How to Obtain Refractory Metals

Abstract

Described herein is a method for obtaining refractory metals, comprising the steps of: - providing a pulverized precursor material in oxide-bound form from or with the metal to be obtained; - providing a bulk reactant that undergoes an exothermic reaction after ignition, consisting of or including a slag-forming agent with a higher O2 affinity than the metal to be obtained; - providing a bulk-material mixture (5) consisting of precursor material and reactant; - filling a batch of the bulk-material mixture (5) into a heat-resistant reaction vessel (1), leaving a void volume; - applying an inertial force acting on the reaction vessel (1) and its contents. - locally supplying thermal energy to the bulk material mixture (5) starting from the edge thereof while inertial forces are acting on the bulk material mixture (5), thereby triggering an exothermic reaction in the bulk material mixture (5), thereby melting the metal to be obtained, and separating the molten liquid metal from the slag (7) based on the inertial forces acting during the progress of the redox reaction; - after the redox reaction is completed, terminating the inertial forces acting on the reaction vessel (1) and its contents; - after the reaction vessel contents have cooled, removing the reaction products (6, 7) from the reaction vessel (1) and separating the obtained metal from the slag (7).

Description

[Technical Field]

[0001] The subject of the present invention is a method for obtaining refractory metals, in which the metal to be obtained is obtained from a precursor material by means of an exothermic redox reaction with respect to its energy balance.

[0002] Obtaining high-melting-point metals or metal alloys requires considerable effort. This requires extensive mineral processing and multiple melting or thermal transformations of the respective pre-processed precursors. Typical alloys of this type are those containing the elements Ti, V, Ni, Ta, Cr, Mo, Nb, and W. In nature, these transition metals exist as oxides and hydroxides as well as other ceramic compounds. These compounds sometimes contain additional elements, such as Pb, Fe, Ca, Si, or Mg.

[0003] U.S. Pat. No. 7,527,669 discloses a method for melting a metal to be obtained by introducing it into a reaction vessel together with a reactive metal. Li, Ca, or Mg can be used as the reactive agent. After ignition, the reactive agent generates sufficient heat energy to melt the metal to be obtained from the precursor material. To trigger this exothermic process, the reactive agent is appropriately ignited. The reaction results in molten metal or metal alloy and slag remaining in the reaction vessel. The molten metal or metal alloy forms a sponge-like structure in the reaction vessel, perforated by slag particles. To separate the metal or metal alloy from the slag, the reaction vessel is subsequently introduced into a furnace, thereby melting not only the remaining precursor material but also, among other things, the remaining slag. According to the prior art, lithium is preferred as the reactive agent. This is because lithium oxide melts already at about 1,500°C, while magnesium oxide, for example, requires a temperature of about 3,000°C for melting. The melting here destroys the sponge-like structure of the metal or metal alloy melted in the first obtaining step, and the metal or metal alloy to be obtained increases due to their different densities, so that the two reaction products can then be separated from each other. As far as is known, this method has not been implemented in industrial applications. Furthermore, multiple heat treatments are considered to be disadvantageous.

[0004] Chinese Patent No. 105132724 proposes the use of an aluminothermic method to obtain TiAl-based alloys. This process is essentially similar to the aforementioned method described in U.S. Patent No. 7,527,669. However, this known method does not require a second heating step in a furnace. The prior art uses precursor materials TiO2, Al powder, reactants, anhydrous ethanol for the mixing process, and a slag-forming agent. To separate the reaction products from each other, the reaction vessel is subjected to an inertial force of at least 500 G, preferably greater than 800 G. The Ti precursor, Al powder, and anhydrous ethanol are mixed and milled in a ball mill to a particle size of 0.5 μm to 3 μm, to prepare a material mixture introduced into the reaction vessel. The powder is then mixed with the reactants and slag-forming agent and pressed under a compressive force of 5 MPa to 20 MPa to form a tablet. An ignition agent is applied to the top of the tablet introduced into the reaction vessel, and the reaction vessel is then placed in a high-speed centrifuge. When the desired inertial force (800-1200 G) is reached, the ignition agent ignites, triggering an exothermic redox reaction. The inertial force separates the molten metal alloy from the slag, which is lighter in terms of its density. The methods known from the above-mentioned literature are not applicable for industrial use due to the extremely high inertial forces required to separate the molten alloy from the slag. Furthermore, the duration of the methods using milling, the subsequent drying process required, and the duration required to maintain the melting temperature are quite long. However, if Al has to be milled to the desired particle size, the milling process does not pose any danger due to the reactivity of Al.

[0005] A metallothermic process for producing high-entropy alloys is known from SANIN, VN [et al.]: Centrifugal metallothermic SHS of cast Co-Cr-Fe-Ni-Mn-(X) alloys, In: Russian Journal of Non-Ferrous Metals, Vol. 61, 2020, No. 4, pp. 436-445, ISSN 1067-8212. To produce such alloys, a self-propagating high-temperature synthesis process is used, using inertial forces acting on the reaction vessel or its contents. The special feature of such alloys is that the main alloying elements are contained in the alloy in approximately equal alloying proportions. The starting product of this known process is a mixture of Ni oxide, Cr oxide, Fe oxide, Co oxide, and Mn oxide mixed with Ti, Si, B, and C. The exothermic reaction is carried out at an inertial force of 20 to 70 G, with an inertial force of 65 G ± 5 G being preferred to achieve the desired structure and properties of the desired high-entropy alloy.

[0006] The aim of the above experimental study was to determine whether the aluminothermic process, known per se, is also suitable for the production of complex alloys (high-entropy alloys). Many factors influence the formation of the resulting melt structure. Since the above study is specifically oriented towards high-entropy alloys, the results cannot be easily transferred to the production of other alloys. Furthermore, the above study does not allow for inferences as to whether the process here is feasible on an industrial scale and therefore whether the above-described method is scalable.

[0007] Starting from the above-mentioned prior art, the object on which the present invention is based is to propose a method which is simplified compared to the conventional industrial routes for obtaining refractory metals or refractory metal alloys, which is particularly suitable for the metallurgical engineering of obtaining metals, and which further avoids or at least significantly reduces the disadvantages mentioned in relation to the above-mentioned prior art.

[0008] The above problem is solved according to the invention by a method having the features of claim 1 or alternatively by a method having the features of claim 2.

[0009] Advantageous configurations emerge from the respective dependent claims and the description.

[0010] The term "metal" as used within the scope of the embodiments herein includes transition metals as well as metal alloys. Thus, the following embodiments apply equally to the direct acquisition of metals, transition metals and metal alloys.

[0011] The term "high melting point" as used within the scope of the embodiments herein refers to a metal or metal alloy and is to be understood as a material having a melting temperature of at least 900°C.

[0012] In the method according to the present invention, precursor products are prepared independently to form a bulk material mixture that is introduced into the reaction vessel. If the material from which the metal is to be obtained does not originally have the intended particle size or grain size, it is crushed. A precursor material having a target particle size of 10 μm to 500 μm is prepared. Preferably, the material is crushed to have a fairly narrow particle size distribution. Importantly, the particle size of the precursor material can be larger than the specifications set forth in Chinese Patent No. 105132724 by an index of 1 or even 2 or more. Accordingly, operational milling costs are reduced. The same applies to the provision of the reactants. Typically, the target particle size of the reactants is in the range of 50 μm to 500 μm, and therefore can be handled safely with standard safety precautions. Since the processing steps required for the desired target particle size of the precursor and reactants are carried out independently of each other, each crushing step can be adapted to the material to be crushed. This also applies to the machines used for crushing. In particular, precursor-independent milling is advantageous for providing the desired particle size of the reactants, since the reactants often have to be milled with high precision requirements. Furthermore, the process steps provided for milling are essentially carried out in a dry state, so that drying of one of these precursor products is not necessary.

[0013] The material mixture is introduced into the reactor as a filling. Based on the properties of the material mixture, the reactor is filled so that its cavity is filled cross-sectionally, particularly regardless of its cross-sectional geometry and dimensions. This allows the cavity formed by the reactor to be filled as cross-sectionally as possible and optimally utilized for introducing the material mixture. Following the introduction of the bulk material mixture into the reactor, according to the first proposed solution, a step of compacting the bulk material mixture filled into the reactor is carried out to reduce the void volume. Typically, the powder material mixture filled into the reactor still has a void volume that is too large for the intended purpose. This compaction is carried out by introducing mechanical vibrations into the reactor or its contents. This process can be carried out, for example, on a vibrating plate. For relatively large reactors, a separate vibration actuator can also be used.

[0014] The above-described process of compressing the bulk material mixture introduced into the reaction vessel allows for significantly better control of the progress of the exothermic reaction, which is why the claimed method is scalable, i.e. can be used on an industrial scale without any problems.

[0015] In a preferred embodiment, the bulk material mixture filled in the reaction vessel is compressed in two stages to reduce its void volume. The first compression step is performed at a lower frequency and with a lower vibration force than the second compression step. Depending on the bulk material mixture present in the reaction vessel, the first compression step can be performed, for example, at a frequency of 40 Hz to 65 Hz and with a vibration force of 300 N / kg to 500 N / kg of total weight. The second compression step can be performed at a frequency of 80 Hz to 180 Hz and with a vibration force of 450 N / kg to 800 N / kg of total weight. In these compression steps, typically, sinusoidal vibrations are introduced into the bulk material mixture or into the reaction vessel containing the bulk material mixture. In such two-stage compression of the bulk material mixture, the second compression step is designed to be longer in duration than the first compression step, for example, 1.5 to 2.5 times longer than the first compression step. For example, the duration of the first compression step can be set to 8 to 12 minutes, in particular about 10 minutes, and the duration of the second compression step can be set to 7 to 25 minutes, in particular about 20 minutes.

[0016] While this method does not preclude compaction of the material mixture introduced into the reaction vessel by applying a relatively large compression force, such compaction cannot guarantee that the material mixture will form a uniform void volume throughout the reaction vessel's filling height. To better control the surface material of the material mixture present in the reaction vessel during the vibration treatment and to induce some compaction in this area as well, this compaction can be combined with a pressing process using a smaller force, for example, a stamp acting on the surface with a small preload, which follows the filling height in the reaction vessel that decreases as a result of this compaction process, or a uniaxial force is applied to the bulk material mixture during the compaction process. The uniaxial force is, for example, 5 N / kg to 40 N / kg, where the weight refers to the weight of the bulk material mixture filled into the reaction vessel. The uniaxial force applied to the bulk material mixture in the reaction vessel depends further on the geometry of the reaction vessel, particularly its diameter. A larger diameter reactor requires a correspondingly larger force to achieve the same degree of compaction as a smaller diameter reactor. In a two-stage compaction process design, this uniaxial force acting on the bulk-material mixture is preferably applied only during the second compaction step. The void fraction of the material mixture remaining in the reactor is preferably 20% or less. The void fraction of the bulk-material mixture can also be used to control the combustion rate. A void volume of 45% to 50% is considered insignificant. The void volume in the bulk-material mixture is used as the passage rate through which the molten liquid metal can flow to the bottom of the reactor due to the inertial force acting on the bulk-material mixture after the exothermic reaction to melt the metal to be obtained is triggered.

[0017] In the next step, the reactor vessel and its contents are subjected to inertial force. This is typically achieved by placing the reactor vessel in a centrifuge. This method requires significantly lower inertial forces, significantly below the order of magnitude required to obtain the TiAl alloy disclosed in Chinese Patent No. 105132724. The inertial forces are typically significantly lower than 350 G. In many cases, an inertial force of 80 G to 170 G is sufficient to achieve the desired material separation within the reactor vessel. Because a residual void volume exists in order to effectively separate the molten metal from the slag in the material mixture, and the void size is correspondingly large based on the particle size of the material mixture, a relatively small inertial force is already sufficient to effectively separate the molten liquid metal from the slag.

[0018] The exothermic reaction process is triggered by applying heat locally to the bulk material mixture. For example, a heat-resistant ignition wire, such as a tungsten wire, placed in contact with or next to the material mixture in the reaction vessel can be used for this purpose. The exothermic reaction in the bulk material mixture can also be triggered by a laser beam incident on the surface of the material mixture in the reaction vessel. In most cases, the exothermic redox reaction in the bulk material mixture is triggered on a surface facing away from the inertial force. The hot surface created by the triggering process then continues in the direction of the inertial force. Furthermore, the exothermic reaction can be triggered at multiple locations in the bulk material mixture, either simultaneously or with a time lag. How the exothermic reaction in the bulk material mixture is triggered, and if multiple triggering locations are envisioned, whether the exothermic reaction is triggered simultaneously or with a time lag at one or more locations, depends on the desired progression of the redox reaction. This depends on the particle size of the reactants, the void volume, and the shape and dimensions of the hollow chamber of the reaction vessel. The void fraction of the molten metal can also be controlled by the progression of redox reactions and the movement of hot surfaces with the material mixture in the reaction vessel. The exothermic reaction of the bulk-material mixture is triggered while an inertial force is applied to the bulk-material mixture.

[0019] According to the second proposed solution, the bulk material mixture is heated by an exothermic reaction so that both the metal to be obtained and the slag are at least partially melted. The metal to be obtained is separated from the slag in a liquid state, at least as long as the slag is molten. In this case, the separation of the two components (metal to be obtained and slag) is particularly good, and in particular usually results in a complete absence of inclusions. This measure intelligently exploits the greater density contrast between these two components when they are in their liquid state. The density of a substance in the liquid phase is usually lower than its density in the solid phase. Therefore, the density contrast between the molten metal and the slag is greater when the metal is also at least partially, preferably mostly, or even completely liquid, than when the metal is in its solid, unmelted state. By amplifying the density contrast between the heavier metal to be obtained and the lighter slag to be separated from it, the separation process can be carried out with a smaller inertial force acting on the reaction vessel to achieve the desired results. This is a separate and for the time being independent step from the step of compaction of the bulk material mixture filled in the reaction vessel, for the purpose of scalably carrying out the process herein. Preferably, both the proposal of the first solution and the proposal of the second solution are combined with each other to carry out the method.

[0020] The degree of slag liquefaction can therefore also influence the quality of the molten metal. While melting the entire slag is particularly advantageous, equally good results can be obtained if only 70%-80% of the slag is melted. In this connection, it should be noted that the already slightly liquefied slag components also favorably influence the quality of the separation process. According to one embodiment, the melting reaction is carried out so that 25%-30% of the slag is melted by the heat input.

[0021] The inertial forces acting on the slag during the exothermic reaction result in particularly good separation of the molten liquid metal from the slag, even when the slag is not melted. This separation is even better when the two phases are in a liquid state, resulting in a stratification in the reaction vessel: the metal to be collected is located in a section extending from the bottom of the reaction vessel, and the slag is located above it. The molten metal is collected in a collection volume. In this case, the collection volume can be a section extending from the bottom of the reaction vessel. Similarly, the collection volume can be formed by a collection vessel connected to the reaction vessel. The collection volume can simultaneously serve as a mold for hardening the molten metal. This process allows the production of semi-finished products or cast bodies from the precursor material in a single melting step, even those with particularly complex geometries. Such semi-finished products or cast bodies can have various shapes. If the section of the collection volume where the collected metal is located is openable for removal of the hardened metal, the rear section itself can also be produced in this way. It is also possible to use a collection volume that is broken to remove the hardened metal (semi-finished product or cast body). In this case, the collection volume can be a pottery mold, which is then replaced with new melt for the next melting process. If a part of the reaction vessel has such a primary mold as a collection volume, its cross-sectional area is designed to be smaller than the cross-sectional area of the section located above the opening of the reaction vessel to ensure that the primary mold is completely filled with molten metal. In this case, slag is present in the area of the reaction vessel following the casting mold. Whether for producing semi-finished products or cast bodies with complex geometries, in a reaction vessel configuration with such a primary mold, the reaction vessel can be filled so that the bulk material mixture does not fill the collection volume, but only the section located above the filling opening in the direction toward the filling opening. For example, a sieve made of heat-resistant wire can be used to empty the primary mold when filling the reaction vessel. According to another embodiment, in order to separate the antechamber of the reaction vessel into which the bulk material mixture is to be filled, the primary mould following this antechamber is also provided with a metal foil.The metal foil is preferably made of a metal that is also contained in the metal to be obtained. For example, if a Ni alloy is to be obtained by this method, Ni foil is advantageously used. If the alloy to be obtained contains, for example, Al, Al foil can be used to separate the antechamber from the primary mold. These foils are also melted during the melting of the metal and then become a constituent of the alloy. In this case, advantageously, no slugs are formed in the primary mold during the process; the slugs are separated from the primary mold by the applied inertial force. This reduces the duration of the method. Such semi-finished products can be, for example, rods or hollow rods.

[0022] A plurality of primary forming dies can be provided in connection with such a reactor vessel or in connection with parts of the reactor vessel, as collection volumes into which the molten metal flows under the action of inertial forces. In particular, if relatively small semi-finished products or workpieces are required, a plurality of these semi-finished products or workpieces can be formed in a single melting process.

[0023] In the above-described method, if an alloy, rather than an elemental metal, is to be melted as the metal to be obtained, it is also possible to provide a number of different pulverized precursor materials. It is also possible to add recycled materials (recycled scrap) to the precursor material. In this case, the material that forms the alloy is completely obtained. In another method configuration, the reactants contain one or more alloying elements that exist as elements or in a combined form and form a compound with the metal to be obtained from the precursor material. This is particularly advantageous for high-melting-point metals. In this way, Ti, Ni, Cr, and other high-melting-point alloys can be produced using virtually any alloying element in a single melting process heated by a defined exothermic reaction.

[0024] The bulk material mixture introduced into the reaction vessel is present in a gradient within the reaction vessel. The gradient here typically occurs in the direction of the inertial forces acting on the metal as it melts. The gradient can be, for example, a different mixing ratio of the individual components contained in the bulk material mixture, or it can be the uneven presence of a particular precursor or additive throughout the height of the reaction vessel in the bulk material mixture. Similarly, since the method provides a direct route for obtaining the metal, the method can easily form a material gradient.

[0025] Depending on the dimensions of the reaction vessel, particularly the inertial forces acting on the reaction vessel and the volumetric height or extent of the bulk-material mixture, the exothermic reaction process can be carried out in a relatively short time. Depending on the aforementioned conditions, the process can be carried out in just a few tens of seconds. Even with a relatively large volume of the bulk-material mixture, the reaction duration may only require a few minutes. The calculations here take into account the melting of one or more metals and their crystallization (hardening). The combustion duration and the movement of the hot front through the bulk-material mixture must take into account the inertial forces acting on the reaction vessel and its contents during the reaction process to complete the desired separation of the molten metal and slag over the entire extension length of the reaction vessel in the direction of the inertial forces. This flow of molten metal simultaneously leads to the homogenization of the melt, which is particularly important when metal alloys composed of different precursor materials are melted. In one embodiment of the method, the reaction vessel is provided with a thermal insulation function so that the heat generated by the exothermic reaction remains in the reaction vessel at a temperature level at which the metal to be obtained does not harden, longer than the actual reaction. This method therefore allows for a higher yield to be obtained from the precursor materials used.

[0026] The reaction vessel is typically inert with respect to the elements or compounds present in the bulk material mixture, and it is typically undesirable for elements to dissolve from the reaction vessel and migrate into the melt during the exothermic reaction process.

[0027] The considerably smaller inertial forces specified in the present method compared to known methods make the method scalable, in particular in that the amount of each batch of metal to be obtained is large enough for commercial use of the method. Using the aforementioned forces, samples of tens or hundreds of kilograms can be produced in the reaction vessel. Reaction vessels capable of producing semi-finished products or cast bodies with a relatively large weight are also perfectly usable.

[0028] A notable feature of this method is that the metal extraction process can be controlled by two important control variables: the temperature triggered by the exothermic reaction and inertial forces. The temperature of the molten metal can affect the viscosity of the molten metal. Essentially, the lower the viscosity of the molten metal, the smaller the inertial forces required for the separation process. The temperature and inertial forces of the metal melting process and the separation process are determined depending on the metal to be extracted and the design of the part of the reactor into which the molten metal flows.

[0029] Depending on the metal, different temperatures are required to melt the metal from the oxide used as the raw material. The exothermic process used to melt metals or metal alloys can be controlled by physical parameters, such as the particle size of the pulverized precursor material, the inertial forces acting on the bulk-material mixture, the degree of compression or controlled void volume, and the design of the reaction vessel. The smaller the particle size, the shorter the time required to obtain the metal to be melted from the raw material. Through inertial forces, the speed at which the hot surface moves through the bulk-material mixture in the reaction vessel can be controlled, as well as the reaction temperature. The greater the inertial forces, the faster the hot surface moves through the bulk-material mixture. A greater inertial force, when created by a commonly used centrifuge, affects the reaction temperature because a relatively high rotation speed results in a greater cooling effect.

[0030] The intensity and duration of the exothermic reaction in individual particles can be controlled by the degree of compaction, as can the conveying speed of the molten metal into the collection volume. The dimensions and design of the collection volume provided for collecting the liquid melt influence the cooling rate or cooling curve of the molten liquid metal collected in the collection volume. Furthermore, the collection volume and the bulk material mixture introduced therein can be configured to be preheated, for example, to a temperature of 500°C to 600°C, before the exothermic reaction is initiated. In this case, the molten liquid metal components initially collected in the collection volume cool correspondingly more slowly on the preheated inner walls of the vessel used as the collection volume, as a result of the crystal structure of the collected metal becoming more homogenized as a whole.

[0031] The metal acquisition process can be controlled chemically by the composition of the reactants or by additives. Here, the reactants or additives can include, for example, oxides that increase or decrease the reaction temperature. Other reactant components can also be used to slow down the exothermic reaction. For example, additives that can increase or decrease the melting temperature of the slag can be used. The substances used for this purpose, generally oxides, are typically inert to the metal to be acquired. The melting point of the slag can be decreased with CaO and increased with MgO. CaO is used when a metal with a relatively low melting temperature is to be acquired. When the melting point of the slag is lower than that of the metal to be acquired, MgO can be used to increase the melting temperature of the slag.

[0032] The particle size of the precursor material and the particle size of the reactant are also taken into consideration when controlling the energy involved in the melting reaction in the reaction vessel. The smaller the particle size, the faster the reaction per particle. Therefore, the reaction of the exothermic reactive material mixture, in particular, can be slowed down by providing a larger particle size. A relatively large particle size has a positive effect on the preceding grinding process, because the grinding process can be carried out in a correspondingly shorter time. In this way, particle size is also used intelligently for energy control.

[0033] The above mentioned factors ensure the scalability of the method, making it possible to manage relatively large batches, for example 10 kg to 200 kg, and particularly to carry out the method with comparable results.

[0034] The above-described embodiments make it clear that the present method is not only distinguished by a significantly reduced number of process steps compared to the currently industrially used methods, but also, inter alia, by the significantly improved energy efficiency on which it is based. Furthermore, the properties of the ores used as precursors can be better utilized. Furthermore, emissions, especially CO2 emissions, are significantly reduced. For example, in the production of Ni, energy consumption has been reduced by approximately 20% and CO2 emissions by approximately 30%. The same applies to all other alloys. [Brief explanation of the drawings]

[0035] [Figure 1] 1 is a flowchart illustrating an embodiment of the present invention.

[0036] The invention will now be described on the basis of an embodiment with reference to the flow chart of Figure 1. As will be explained below, the method according to the invention is applied to directly obtain the Alloy 600 alloy (EN 2.4816). The method according to the invention produces a NiCrFe alloy with the following composition by weight: 15% Cr, 8% Fe, the remainder Ni and less than 1% total of unavoidable impurities, where the alloy in question is the alloy known under the term Alloy 600 (EN 2.4816).

[0037] The starting materials used are primarily NiOCr2O3 and Fe2O3. In this example, these starting materials are commonly ground to a particle size of approximately 85 μm (step 1). In this example, Al is used as the reactant. Similarly, Mg, Si, or a mixture can also be used as a reactant, typically with a conventional flux. The relevant precursor products are refined to a particle size of 70 μm (also step 1). In the next step (process step 2), the precursor products and the reactants are mixed together. For this purpose, an industrial mixer is used. The mixing process is carried out in such a way that the energy introduced into the mixture by mixing is as small as possible. Both the grinding and mixing steps are carried out in a dry state.

[0038] The bulk material mixture removed from the mixer is then filled into the reactor 1 (step 3). The illustrated reactor 1, with respect to its design, should be understood as merely an exemplary embodiment of a reactor. The reactor 1 comprises a lower section 2, which is envisioned as a primary mold. At the end of the production process, the hardened alloy is present as a cast block. The lower section 2 merges into an upper section 4 in the direction toward the filling opening 3 of the reactor 1. The upper section 4 has a larger diameter than the lower section 2, which serves as the primary mold. After filling the reactor 1, the bulk material mixture present in the reactor 1 is compressed on a vibrating plate (step 4). This reduces the void volume of the bulk material mixture present in the reactor 1 by approximately 20%. In the illustrated embodiment, the compression process is carried out in two stages. In the first compression stage, the reaction vessel 1 filled with the bulk material mixture 5 was compressed for 10 minutes with a vibration force of about 375 N / kg by sinusoidal vibration at 50 Hz. Compression in the second compression stage was carried out at a higher frequency and with a higher vibration force (125 Hz; 575 N / kg). Additionally, in the second compression stage, an axial force was applied to the bulk material mixture 5 present in the reaction vessel 1, in particular at a lower pressure of about 18 N / kg. The second stage of the compression process was carried out for a duration of 20 minutes.

[0039] Next, the reaction vessel 1 is connected to the reaction vessel holder of the centrifuge (step 5). The centrifuge is started, applying an inertial force of approximately 85 G to the reaction vessel 1 or its contents, as indicated by the block arrow. When the desired inertial force is reached, an exothermic redox reaction intended for melting the metal is triggered (step 6). In the illustrated embodiment, this exothermic redox reaction is carried out by a laser beam introduced from the direction of the centrifuge's rotation axis into the reaction vessel, which is open on the side opposite the direction of the inertial force. The resulting temperature melts the metal from the precursor material. As shown in the process steps in the figure, combustion, which begins at the surface of the bulk-material mixture 5 facing the filling opening, progresses in the direction of the inertial force. Due to this inertial force, the molten metal flows, following the moving hot front, into the lower section 2 of the reaction vessel 1. This ensures effective separation between the metal alloy to be obtained and the slag produced in this process, due to the relatively low density of the slag produced in this process. Once the combustion and separation process is complete (step 7), the centrifuge is stopped and the reactor 1 is removed and cooled. The reaction products (cast bodies 6 and slag 7) layered in the reactor 1 are then removed and can be separated from each other. The cast bodies 6 are cylindrical cast bodies of high purity Alloy 600 in the illustrated embodiment (step 8).

[0040] In connection with the exothermic reaction, the following reaction takes place during the production of Alloy 600 alloy:

[0041] [Table 1]

[0042] To produce 1 kg of the alloy (Alloy 600) obtained using the above-described method steps, 0.4 kW / kg of energy was used. Since the metal acquisition process is CO2-neutral, the CO2 footprint of this method is 0 kg per kg of obtained alloy. Considering the entire supply chain, including ore processing, the energy required when using the method according to the present invention is 19.8 kW / kg. The CO2 footprint is 4.2 kg per kg of obtained metal. By comparison, the energy consumption in the conventional industrial acquisition of the above alloy amounts to 124 kW / kg, and the CO2 footprint is measured as 13.4 kg per kg of obtained alloy. This clearly demonstrates the advantages of the above-described method over the conventional industrial metallurgical melting route. Furthermore, the time required to carry out this method is significantly shorter than that of the conventional industrial acquisition route.

[0043] From the description of the present invention, it is clear that the present method allows for the direct production of high-melting metals, including metal alloys, as semi-products or workpieces from ores. This route can also be used, in particular, for the production of highly alloyed metals, which can be obtained in a single process step, compared to conventional methods. In this method, the alloy is adjusted via the precursor material used and / or via additives, such as scrap, comprising the desired alloy components. Furthermore, if the precursor material used is an alloy, the particular homogeneity of the molten metal is also noticeable.

[0044] The present invention has been described above on the basis of exemplary embodiments, and numerous further applications are available to those skilled in the art without departing from the scope of protection of the corresponding claims, which will not be described in detail separately. [Explanation of symbols]

[0045] 1 reaction vessel 2 sections 3 Filling opening 4 sections 5 Bulk - Material Mixture 6 Cast molding 7. Slug

Claims

1. A method for obtaining a high melting point metal, From the precursor material, the metal to be obtained is obtained by an exothermic redox reaction in terms of its energy balance, through the following steps, namely: - A step of preparing a pulverized precursor material in an oxide-bonded form from or using the metal to be obtained, - The reactant that causes an exothermic reaction after ignition is made more expensive than the metal to be obtained. ２ A step of preparing a bulk material consisting of or containing an affinity slag-forming agent, - A step of preparing a bulk material mixture (5) consisting of the precursor material and the reactant, - A step of filling a heat-resistant reaction vessel (1) with a batch of the bulk material mixture (5) while leaving void volume, - A step of reducing the void volume of the bulk material mixture (5) introduced into the reaction vessel (1) by compressing the bulk material mixture (5) by introducing mechanical vibration, - A step of applying an inertial force to the reaction vessel (1) and its contents, - A step of supplying thermal energy locally to the bulk material mixture (5), starting from the edge of the bulk material mixture (5), thereby triggering an exothermic reaction in the bulk material mixture (5) while an inertial force is acting on the bulk material mixture (5), thereby melting the metal to be obtained, and separating the molten liquid metal from the slag (7) based on the inertial force acting during the progress of the redox reaction, - A step to terminate the inertial force acting on the reaction vessel (1) and its contents after the completion of the redox reaction, - After cooling the contents of the reaction vessel, the reaction products (6, 7) are removed from the reaction vessel (1), and the obtained metal is separated from the slag (7). A method of obtaining something.

2. A method for obtaining a high melting point metal, From the precursor material, the metal to be obtained is obtained by an exothermic redox reaction in terms of its energy balance, through the following steps, namely: - A step of preparing a pulverized precursor material in an oxide-bonded form from or using the metal to be obtained, - The reactant that causes an exothermic reaction after ignition is made more expensive than the metal to be obtained. ２ A step of preparing a bulk material consisting of or containing an affinity slag-forming agent, - A step of preparing a bulk material mixture (5) consisting of the precursor material and the reactant, - A step of filling a heat-resistant reaction vessel (1) with a batch of the bulk material mixture (5) while leaving void volume, - A step of applying an inertial force to the reaction vessel (1) and its contents, - A step of supplying thermal energy locally to the bulk material mixture (5), starting from the edge of the bulk material mixture (5), thereby triggering an exothermic reaction in the bulk material mixture (5) while an inertial force is acting on the bulk material mixture (5), thereby melting the metal to be obtained, and separating the molten liquid metal from the slag (7) that has been at least partially melted by the heat input, based on the inertial force acting during the progress of the redox reaction, - A step to terminate the inertial force acting on the reaction vessel (1) and its contents after the completion of the redox reaction, - After cooling the contents of the reaction vessel, the reaction products (6, 7) are removed from the reaction vessel (1), and the obtained metal is separated from the slag (7). A method of obtaining something.

3. The method according to claim 2, wherein after filling the reaction vessel with a batch of the bulk material mixture (5), mechanical vibration is introduced to compress the bulk material mixture (5), thereby reducing the void volume of the bulk material mixture (5) introduced into the reaction vessel (1).

4. The method according to claim 1 or 2, wherein the extract is ground to a particle size of 10 μm to 500 μm in order to prepare a precursor product.

5. The method according to claim 1 or 2, wherein the reactant has a particle size of 50 μm to 500 μm.

6. The method according to claim 1 or 2, wherein, in order to prepare the bulk material mixture (5), the pulverized precursor material and the reactant are preferably mixed in a closed mixing vessel without introducing energy into the mixture.

7. The method according to claim 1 or 2, wherein the reaction vessel (1) having the bulk material mixture (5) is subjected to a subsequent process step while leaving a void volume of 10% to 30% in the reaction vessel (1).

8. The method according to claim 1 or 2, wherein the bulk-material mixture (5) is introduced into the reaction vessel (1) at a predetermined gradient with respect to its various components.

9. The method according to claim 1 or 2, wherein the inertial force applied to the reaction vessel (1) is less than 350 G, and more particularly less than 200 G.

10. The method according to claim 9, wherein a centrifuge equipped with a plurality of reaction vessel holders is used to apply the inertial force, and two of each of the reaction vessel holders are arranged facing each other in the diametrical direction with respect to the axis of rotation.

11. The method according to claim 1 or 2, wherein the triggering of the exothermic reaction is performed using a resistive heating element and / or by a laser beam.

12. The method according to claim 1 or 2, wherein the reaction vessel (1) is used as a collection volume in which the molten liquid metal is collected during the progress of the exothermic reaction, and at the same time, primary shaping for the metal to be obtained is performed in the collection volume, and the molten metal is hardened in the collection volume while forming the cavity of the collection volume.

13. The collection volume, which is connected to the reaction vessel (1) for collecting molten metal, is not filled with the bulk-material mixture (5), but only the volume located in the direction toward the filling opening is filled. In order to leave the collection volume empty, a bulk-material mixture barrier penetrating the molten metal is used to separate the bulk-material mixture (5) filled in the reaction vessel (1) from the collection volume. The method according to claim 1 or 2.

14. The method according to claim 13, wherein the bulk-material mixture barrier is provided from a heat-resistant material, for example, as a ceramic filter or as a sieve made from a heat-resistant wire.

15. The method according to claim 13, wherein the bulk-material mixture barrier for separating the bulk-material mixture (5) in the reaction vessel (1) from the collection volume is made of a metal that is also contained in or made from the metal to be obtained.

16. The method according to claim 1 or 2, wherein the reactant is also the slag-forming agent.

17. The method according to claim 1 or 2, wherein the reactant comprises a slag-forming agent.

18. The method according to claim 1 or 2, wherein one or more of the elements Al, Mg, and / or Si are used as a reactant.

19. The method according to claim 1 or 2, wherein the exothermic reaction of the bulk-material mixture (5) in the reaction vessel (1) is triggered at various points.

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