anodes with the possibility of vertical movement along the central axis, a cup mounted above the plate cavity, inside of which a rod with a knife for cutting the cathode deposit is mounted with the possibility of vertical movement, on which a protective cap is fixed, inside which there is a mechanism for moving the cathode and rod with a knife, a salt feeder and inert gas nozzles and removal of anode gases (RF Patent No. 77869, IPC C25C 3/26, publ. 2008.11.10).

The proposed design does not provide sufficient protection of the inner cavity of the cell from the air atmosphere and the walls of the housing from destruction under the influence of the electrolyte.

Known sealed electrolyzer for producing metals by electrolysis of molten salts, for example titanium, zirconium, hafnium and others, including a sealed bath with water-cooled double steel walls and a bottom, with a lid and a rubber gasket, four graphite electrodes, two of which are intended for supplying alternating electric current for heating and melting of the electrolyte, and two are anodes, a metal (nickel) cathode located vertically in the center of the electrolyzer, a chamber for cooling sediment that can be replaced by a detachable vacuum gateway without disturbing the inert gas atmosphere, a feed hopper with a vacuum shutter and feeder, nozzles for supplying inert gas and removing anode gases, a tap hole for removing molten electrolyte (USSR Author's Certificate No. 119681, application. 1958.07.22) .

The disadvantage is the fragility of the electrolyzer’s operation, due to the destruction of the bath, since the skull from the frozen electrolyte formed on the water-cooled walls and the bottom of the bath does not provide reliable protection of the bath from the effects of the melt at elevated temperatures.

The closest in technical essence to the claimed solution is an installation for electrochemical reduction of powders and / or granules of a metal oxide containing an electrolyzer with a bath of molten electrolyte, a cathode in the form of an element (plate), which has an upper surface for supporting powders and / or granules of metal oxide, immersed in the electrolyte bath, consumable graphite anode, means for moving the anode down into the electrolyte bath, a system for applying potential between the anode and cathode, including an electric circuit with a power source, means for feeding powders and / or granules of the metal oxide into the electrolyte bath, an apparatus for removing at least partially electrochemically reduced granules of the metal oxide from the electrolyte bath, a water spray chamber for cooling the discharged material, a system for removing and processing gases, stand out from the electrolyzer (RF Patent No. 2347015, IPC C25C 5/00, publ. 2007.07.27).

The proposed design does not provide the production of powders with homogeneous physical and mechanical properties, due to the use of a graphite block as a sacrificial anode and carbon ingress into the finished product, and to protect the walls of the casing from destruction under the influence of an electrolyte melt and aggressive chlorine-containing reaction products formed.

The technical result of the claimed utility model is the elimination of electrochemical destruction of the working surfaces of the electrolyzer with the simultaneous production of powders with uniform physical and mechanical properties.

This result is achieved in that the installation for the electrochemical production of refractory metal powders, comprising an electrolyzer with a molten electrolyte bath, a cathode, a consumable anode mounted vertically in the center of the electrolyzer, a current supply system to the anode and cathode containing a power source, a powder unloading unit containing the product, the gas exhaust system, according to the utility model, further comprises an electrolyte preparation unit located on the carrier frame of the locks a chamber, on the housing of which the guide posts of the anode group are installed, while the anode rod, on which the anode or a scraper-type device for cleaning the walls of the electrolyzer is mounted, is equipped with a rotation drive, the lock chamber is in communication with the electrolyzer with a lock channel for supplying electrolyte and the passage of the anode rod, which has a slide gate installed, while the electrolyzer is made in the form of a crucible with a sealed cover and a conical bottom and is equipped with a valve for the release of powder containing the product, powder unloading unit the containing product is equipped with a cooling system and is made in the form of a sealed crucible, the electrolyte preparation unit is made in the form of a crucible, in the bottom of which there is an electrolyte discharge valve, and the electrolyzer and the electrolyte preparation and unloading units the powder of the containing product to ensure the integrity of the installation and maintain a given atmosphere other thermally insulated pipelines and equipped with valves for supplying and removing gases.

In addition, the lock chamber, the electrolyzer and the units for preparing the electrolyte and unloading the powder of the containing product are connected to each other by a gas supply and exhaust system, an ingot, a rod or a plate made of metal of the obtained powder are used as an anode consumed, the cathode is the wall of the electrolyzer crucible and the cathode is made of metal of the resulting powder.

The figure shows the installation diagram for the electrochemical production of refractory metal powders. The installation contains:

- an anode group consisting of an electric drive of vertical movement 1 of a traverse 4 mounted on an upper platform 3, an electric drive of rotation 2 of the anode rod 6, guide racks 5, supported by supporting nickels 11, a consumable anode 16 (an ingot, bar or metal plate) is attached to the anode rod obtained powder) or a scraper type device 17 for cleaning the walls of the crucible 45 of the electrolyzer;

- a lock chamber placed on a supporting frame 61, consisting of a housing 18, with a process hatch 15, a vacuum tight stuffing box 12, supply valves 13 and gas outlet 14. The lock chamber is in communication with the electrolyzer through the lock channel 32 for supplying electrolyte and the passage of the anode rod 6, on which the slide gate 31 is mounted;

- an electrolyte preparation unit, made in the form of a crucible 25 placed in a resistance furnace 26, the bottom of which is equipped with an electrolyte discharge valve 27, and the upper part is equipped with a sealed cover 24 with a feedstock loading hatch 23 and gas supply and exhaust valves 21. The heat-insulated pipeline 28 connects the crucible 25 to the lock channel 32;

- an electrolyzer consisting of a crucible 45 (made of metal of obtained powder) placed in a resistance furnace 46 with an airtight lid 43 provided with valves for supplying 41 and exhaust gas 42. The conical bottom of the crucible 45 is equipped with a valve for the release of powder containing product 48;

- the unit for unloading the powder of the containing product, made in the form of an airtight crucible 55 with a cover 53, equipped with a cooling system 54, valves for supplying and discharging gas 52, a manhole 56 for unloading the powder of the containing product;

- a gas supply system 71 (nitrogen and argon) with a pressure reducing valve 72 connected to the gas supply valves 13, 21, 41, 51 and a gas exhaust system 81, with a fore-vacuum pump 82 connected to the gas exhaust valves 14, 22, 42 and 52 ;

- a system for supplying current to the anode 16 and the current collector 44 located on the wall of the crucible 45, which is the cathode, including a direct current source 91;

- power supply and installation control system 92.

An example of the operation of the inventive installation for the electrochemical production of powders of refractory metals.

Electrolyte preparation.

The electrolyte discharge valve 27 in the electrolyte preparation unit is in the closed position. Measured amounts of alkali and alkaline earth metal halide salts are poured into the loading hatch of the feedstock 23, after which the loading hatch 23 is closed to ensure tightness. The gas exhaust valve 22 is moved to the position - openly and the fore-vacuum pump 82 pumps out air from the crucible 25 with loaded salts. Then, the valve 22 is closed, and the foreline pump 82 is turned off. The gas supply valve 21 is opened and nitrogen filled with a crucible 25 filled with salts. The required nitrogen pressure is provided by pressure reducing valve 72.

The gas supply valve 21 is brought into the closed position and nitrogen is pumped out of the crucible 25 of the electrolyte preparation through the valve 22 by the foreline pump 82. After that, the valve 22 is brought into the closed position and the foreline pump 82 is turned off. In total, three filling cycles are performed - nitrogen pumping. Then, through the gas supply valve 21, the crucible 25 is filled with argon and the supply valve 21 is brought into the closed position.

Through the power supply system 92, current is supplied to the resistance furnace 26, raising the temperature in the crucible 25 to 700-800 ° C and maintain the set time until the electrolyte salts are completely melted.

Through the vent valve 22 by the foreline pump 82, gas is pumped out of the crucible 25, the valve is closed, and the pump is turned off. Through the gas supply valve 21, the crucible 25 is filled with argon.

Preparation of the anode group for electrolysis.

The gate valve 31 overlaps the lock channel 32. The anode rod 6 with the scraper device 17 for cleaning the walls of the crucible is brought into the readjustment position (the highest position), while the process hatch 15 is open. After dismantling the scraper device 17 and placing it on the auxiliary technological platform, the prepared sacrificial anode 16 is mounted, the process hatch is closed 15. The gas exhaust valve 14 is brought into position - open and the fore-vacuum pump 82 pumps the air out of the lock chamber 18. The exhaust valve is brought into the closed position and the foreline pump is turned off.

The gas supply valve 13 is brought into the open position and the lock chamber 18 is filled with nitrogen. The necessary nitrogen pressure is provided by the pressure reducing valve 72, the valve 13 is closed.

In total, three filling cycles are performed - nitrogen evacuation.

The gas supply valve 13 is brought into position - open and fill the lock chamber 18 with argon, the supply valve 13 position - everything is closed.

Download the prepared electrolyte.

Air is removed from the crucible 45 of the electrolyzer through the gas exhaust valve 42 by the fore-vacuum pump 82, the valve 42 is closed, the fore-vacuum pump is turned off.

Through the gas supply valve 41, the crucible 45 of the electrolyzer is filled with nitrogen. The required nitrogen pressure is provided by pressure reducing valve 72.

Nitrogen is pumped out from the crucible 45 of the electrolyzer through the gas exhaust valve 42 by the fore-vacuum pump 82, and the gas exhaust valve 42 is closed.

In total, three filling cycles are performed - nitrogen evacuation.

Through the gas supply valve 41, the electrolyzer crucible 45 is filled with argon, the gas supply valve 41 is closed.

By supplying current to the electrolysis furnace 46, the crucible 45 is preheated to a temperature of 700-800 ° C and refilled with argon, ensuring equal argon pressures in the electrolyte preparation unit and the electrolysis crucible 45.

Through the valve for the release of electrolyte 27 through the pipe 28 through the lock channel 32, the molten electrolyte from the crucible 25 flows into the crucible 45 of the electrolyzer, after which the exhaust valve 27 is closed.

Electrolysis to obtain a powder containing product.

The crucible 45 of the electrolyzer, placed in a resistance furnace 46, is heated to a temperature of 700-850 ° C. The slide gate 31 of the channel 32 is moved to the open position. The anode rod 6 with a sacrificial anode 16 is moved to its lowest position by lowering the traverse 4 along the guide posts 5 using a vertical displacement electric drive 1, which is installed on the upper platform 3. The rotation speed of the anode rod 6 with a sacrificial anode 16, an electric rotation drive 2 is set within 1 up to 90 rpm Using a direct current source 91, current is supplied to the anode 16 and the current collector 44 located on the wall of the crucible 45. After a predetermined time, the anode rod 6 is lifted and transferred to the changeover position. The gateway channel 32 by the gate 31 is transferred to the closed position.

Produce a time delay and open the technological hatch 15.

Extract powder containing product.

Dismantled anode 16 is removed from the anode rod 6 and a scraper device 17 for cleaning the walls of the crucible 45 is installed. The process hatch 15 is closed, air is pumped out of the lock chamber 18 through valve 14, the valve is closed, and the foreline pump 82 is turned off.

Through the gas supply valve 13, the lock chamber 18 is filled with nitrogen, adjusting the pressure with a pressure reducing valve 72, the valve 13 is closed.

In total, three filling cycles are carried out - nitrogen evacuation, then the chamber is filled with argon, valve 13 is closed.

Similarly, using valves 41 and 42 create a gas atmosphere in the crucible 45 of the cell.

The slide gate 31 is moved to the open position. Using the vertical displacement electric drive 1 installed on the upper platform 3, lower the anode rod 6 with the scraper device 17 for cleaning the crucible 45 to the lowermost position using the crosshead 4 and the guide rails 5. The electric drive 2 provides rotation of the anode rod 6 in the lowermost position, the blades open scraper device 17, cleaning the walls of the crucible 45 of the electrolyzer and bringing the electrolysis products to a homogeneous mass.

Then, the exhaust valve 48 is opened and the products of electrolysis are displaced into the discharge crucible 55 using a nitrogen pressure 47. Using the power supply system and control system 92, the anode rod 6 is returned to its highest position. The gate 31 of the lock channel 32 is moved to the closed position, the process hatch 15 is opened.

Powder extraction.

Release valve 48 is in the closed position. The valves supply 51 and exhaust 52 are in the closed position. The cooling system 54 of the crucible 55 is activated, the set time is maintained and the discharge hatch 56 is opened. The cooled electrolysis products (powder containing the product and electrolyte) are unloaded, the hatch 56 is closed.

The advantages of the claimed utility model are to increase the efficiency of the equipment when receiving powders of refractory metals by eliminating stops and regulating the thermal regime of the electrolyzer. The proposed utility model relates to industrial plants and allows to obtain powders of refractory metals of a condenser grade in a continuous mode.

Claims (5)

1. Installation for the electrochemical production of refractory metal powders, including an electrolyzer with a molten electrolyte bath, a cathode, a consumable anode mounted vertically in the center of the electrolyzer, a current supply system to the anode and a cathode containing a power source, a powder-containing product unloading unit, an output system gas, characterized in that it further comprises an electrolyte preparation unit, a lock chamber placed on the supporting frame, on the housing of which guiding racks of the anode group, the anode rod on which the anode or the scraper type device is installed for cleaning the walls of the electrolyzer is provided with a rotation drive, the lock chamber is in communication with the electrolyzer with a lock channel for supplying electrolyte and the passage of the anode rod on which the slide gate is installed, while the electrolyzer is made in the form of a crucible with a sealed lid and a conical bottom and is equipped with a valve for the release of a powder-containing product, the unit for unloading a powder-containing product is equipped with a cooling system deposition and is made in the form of a sealed crucible, the electrolyte preparation unit is made in the form of a crucible, in the bottom of which there is an electrolyte discharge valve, and the electrolyzer and the units for preparing the electrolyte and unloading the powder-containing product to ensure the tightness of the installation and maintain a given atmosphere are connected to each other by heat-insulated pipelines gas supply and exhaust valves. 2. Installation for the electrochemical production of powders of refractory metals according to claim 1, characterized in that the lock chamber, electrolyzer and units for preparing the electrolyte and unloading the powder-containing product are connected to each other by a gas supply and exhaust system. 3. Installation for the electrochemical production of powders of refractory metals according to claim 1, characterized in that as an expendable anode, an ingot, rod or plate from a metal of the obtained powder is used. 4. Installation for the electrochemical production of powders of refractory metals according to claim 1, characterized in that the cathode is the wall of the crucible of the electrolyzer. 5. Installation for the electrochemical production of powders of refractory metals according to claim 1, characterized in that the cathode is made of metal of the obtained powder.