Plasma-carbon production method of rare-earth metals, and device for its implementation. RU patent 2499848.
 Cerium extraction method / 2495147Cerium extraction is performed after preliminary preparation of a catalyser. Crushing of the used catalyser is performed. Crushed catalyser is subject to annealing at the temperature of 650-800°C during 3-6 hours. After annealing the catalyser is cooled down to room temperature and cerium compound is extracted by dilution of ignited catalyser in concentrated hydrochloric acid. Obtained solution with suspended particles of cerium dioxide is heated to boiling, exposed at boiling temperature of 100-110°C during 30-120 minutes and during 3-12 hours at temperature of 0-20°C so that a deposition is obtained. The obtained deposition is separated from mother solution by means of filtration by draining the solution from the deposition surface to a filter with the size of filtering material pores of not more than 2 mcm. Deposition on the filter is washed from iron compound and dried till constant weight of cerium dioxide. |
 Method of extraction of rich components from production solutions for processing of black-shale ores / 2493279Method includes sorption of rich components from production solutions by ion-exchange material counterflow under controlled pH of environment and oxidation-reduction potential Eh. Sorption is performed by ion-exchange materials in stages from production solutions containing uranium, molybdenum, vanadium and rare earth elements. At the first stage uranium and molybdenum are extracted by anion-exchange material sorption. At the second stage vanadium is extracted by anion-exchange material sorption with hydrogen dioxide available at Eh of 750-800 mV, pH of 1.8-2.0 and temperature of 60°C, at that vanadium sorption is performed till complete destruction of hydrogen dioxide and till Eh is below 400 mV. Then barren solutions are transferred to cationite at pH of 2.0-2.5 and Eh of 300-350 mV for extraction of rare earth elements. |
 Processing method of black-shale ores / 2493273Processing method of black-shale ores includes crushing, counterflow two-stage leaching by sulfuric acid solution upon heating, separation of pulps formed after leaching at both stages by filtration. Then valuable soluble materials are washed from deposit at the second stage with strengthened and washing solutions being produced, marketable filtrate is clarified at the first stage for its further processing. Ore is crushed till the size of 0.2 mm, leaching at the first stage is performed by cycling acid solution with vanadium under atmospheric pressure, temperature of 65-95°C during 2-3 hours, till residual content of free sulphuric acid is equal to 5-15 g/l. Leaching at the second stage is performed at sulphuric acid rate of 9-12% from the quantity of initial hard material under pressure of 10-15 atm and temperature of 140-160°C during 2-3 hours. Cake filtered after the first stage is unpulped by part of strengthened solution which content is specified within 35-45% of total quantity. |
 Processing method of black-shale ores with rare metals extracting / 2493272Processing method of black-shale ores with rare metals extracting includes leaching of ore by sulphuric acid solution with dilution of rare metals. Leaching is performed in autoclave by sulphuric acid solution consisting of free and combined sulphuric acid with ratio of H2SO4(free):H2SO4(comb)=2:1, and containing 25-45 g/l of iron sulphate, 70-90 g/l of aluminium sulphate and 0.5 g/l of nitric acid. At that the process is performed under pressure in autoclave equal to 10-15 atm with mixing at temperature of 140-160°C in concentration range of general H2SO4(gen) equal to 350-450 g/l under pulp density S: L=1:0.7-0.9, preferably 1:0.8, under constant oxidation-reduction potential Eh in the system equal to 350-450 mV during 2-3 hours till residual concentration of free H2SO4(free) is within 45-75 g/l. |
 Method of extracting rare-earth metals (rem) from phosphogypsum / 2492255Proposed method comprises REM and phosphorus leeching by sulfuric acid solution to obtain leaching solution and insoluble residue. Said insoluble solution is processed by calcium compound to pH over 5. PEM concentrate is extracted from said solution by crystallisation and fed to REM and phosphorus leaching stage. Prior to leaching phosphogypsum is subjected to flushing with water to obtain flushing solution containing REM and phosphorus. Said insoluble residue is flushed before processing by calcium compound. Obtained flushing solution is processed by calcium compound to produce pulp with pH not over that of REM phosphate precipitation beginning and combied with said flushing solution. REM is sorbed by cation exchangers and separated to desorb REM therefrom to produce desorbent and recovered cation exchanger. Said recovered cation exchanger is sent to REM sorption while desorbent is sent to REM concentrate production stage. Phosphorus and associated impurities are deposited from sorption mother pulp. Obtained pulp is separated in residue to be recovered and water phase to be used as circulating water. |
 Method of extracting rare-earth metals from phosphogypsum / 2491362Method includes leaching of rare-earth metals (REM) from phosphogypsum with 1-5% solution of sulphuric acid, REM sorption from leaching solution with cationite, REM desorption, precipitation of REM concentrate from desorbate, obtaining REM concentrate and mother liquor, which is used for REM desorption. Cationite after desorption is returned at sorption stage. Phosphor and fluorine are precipitated from mother liquor, phosphor -and fluorine-containing sediment are filtered and filtrate is used as return water in leaching. REM leaching and sorption are carried out simultaneously. Obtained pulp is filtered through mesh filter with separation of saturated REM cationite. After that, pulp is filtered with obtaining non-dissoluble residue and mother liquor of sorption. Before desorption cationite is treated with part of desorbate. |
| Method for quantitative determination of cerium in steels and alloys / 2491361 Method includes dissolution of a sample of analysed alloy and separation of cerium from the base of the alloy and macrocomponents. At the same time the base and macrocomponents are separated from cerium by serial deposition and extraction of the alloy base and macrocomponents of the alloy from the solution. Deposition is carried out with sodium diethyldithiocarbamate, extraction - with dithizone in chloroform. After separation of the organic phase, the cerium content is detected in water phase with the spectrometric method. |
| Method of extracting rare-earth metals from phosphogypsum / 2487185 Invention is meant for extracting rare-earth metals from phosphogypsum obtained in production of phosphorus fertiliser during sulphuric acid treatment of apatite. The method of extracting rare-earth metals from phosphogypsum involves converting phosphogypsum, dissolving the converted chalk to obtain an insoluble residue containing rare-earth metals. The obtained insoluble residue containing rare-earth metals is dissolved in nitric acid solution at solid-to-liquid ratio of 1:1.5 to obtain a solution and an insoluble residue. The insoluble residue is then washed with water; the obtained solution is mixed with the washing solution; the mixed solution is neutralised to acidity of 0.5-0.25 N with concentrated aqueous ammonia solution and taken for precipitation of rare-earth metal oxalates. The oxalates are precipitated with saturated oxalic acid solution; the residue is washed with 1.5-2.5% oxalic acid solution at solid-to-liquid ratio of 1:2-3. The oxalates are then dried and calcined until rare-earth metal oxides are obtained. |
| Solid extractant for extraction of scandium and method of its production / 2487184 Solid extractant is proposed (SEX) for extraction of scandium from scandium-containing solutions, containing a styrene divinyl benzene matrix with di-(2-ethyl hexyl)phosphoric acid. At the same time it additionally contains dibenzo-18-crown-6 at the following ratio of components, wt %: di-(2-ethyl hexyl)phosphoric acid 28-30, dibenzo-18-crown-6 28-30, styrene divinyl benzene - balance, besides, the ratio of styrene and divinyl benzene in the matrix is equal to 65÷70:30÷35. There is a method also suggested for production of the above extractant. |
 Method of extracting scandium / 2485049Invention relates to hydrometallurgical processing of mineral material, particularly scandium-containing "tailings" obtained during beneficiation of titanium-magnetite ore by wet magnetic separation. The method of extracting scandium is three-step sulphuric acid leaching of scandium, wherein at the first step, leaching is carried out with recycled solution after extraction of scandium at temperature of 30-50°C and solid to liquid ratio of 1:6-7 for 3-4 hours; the pulp is then divided into a solid phase and a liquid phase; at the second step, a portion of the solution obtained from the first step is returned to the solid phase and sulphuric acid is added to concentration of 340-360 g/l and sodium fluoride is added in amount of 20-25 kg fluorine/t solid; leaching is carried out at temperature of 95-98°C and solid to liquid ratio of 1:2.5-3 for 3-4 hours; further, at the third step, the pulp is diluted in solid to liquid ratio of 1:6.5-7.5; treatment is carried out at temperature of 95-98°C for 3-4 hours. |
| Method of processing kyanite concentrate / 2489503 Method involves mixing a concentrate, a carbonaceous reducing agent and a pore-forming additive in form of ammonium sulphate, pelletising the obtained mixture, firing and holding at maximum temperature with reduction of silicon dioxide to a gaseous monoxide, crushing the obtained sinter, treatment thereof with ammonium bifluoride and calcining the reaction mass to obtain an aluminium-containing product, wherein ammonium sulphate is taken in an amount of 10-20% of the mass of the concentrate; before pelletising, the mixture is milled to obtain particles with size of 50-75 mcm in amount of at least 80%; the mixture is fired at temperature of 1690-1750°C; ammonium bifluoride is taken in amount of 0.4-14% of the mass of the sinter; and the reaction mass is calcined at 700-900°C. Before treatment with ammonium bifluoride, the sinter can be treated with 10-20% hydrochloric acid. The degree of extraction of aluminium oxide from the concentrate is increased by 1.3-9.9%. Content of aluminium oxide in the end product reaches 97.7% with content of silicon oxide impurities of 0.13-1.0%. |
 Method of processing solid or melted substances / 2484152Solid or melted substances are loaded on graphite body heated, at least, partially, inductively. Reducing agents are introduced therein, other than graphite carbon to collect flowing reduced and/or gasified melt. Note here that reducing agents are introduced along with solid or melted loaded particles. Said reducing agents represent natural gas, coal dust, brown coal dust, hydrocarbons, hydrogen, carbon oxide and/or ammonia to be introduced together with steam, oxygen, carbon dioxide and/or halogens or halogen hydrides. |
 Reducing method of metals from oxides / 2476035Reducing method of metals from oxides refers to reducing technologies of metals from non-organic oxides, at which preparation of homogeneous mixture is performed from ultradisperse powders of metal oxide and carbon, supply of prepared mixture under pressure to high-temperature zone in the well, which is formed with plasmatron jet, decomposition of metal oxide with formation of carbon dioxide that is removed through upper tuyeres of the well, and finished product is removed in the form of ultradisperse metal powder through tap holes in lower part of the well. |
| Procedure for depletion of solid copper-zinc slag / 2398031 Invention refers to procedure for depletion of solid copper-zinc slag. The procedure consists in supply of charge containing solid copper-zinc slag and carbonic reducer at weight ratio of slag to solid carbonic reducer 1: (0.06-0.1) into heated furnace. Also charge in the heated furnace is blasted with oxygen containing oxidant by means of upper not-immersed blast; consumption of oxygen-containing oxidant is determined by contents of oxygen in it from condition of 60-110 kg per ton of slag. Further there is produced a rich with copper phase and zinc is transferred into a gas phase. |
 Method of processing of iron-titanium concentrate / 2385962Method includes formation of charge consisting of concentrate and sodium carbonate by means of intergrinding of components and reduction of charge components at presence of taken with excess carbonaceous reducing material at temperature 850-1300°C. Additionally batch material reduction is implemented up to providing of content of metallic iron in the range of particles dimensions 10-300 mcm not less than 80%. Received partly reduced conservative mass, consisting of metalise phase containing main part of iron and vanadium and oxide phase, containing main part of titanium and vanadium, it is grinned up to size not more than 300 mcm. Then it is implemented leaching of vanadium from reaction mass and leaching residue is separated from vanadate solution. After separation residue of leaching is subject to gravitational separation in water flow with separation of metalised and oxide phases. Metalised and oxide phases are separately subject to wet magnetic separation for receiving of metallic iron and titanium oxide concentrate. Additionally wet magnetic separation is implemented in the range of field intensity 20-300 E. |
 Reduction method of metal and oxygen compositions / 2360982At reduction of metal and oxygen composition effect as reducer, herewith at first stage gaseous CO is passed into reaction chamber, containing specified composition of metal and oxygen. In conditions, providing conversion of CO into solid carbon and carbon dioxide, formed solid carbon is introduced into metal and oxygen composition. At the second stage solid carbon, which is introduced into metal and oxygen composition at the first stage, reduces metal and oxygen composition. Additionally at the second stage it is, at least, the first material- promoter, conducive reduction of specified metal and oxygen composition. Additionally the first material- promoter contains the first metal- promoter and/or composition of the first metal- promoter. |
| Method of tin manufacturing from cassiterite concentrate / 2333268 Invention concerns tin metallurgy field and can be used for tin manufacturing while treatment of cassiterite concentrates. Method of tin manufacturing from cassiterite concentrate with content of 35-50% SnO2 includes batch preparation by blending of tin concentrate with coal and flux additive. In the capacity of flux additive it is used sodium carbonate and sodium nitrate. Melting is implemented at temperature 850-1000°C during 2 hours. For mentioned concentrate it is kept up following mass ratio: concentrate : coal : sodium carbonate : sodium nitrate, equal to 1 : (0.2-0.25) : (0.12-0.15) : (0.06-0.08). It allows without concentrate pretreatment to provide tin manufacturing of 98% purity at less in comparison with tradition approach, temperature. |
 Method of reduction of metal oxides / 2317342Charge in form of mixture of oxides and reductant is fed to heated furnace and is mixed in way of temperature rise at passage of gas mixture through charge in way of temperature rise. Size of particles of oxides does not exceed 2-4 mm. Used as reductant are hydrocarbons and/or oxygen derivatives of hydrocarbons and/or their polymers. Reduction process is completed within range of temperatures of forming final product at preset phase state. |
 Method of production of cleaned coal for metallurgical processes and method of production of reduced metal and slag containing oxidized non-ferrous metal with the use of this coal / 2302450Proposed method is based on use of cleaned coal for production of high-quality reduced metal. Coal is first kept in organic solvent simultaneously with heating, thus obtaining cleaned coal suitable for metallurgy which possesses higher thermoplasticity as compared with starting coal. Then, mixture of cleaned coal and starting material is subjected to agglomeration in agglomerator and agglomerate thus obtained is reduced at heating in furnace provided with movable hearth; then, it is molten by further heating, thus obtaining reduced melt which is cooled and hardened in furnace provided with movable hearth, thus obtaining solid material, after which reduced solid material is withdrawn from furnace. Then, slag is removed with the use of screen and reduced metal is extracted. |
| Method of production of cleaned coal for metallurgical processes and method of production of reduced metal and slag containing oxidized non-ferrous metal with the use of this coal / 2302450 Proposed method is based on use of cleaned coal for production of high-quality reduced metal. Coal is first kept in organic solvent simultaneously with heating, thus obtaining cleaned coal suitable for metallurgy which possesses higher thermoplasticity as compared with starting coal. Then, mixture of cleaned coal and starting material is subjected to agglomeration in agglomerator and agglomerate thus obtained is reduced at heating in furnace provided with movable hearth; then, it is molten by further heating, thus obtaining reduced melt which is cooled and hardened in furnace provided with movable hearth, thus obtaining solid material, after which reduced solid material is withdrawn from furnace. Then, slag is removed with the use of screen and reduced metal is extracted. |
| Method of reduction of metal oxides / 2317342 Charge in form of mixture of oxides and reductant is fed to heated furnace and is mixed in way of temperature rise at passage of gas mixture through charge in way of temperature rise. Size of particles of oxides does not exceed 2-4 mm. Used as reductant are hydrocarbons and/or oxygen derivatives of hydrocarbons and/or their polymers. Reduction process is completed within range of temperatures of forming final product at preset phase state. |
FIELD: metallurgy.
SUBSTANCE: method involves carbon thermal reduction of oxide compound of rare-earth metal in vacuum so that powder of rare-earth metal carbide, which is free from residues of oxygen impurity, is obtained. Then, it is cooled down and mixed with high-melting metal powder in the ratio that is sufficient for performance of exchange reactions between rare-earth metal carbide and high-melting metal, and mixture is heated with hot volumetric plasma discharge to the temperature of ≥1800°C. With that, evaporating rare-earth metal is collected on condensers and hard-alloy carbide of high-melting metal is obtained. The device includes a vacuum system, cathode and anode assemblies arranged concentrically in the chamber, and a steam line and a condenser-cooler, which are coaxial to them. With that, an internal electrode represents an anode of high-current vacuum plasma discharge burning in an annular discharge cavity formed with coaxial cylindrical electrodes. The anode is made from high-melting electrically conducting material in the form of a crucible having a capacity, and a thin-wall cathode enveloping it, outside which there located is a starting resistance heater, is also made from high-melting electrically conducting material, for example tungsten, tantalum or graphite.
EFFECT: improving extraction of rare-earth metal.
5 cl, 1 dwg
The invention relates to metallurgy, in particular the production of rare earth metals III group of the periodic system of elements, including scandium (Sc)yttrium (Y), lanthanum, cerium (CE), praseodymium (Pr), neodymium (Nd), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (But)erbium (Er), lutetium (Lu). This group of rare earth elements share a common chemical analogy all twelve of metals, high chemical activity and close their temperature of boiling (T k >2500 C).
The current level of technology a method of obtaining considered rare-earth metals from oxides compounds (see metallurgy of rare metals. Zelikman A.N., Crane UNIT, V. Samsonov / M: «metallurgy», 1978. 560 S. .529-540), consisting of the following operations:
1. oxides gaseous fluorine, chlorine or solutions hydrofluoric acid and hydrochloric acids. Filtration and drying received halide salts.
2. A mixture of dry powders halide salts with shavings metals-reducing agents, e.g., Mg, Na, or Sa.
3. Heating the resulting charge to temperatures of the beginning of active recovery halide salts (T heating & GE 1000 OC) and extract the reactive mass at this temperature, without access of air to the cessation of all reactions.
4. Cooling reacted mass and separation of the reduced metal from slag.
5. Double remelting of recovered metals under vacuum for cleaning of toxins and impurities metals-reducing agents.
6. Processing of slags for the separation of rare earth metals.
The disadvantages of this method, the elimination of which is our offered invention are:
1. The low yield of the products, as processes up to 20% of the product remains in the slag.
2. Production hazard and pollution fluorine, chlorine or acids at oxides.
3. High production costs, so reducing agents receive by the electrolysis of fused fluorides and chlorides; the environment is polluted with fluorine or chlorine; the need for dual remelting for reception of pure metals.
4. Presence in metals-reducing agents, albeit minor, but still unavoidable impurities that when restoring pass into obtained rare-earth metals.
The task, the solution of which is sent to the claimed technical solution is to create the device and the development of a method for producing pure rare-earth metals by restore their oxide compounds with obtaining intermediate product in the form of rare earth metals carbides, not containing residues failed-to-retrieve oxides.
This task is solved by the fact that the implementation of the proposed method for rare earth metals Sc, Y, La, CE, Pr, Nd, Gd, Tb, Dy, But, Er, Lu, boiling at a temperature of more than 2500°by restore their oxide compounds with the receipt of the metal carbides, not containing oxygen; subsequently, for distillation allocation recovered rare-earth metals from carbides and receiving of these metals in their pure form powders carbides after cooling mixed with powders of refractory metals in the ratio of required and sufficient for the occurrence of metabolic reactions between carbides of rare-earth metals and refractory metals, and heated to & GE 1800 degrees C for carrying out the exchange reactions with the receipt of carbides of refractory metals and evaporation the obtained pure rare-earth metals with the subsequent condensation of vapor on the capacitors; the result is one operation receive two commodity product: pure rare-earth metal and carbide refractory metal, and as a refractory metals for the implementation of metabolic reactions using powders of metals, for example, powders of metal tungsten (W); the process is conducted in the device containing a vacuum chamber with exterior surfaces, vacuum system, cathode and anode nodes, concentrically placed in the chamber, coaxial with them both the steam and the condenser-refrigerator, used to collect evaporated metals; according to the invention, internal electrode is the anode of a high-current vacuum plasma discharge burning in the ring bit cavity formed by coaxial cylindrical electrodes and anode made of refractory conductive material in the form of a Cup (crucible), which is the entire process of uploading and the surrounding thin cathode is made also of conductive material, refractory, for example, tungsten, tantalum, or graphite, to run electric furnaces around the cathode installed heaters resistance.
The technical result, at the expense of the totality of features of the claimed method and the device is to increase the recovery of the main product of the source materials, the creation of non-waste production with minimal environmental pollution, the production of pure and superpure metals, cost reduction for rare-earth metals.
The technical result is achieved by the fact that pure rare-earth metals produced by restore their oxide compounds with obtaining intermediate product in the form of rare earth metals carbides, not containing residues failed-to-retrieve oxides, semi-finished product is mixed with powders of refractory metals to ensure exchange reaction:
M e C 2 + 2 W = M e ^ a b + 2 W C , ( 1 )after that rare-earth metal evaporated is adjacent to the line in the settings realm of the capacitor and condenses, and refractory metal carbide (for example, W) in powdered form remains in the crucible electric furnace. Extraction of valuable rare metals increases with 80% of the known techniques to 95% and more using the proposed method for products. Reduced technological cycle for the production of metals, are excluded procedures of processing of slags for the extraction of rare earth metals, as well as the use of toxic materials.
The technical result is achieved by the fact that the claimed device for realization of this method has the cathode-anode site that provides heating of crucible-the anode at the expense of high-current vacuum plasma discharge, burning in a ring cavity formed by cylindrical electrodes, internal electrode is made in the form of a Cup (crucible)that holds recovered the initial mixture: Month 2 +W; the mixture is heated to a temperature T & GE 1800 degrees C and is substitution reaction.
The proposed plasma-carbon way to get listed above metals consists of the following operations:
1. Mixing powdered oxides of rare earth metals from component, for example, with acetylene carbon black. The amount of carbon-containing component is taken by calculation from stoichiometry for holding recovery of metal oxide and binding reduced metal in the most durable carbide, for example, neodymium, i.e. double carbide neodymium (NdC 2 ). The ratio of initial components for PTA-process of obtaining carbon metal neodymium is calculated by the reaction:
N d 2 O 3 + 7 C = 2 N d C 2 + 3 C O ^ a b . ( 2 )Eleven of the above metals are chemical analogues neodymium included in the III group of the periodic system of elements. The above for neodymium reaction and the formula will be identical to all the others - only to the inevitable replacement of chemical designations themselves metals and related nuclear constants.
2. Heating of the charge, without access of air to a temperature of more than 2,000 OC with the pumping released during the restoration of carbon oxides and receipt of powders of pure carbides. The binding of metals recovered carbon is the necessary condition for the fulfillment of which, along with high temperature heat and vacuum applied, to ensure the success of the new technical solutions for rare-earth metals, i.e. receiving ultimately substances not containing oxygen, eliminating environmentally harmful operations recovery. A positive result is ensured by two circumstances the physical and chemical nature. First, any excess of the reagent (in this case, carbon, see the reaction (2)) promotes the course of processes in the direction of the flow of this reagent and selection. But this is a purely quantitative pattern «mass action», are amplified if the excess carbon binds scrap metal in a strong connection, for example, NdC 2 . In this case, the generation of solid carbide by the reactions of the type (2) provides the ultimate success, because only in this case it is possible to hold recoverable metals in the condensed phase and prevent evaporation temperatures required for the flow of recovery, freeing system from oxygen.
3. Cooling of the obtained powders carbides of rare-earth metals and their mixing with powders pure refractory metals in the ratio, ensuring at heating to the temperature T & GE 1800 degrees C flow exchange reaction on the example of neodymium by type of reaction (I):
N d C 2 + 2 W = N d ^ a b + 2 W C . ( 3 )Exchange reaction (3) written using refractory metal-Wolfram, because the obtained products (condensate Nd and WC) are solid products, which are widely used in industry: neodymium as a basis of new magnetic materials (Nd-F-B), tungsten carbide as a base alloys are widely used in mechanical processing of metals. Getting them together for one technological operation is an important sign of the significant differences in determining the benefits of the new solution.
The technical nature of the proposed technical solution is illustrated by a drawing, which shows the device to realize the proposed plasma-carbon way for rare-earth metals.
Vacuum furnace with surround plasma discharge contains capacitor 1, which is formed stackable condensate 2, vacuum chamber 3, a steam line 4, screen heat insulation 5, cathode 6, crucible-anode 7, bit 8 hollow 10, 11, insulating covering 12, 13 tinsel leads, insulator seal 14, starting resistance heaters 15. Electric furnace is equipped with a standard vacuum system, providing a working pressure in the vacuum chamber prior to 1·10 -3 mm Hg
The crucible-anode 7 is made from graphite, tantalum and tungsten and mounted on the axis of the kiln. In the crucible is loaded loose or tablets charge 9. Coaxially with the crucible-anode with a gap of 10-15 mm is installed cathode 6, made of graphite, tantalum and tungsten. Outside the cathode on the perimeter there are graphite rod heaters provide heating the cathode to a temperature of 1900 degrees, if that ignited surround plasma discharge between the cathode and the crucible-anode. After discharge ignition resistance heaters are switched off. Coaxial this system, outside resistance heaters are installed reflective screens made of graphite, tantalum, tungsten and heat-resistant steel. Capacitor electric furnace 7, installed coaxially with the crucible-anode 7, cooled by water or air, providing the condensation surface temperature below the condensation of vapor of rare earth metals.
Direct experiments it was found that the developed system of heating has high energy efficiency and in the crucible-the anode, where is the charge, are achieved and maintained hot surround plasma discharge temperature required for the implementation of the reaction (1) or (3). A bit cavity between crucible-the anode and the cathode is served argon in the atmosphere on fire surround ring vacuum plasma discharge when powered electric circuit DC voltage up to 60, working current of up to 7000 A). When this mixture is located in the crucible-the anode, is heated and it runs reaction (3) with the release of the product (rare earth metal) in the vapour phase. A pair of metal on adjacent to the line 4 enter the condenser cooling surface, condenses in the solid phase and form the obtained product. In the crucible-the anode in the solid phase remains the second product of technology - tungsten carbide.
The proposed method and device for its implementation have the following advantages:
1. A new method to produce rare-earth metals is wasteless technology, eliminating the emissions of harmful components. Carbon monoxide emitted when the translation of oxide metals in carbide (see the reaction (2)), easy to carbon dioxide output from the furnaces.
2. Direct access and extraction of rare earth metals from oxides increases with 80% of the known techniques to 95% and more of offered.
3. Reduces the number of technological repartitions and eliminated operation with the processing of slags for the extraction of rare earth metals.
4. By paired and the joint production of the two commodities, condensates of rare-earth metals and metal carbides of refractory metals significantly reduced consumption of energy and other operating costs characteristic for multi-stage methods for rare-earth metals.
1. The method of obtaining the rare-earth metal boiling at a temperature of & GE 2500°C from range: Sc, Y, La, CE, Pr, Nd, Gd, Tb, Dy, Ho, Er, Lu, including restore its oxide compounds in vacuum with obtaining carbide powder rare earth metal, free of residual impurities oxygen, cooling carbide powder, blending it with refractory metal powder in a proportion, a necessary and sufficient for the flow of exchange reactions between the carbide rare-earth metal and refractory metal, and heating the mixture of hot surround plasma discharge to a temperature of & GE 1800 degrees C with carbon capture evaporating rare earth metal on the capacitors and obtaining carbide carbide refractory metal.
2. The method according to claim 1, characterized in that as refractory metal use powders of metal tungsten.
3. Device for obtaining rare earth metal boiling at a temperature of & GE 2500 degrees centigrade) from a number: Sc, Y, La, CE, Pr, Nd, Gd, Tb, Dy, But, Er, Lu, containing a vacuum chamber with water-cooled outer walls, the vacuum system, cylindrical electrodes, concentrically placed in the chamber, coaxial with them both the steam and the condenser-refrigerator, used for the collection of REM, the internal electrode, which is the anode of a high-current vacuum plasma discharge, is located in the ring bit cavity formed by coaxial cylindrical electrodes made of refractory in a conductive material as a crucible having sufficient capacity to house the charge of carbide of the rare-earth metal and powder refractory metal and the surrounding thin electrode, which is the cathode is made also with refractory electrically conductive material, such as tungsten, tantalum, or graphite.
4. The device according to claim 3, wherein the outside of the cathode is starting the heater resistance.