Tantalum-base alloy refining method. RU patent 2499065.

FIELD: metallurgy.

SUBSTANCE: tantalum-base alloy refining method involves vacuum electronic beam remelting in a horizontal crystalliser of the charge placed into it so that fumes of its metallic impurities are released on the surface that condenses them, and fumes of gas-containing impurities and production of a tantalum ingot by movement of an electronic beam from the beginning to the end of the crystalliser throughout the charge surface with its further switch-off. The charge contains metallic impurities of high-melting metals with the melting temperature close to that of tantalum. Vacuum electronic beam remelting is performed in two stages. The tantalum ingot produced at the first stage and containing impurities of high-melting metals is subject to electrochemical processing with release of tantalum-containing cathode residue that is subject to the second remelting stage so that an ingot of conditioned tantalum and fumes containing tantalum, which are returned to electrochemical processing, are obtained. From the first stage of the remelting process to the second one the specific power of an electronic beam is increased from 0.024-0.035 to 0.040-0.045 kW/mm², and beam travel speed is decreased from 40-60 to 4-6 mm/min.

EFFECT: improving degree of extraction and purity of tantalum.

6 cl, 1 dwg, 2 tbl, 2 ex

The invention relates to metallurgy, in particular the production of refractory metals and alloys and may be used in the refining of alloys on the basis of tantalum.

There are ways of refining tantalum:

- refining, carried out at high temperature in the melt with the operations of sublimation and condensation deleted factions, such as electron beam melting (Pilipenko N.N., « by the method of electron beam melting», Zh. «Issues of atomic science and technology», 2002, №1, p.37-39);

- electrolytic refining, representing a electrolysis, such as molten salt, in which separation of metals may be due to differences of electrochemical potentials of impurities and base metal (A. V. Elyutin, «Electrolytic refining of niobium and tantalum in chloride-fluoride melts», part 2, Zh. «Non-ferrous metals», 1996, №3, p.48-54).

Electron beam melting is the main rafinirovochny operation, providing production of ingots of high-purity tantalum of tantalum charge, including waste Metalworking in the form of scrap metal after rolling, stamping, die cutting, and tantalum powder.

A method of obtaining tantalum ingot (RF patent №2204618, IPC 22 9/22, publ. 20.05.2003,), in which the charge in the form of pieces of tantalum plate or in the form of waste his rolling production (, sheets, foils, rods) placed in metal container. Collected in this way reduce the workpiece with a melting point of the container below the melting temperature of tantalum charge serves the area of influence of the electron beam. There takes place accelerated melting of the container before the zone of remelting of metal in the vertical crystallizer, and tantalum the mixture is poured on the bottom melting capacity.

However, a well-known method is suitable only for the recovery of tantalum ingot of restricted kind of blend of the material in the container that contains a fixed number of impurities with melting temperature close to the melting temperature of tantalum, niobium, molybdenum, tungsten.

In addition, upon receipt of an ingot observed abundantly emitted by electron-beam melting sublimates tantalum and impurities refractory metals that are lost, that would not achieve the required degree of extraction of base metal.

Also known method of obtaining high-purity tantalum (RF patent №2233899, IPC 22 34/24, publ. 10.08.2004,). The method involves removing the metal tantalum in the form of powder containing tantalum ore with low content of impurities, which have a melting temperature close to the melting temperature of tantalum: niobium, molybdenum, tungsten. Tantalum powder is melted by electron-beam drip of melting in vertical crystallizer in a vacuum to create a cast ingot of the big diameter. This basis large surface melt on the border of metal vacuum provides the necessary speed and degree of purification from impurities more than tantalum, fusible metals.

However, impurities of refractory metals with unlimited solubility in tantalum: niobium, molybdenum, tungsten, are present in high-purity tantalum and refining them regimes, known method is not possible. In this regard, the degree of extraction is defined for high-purity tantalum, only purified from impurities, more than tantalum, fusible metals.

Also known method of electron-beam melting metals, mainly tantalum (RF patent №2027783, IPC 22 9/22, publ. 27.01.1995,), including electron-beam remelting in vertical crystallizer. The method includes guidance bath of liquid metal in a mould with its widened conical part and with its diameter, a large ingot diameter. This eliminates the formation of defects on the surface of ingot: cracks, nicks, overlaps, due to the impossibility of the penetration of a liquid metal in the gap between the strand and mould, which is formed by the natural shrinkage of the ingot. Thus, eliminating the need for Stripping the surface of ingot and the degree of extraction of tantalum meets the requirements.

Disadvantages of this method are manifested in the case of use in remelting of tantalum procurement, which contains a large number of low-melting and refractory impurities. When this occurs, the education edge of the mirror of the melt pool solidified his pieces, which at a certain ratio of the size of the diameter of the mirror of the melt pool, ingot diameter are tightened in his body. This leads to insufficient purity of the metal ingot and not high degree of extraction of tantalum when remelting.

Also known method of electron-beam melting of metals and alloys, for example on the basis of tantalum-tungsten (RF patent №2238991, IPC 22 9/22, publ. 27.10.2004,). The method includes the portion accumulation of melt in the upper widened part of a vertical crystallizer. Strictly certain aspect ratio of the diameter of the mirror of the melt pool at the top of the mould and ingot diameter, formed in the lower part, allows to get high-quality ingot with a surface that does not contain defects, and thus to ensure a sufficiently high purity of tantalum.

However, the loss of tantalum in , necessarily related , does not allow to get the most possible degree of extraction of tantalum.

Also known method of refining of refractory metals and alloys, including tantalum, multiple electron beam remelting (RF patent №2204617, IPC 22 9/22, publ. 20.05.2003,). The method includes electro-beam remelting, with pre-formed by melting of the charge of preparation by rotating it around the longitudinal axis and alloying in vertical crystallizer. Melt the lateral surface allows you to clear the metal from mixtures, which are fixed to the lateral surface of ingot at remelting of strongly contaminated metal because of their deposition on the walls of the vertical crystallizer and pulling together with the ingot.

Multiple electron-beam remelting contributes to increasing the purity of tantalum, but the degree of extraction of tantalum is still insufficient because of the departure of tantalum in the fumes from molten metal bath caused by repeated unit direction of an ingot in the vertical mold.

Also known method of refining metal materials, such as refractory metals, including alloys based on tantalum (US patent # 5222547, IPC 22 9/22, publ. 29.06.1993,). The method includes electro-beam remelting by melting piece of metal in the intermediate tank one electron beam melting metal throughout the volume of the other electron beam and spill melt in vertical crystallizer with the influence of the third electron beam. impurities collect on their design conditions for condensing surface of the screen, horizontally placed over the melt in an intermediate tank. Through the vibration of the screen desired alloying components in the form of powder peel off from it and fall back into the melt.

The disadvantage of this method is to obtain refined alloy with a low degree of extraction of impurities, as together with the desired alloying components prevents removal of the melt and unwanted impurities.

Also known method of refining refractory metals, that is, including tungsten and its alloys (RF patent №2401872, IPC 22 9/22, publ. 20.10.2010,).

The method includes electro-beam remelting by melting of charge in an intermediate tank with subsequent discharge of the melt in the vertical crystallizer. Sublimates the base metal and the impurities are allocated for their design conditions for condensing surface, screening elements removable lining, and together with them removed from the smelting space. This eliminates the ingress of evaporated from a bath of molten metal impurities back into the melt on the walls and under the furnace. In addition, the condensation of the fumes of the base metal and impurities regulate by setting the desired temperature items or surfaces, which are sublimates. This allows the separation of the fields condensation fumes before disposal.

No refund fume base metal on remelting with the next portion of the charge leads to insufficient high degree of extraction of refractory metal.

Also known method of refining superalloys, containing tantalum, as one of the elements in the alloy of his extra part together with refractory metals, close to temperature melting point: in, tungsten, molybdenum (RF patent №2313589, IPC 22 7/00, publ. 10.08.2004,). The method includes electrochemical decomposition in which the electrolyte used inorganic acids and carry out separation of main and auxiliary component parts of the alloy. However, in the known method cannot obtain selective extraction of tantalum and separate it from the other impurities refractory metals.

Super alloys of this kind cannot be divided by the electrolysis of aqueous solution, as proceeding from the nature of tantalum - enhanced ability to oxidation, after a short time, electrolysis on the surface of metal formed surface passivating layer that leads to the cessation of DC electrolysis.

In addition, a technological scheme of the method consist of tens of interconnected transactions with numerous turns solutions and intermediates. The formation of various tantalum compounds and their interaction with solutions reduces the degree of extraction.

Known methods of refining alloys based on separately used by various physico-chemical principles do not provide the required degree of extraction of tantalum.

The closest analogue, for the prototype, is the method of refining alloys on the basis of refractory metal tantalum, (A. V. Elyutin, «Installation for electron-beam melting of refractory metals», http://rvs.itsoft.ru/article/sart.html).

The method includes vacuum electron-beam remelting in a horizontal copper water-cooled mould placed in charge him with obtaining a flat ingot. Thus, remelting lead by moving the electron beam from the beginning to the end of the mould along the entire surface of the mixture. This is done by scanning the charge electron beam within the width of the baths of the mould with the relative displacement of the beam in the longitudinal direction of the mould and then disconnecting.

In addition, the method is carried out with the release of fumes gassy impurities, as well as fume metallic impurities charge at the design conditions for condensing of their surface - water-cooled screen pipe, removable metal screens, closing the side walls, ceiling and door from the inner side of the melting chamber.

The disadvantages of this method is the low degree of extraction of tantalum. The degree of extraction of tantalum is limited by the inability of the selective effect in electron-ray remelting known method on different types of impurities if their presence in the alloy: refractory metals with melting temperature close to the melting temperature of tantalum and usually available in the alloy impurities, more than tantalum, fusible metals and gas-bearing admixtures. All these impurities are in the alloy based on tantalum together. Impurities of refractory metals cannot be separated from tantalum at remelting due to the proximity of their melting temperature. Impurities, more than tantalum, fusible metals and tantalum in the form of fume at remelting stand out for their design conditions for condensing surface in an associated form and cannot be selective separation.

Moreover, the regimes of electron-beam melting is not specified that it is not possible to achieve a high degree of extraction of tantalum of tantalum alloy containing refractory metals with close to melting point.

The task to be solved by the claimed invention is to increase the degree of extraction and purity of tantalum.

The task is achieved by the technical result, which can be obtained by carrying out the invention: the creation of conditions for the separation of tantalum from the impurities of refractory metals with close to melting due to the combination of effects on the alloy based on various physical and chemical principles.

The task is achieved by the fact that in the process of refining alloys on the basis of tantalum, including vacuum electron-beam remelting in a horizontal mould placed him in charge emitting fumes its metallic impurities on their design conditions for condensing surface and fume gas-bearing admixtures, as well as obtaining tantalum ingot by moving the electron beam from the beginning to the end of the mould along the entire surface of the charge with its subsequent disconnection, according to the invention, the mixture contains metal impurities of refractory metals with close to melting temperature, and electron-beam remelting lead in two stages, with the released at the first stage of electron-beam melting sublimates tantalum processed and returned for the remelting and fumes gassy and more than tantalum, fusible metal impurities are removed, in addition, received at the first stage of electron-beam remelting ingot tantalum with admixtures of refractory metals, subjected to electrochemical processing emitting cathodic sludge and related products with admixtures of refractory metals, which is removed and the cathode sediment subjected to the second stage of electron-beam melting, producing bullion standard tantalum containing tantalum fumes that return on electrochemical processing, thus, from the first stage of electron-beam melting to the second specific power electron beam increases with 0,024-0,035 kW/mm 2 to 0.040-0.045 kW/mm 2 , and speed of movement of the electron beam reduced from 40-60 mm/min up to 4-6 mm/min, in addition, during the first and second stages of electron-beam melting create a vacuum 10 -3 -10 -4 mm Hg and 10 -4 -10 -5 mm Hg, accordingly, and in the beginning of the second stage of electron-beam melting electronic beam survive at the beginning of the mould 400-500 C, and electrochemical processing is performed at the following conditions: in the electrolyte, consisting of 50-60% of mass sodium chloride, 15-35% of mass fluoride sodium, 15-25% of mass potassium, when its temperature 880-940°C, the cathode and anode current density of 0.7-0.9 A/cm 2 and 0.4-0.5 A/cm2 , respectively.

In addition, the charge may contain impurities of refractory metals with close to melting point: niobium, tungsten, rhenium, molybdenum, zirconium.

In addition, at the end of the first and second stages remelting after disabling the electron beam melt cooling not less than 0.5 hours.

In addition, sublimates surface cooling to 14-15°N

Also released on the first stage remelting sublimates tantalum can to double hydrometallurgical processing of known ways of obtaining insoluble residue.

In electron-ray remelting of the proposed method in the process of melting into liquid zone go to accumulate and then move into fumes at the first stage of melting impurities, more than tantalum, fusible metals, gas admixtures, as well as tantalum. It should be noted that the specific power of the electron beam 0,024-0,035 kW/mm 2 , which creates the required temperature for the melting of charge, and the presence of design conditions for condensing metal fumes surface conditions are created for the receipt of fumes in form. It plays a big role for further processing fume tantalum, for example by means of hydrometallurgy, and return them to the start of the process at the first stage of remelting with a new portion of the charge. This allows a higher degree of extraction of tantalum.

Remove fumes, more than tantalum, fusible metals and fume gas-bearing admixtures creates conditions for high-quality subsequent electrochemical processing exempted from such impurities ingot of the first stage of melting, containing only tantalum and impurities refractory metals, close to the melting point. This allows for electrochemical processing ingot of the first stage of melting, given the limited number of electrode potentials of refractory metals, such as niobium, tungsten, rhenium, molybdenum, zirconium.

Ingot subjected to electrochemical processing in chloride-fluoride melt. Electrochemical potentials of a number of refractory metals, such as molybdenum, tungsten and rhenium, in a number of electrode potentials have the most positive value, and therefore they do not disappear, but become anode balance. Such impurities, such as niobium and zirconium, according to the electrode potentials, first of all dissolved in molten salt. These products electrochemical processing is removed, thereby improving the cleanliness and the degree of extraction of tantalum.

Tantalum is also dissolved in molten salt at a speed greater than that of other refractory metals, such as niobium and zirconium, due to the fact that its concentration in the ingot of the first stage of melting much higher. And at the cathode from the melt of salts tantalum is deposited primarily in connection with the fact that his electrode potential more than any other refractory metals, such as niobium and zirconium.

So in the process of electrochemical refining there is a clearing of refractory compared with tantalum impurities: for example, tungsten, molybdenum, rhenium, which remain in the anode balance and electronegative impurity: for example, niobium and zirconium, which accumulate in the electrolyte. Tantalum together with close to him on the electrochemical properties of refractory metal niobium, is deposited on the cathode. For this separation, tantalum from the admixture of metals with close to him melting, choose certain conditions: electrolyte, consisting of 50-60% of mass sodium chloride, 15-35% of mass fluoric sodium, 15-25% of mass potassium at 880-940°, cathode and anode current density of 0.7-0.9 A/cm 2 and 0.4-0.5 A/cm2 , respectively. Compliance with such conditions can increase the degree of extraction and purity of tantalum.

The second stage of electron-beam melting subjected to the cathode sediment, not containing impurities, more than tantalum, fusible metals and most of refractory metals. In connection with this excludes their evaporation together with tantalum and, consequently, its pollution, and hence increased the degree of extraction of tantalum.

Increased to 0.040-0.045 kW/mm 2 power density of the electron beam and slower moving with a speed of 4-6 mm/min, provide the fusion of charge in volume concentration of the increased amount of refractory metals. In addition, an exposure of the beam at the beginning of the mould during 400-500 before moving allows you to create a bath of molten metal are necessary and sufficient for the evaporation of her impurity of refractory metals, and thereby contribute to clearing them of tantalum.

Vacuum creation in the specified ranges: 10 -3 -10 -4 mm/Hg at the first stage remelting and 10 -4 -10 -5 mm/Hg at the second stage remelting allows removed more volatile gaseous and , more than tantalum, low-melting metals at the first stage remelting and less volatile refractory metals at its second stage, which facilitates cleaning them tantalum and a higher degree of extraction.

At the first stage of electron-beam melting with specific power beam claimed in the range and speed of its movement less than 40 mm/min, the charge is not able , while at the speed of motion of the beam of more than 60 mm/min, such conditions are heating of the charge under which tantalum largely goes into the melt and the degree of extraction decreases.

With specific capacity of the electron beam less 0,240 kW/mm 2 not charge is melted, and with a larger value for this parameter is very active gas emissions and tantalum flies away from the melt in the form of drops, which leads to its losses and lower degree of extraction. Created at the first stage vacuum remelting provides volatilization fumes, more than tantalum, fusible metals and fume gassy inclusions. Lower vacuum than 10 -3 mm Hg, fumes will not be removed from the melt and higher than 10 -4 mm Hg vacuum leads to loss of tantalum.

At the second stage of electron-beam melting power density of the electron beam increases to 0.040-0.045 kW/mm 2 , which allows the heat in the conditions providing for the separation of similar by their properties, mutually soluble and hardly separable tantalum and, for example, niobium. Thus, the range of values of parameters is quite narrow, the same as the interval of speed of movement of the electron beam, providing the penetration of the total volume of the mixture.

Vacuum lower than 10 -4 mm Hg sublimates tantalum will not be deleted.

Vacuum higher than 10 -5 mm Hg tantalum will actively evaporate together with admixtures of other refractory metals, resulting in significant losses.

When conducting electrochemical processing were selected parameters, ensuring the required separation of tantalum with and impurities.

Reducing the concentration of sodium fluoride less than 15 wt.% results in smaller particles tantalum, deposited on the cathode, the seizure of the electrolyte and the increase in the concentration of impurities refractory metals, such as niobium and zirconium in beset by real cathode tantalum.

The increase in the concentration of sodium fluoride more than 35% of mass increases the melting temperature of the electrolyte and the viscosity of the melt, which increases the concentration of impurities in each draught of tantalum.

Decrease in the concentration of potassium below 15 wt.% shifts the cathode potential of tantalum in the negative region, the potential allocation of refractory metal impurities, such as niobium, becomes close to the potential allocation of tantalum. Cathode product - tantalum, polluted niobium.

The increase in the concentration more than 25% of mass significantly increases the viscosity of the electrolyte and worsens the purity allocated to the cathode of tantalum.

Lowering the temperature of the electrolyte below 880°increases the viscosity of the electrolyte and the electrolysis process to become unstable, and the purity of the emitted from the cathode tantalum worsens.

The increase in the temperature of the electrolyte above 940°leads to a significant electrolyte evaporation, which reduces the direct retrieval of tantalum in the finished product.

Increase of cathodic current density higher than 0.9 And/cm2 leads to increased concentrations of electronegative impurity, in particular niobium, cathode sediment and ultimately to the deterioration of the purity of the final product - tantalum.

Reduction of cathode current density below 0.7 A/cm 2 leads to the formation on the cathode small particles of tantalum, that are contaminated metal admixtures, concentrated in the electrolyte, for example, niobium and zirconium.

Increasing the anode current density more than 0.5 A/cm2 leads to the dissolution of towards impurities, for example, tungsten, rhenium, molybdenum, and their deposition on the cathode, thereby polluting the final product - tantalum. Reduction of anode current density of less than 0.4 A/cm2 leads to incomplete dissolution of tantalum on the anode and decrease the degree of its extraction in the final product.

Thus, a gradual increase of the content of tantalum at declared sequence of operations that implement the various principles impact on alloy, can get tantalum ingot, which meets requirements of the commodity. The declared modes of operations are necessary and sufficient for the implementation of the objectives of the invention.

All the signs are different from the signs of the closest analogue, and together with the General data of the objects characteristics, to provide the technical result, therefore, the claimed invention is new.

The proposed invention meets the inventive step requirement. Considering the totality of its essential features, it can be noted that they are obvious from the prior art. As distinctive signs are quantitative characteristics of the invention, the signs that cannot be addressed in isolation from the sign to which they relate and in isolation from the whole object. Given this, it should be noted that among the objects of the same purpose is the well-known technology with the same set of essential features not found. Regularities in a certain sequence of operations of refining alloys on the basis of tantalum is not revealed.

The operation method, their sequence in combination with a special material, which directed the operation, ways, modes of operations provide interrelation and mutual influence of the characteristics of the method by which achieves a new technical result.

Take the feedstock - charge (1) weighing 5000 alloy based on tantalum containing impurities of refractory metals with close to melting point: niobium, tungsten, rhenium, molybdenum, and zirconium. In addition, the charge related contained impurities, more than tantalum, fusible metals: iron, titanium, Nickel, chromium, aluminum, cobalt, barium and mixtures containing gases: carbon, nitrogen, oxygen, hydrogen.

The charge for refining waste served secondary alloy based on tantalum scrap products, scrap tantalum strip.

The charge is placed in horizontal mold, was subjected to vacuum electron-beam .

For remelting used vacuum installation for electron-beam melting with a copper water-cooled mould «boat», which melted charge (1).

Electron-beam remelting carried out in two stages. At the first stage remelting (2) exhibited an electron beam with specific power 0.03 kW/mm 2 and the size of the focal spot 70 mm at the beginning of the mould and moved it to the end of the mould with a speed of 50 mm/min, simultaneously scanning width mould, i.e. moved it all over the surface of the mixture.

This stage remelting conducted in a vacuum 10 -4 mm Hg, and at the end of the operation the electronic beam switched off after the melt is cooled 0.5 hours to remove from it the most possible amount of impurities.

Sublimates (2.1) gassy impurities this stage remelting removed. Sublimates (2.2) metallic impurities, more fusible than tantalum, were on their design conditions for condensing surface, which is cooled to + 14 C. Then these fumes removed from the surface by means of hydrometallurgy (3, 4) serial release of containing tantalum residues (3.1, 4.1, and the receipt of solutions of (3.2, 4.2), containing impurities of more than tantalum, fusible metals. Spent two consecutive hydrometallurgical processing (3, 4) with known techniques, on the first of them (3) - using hydrochloric acid, on the second (4) - sulfuric acid and sodium fluoride, and received insoluble residue tantalum (4.1).

Such a balance contained niobium, traces of impurities, more than tantalum, fusible metals and gas-bearing admixtures, so it returned the first stage of remelting with the next portion of the charge. Solutions of (4.2) hydrometallurgical treatment containing more than tantalum, low-melting metals were removed.

Obtained in the result of the first phase remelting ingot tantalum (2.3) with admixtures of refractory metals, traces of impurities more than tantalum, fusible metals and gas-bearing admixtures, subjected to electrochemical processing (5) the electrolyte containing 55% of mass sodium chloride, 25 wt.% fluoric sodium, 20 wt.% potassium at electrolyte 900 OC and to the cathode and the anode current density 0.8 A/cm 2 and 0.45 A/cm 2 , respectively.

Received at the electrochemical processing of related products with admixtures of refractory metals: anode balance (5.1) with molybdenum, tungsten and in, and the melt of salts (5.2) with niobium and zirconium, removed.

Cathodic sludge tantalum (5.3) with admixture of niobium and traces of gassy impurities subjected to the second stage of electron-beam melting (6).

Exhibited an electron beam with specific power 0.04 kW/mm 2 and the size of the focal spot, equal to the width of the mould, and moved it from the beginning to the end of the mould with the speed of 5 mm/min, that is, on the whole surface of the charge of the second stage of melting. At the end of the mould electronic beam switched off.

The second stage of remelting conducted in a vacuum 10 -5 mm Hg After disabling the electron beam melt is cooled 0.5 h for complete removal of the melt fume tantalum (6.1) with traces of niobium, which stood out on their design conditions for condensing surface, cooled to + 14 C.

Then fumes were sweeping the surface and returned to electrochemical processing (5) in the specified chloride-fluoride melts with the following strand of the first stage of remelting of a new cycle of refining.

Then fumes were sweeping the surface and returned to electrochemical processing (5) in the specified chloride-fluoride melts with the following strand of the first stage of remelting of a new cycle of refining.

Obtained at the second stage remelting ingot (6.2) tantalum investigated for the presence of impurities.

Control of chemical composition of ingots on conformity to requirements him requirements was carried out as follows:

- mass fraction of each impurity was determined by the appropriate this mixture of standard,

- tantalum content was determined as difference between 100% and the sum of the mass share of all determined impurities.

Table 1 shows the dependence of the degree of extraction of (product) tantalum and impurities from the alloy based on tantalum on the initial concentration of impurities in the charge by electron-beam melting (on the 1st and 2nd stages), at the electrochemical processing and hydrometallurgical processing.

To obtain comparative data of the proposed method with the method of the prototype, the charge corresponding to the present method, subjected to the operations of the prototype method. The results of comparative data are presented in table 2.

As can be seen from this table, the purity of tantalum by the proposed method is compared with the known technology with more than fivefold decrease the amount of impurities: 430 ppm in the known method to 88 ppm in the proposed programme.

The proposed method is a technological scheme for the comprehensive processing of alloys based on tantalum obtaining high-purity tantalum (99,991%mass.), ready for industrial use. The claimed solution can be the basis for closed waste-free technology of ecologically clean production of tantalum.

Indicators the proposed and known ways of refining alloys on the basis of tantalum

The chemical composition of raw materials (charge)

The chemical composition of the final product (standard ingot)

Tantalum, % of mass.

The sum of all impurities, % of mass.

The presence of refractory metals

Tantalum, % of mass.

The sum of all impurities, ppm

The presence of refractory metals

The famous

The proposed

Note: example 1 - way of the prototype with the original charge of the proposed method; 1 ppm is equal to 1·10 -4%mass

1. The method of obtaining tantalum alloys on its basis includes vacuum electron-beam remelting in a horizontal mould placed him in charge emitting fumes its metallic impurities on their surface design conditions for condensing and fume gas-bearing admixtures, as well as obtaining tantalum ingot by moving the electron beam from the beginning to the end of the mould along the entire surface of the charge with its subsequent disconnection, characterized in that used a mixture containing metallic impurities of refractory metals with close to melting temperature and vacuum electron-beam remelting lead in two stages, and released on the first stage of electron-beam melting sublimates tantalum processed and returned for the remelting to obtain ingot and fumes gassy and more fusible, than tantalum, metallic impurities are removed, received at the first stage of electron-beam remelting ingot tantalum with admixtures of refractory metals subjected to electrochemical processing emitting cathodic sludge and related products with admixtures of refractory metals, which is removed and the cathode sediment subjected to the second stage of electron-beam melting with obtaining ingot standard tantalum containing tantalum fumes that return on electrochemical processing, and the first phase of electron-beam melting to the second specific power electron beam increases with 0,024-0,035 kW/mm 2 to 0.040-0.045 kW/mm 2 , and speed of movement of the electron beam reduced from 40-60 mm/min up to 4-6 mm/min, and for the first and second stages of electron-beam melting create a vacuum 10 -3 -10 -4 mm Hg and 10 -4 -10 -5 mm Hg respectively and in the beginning of the second stage of electron-beam melting electronic beam survive at the beginning of the mould 400-500 C, and electrochemical processing is carried out in the electrolyte, consisting of 50-60% Mas. sodium chloride, 15-35 wt.% fluoric sodium, 15-25 wt.% potassium, when its temperature 880-940°C, the cathode and anode current density of 0.7-0.9 A/cm 2 and 0.4-0.5 A/cm2, respectively.

2. The method according to claim 1, characterized in that the mixture contains the admixtures of refractory metals with close to melting point: niobium, tungsten, rhenium, molybdenum, zirconium.

3. The method according to claim 1, characterized in that in the end of the first and second stages remelting after disabling the electron beam melt is cooled not less than 0.5 hours

4. The method according to claim 1, characterized in that sublimates surface is cooled down to 14-15°N

5. The method according to claim 1, characterized in that released on the first stage remelting sublimates tantalum subjected to double hydrometallurgical processing of known ways of obtaining insoluble residue.

6. The method according to claim 1, characterized in that concomitant draught products are anode balance and melt of salts.