EA050552B1 - THERMOCHEMICAL TREATMENT OF EXOTHERMIC METAL SYSTEMS - Google Patents

Abstract

This invention relates to a method for controlling exothermic reactions between chlorides of metals such as Zn, V, Cr, Co, Sn, Ag, Ta, Ni, Fe, Nb, Cu, Pt, W, Pd and Mo, and Al, as well as to the use of the method for producing metal alloys and compounds based on base metals such as Zn, V, Cr, Co, Sn, Ag, Ta, Ni, Fe, Nb, Cu, Pt, W, Pd and Mo. The method provides a mixture of chemical precursors, including at least one solid chloride of the base metal, which is mixed and exothermically reacts with a control powder based on Zn, V, Cr, Co, Sn, Ag, Ta, Ni, Fe, Nb, Cu, Pt, W, Pd and Mo, and then the resulting intermediate products react with an aluminum (Al) absorber. The reduction is carried out in a controlled manner, controlling the reaction rate and preventing an excessive increase in the temperature of the reactants and reaction products.

Description

Field of technology

The present invention relates to a method for producing alloys and compounds based on one or more metals selected from Zn, V, Cr, Co, Sn, Ag, Al, Ta, Ni, Fe, Nb, Cu, Pt, W, Pd and Mo and/or Pb, Sb, Bi, In, Cd, Ga, Rh, Ir, Ru, Os, Re.

State of the art

Metal powders based on transition metal alloys and compounds can be used in a variety of industrial applications. Metal powders are often produced through a multi-stage melting process, including melting ingots of the required alloy components followed by evaporation or atomization. The melting process poses significant challenges in the production of many compositions when these alloys include reactive additives. There is also a need for a precise and uniform composition throughout the powder product, which is difficult to achieve when the constituent elements have widely varying physical properties.

Some pure metal powders are produced using the carbonyl route, where metallic components are converted into gaseous metal carbonyls, which are then heated under conditions suitable for decomposition into the corresponding metal, with the product typically in powder form. This route is used on an industrial scale to produce certain materials, such as Ni, but is generally unsuitable for producing most alloys.

There is a need for a new technology to overcome the difficulties associated with the existing indirect melting process for alloy production, allowing for the production of high-quality powders at a low cost. Similarly, there is a need for a new method to produce compounds that cannot be produced using current melting methods when the constituent elements are chemically incompatible.

The present invention relates to a method and device for producing transition metal powders, metal alloy powders or metal compound powders at low production costs.

The essence of the invention

The following terms have the following meanings unless otherwise specified.

The term base metal refers to one or more elements such as Zn, V, Cr, Co, Sn, Ag, Ta, Ni, Fe, Nb, Cu, Pt, W, Pd, Mo, Pb, Sb, Bi, In, Cd, Ga, Rh, Ir, Ru, Os and Re.

The term base metal alloys refers to base metal based alloys or compounds containing base metals in a total concentration of more than 10 wt.%, in particular more than 25 wt.%, or in particular more than 50 wt.%.

The term alloying additives refers to one or more elements or compounds based on O, N, S, P, C, B, Si, Mn, Ti, Zr, and Hf. The metallic additives may have individual concentrations preferably below 10 wt.%, and the total concentration of all additives may preferably be less than 50 wt.%. However, the concentration of Al may reach up to 90 wt.%, and the concentrations of C, B, and Si may be greater than 25 wt.%.

The term Al reducing agent refers to pure Al or aluminum alloy in powder form used to reduce base metal halide reagent.

The terms control powder or control agent refer to powders added to reactants to control or alter the energy/kinetics of a reduction reaction. A control powder is a solid powder whose reactivity with base metal halides or an Al reducing agent is less than the reactivity of the halides with an Al reducing agent. The control powder or control agent can be made from a pure metal or a metal-based compound, such as an alloy, intermetallic, halide (e.g., chloride), oxide, or nitride.

The term major metal halide(s) refers to the parent halide(s) of the major metal, such as chloride(s), and the term major metal subhalide(s) refers to halides of lower valence than the parent halide(s).

The terms AlCl ₃ , aluminum chloride, and aluminum chlorides can refer to all Al-Cl compounds, including AlCl ₃ and Al ₂ Cl ₆ in both gas and solid phases. Aluminum halide has a similar meaning.

The term "fine particle form" refers to powders with an average particle size of less than 500 µm, preferably less than 50 µm, and more preferably less than 15 µm in at least one dimension.

For the base metals to which this invention pertains, the reduction reaction of base metal chlorides with Al is highly exothermic, which can lead to thermal runaway with excessive increases in the reactant temperature. The present invention provides a method for controlling exothermic reactions between base metal chlorides and Al, and this method is used to reduce solid metal chlorides based on Zn, V, Cr, Co, Sn, Ag, Ta, Ni, Fe, Nb, Cu, Pt, W, Pd, and Mo to produce base metals or their alloys.

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In one embodiment, the method overcomes thermal runaway effects due to exothermic reactions by contacting a base metal halide powder with a control powder and then contacting this mixture with an Al reducing agent. The inclusion of the control powder helps slow the rate of the exothermic reaction, adds thermal mass, and possibly acts as a reducing agent, partially reducing the base metal halides to an intermediate compound. Reference will now be made to base metal chlorides to illustrate the method and explain the various processing steps. However, the use of other halides is within the scope of the invention, and the chloride example used is not limiting.

The reactions between the chlorides of the main metals and Al can be divided into two stages, where the chlorides of the main metals are mixed and reacted with a control powder based on Zn, V, Cr, Co, Sn, Ag, Ta, Ni, Fe, Nb, Cu, Pt, W, Pd and Mo, and then the resulting intermediate product is reacted with an Al absorber. The two reaction stages are carried out in such a way that a combination of control mechanisms is ensured, including providing a control powder for: (i) reaction with the chlorides of the main metals, (ii) slowing down the reaction rate, (iii) reducing the intensity of exothermic heat release and (iv) absorbing the heat released as a result of the reaction; and possibly providing external additional means for controlling the reaction rate through gradual mixing and interaction of solid reactants; and possibly providing external effective energy management for removing the heat generated during the reactions.

The recovery process can be divided into two stages:

a reduction step for carrying out controlled reduction of the chlorides of the base metals using a control powder and an Al absorbent at temperatures below 660°C, preferably below 500°C; and a cleaning step at temperatures above the sublimation/evaporation points of the chlorides to clean the powder product and induce agglomeration when necessary.

The process can be carried out entirely in batch mode, in semi-batch mode or entirely in continuous mode.

The present invention includes several aspects.

In the first aspect, a method is provided for the controlled exothermic reduction of a halide of one or more metals selected from Zn, V, Cr, Co, Sn, Ag, Ta, Ni, Fe, Nb, Cu, Pt, W, Pd, Mo, Pb, Sb, Bi, In, Cd, Ga, Rh, Ir, Ru, Os and Re, with an Al reducing agent, wherein the method comprises:

contacting said one or more metal halides, a control powder and an Al reducing agent in the form of fine particles at temperatures between 25°C and a maximum temperature _Tmax to form metals or a metal alloy product in the form of a powder and a by-product comprising aluminum chloride; and separating the by-products from the metal alloy powder product;

wherein the control powder comprises one or more metals selected from Zn, V, Cr, Co, Sn, Ag, Ta, Ni, Fe, Nb, Cu, Pt, W, Pd and Mo or an alloy or compound thereof, and serves to control the exothermic heat release during the reduction reaction, thereby maintaining the reaction temperature below T _max ; and wherein T _max is between 400°C and 1100°C, wherein it is below the melting point of the base metal or metal alloy product.

The control powder may be the final, fully reduced product of the process, or an intermediate, partially reduced product of the process, or a powder different from the final product but selected from one or more other base metals compatible with the desired composition of the desired final product. In a preferred embodiment, the control powder may also include aluminum chlorides, and upon sublimation of the aluminum chloride, it acts as a cooling agent, removing heat from the reaction zone where the exothermic chemical reactions occur.

In the second aspect, a two-stage method for producing inorganic powders based on Al, Zn, V, Cr, Co, Sn, Ag, Ta, Ni, Fe, Nb, Cu, Pt, W, Pd and Mo and/or Pb, Sb, Bi, In, Cd, Ga, Rh, Ir, Ru, Os, Re is proposed, wherein in the first reduction stage (hereinafter referred to as the reduction stage), chlorides of the base metals, a control powder and an aluminum alloy powder are gradually introduced into the first reaction zone at a temperature of from 25°C to 700°C, preferably from 160°C to 660°C, more preferably from 200°C to 600°C, and the mixture gradually reacts while adjusting the reagent feed rate to maintain a moderate temperature of the reagents below 660°C, preferably below 600°C; the control powder can be the obtained products from the base metals. Feed rate, mixing and the ratio of control powder to base metal chlorides are control mechanisms that can be used to limit the temperature rise due to

- 2 050552 release of exothermic energy and maintaining equilibrium between the heat released during reactions and the heat removed by external cooling. At the end of the reduction stage, a solid powdered metallic product is formed, which may include residual chlorides of the main metals and residual Al reducing agent;

In the second purification stage (hereinafter referred to as the purification stage), the products from the reduction stage are transferred to the second reaction zone and heated to a temperature that is higher than the sublimation/evaporation temperature of the base metal chlorides and preferably lower than the melting temperature of the base metal alloy products; the purification stage serves to purify the powder product and complete the reaction resulting in the formation of a solid powder product and gaseous by-products.

In the third aspect, a method for producing catalysts and structured materials is proposed, wherein the product is a metal, alloy or compound based on one or more base metals selected from Zn, V, Cr, Co, Sn, Ag, Al, Ta, Ni, Fe, Nb, Cu, Pt, W, Pd and Mo and/or Pb, Sb, Bi, In, Cd, Ga, Rh, Ir, Ru, Os, Re, and additionally includes alloying additives. According to the method of this aspect, the base metal or alloy of base metals is obtained in accordance with the methods of the first or second aspects, and the method may include an additional step of post-processing the obtained base metal alloy powder to cause changes in its composition and/or morphology. The means for performing the additional step may include dissolving Al in an alkaline or acidic solution and reacting the base metal powder with reactive elements such as oxygen, hydrogen, sodium and/or sulfur. The control powder may be a final or intermediate product of the process, or a powder different from the final product and added to the starting chemicals.

The fourth aspect provides a method for producing multicomponent powder alloys and composites, wherein the control powder has a significantly different composition compared to the elemental composition obtained by reducing the initial chlorides of the base metals using Al, and wherein the final product contains a significant amount of unreacted control powder; the control powder may be in the form of a powder with a melting point above 660°C. The control powder forms one of the components of the product.

Heat can be removed from the reactants to limit the temperature rise to an acceptable level due to exothermic energy release.

In the fifth aspect of the invention, a modular device is proposed for producing base metals or powders from base metal alloys based on Al, Zn, V, Cr, Co, Sn, Ag, Ta, Ni, Fe, Nb, Cu, Pt, W, Pd and Mo and/or Pb, Sb, Bi, In, Cd, Ga, Rh, Ir, Ru, Os, Re.

This device may include containers for storing solid reactants in an inert atmosphere, and additional devices for feeding powder, and mixers for powders, and a first reactor capable of handling metal powders and metal chlorides at a temperature of up to 700°C; this reactor includes means for feeding, mixing, stirring and reacting a separate stream of materials containing reducible chemicals, a control powder and an Al reducing agent; the reactor is designed to heat the reactants to a first temperature sufficient to carry out a reaction in the mixture between the reducible chemicals, the control powder and aluminum, with the formation of intermediate products based on basic metals; the reactor includes a section with a lower temperature for condensation of chemicals from the reactor and aluminum chlorides, if necessary.

The first reactor includes a device for moving reactants into the reactor, as well as for recycling at least a portion of the intermediate products for use as a control powder, and a second high-temperature reactor capable of heating to 1100°C, and which is designed to heat the reactants from the first reactor to a second temperature sufficient for further interaction of the intermediate powder product and the formation of a solid powder product based on basic metals;

by-product collection container and product collection container.

Typically, the device includes a heating/cooling device to regulate the temperature of the reactants within the required operating range and product characteristics. Ports may be provided for the introduction of inert and chemically active gases.

The device according to the fifth aspect of the invention is preferably suitable for implementing the method according to any of the aspects of the invention described herein.

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One aspect of the present invention provides a new method for controlling exothermic reactions between base metal chlorides and Al, and a process that enables the direct production of base metals or powder alloys using inexpensive chemicals. The invention overcomes difficulties typically associated with the melting/atomization route, such as segregation, and enables the production of alloys with properties that are not obtainable via the melting route. The present invention relates to base metals Mb, wherein all reactions between Al and any stable chloride species based on _Mb and Cl ( _{Mb Clx} ), leading to the base metal, are exothermic at all processing temperatures from 25°C to 1000°C, relevant to the processing conditions of the desired base metal alloys.

In a particularly preferred embodiment, the method comprises procedures for reducing chlorides of base metals selected from Zn, V, Cr, Co, Sn, Ag, Ta, Ni, Fe, Nb, Cu, Pt, W, Pd, and Mo to produce base metals or alloys. The method utilizes Al as a chlorine scavenger and provides a safe and effective means for overcoming the difficulties associated with the extreme reactivity of Al and the reduced chlorides of base metals. The method allows for the inclusion of additives based on alloying elements and Al. The embodiments discussed in the following sections describe procedures and rules for implementing the method and for controlling the thermal effects caused by the energy released during the reduction reaction.

The method of the present invention can be carried out in a batch mode, a semi-continuous mode, or a continuous mode by an exothermic reaction between solid chlorides of the base metals, a control powder, and reducing agents containing Al. The reaction stage is preferably carried out by first reacting the chlorides of the base metals with the control powder, and then by reacting the resulting mixture with Al. The method provides that separate streams of the reduced chlorides of the base metals and the Al reducing agent should be continuously fed into the reaction zone containing the control powder, according to a scheme designed to effectively manage the heat released by the reacting reagents during the exothermic reduction.

In one preferred embodiment, the method comprises the steps of mixing and reacting a first stream of reducible precursor chemicals comprising at least one reducible solid chloride of the parent metal, a second stream comprising a control powder, and a third stream comprising an Al reducing agent in the form of fine solid particles, at temperatures from T ₀ to T _max to form a product in the form of a powder and a by-product including gaseous aluminum chloride; T ₀ is preferably below the melting point of the Al reducing agent, and T _max is from 400 °C to 1100 °C; the reactions between the reducible chloride(s) and the Al reducing agent are exothermic, and the method comprises means for controlling the reaction rate and limiting the temperature of the reactants to less than 1100 °C, more preferably to less than 1000 °C, and even more preferably to less than 900 °C. The mixture being reduced may contain chemical precursors to alloying additives, including metals, semimetals, and nonmetals from the Periodic Table.

_Tmax depends on the physical characteristics of the base metal products and is usually limited by their melting point. _Tmax ranges from 400°C to 1100°C and is preferably higher than the sublimation/evaporation temperature of the parent base metal chlorides, but preferably lower than the melting point of the base metals or the alloy product.

In one embodiment, T _max is below 1100°C. In a second embodiment, T _max is below 1000°C. In a third embodiment, T _max is below 900°C. In a fourth embodiment, T _max is below 800°C.

In the fifth embodiment, T _max is below 700°C. In the sixth embodiment, T _max is below 600°C.

The initial amount of Al reducing agent depends on the amount of the starting chemicals being reduced and the required Al concentration in the final products. The amount of Al in the starting materials relative to the chemicals being reduced preferably corresponds to a value of 80% to 5000% of the amount required to reduce all the precursor chemicals to their elemental base metals. The amount of Al in the base metal product ranges from 0.0001 wt.% to 90 wt.%.

The choice of control powder depends on the desired characteristics of the powder alloy products. For conventional alloys and compounds, the control powder may be a pretreated product or a semi-finished reaction product, which is preferably mixed and reacted with the starting solid reducible precursors before the reaction with the aluminum (Al) alloy. Furthermore, the control powder may be one of the components of the desired base metal or alloy product. The Cl content of the base metal particles in the control powder is preferably less than 50%, preferably less than 75%, of the starting reactants. For the production of composite or multicomponent products, the control powder may be one of the product components and may differ from the base metal species being processed.

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The relative amounts of the parent solid chlorides of the base metals and the control powder depend on a combination of factors including the Gibbs free energy of the reaction between the base metal chloride and Al and the thermal properties of the reactants and the control powder, and typically range from 0.03:1 to 50:1 or 100:1 by weight; for some highly exothermic reactions, the ratio between chloride and control powder may be 1:35 by weight.

The present approach enables the low-cost production of a wide range of existing, common alloys and compositions, in addition to other compositions that would otherwise be unattainable in commercial quantities. The advantage of the present approach in its preferred forms over the prior art lies in the ability to achieve effective control over reaction mechanisms and maximize reaction yields with smaller amounts of precursor starting materials.

Features of preferred forms of this approach include:

1. Exothermic reduction reactions between the reducible chlorides of the base metals and Al are carried out under safe, controlled conditions.

2. The control powder can serve as an intermediate reducing agent, allowing for control of reaction kinetics. This is especially important for multicomponent systems and polyvalent base metal chlorides, where reactions between the base metal chlorides and the control powder play a key role in slowing the release of exothermic energy.

3. The reduction of the base metal chlorides is generally carried out in the reduction step at temperatures below 600°C, generally below 500°C. In aspects of the methods of the present invention, at least 50%, and preferably at least 60% or more, preferably at least 75% of the chlorine contained in the starting base metal chlorides is removed in the reduction step.

4. The method does not depend on the intermediate compounds obtained, and for most basic metals the reduction reactions proceed with the formation of elemental species directly.

5. The control powder serves as a heat absorber and reduces the reaction rate between the starting chemicals, thereby reducing the intensity of exothermic energy.

6. - Most reactions between the chlorides being reduced and the Al reducing agent occur at temperatures below 500°C, where aluminides are formed weakly and slowly, allowing the Al reducing agent to remain active for further reactions.

7. The hot byproduct gas generated by the reactions causes significant mixing of the reactants and helps restore the contact surface between them, increasing the reaction yield. This helps overcome the limitations of solid-state reactions typically associated with diffusion-controlled kinetics, where the reaction products form layers around the reactants.

8. Exothermic reactions may include reactions involving the interaction of alloying elements or alloying element precursors with other types of base metals or Al, and such exothermic reactions may be controlled by the procedures and embodiments described herein as part of the method.

9. The method will be illustrated in the following discussion with examples based on simple stoichiometric reduction reactions with pure aluminum leading to the parent metal(s).

The general reaction between chlorides of the main metals and Al is as follows:

_Mb represents the host metals, MbClx represents the corresponding reducible chlorides of the host metals, _AlCl3 (g) represents gaseous aluminum chloride, and ΔG is the Gibbs free energy for the reaction (R1). _Mb can be in the form of a pure element such as Ta, a solid solution such as Ni-Cu, a compound such as _Ni3Al , or a multicomponent system such as metal matrix composites.

The ability of Al to reduce metal chlorides (halides and oxides more generally) is well known, and the aluminothermic reduction of oxides and halides has been known for over 100 years. Al is known to be a versatile reagent, and its ability to reduce metal halides is commonly cited as an example of substitution reactions commonly found in undergraduate textbooks and basic chemistry essays (e.g., see Aluminium Alloys - New Trends in Fabrication and Applications, Ed. Z Ahmad, InTech, 2012, DOI: 10.5772/52026; and Jena and Brocchi in Min. Proc. Ext. Met. Review vol. 16, pp. 211–37, 1996). Examples of early attempts to produce metal alloys by reducing various metal chlorides with Al can be found in US 3,252,823 and US 5,460,642. Other relevant literature concerning Al can also be found in many early descriptions relating to the reduction of metal chlorides and the production of metal alloys (e.g., US 1,373,038, US 2,791,499 and US 2,986,462 and US 3,801,307, US 4,60,462 and US 4,191,557).

Aluminothermic reduction of transition metal compounds has been an active area

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R&D has been underway since the beginning of the last century. The main difficulties in the aluminothermic reduction of transition metal chlorides stem from two factors: (i) the tendency of Al to readily alloy with other metals and (ii) the exothermic reactions between most transition metal chlorides and Al often lead to uncontrolled reactions with the formation of arbitrary aluminide phases. The solution to these difficulties depends on the individual chemical properties of the metals, and from the perspective of aluminothermic reduction of metal chlorides, transition metals can be classified into three categories:

Category 1. Systems in which reactions between metal chlorides and Al are non-exothermic (i.e., Sc, Y, and Hf). For this category, aluminothermic reduction of metal chlorides can only occur by shifting the equilibrium to the right, as described for Sc in WO2014138813, where the reaction was carried out at reduced pressures to disturb the equilibrium and produce metallic Sc compounds. For this category, the end products are typically metal aluminides.

Category 2. Systems where the chlorides are multivalent and the reactions are only partially exothermic, and where the difficulty is primarily due to excessive affinity between the metal and Al; that is, Ti, Zr, and Mn. For this category, the chemical composition of the Ti-Cl-Al, Zr-Cl-Al, and MnCl-Al systems differs from all other transition metals, since the reactions leading to the metal are only partially exothermic, whereas those leading to aluminides are exothermic.

For Mn and Zr, the Al reduction pathway has not received much attention in the literature. In contrast, extensive attempts have been made to prepare Ti alloys and Ti-alloys by the aluminothermic reduction of titanium chlorides. For Ti, the reaction of TiCl4 with Al, leading to _TiCl2 and _TiCl3 , is exothermic, but the further reaction of titanium subchlorides with Al is endothermic below 550°C. However, all reactions between TiClx and Al leading to aluminides are exothermic, and the affinity between Ti and Al is such that the formation of aluminides is thermodynamically more favorable than the reduction of titanium subchlorides. The combination of the exothermic energy release for the _TiCl4 ^ _TiCl3 reaction and the Ti-Al affinity means that the reduction of _TiCl4 directly to Ti-based metallic particles leads to products with uncontrolled compositions and phases. In order to separate the exothermicity factor from the Ti-Al affinity factor, various approaches have been described (e.g., US2745735, US8562712, US8632724, US8821612, and US8834601) where the reaction is divided into two steps; in the first step, _TiCl4 is reduced to TiCl( _2,3 ), and then in _the second step _, the resulting TiCl( _2,3 ) reacts endothermically with Al to form Ti. This approach weakens the affinity factor between Ti and Al. Several efficient routes exist for the first step reaction from _TiCl4 to subchlorides (e.g., US3010787, US3172865, including references therein).

In most reports on the preparation of Ti and Ti alloys using the Al reduction route, the reaction conditions were designed to control/minimize the formation of titanium aluminides by altering the equilibrium.

In general, aluminothermic processes for producing metals and alloys in Categories 1 and 2 are not suitable for other metal systems involving exothermic reactions.

Category 3. This third category includes the remaining transition metals, where all reactions between chlorides and Al are exothermic; here, reactions between metal chlorides and Al typically result in the formation of runaway phases due to the loss of control over the reaction kinetics as a result of exothermic heat generation.

For this third category, consisting of Zn, V, Cr, Co, Sn, Ag, Ta, Ni, Fe, Nb, Cu, Pt, W, Pd, Mo, Rh, Ir, Ru, Os, Pb, Sb, Bi, Cd, Ga, and Re, the formation of aluminides due to melting of Al particles due to exothermic thermal effects predominates over the normal alloying activity that leads to aluminides. The inventors found that Al retention in the final products can be minimized by avoiding the thermal effects associated with the release of exothermic energy. Exothermic reactions between Category 3 transition metal chlorides and Al can generate excess heat along with significant amounts of gaseous byproducts, which can be hazardous. For example, the reaction FeCl ₃ + Al ^ Fe + AlCl3 AG = -264 kJ / mol (at 200 ° C) occurs very rapidly and the temperature of the resulting products can increase to 2000 ° C or more, which makes this reduction route unsuitable for producing iron-based powder alloys with the appropriate material properties at acceptable production costs. Such reactions are difficult to control, and the main objective of the present invention is to describe procedures for conducting reduction reactions that effectively lead to the formation of high-quality powder alloys in a controlled and safe manner. Another main objective of the present invention is to provide a method for controlling substitution reactions between chlorides of the main metals and Al at a highly localized level, while preventing and/or minimizing the temperature increase for all reactants.

The present invention falls into this third category and provides a method for controlling the reaction between Al and transition metal chlorides including Zn, V, Cr, Co, Sn, Ag, Ta, Ni, Fe, Nb, Cu, Pt, W,

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Pd, Mo, Rh, Ir, Ru, and Os, and/or Pb, Sb, Bi, In, Cd, Ga, Rh, Ir, Ru, Os, and Re, enabling the production of high-quality powder alloys and compounds based on metals in this category. To our knowledge, the production of powder alloys of this type has not been described in the prior art.

The present invention relates to Mb base metals, wherein all reactions between Al and stable Mb- and Cl-based chloride species ( _{MbCl1 -n} ) resulting in the elemental base metal are exothermic at all processing temperatures from 25°C to 1000°C in accordance with the processing conditions of the desired base metal alloy - according to any of the following embodiments; Mb,Cl1 _-n represents all stable chloride species that may be formed during processing. Hereinafter, this condition is referred to as the exothermicity criterion and, as defined in the context of the present invention, only base metals that meet this criterion are included. The inventors have found that when using materials that do not meet the exothermicity criterion, excess Al is retained in the final products, and base metal aluminides are formed. Furthermore, metals that do not meet the exothermicity criterion tend to react as reducing agents for the base metal chlorides, resulting in high levels of unreacted chlorides remaining in the final products. For example, when zirconium is used, the final product will contain high levels of Al along with residual zirconium chlorides/subchlorides.

Previous attempts to reduce a mixture of halides (e.g., chlorides) to directly produce alloyed products have been popular and have been described in both the open and patent literature. Examples can be found in the following literature: e.g., DeKock and Huffman, Met. Trans. B, volume 18B (1987) 511; Cost-affordable titanium IV, Imam, Froes and Dring, Trans Tech Publications 2010; and U.S. Patents US4902341, US4830665, US6955703, US4687632, US6699305, US7435282, and US6902601. A more recent example is U.S. Patent Application US20160243622, which describes a method for producing metal powders by reducing metal halides with reducing elements, including Al. In this description, halides of many transition metals are reduced by stirring in a bath with a metallic reducing agent (e.g., Al), and the resulting powders are then separated from the by-product salt in a second step.

The purpose of the present invention is not to patent the reduction of mixtures of reducible compounds, but to provide a new method for the safe and efficient reduction of a mixture of reducible chlorides using Al to form useful products with controlled characteristics.

In US Patent No. 6,902,601, Nie et al. also used Al to reduce metal chlorides to produce metals and alloys, starting with the reduction of metal chlorides. Nie et al. used _H2 as an intermediate medium to avoid contact between metal-based elements (metal chlorides and metals) and Al, thus avoiding the formation of uncontrolled aluminide phases typically formed during exothermic heat generation. However, the use of _H2 in US Patent No. 6,902,601 has limitations related to various aspects, including material safety and quality due to the possible formation of hydrides and diffusion of _H2 into powder particles. The present invention offers significant improvements over the approach described in US Patent No. 6,902,601 in that it addresses the difficulties associated with the energetics of the process, while expanding the range of base metals that can be used, and does not degrade the quality of the products due to the inclusion of impurities.

The inventors found that adding a control powder to the base metal and aluminum reactants provides adequate control of the reaction kinetics and allows for the safe reduction of base metal chlorides using aluminum under controlled conditions. The inventors also found that the control powder mitigates the effects of exothermic energy release in several different ways.

(i) The control powder allows the reaction (R1) to be divided into two parts:

M _b C1 _X + η M _c = M _R C1 _X + AG _b ΔΘι < 0 (R2)

M _R C1 _X + x/3 A1 = M _p + x/3 A1C1 ₃ (g) + ΔΘ ₂ , ΔΘ ₂ <0 (R3)

AG = AGi + AG ₂

M _c is the control powder, ΔG ₁ and ΔG ₂ are the Gibbs free energy for reactions R2 and R3, respectively. M _p is the average composition of the product of the Mb-Mc combination with a total mass equivalent to Mb+nMc, where n is the ratio of M _c to MbClx in the starting precursors. MbClx is the average composition of the Mc-Mp-Cl mixture obtained from reaction (R2). M _p can be in the form of a pure element such as Ta, a solid solution such as Ni-Cu,

- 7 050552 of a compound such as _Ni3Al , or a multicomponent system such as metal matrix composites. The extension of this scheme to more complex systems for the synthesis of complex alloys will become apparent in the following discussion.

By using intermediate reactions between the reduced chlorides of the base metals and the control powder, it is possible to improve the control of the thermal process and distribute the chlorine throughout the reagent mixture, and therefore increase the reaction efficiency.

Reactions involving the control powder include reactions with reducible chlorides of the base metals M _b Cl _x , reactions with the base metals M _b , reactions with Al and reactions with Al chloride by-products.

For embodiments where the control powder is based on a single element and has the same composition as the base metal alloy, reactions between M _c and M _b Cl _x will be limited to chlorine exchange reactions. Although this type of reaction does not contribute significantly to energy transfer, it facilitates chlorine transport and influences the overall reaction yield. In such cases, the role of the control powder is primarily to control the reaction rates between M _b Cl _x and Al.

For embodiments where M _c differs from M _b , reactions between M _c and M _b Cl _x become a key factor in the reaction pathway and overall reaction kinetics. The control powder also serves as a reducing agent, removing heat and slowing the reaction rate. For example, for an alloy containing Ni and Cr obtained by reducing NiCl2 and _CrCl3 with Al in the presence of a Ni-Cr control powder, NiCl2 in the initial precursor chemicals can react with Cr in the control powder to form chromium chloride, which then reacts with Al to achieve complete reduction.

In another example, to obtain pure Ta, TaCl ₅ in the starting chemicals reacts with Ta in the control powder to form tantalum subchlorides (TaCl ₂ - ₄ ), which then react with Al to achieve complete reduction. Thus, the intensity of the exothermic energy release is reduced, allowing for improved control over the reduction process.

Reactions between Mc and Al, although they can lead to the formation of aluminides, are likely of secondary importance, since all reduction reactions occur at temperatures below 600°C, where aluminide formation is unlikely. Furthermore, for most base metals covered by this discussion, the reduction of base metal chlorides by aluminides, leading to the base metals, typically occurs. Other important reactions involving _Mc and aluminum chlorides are the reverse reactions leading to the formation of Mc _{Cl y} , which shift/swing the reactions to the left and, therefore, reduce the intensity of the forward exothermic reactions during reduction.

The inventors discovered that _the control powder serves as an inertial heat sink, helping to overcome the difficulties associated with the exothermic reactions discussed above; for example, for reaction R1, mixing the starting chloride powder _MbClx with pretreated base metal powder Mb before reaction with the Al reducing agent helps control the thermal runaway effect and all the difficulties associated with it. The control powder serves to reduce the energy density per unit mass and thus limits the temperature rise during exothermic heat release, since the exothermic energy generated by the reaction is distributed over a larger mass consisting of the reaction products.

The reactant material streams are fed separately and only interact within the reaction zone. The mixing rate of the three streams serves as an additional control mechanism that determines the reaction rate.

Other mechanisms that help reduce the rate of exothermic energy release and provide more efficient external cooling of the reactants include:

a) a decrease in the reaction rate due to a decrease in the surface area of direct contact between MbClx and Al; and

b) a shift of the equilibrium to the left due to the reversible reactions between _Mb and _AlCl3 . For the process of the present invention, equilibrium conditions are preferred, and during the reduction step, the reactants, including aluminum chlorides, are preferably kept in the reaction zone (or returned to the reaction zone) in order to optimize the equilibrium conditions and direct the reaction towards the formation of equilibrium products. For all the base metals considered here, the reactions are very favorable, and active departure of the reaction from equilibrium can hinder the outcome of the process and increase the rate of exothermic heat release.

The control powder serves to moderate exothermic reactions with the Al reducing agent and convert the reaction momentum into effective mixing of the reactants, thereby ensuring increased reaction yield. For most base metal chlorides covered by this description, the amount of control powder is several times greater than the amount of the chemicals being reduced. Because the reactants being reduced are localized within the microcavities of the control powder, a more efficient means of absorbing the energy released during the reaction is provided. Furthermore, the hot by-product gas generated during the reaction can significantly improve mixing of the reactants.

- 8 050552

The control powder is preferably prepared from final or intermediate reaction products based on the base metals. Pretreated powders or alloys preferably have a lower Cl content than the starting base metal chloride. Preferably, the mixing of the base metal chloride powder and the control powder with the Al reducing agent powder is controlled to enhance the reactivity between the reactants and achieve external control over the reaction rates and the resulting exothermic heat. Under all conditions, the reactivity of the control powder with base metal chlorides or Al is lower than the reactivity between base metal chlorides and Al.

Further illustrative examples of the invention will be apparent from the following description and drawings, as well as from the claims.

Brief description of the drawings

The features and advantages of the present invention will become apparent from the following description of its embodiments, serving only as an example, with reference to the accompanying drawings:

Fig. 1 shows the increase in temperature due to the energy released during the exothermic reaction compared to the melting point of the base metals; Fe-2 indicates that the starting material is FeCl ₂ , and Fe-3 indicates that the starting material is FeCl ₃ .

Fig. 2 shows the maximum quantities of control powder (base metal powder) required to limit the temperature increase to 200°C during the release of exothermic energy.

Fig. 3 shows the amount of control powder (base metal powder) required to limit the temperature increase to 200°C during the release of exothermic energy, provided that the reactants at 25°C are fed into the reaction zone with the control powder at a reaction temperature of 400°C.

Fig. 4 shows a general block diagram illustrating the main stages of processing according to the method.

Fig. 5 shows a general block diagram illustrating one general embodiment of the method.

Fig. 6 is a general flow chart illustrating one embodiment of a method including processing volatile chloride precursors (e.g., Tads).

Fig. 7 shows a schematic representation of a reactor for carrying out the process in continuous mode.

In fig. Figure 8 shows an X-ray diffraction pattern for a sample of powdered Ni product.

In fig. Figure 9 shows an X-ray diffraction pattern for a sample of Fe powder product.

In fig. 10 shows an X-ray diffraction pattern for a sample of SS316 powder product.

In fig. Figure 11 shows an X-ray diffraction pattern for a sample of Inconel 718 powder product.

Fig. 12 shows an X-ray diffraction pattern for a sample of Co superalloy MAR-M-509.

In fig. Figure 13 shows an X-ray diffraction pattern for a Ta powder sample.

Fig. 14 shows the X-ray diffraction pattern for the FeNiCoAlTaB sample.

Fig. 15 shows an X-ray diffraction pattern for a sample of a high-entropy alloy powder product (AlCoCrCuFeNi).

Fig. 16 shows an X-ray diffraction pattern for an Al ₃ Co sample.

Fig. 17 shows the X-ray diffraction pattern for an Al ₃ Co sample after washing in NaOH.

- 9 050552

Detailed description of preferred embodiments

Table 1

Thermodynamic data related to base metals

1 2 3 4 5 6 7 8 Base metal Melting Point (°C) Sub-boil (°C) The original chemical substance AG, kJ/mol at 400 °C Approximate temperature increase (°C) Counter, powder Contact, weight (kg) Zn 419 907 ZnCl ₂ -51 323 Zn 0.8 V 1910 3380 VC1 ₃ -124 1138 V 2.4 SG 1907 2672 CrCl ₃ -150 1377 SG 3.4 So 1495 2870 СоС1 ₂ -149 1662 So 4.6 Sn 232 2270 SnCl ₄ -359 2647 Sn 3.1 Sn 232 2270 SnCl ₂ -133 1624 Sn 1.1 Ag 962 2212 AgCl -94 1711 Ag 5.1 That's it 3014 5425 TaCl ₅ -293 1817 That's it AND. Ni 1455 2732 NiCl ₂ -165 1935 Ni 5.1 Fe 1538 2750 FeCl ₃ -289 2472 Fe 4.7 Fe 1538 2750 FeCl ₂ -112 1250 Fe 7.1 Nb 2477 4742 NbCl ₅ -358 2216 Nb 2.9 Cu 1084 2567 CuCl ₂ -245 3036 Cu 9.7 Pt 1768 3827 PtCl ₂ -288 3520 Pt 9.7 w 3407 5660 WC1 ₄ -482 3599 W-4 17.2 w 3407 5660 WC1 ₆ -809 4311 W-6 23.8 Pd 1555 1554 PdCl ₂ -297 3642 Pd 33.5 Mo 2623 2617 M0CI5 -634 3927 Mo 14.8

Table 1 presents the preferred base metals (column 1) together with the corresponding melting and boiling points (column 2 and column 3, respectively), the preferred starting chemicals (column 4) and the corresponding Gibbs free energy (AG) (column 5) for the reaction of 1 mol of the base metal chloride with Al at 400°C according to (R1), the magnitude of the temperature rise (column 6) based on ΔG, the allowable control powder (column 7), and the amount of control powder per 1 kg of starting base metal chloride (column 8) required to limit the temperature rise to no more than 200°C.

From Table 1 it can be seen that for all the preferred starting chlorides ΔΘ is negative, which indicates that their reaction with Al according to scheme (R1) is exothermic and an excessive increase in the temperature of the products and surrounding reactants may occur, as per the results in column 6, which shows the approximate increase in temperature AT due to the release of exothermic energy. AT was estimated by solving the equation:

T _r +NT ^G= \(M _b C _p _ _b +M _Alcl3 C _p _ _Alcl3 )dT (1) t;

where T _r is the threshold reaction temperature, C _pb is the specific heat capacity of the base metals, M _b is the mass of the product M _b per 1 mol of the initial base metal chlorides M _b Cl _x , and M _AlCl3 and C _p-AlCl3 are the mass and specific heat capacity of the formed by-product aluminum chloride per 1 mol M _b Cl _x , respectively. From the results in Table 1, it can be concluded that the release of exothermic energy occurs in one step according to reaction R1, and the resulting heat is completely absorbed by the resulting products (Mb) and by-product AlCl ₃ . Therefore, the calculations represent the extreme case where the control powder acts only as a heat sink. For multivalent chlorides of the base metals and for multicomponent products, the effects of splitting the reaction into two steps due to chemical reactions between the control powder and the chlorides can dominate, and therefore the heat load associated with the process is reduced.

The calculated temperature increases in Table 1 are compared in Fig. 1 with the melting temperatures

- 10 050552 of the corresponding base metals. It can be seen that the expected temperature increase is mostly above 190°C, and, with the exception of Zn, this increase is comparable to or higher than the melting point of the base metals, and all of them are higher than the sublimation temperature of the corresponding chlorides. Therefore, if the reaction were rapid, the resulting conditions could damage the reactor, and together with excessive heat generation and superheated gaseous byproduct, this could lead to a hazardous regime.

The data in Table 1 demonstrate that the heat generated by the reaction of precursor chlorides with Al can melt the Al reducing agent. If this occurs, it will lead to the formation of large particles of random aluminide phases, slowing or suppressing further reduction of the original chemical species. This will result in the formation of alloys with a high aluminum content and a non-uniform composition. Therefore, the preferred forms of the present invention also aim to provide mechanisms for controlling the amount of Al in the final product and to enable the production of alloys with controlled Al content down to 10 wt.%, preferably down to 0%.

The mass of control powder (base metal powder for the results given in Table 1) required per 1 kg of base metal chlorides is determined based on the requirements for limiting the temperature rise of the resulting products below a certain specified value. Table 1, column 8, lists the maximum amount of base metal powder required to limit the temperature rise of the reaction product to less than 200°C above the externally set temperature for reactions involving base metal chlorides given in column 4. From the results given in Table 1, it is evident that all reagents and the control powder are heated externally to the reaction threshold temperature, presumably equal to 400°C. The results in column 8 were obtained by solving Equation 2 for M _c (mass of control powder):

A1C13

ΔT = 200 °C.

(2)

The data in column 8 of Table 1 are presented in Fig. 2 for ΔT=200°C. It can be seen that the required amount of control powder ranges from ~1 kg of Sn powder per 1 kg _{of SnCl2} to more than 20 kg of W per 1 kg of WCl6. From the data in Table 1 and the data presented in Figs. 1 and 2, it is evident that the obtained exothermic energy is completely absorbed by the reactants without heat loss due to any other effect, and that all reactants and the control powder are heated externally to the reaction temperature. Accordingly, the estimated values for both the expected temperature rise and the amount of control powder represent upper limit values for the full group technology.

According to some embodiments of the present invention, reactants at room temperature (25°C) are gradually fed into a reaction zone containing a control powder at the reaction temperature. Consequently, the reactants will absorb energy to reach the reactant temperature and can help limit the temperature increase due to exothermic energy release. Figure 3 compares the amounts of control powder required for the two configurations discussed herein; that is, a fully batch process and a gradual feed of reactants. It can be seen that some reactants at room temperature can have a significant cooling effect.

In addition, there are other heat losses such as conduction through the reactor wall and heating/sublimation of diluents introduced with the reactants (e.g., _AlCl3 ). In some embodiments of the method, aluminum chloride is introduced together with the reactants and the control powder, and then it can play an important role in cooling the reactants in the reaction zone and helps control the temperature. Under most practical conditions, the required amount of control powder can be expected to be less than 50% of the amounts given in Table 1. As mentioned earlier, the addition of the control powder slows down the reaction rate between the MbClx being reduced and the Al reducing agent, which provides more efficient external cooling and higher heat losses due to conduction and convection occur. In addition, the amount of control powder required decreases as the allowable temperature range increases, and if the allowable maximum temperature is 400°C above the reaction threshold temperature, then the amounts of control powder required given in Table 1 will be reduced by 50%.

From the previous discussion it follows that the reactants still need to be cooled externally at a rate equivalent to the amount of heat released by the reactants, but following the procedures described

- 11 050552 nym here, allows for cooling and overall process heat management under mild conditions, with only a moderate increase in reactant and reactor temperature.

The inventors found that when the mass ratio of the control powder to the reducible chlorides of the base metals is equal to one, the reaction rate between the reducible precursors and Al is reduced by a factor of 4, thus allowing the reaction to proceed over a longer period and ensuring more efficient energy management; as a result, a smaller amount of control powder may be required.

Other factors that may influence the required amount of control powder include the reaction threshold temperature (T _r ), the characteristics of the base metals, and the specific heat capacity and total enthalpy of formation of the base metals and base metal chlorides. The control powder may be a mixture of different materials, but reactions between the control powder and other reactants should not increase the thermal load generated by the reactions in the system.

Accurately determining the required amount of control mass requires an analysis of all relevant processing conditions, taking into account the physical properties of the reactor, as well as heat losses and cooling mechanisms available in the reaction zone. The estimated data in Table 1 are provided as a guide only, and these listed values may vary depending on specific experimental conditions, as will be apparent to those skilled in the art.

The applicants have determined that, under practical conditions and with proper control of reagent flows and mixing, the amounts of control powder listed in Table 1 can be further reduced by at least a factor of 2-5. In all embodiments, the amount of control powder should be between M _c /100 and M _c , where M _c is determined by equation (2).

The control powder can be added in several ways, depending on the reactor configuration. In one embodiment, the control agent is mixed with the parent metal chlorides prior to reaction with the Al reducing agent. In another embodiment, the control agent is mixed with the Al reducing agent prior to reaction with the parent metal chlorides. In a third embodiment, the control agent, the parent metal chlorides to be reduced, and the Al reducing agent are fed separately to the reaction zone, where they are mixed and reacted. The choice of the appropriate route depends on the relative reactivity of the control agent and the chlorides to be reduced and the Al reducing agent. In a preferred embodiment, the control powder is a fully processed product or a semi-processed product of the reaction between the parent metal chlorides and the Al alloy. In another preferred embodiment, the control powder is a product of the parent metal alloy and is produced in situ.

The applicants discovered that if no control agent is added, the hot byproducts formed during the reaction can cause a significant increase in pressure due to rapid gas movement, which can blow reactants out of the reaction zone. If the control powder has a lower reactivity with the reactants and is present in greater quantities than the reactants, the reactants will be distributed into small localized regions within the control powder matrix, each region surrounded by control powder. When the reaction occurs, the gaseous byproducts, moving rapidly from the localized reaction regions, collide with the surrounding control powder, transferring their kinetic energy to the powder and causing significant mixing throughout the reactants. The applicants discovered that even with very slight mixing of the chlorides being reduced and the Al powdered reductant, the reaction efficiency is significantly enhanced by self-mixing created by microstreams of byproduct gas. As noted below, for most of the base metals and base metal chlorides of the present invention, the increase in temperature of the reaction products due to the release of exothermic energy is 200°C above the threshold reaction temperature _Tr . Thus, the resulting local pressure at localized reaction sites is greater than 1.01 atmospheres and is likely greater than 1.1 atmospheres. This will generate rapid, localized gas flows (short bursts) within the reactant volume at velocities of up to more than one hundred meters per second, causing significant mixing within the reactant volume and playing a key role in the transfer of the exothermic energy released during the reaction from the localized reaction sites and the immediately surrounding control powder.

The applicants have found that for pure Al powder (with an average particle radius R) with the ratios [M _b Cl _x ]/[Al]=a and [M _c ]/[M _b Cl _x ]=b, and with a reactant packing density D (reagents M _c , M _b Cl _x and Al), the local pressure increase due to rapid reactions between the chlorides of the base metals and Al can be expressed by the following formula:

DN LAS

A/' =--------------(i+a + ab} where N is Avogadro's number, NA _r is the number density of Ar at the reaction temperature, and ΔN _αι is the amount (number of atoms per cm ³ ) of reacting Al. The applicants found that even for one in a thousand dos

- 12 050552 blunt reacting Al particles (AN _AI /N _Ar = 0.001) the resulting increase in local pressure can be up to 0.25 atm. For AN _AI /N _Ar = 1% AP can reach 2.5 atm with local pressure reaching 3.5 atm.

The mass ratio of solid base metal chlorides to the control powder can be determined based on the permissible increase in product temperature that may result from the release of exothermic energy. Preferably, the heat released during the exothermic reaction does not increase the temperature of the products in the reaction zone above the melting point of the base metals. Preferably, this heat generated during the exothermic reaction does not increase the temperature of the products in the reaction zone above the melting point of the Al reducing agent.

In one embodiment, the temperature increase resulting from the release of exothermic heat during the reaction of the base metal chlorides and Al is limited to less than 600°C.

In another embodiment, the temperature increase resulting from the release of exothermic heat during the reaction of the chlorides of the base metals and Al is limited to less than 400°C.

In the third embodiment, the temperature increase resulting from the release of exothermic heat during the reaction of the chlorides of the base metals and Al is limited to less than 200°C.

In a preferred embodiment, the present invention provides a method for producing alloys of parent metals in powder form, comprising the following steps:

obtaining a first stream (stream 1) of materials from a mixture with a predetermined amount of precursor chemicals, comprising at least one solid chloride of the parent metal and, optionally, comprising precursor materials for alloying additives; and obtaining a stream of materials (stream 2) comprising primarily an Al reducing agent and, optionally, comprising precursor materials for alloying additives; and obtaining a control powder (stream 3). The control agent is preferably, but not necessarily, the parent metal of the parent chloride of the parent metal; and

A reduction step: feeding certain quantities of stream 1 and stream 2 into a first reaction zone comprising a certain quantity of stream 3, and treating the resulting mixture at given external temperatures between T ₀ and T ₁ to reduce at least a portion of the chemicals in stream 1 and to obtain an intermediate product, wherein this treatment step comprises mixing, agitating and heating; T ₀ is above 25°C, preferably above 160°C and more preferably above 200°C, and T ₁ is below 1000°C, preferably below 660°C, more preferably below 600°C and even more preferably below 500°C; and the reaction zone is designed to remove the heat released as a result of the reaction and to limit the overall temperature of the reactant to a temperature Tm; Tm is preferably below the melting point of the Al reducing agent (for pure Al, T _m is less than 660°C); and the materials evaporated from the first reaction zone are condensed elsewhere at lower temperatures and recycled; and means are provided for additional mechanisms to control the mixing and feeding speed; and the solid intermediate products from the reduction step may include residual unreacted chlorides of the base metals and residual Al reducing agent, as well as solid _AlCl3 ; and the base metals in the control powder have a Cl content of less than 50%, preferably less than 75% of the original base metal precursors.

if necessary, recycling all or part of the intermediate products in the recovery step as control powder; and

A purification step: treating the solid products from the reduction step in a second reaction zone at temperatures between T ₂ and T _max to purify the intermediate products from the reduction step and complete the reduction reaction, and evaporating and/or sublimating unreacted materials in the solid reactant mixture; T ₂ is preferably above 200 °C and T _max is preferably below 1100 °C; and continuously removing by-products from the reactants and collecting and recycling the recoverable chemicals evaporated from the high temperature zone; and modulating T _max and the residence time to control the particle size and the degree of agglomeration of the final products; and separating the base metal alloy powder from the residual unreacted materials and performing subsequent processing; and all reactions between the Al reducing agent and the stable Mb- and Cl-based chloride species (M _b Cl ₁ .n) are exothermic at all processing temperatures from 25 °C to T _max .

The maximum set temperature T ₁ in the reduction stage is determined by factors including the kinetic barrier of the reaction between the precursor material and the Al reducing agent, and the characteristics of the reactants, such as the purity and particle size of the Al alloy powder. T ₁ is preferably below the melting point of Al, more preferably below 600°C. As an illustrative example only, the following example can be given if nickel is the base metal, and

- 13 050552

Since NiCl2 is a reducible chloride of the base metal, the maximum set temperature in stage 1 will be below 500°C.

The maximum set temperature, _Tmax, in the cleaning stage is determined by factors including the morphology and composition of the final product, in addition to the requirement for evaporation of any residual unreacted chemicals remaining in the solid products. _Tmax is preferably set at a temperature slightly above the highest sublimation/evaporation temperature of the base metal chlorides being processed. If nickel is the base metal and NiCl2 is the reducible base metal chloride, then _Tmax is below 900°C.

In one preferred embodiment, the Al reducing agent is pure Al. In another embodiment, the Al reducing agent is pure Al alloyed with other elements. The Al reducing agent is preferably a powder or flake in the form of fine particles.

In one preferred embodiment, aluminum chloride is mixed with Al to form an Al-AlCl ₃ mixture, corresponding to 10% to 500% by weight of the base metal chlorides. The addition of AlCl ₃ promotes dilution and more uniform distribution of the Al when the Al-AlCl ₃ mixture is mixed with the base metal chlorides, and increases the surface area in contact with the chlorides, thereby increasing reaction efficiency. Furthermore, AlCl ₃ can serve as a cooling agent for the reactants during the reduction step.

In one embodiment, the byproducts from the reduction step, along with any base metal compounds released with the gaseous byproducts, are collected and returned to the reduction step for processing. In one embodiment of this embodiment, the recycling process is continuous. In another embodiment, the collected materials are mixed with the products obtained at the end of the reduction step, and the resulting mixture is then subjected to the reduction step again, as described above. In yet another embodiment, a portion of the intermediate products from the reduction step are used as a control powder. In one form of this embodiment, the intermediate products include AlCl3.

In all preferred embodiments _{, the reducible solid precursor is a metal halide (preferably a chloride) or a mixture of base metal halides. Examples of preferred precursor chlorides include ZnCl2, VCl(2,3), CrCl(2,3 ) , CoCl2 , SnCl2 ,} AgCl, TaCl( _{4_5 )} , _NiCl2 , FeCl( _2,3 ), _NbCl5 , CuCl( _1,2 ), PtCl( _4,3,2 ), WCl( _4,5,6 ), _PdCl2 and _MoCl5 , which correspond _{to the base} metals Zn _, V, Cr, Co, Sn, Ag, Ta, Ni, Fe, Nb, Cu, Pt, W, Pd and Mo. The solid base metal chlorides are preferably in the form of a finely ground particulate powder and are reduced by reaction with a control powder based on Zn, V, Cr, Co, Sn, Ag, Ta, Ni, Fe, Nb, Cu, Pt, W, Pd, and Mo in the form of fine particles and a solid Al alloy also in the form of fine particles. In a preferred embodiment, the average grain size of the solid base metal chlorides is less than 100 μm, and they are preferably in the form of powder or flakes in the form of fine particles.

In one embodiment, the chlorides of the primary metals are mixed/milled to homogenize the compositions.

In one embodiment, the chlorides of the base metals are mixed with AlCl3. Mixing can be accomplished by co-milling.

In one embodiment, the base metal chlorides are mixed with AlCl3 to produce at least one base metal chloride- _AlCl3 eutectic phase. Mixing can be accomplished by co-milling.

In one embodiment, the primary metal chlorides are mixed with _AlCl3 to increase the dilution of the primary metal chlorides in the reactant matrix. Mixing can be accomplished by co-milling.

Alloying additives can be incorporated via precursor chemicals into reactant streams or via a separate additional stream, if necessary, depending on the compatibility with the solid base metal chlorides and the Al reducing agent. Alloying additives can be compounds or mixtures of compounds or elements based on one or more elements from the Periodic Table selected from O, N, S, P, C, B, Si, Mn, Al, Ti, Zr, and Hf. Alloying additives can be added in various ways and at various points during the process, either in the reduction stage or the purification stage. Precursors of the additives are preferably in the form of halides.

Alloying additives that do not meet the exothermicity criterion can be challenging and may require special procedures for proper incorporation. For example, additives such as Ti, Mn, and Zr can act as reducing agents for parent metal chlorides, decomposing the final product and causing the retention of excess Al along with Ti chloride, Mn chloride, and Zr chloride impurities. Alloying additives based on Ti, Mn, and Zr should only be included if Al can be present as part of the final product composition. Special precautions must be taken to prevent the formation of segregated aluminide phases, accounting for the loss of _TiClx , _MnClx , and _ZrClx , and minimizing the presence of unreacted chlorides in the final product.

- 14 050552

In one embodiment of the method for producing composite alloys including Ti, Mn, Zr and Al additives, Ti, Mn and Zr chlorides are first partially or completely reacted with a reducing agent, and then the resulting products are thoroughly mixed and treated with other reagents at a temperature above 700°C.

In one embodiment, the reduction step is performed in a batch mode. In another embodiment, the reduction step is performed in a continuous or semi-continuous mode.

In one embodiment, where the reduction step is performed in a batch, continuous, or semi-continuous mode, the intermediate products from the reduction step are used as a control powder. In one form of this embodiment, the control powder is produced in situ. In another form, the final products are used as a control powder.

In one embodiment, the intermediate products from the reduction step are not transferred to the purification step until the reduction step is completed. In another embodiment, the intermediate products from the reduction step are continuously transferred to the purification step.

In one embodiment, to produce a powder alloy with an Al content exceeding 15 wt.%, the reduction step is preferably carried out in a mode in which the Al reducing agent is fed at a rate corresponding to that required to reduce the chlorides of the base metals to pure elemental base metals without excess Al, and then, after the total amount of chlorides of the base metals has been distributed, the remaining Al alloy powder is fed at such a rate that the resulting temperature of the reactants in the reduction step is less than 660°C.

In one embodiment, wherein the precursor feedstocks have a low boiling/sublimation temperature that is lower than the reaction temperature in the reduction step, the method includes an internal recirculation step in the reduction step, wherein the reactor in the reduction step is used to condense and collect the reactants exiting the reaction zone and return them for reuse. In one form of this embodiment, the materials condensed and returned to the reaction zone may include aluminum chloride. The products from the reduction step are then processed in a purification step in accordance with any of the aforementioned or future aspects and embodiments.

In one embodiment, the purification step is carried out in a batch mode. In one embodiment, the purification step is carried out in a continuous mode.

In one embodiment, the ratio of Al to recoverable chemicals is less than the stoichiometric ratio, resulting in an excess of recoverable chemicals in the feedstock. The excess recoverable chemicals are evaporated during processing at the purification stage and then collected and disposed of.

In one embodiment, unreacted precursor materials processed in the purification step at temperatures up to Tmax are evaporated and condensed in regions of lower temperature and then continuously recycled to either the recovery or purification step, as described above. In one form of this embodiment, recirculation is performed continuously.

In all preferred embodiments, the reactants are not pre-mixed since their own reactions may occur, resulting in the release of large amounts of heat with possible pressure increases due to overheating of the gaseous aluminum chloride by-products formed as a result of the reaction.

In any of the embodiments, the method may include a pre-treatment step to form solid metal subchlorides that are used as precursor starting materials.

When the starting chloride is a liquid or gas, the method may include an initial step of reducing the primary chloride to produce a chloride with a lower valence. For example, when Sn is the primary metal and SnCl ₄ is the preferred starting chemical, the method includes an initial step of reducing SnCl ₄ to SnCl ₃ . This can be accomplished using various routes, including alkali metal reduction and high-temperature hydrogen reduction.

This primary reduction step is preferably carried out using an Al reducing agent according to the equation:

M _b Cl _x (l,g) + (xz)/3 Al M _b Cl _z (s) + (xz)/3 A1C1 ₃ (R4) and then the resulting solid M _b Cl _z (s), which may include residual Al, are used as solid precursor materials as described above. MbClx (l,g) is the liquid/gaseous chloride, and M _b Cl _z (s) is the solid chloride.

In one preferred embodiment, the boiling/sublimation temperature of the primary starting chloride is comparable to or lower than the threshold reaction temperature in the reduction step, and the method may also include a pretreatment step to form solid metal subchlorides,

- 15 050552 to be used as starting precursor materials. In one form of this embodiment, to produce Fe, Ta, Mo, Nb, W, and V based alloys, starting precursor materials including _FeCl3 , TaCl( _{4 or} 5), _MoCl5 , NbCl5, WCl(4,6), and VCl( _3,4 ) _are first reduced to form a mixture including subchlorides (i.e., FeCl2, TaCl( _2,3,4 ), MoCl( _{2,3 ), NbCl(3 )} , WCl _{( 2,3,4} ), and VCl( _2,3 ) using any available prior art, including any of _the above and following embodiments, and then _the resulting mixture is reduced to base metals or base metal alloys according to any _{of the} above and following embodiments.

In a preferred embodiment, the method includes a step of continuously removing gaseous byproducts from the reaction zone by flowing gas away from the solid reactants and end products. In one form, the gas may be an inert gas (e.g., Ar or He). In other forms, the gas may include reactive components that can partially or completely react with the precursor materials or solid reactants (e.g., O2 and N2).

In one embodiment, the powder product is based on carbides, silicides, borides, oxides or nitrides of metals selected from Zn, V, Cr, Co, Sn, Ag, Ta, Ni, Fe, Nb, Cu, Pt, W, Pd and Mo. The powder product is obtained by treating metal chlorides with alloying additives including C, Si, B, O2 or _N2 , in accordance with any of the above and subsequent embodiments.

In a preferred embodiment, the aluminum chloride by-products are condensed in lower temperature portions of the reactor and collected separately.

In any of the embodiments, the method can be carried out at pressures from 0.0001 to 2 atm.

In all embodiments, the product is a powder consisting of an alloy of base metals or a compound thereof, and may include any number of alloying additives based on any number of non-inert elements of the Periodic Table.

In all forms and embodiments of the method, the final product of the said method may include aluminum residues.

In all embodiments, the method may include a step of separating the final products from any residual unreacted precursor materials and unreacted aluminum. The method may also include a step of washing and drying the final products.

In one embodiment, the aluminum chloride byproducts react with base metal oxides at a temperature T _Cl-O to form base metal chlorides and aluminum oxide:

_MbOx and AlCl _{3 MbCl Y} and Al ₂ O ₃ (Rol) _where MbOx is the oxide of the parent metal and MbCl is the chloride of the parent metal. MbCl is then separated from the remaining reaction products and recycled as the starting chloride of the parent metal in accordance with any embodiment or aspect described herein.

T _Cl-O depends on the oxide of the parent metal and can vary from room temperature to over 800°C. In one embodiment, T _Cl-O is below 200°C. In another embodiment, T _Cl-O is above 200°C. In another embodiment, T _Cl-O is above 500°C. In another embodiment, T _Cl-O is above 800°C.

In one embodiment, the Rol reaction is carried out under an inert atmosphere. In another embodiment, the Rol reaction is carried out in the presence of Cl or HCl gas.

Fig. 4 is a block diagram illustrating the main processing steps of the present invention.

In the first step, the control powder (1) is mixed and reacted with the chlorides of the main metals (2) in (3). The resulting mixture is then reacted with Al (4) in step (5). Steps (3) and (5) together form the reduction step (6). A portion of the resulting product is recycled (7) to (1) and the remainder is transferred for purification to (8). The products are discharged to (9). A portion of the final product may optionally be recycled (10) as control powder to (1). The by-products (11) from the purification step (8) may optionally react with the oxides of the main metals in (12) to form chlorides of the main metals (13), which may then be recycled (14) to (2). The final by-product from step (12) will then be aluminum oxide (15).

Fig. 5 is a schematic diagram illustrating the processing steps for one preferred embodiment in producing alloys from base metals.

In the first stage (1), the Al reducing agent is mixed with AlCl ₃ to dilute the Al and ensure a more uniform distribution during processing. Other alloying additives can be added and mixed with the Al-AlCl ₃ mixture if necessary. The control powder (2) and the base metal chlorides (3) are mixed preferably continuously in a pre-mixer (4) in an inert gas and under controlled conditions together with other compatible alloying additives to obtain stream 1 (5). The Al reducing agent is mixed (6-7) with the other precursors according to (8) to form stream 2 (9). The remaining alloying precursor additives (10) are prepared as one or more additional 3-n streams (11). Stream 1 (5), stream 2 (9) and stream 3-n (11) gradually react in the reduction stage at temperatures from 160 to 600°C (12). The recovery stage may include an internal recycling stage (12A) in which materials (12B) leaving the recovery zone

- 16 050552 shares of the reduction stage (12A) are condensed and recycled. The materials at the outlet of the reduction stage can be recycled (12C) to (2) for use as a control powder. By-products (13) obtained in the reduction stage, including aluminum chlorides, can be removed from the reaction zone if necessary. However, in a preferred embodiment, the by-products are recycled to (12A) or (12C). The reduction stage can be carried out in a batch mode or in a continuous mode.

At the end of the reduction step processing, the materials are then processed in a cleaning step (14) at a temperature of between 200 and 1000°C to complete the reaction and evaporate/remove residual unreacted chemicals (15). Unreacted chemicals (15) may be recycled (16) to the reduction step or the cleaning step. By-products from the cleaning step (13) are continuously removed from the solid reactants. At the end of the high temperature processing cycle, the products are discharged (17) for further processing or storage (18). A portion of the products (17) may be recycled (17A) for use as a control powder (2). All processing steps, including mixing and preparation of the precursor materials, are preferably carried out in an inert atmosphere, and any residual gas at the outlet of the processing cycle is treated with a scrubber (19) to remove any residual waste (20). In one embodiment, the remaining aluminum chloride byproducts (21) react with base metal oxides (22) to form reaction products including base metal chlorides and aluminum oxide. The resulting products are then processed in (23) to separate the base metal chlorides (24) from other byproducts of the chlorination reaction (Rol) (24). The resulting base metal chlorides (24) can then be removed (25) or recycled in (3).

In one embodiment of the continuous process using low boiling/sublimation point chlorides such as _TaCl5 , _NbCl5 , MoCl5, _WCl4 , _FeCl3 , _{VC14 ,} and SnCl4, the materials evaporated from the reactor during the reduction step are condensed separately or together with other reaction byproducts such as aluminum chlorides outside the reactor in a dedicated vessel and then fed back to the reactor during the same processing cycle through one of the reactor inlets. The condensate feed rate is controlled to avoid reactor overload. In a second embodiment of the process, the collected condensates are recycled to the reduction step, and this recirculation process can be performed multiple times or until all of the original primary metal chlorides are recovered. In this embodiment, recirculation can be performed multiple times or continuously to minimize the concentration of primary metal chlorides in the collected aluminum chloride byproducts. In one embodiment of this embodiment, the condensates are used as a control powder.

Fig. 6 is a general flow chart illustrating one general embodiment of the method involving the treatment of volatile chloride precursors (e.g., TaCl ₅ ).

Here, a condenser associated with the reduction stage can be used, and the temperature in the reactor during the reduction stage is set below 600°C, while the condenser temperature is set below 200°C. The materials evaporated from the reactor are condensed in the condenser zone either as pure molten TaCl ₅ or as a mixture or solution of TaCl ₅ -AlCl ₃ , and then the condensed materials are returned to the reaction zone. This recirculation process provides a mechanism for cooling the materials in the reactor due to evaporation-condensation-recirculation and also provides a self-regulating mechanism for maintaining the reactor pressure close to 1 atmosphere.

In one embodiment, the alloy product is a nickel-based, cobalt-based, or iron-based superalloy.

In one embodiment, the alloy product is a high-entropy alloy (HEA) comprising at least four elements from the group consisting of base metals, Al, and alloying additives, with individual concentrations ranging from 5 wt.% to 50 wt.%. In one form of this embodiment, the constituent elements are in equimolar amounts. The HEA powder must contain at least two base metals.

In one embodiment, the method includes the additional step of post-processing the powder so that it has substantially spherical grains, such as plasma treatment to produce grains suitable for use in 3D printing.

In one embodiment, the alloy product is a magnetic powder based on Fe, Ni, and/or Co. In one form of this embodiment, the product is an Alnico powder based on FeAl-Ni-Co and is produced according to any of the above or subsequent embodiments of the method, followed by additional steps of consolidating the resulting alloy powder, shaping it into a consolidated article, and then magnetizing the shaped article to produce a magnet. The powder produced according to this embodiment may include alloying additives and Al.

In one embodiment of the method for producing catalysts, the powder of the base metals is

- 17 050552 is carried out in accordance with any of the embodiments of the method, wherein the powder base consists of metals such as Al, Zn, V, Cr, Co, Sn, Ag, Ta, Ni, Fe, Nb, Cu, Pt, W, Pd and Mo and, possibly, including alloying additives, and there may also be an additional optional step of further processing the resulting powder from the alloy of the base metals to obtain a catalyst. In one form of this embodiment, the powder product has an Al content of more than 10 wt.%, and there is an additional step of dissolving Al using process means to obtain a skeletal catalyst. The process means include washing the powder product with alkaline solutions (e.g., NaOH) or acidic solutions (H ₂ SO ₄ , HF ...).

In one variant of the last embodiment, a powder with a composition M _bx Al _y C _z is obtained in accordance with any of the above or subsequent embodiments, and then Al is removed by washing the powder product with alkaline solutions (e.g. NaOH) or acidic solutions (H ₂ SO ₄ , HF ...) to obtain a composition M _bx C _z with an adapted pore structure and an adapted morphology; x, y and z represent the molar number for Mb, Al and C. The resulting material structure can be a layered structure or a porous structure or a nanostructured structure with a composition based on the composition M _bx C _z .

In one embodiment, the method includes the optional additional step of treating the powder product with a reactive substance to form a coating on the powder particles.

Typically, the product of the method is in the form of a powder with a spongy structure and a grain size from 5 nm to 500 µm.

In one preferred embodiment according to the fourth aspect, a method for producing a multicomponent powder or a composite powder is provided, in which the composition of the control powder differs significantly from the elemental composition obtained by reducing the starting chlorides of the main metals with Al, and wherein the final product contains a significant amount of unreacted control powder; the control powder may be a mixture of flakes, small or large particles and fibrous materials. In one form of this embodiment, the control powder consists of pure metals or an alloy with a composition different from the elemental composition obtained by reducing the starting chlorides of the main metals with Al. Carrying out the process in accordance with any of the previous embodiments results in the control powder being coated or surrounded by alloys or compounds resulting from the reduction of the starting chemicals with Al. The control powder may contain spherical particles, irregularly shaped particles, flakes or fibers.

Figs. 5 and 6 relate to a process in which the materials to be reduced M _b Cl _x , the control powder M _c and the solid Al reducing agent are fed to a reactor and mixed in situ and heated at temperatures between 160°C and 700°C. Since the amount of M _c exceeds the amount of M _b Cl _x , Al and M _b Cl _x tend to react first with M c and then the resulting intermediates react with the Al scavenger. When the materials react, they form an intermediate product of an alloy of the base metals and residual unreacted materials. In one embodiment, in a batch mode, this intermediate product can serve as a control powder when additional reactants are transferred to the reactor. In a continuous mode, the intermediate products can be continuously or semi-continuously recycled to the reduction step as a control powder. Some initial amount of control powder used at the beginning of the operation may be required.

In all embodiments, an inert gas can be used to direct gaseous chlorides through various processing zones or outward for collection and further processing and/or recirculation. In all embodiments, unreacted base metal chlorides can be condensed and returned for processing at higher temperatures in the reactor, either continuously or batchwise.

The residence time of the reactants in the reduction stage at temperatures below _T1 is determined by a combination of factors including the reaction threshold temperature and the physical characteristics of the base metal chlorides being processed; preferably and where possible, the T1 value is set below the boiling/sublimation temperature of the starting base metal chlorides.

When the materials from the reduction stage are sent to the purification reactor, the remaining unreacted materials react, forming aluminum chloride byproducts. An external gas flow can be used to remove volatiles from the reactants in a direction opposite to the flow of the solid reactants. The external gas flow removes the AlCl3 byproduct from the solid products and exits the reactor, where it is removed from the gas stream in a dedicated collector at a temperature below 160°C. The reactants in the purification reactor are preferably continuously mixed to maximize reaction yield and minimize loss of base metal chlorides. Unreacted materials entering the high-temperature section of the purification reactor are vaporized and directed by the external gas flow to lower-temperature regions, where they condense and are then recycled.

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The residence time of the materials in the reactor during the purification step affects the degree of agglomeration/sintering of the powder products, and the method may include the step of varying the residence time to obtain the desired particle size/morphology distribution.

As discussed previously, the processing temperature in both the reduction and purification stages is determined by the properties of the base metal and base metal chloride materials, in addition to the composition and morphology of the final product. The minimum temperature may also depend on the sublimation temperature of the precursor materials, and the method may include a primary reduction stage, as described in the following embodiments. However, it is preferred that the minimum reactor temperature in the purification stage be approximately 200°C, i.e., above the sublimation temperature of aluminum chloride.

Another objective of the present invention is to provide a reactor for implementing the method as described in various embodiments. The reactor comprises vessels for conducting reactions in the reduction and purification stages and can be made of any material capable of withstanding temperatures up to 1100°C without reacting with the precursor chemicals and end products. The reactor can consist of any protective shell and corresponding accessories capable of ensuring close and effective contact between the flow of materials being reduced and the flow of the reducing Al alloy. The reactor can consist of two separate vessels for the reduction and purification stages or a single vessel configured for use in both the reduction and purification stages. Both the reduction and purification stage reactors can include mechanisms for moving and mixing the reactants. In a preferred embodiment, the reactor for the purification stage consists of a tubular reactor capable of operating at temperatures up to 1100°C, with means for moving, mixing, heating, recirculating and transferring reagents, a by-product collection unit and a final product collection unit.

In a preferred embodiment, the reactor may comprise several separate heating zones, each of which provides for different reactions or condensation functions.

In all embodiments, the reactor may additionally include additional gas inlet ports located throughout the reactor and its auxiliary devices.

In all embodiments, the reactor includes vents to remove gases from the reactor.

In one embodiment, the reactor may include a moving device for moving and mixing the powder from the reactor inlet to the reactor outlet.

Fig. 7 is a schematic diagram showing an example of a reactor configuration that includes both a reduction stage and a purification stage for carrying out the process in a continuous mode.

For this basic configuration, a mixing/reactor system is provided to illustrate the basic functions of a reactor suitable for implementing certain preferred embodiments. The main body (301) of the reactor for the reduction stage is a cylindrical vessel made of materials capable of withstanding base metal-based chemicals and alloying additives at temperatures up to 1100°C. The reactor (301) includes means for heating and cooling the reactor to the required operating temperatures. A continuous pre-mixer (302) is provided with an externally driven mixer (303) (304) for mixing base metal chlorides (305), a control powder (306) and a reducing Al alloy powder (307), and then the resulting mixture is fed through an inlet (309) into the reactor (301). Also provided, but not shown in the diagram, are bins and feeders for storing and transporting reagents to the pre-mixer. The premixer is not critical to reactor operation, and the inlet connections may or may not be directly attached to the reactor vessel. A gas inlet (310 and 310A) is also provided at the reactor inlet, and flow through (301) is in the same direction as the solid reactants. Dopants may be added either directly to the premixer (302) or as a component of other reactants (305) and (307).

At the outlet of the reactor (301), a condenser (311) is provided, in which materials from (301), including gaseous substances released/evaporating from the reactor (301), can be condensed/cooled before being introduced into the holding chamber (312). The condenser is maintained at room temperature and includes means for transporting reactants from the inlet to the outlet. The means for condensing gaseous substances in the condenser can include any means known in the art, including a fluidized bed, cooled scrapers and/or any other means by which gaseous chloride substances can be condensed and mixed with another solid product to obtain a mixture (314) before being fed into (313). The temperature of the condenser is controlled by external cooling means (not shown). Inert gas from (301) can exit through the port (315). A portion of the mixture (314) is fed back to the pre-mixer via a suitable conveyor system (316) and used as a control powder. The remainder is transferred to the purification reactor (317).

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In one embodiment, not shown here, the reactor (301) includes an additional outlet at the powder outlet level, and this additional outlet can be used to remove gaseous aluminum chloride before feeding the reactant to the condenser (311).

For the cleaning step, a basic configuration of a screw conveyor is provided, intended only to illustrate the main functions of a reactor suitable for implementing some preferred embodiments in accordance with the above aspects of the invention described in this document. The main body of the cleaning reactor consists of a tubular main section (317) made of materials capable of withstanding temperatures up to 1100 °C and not reacting with the materials processed therein. In the example in Fig. 7, a screw (318) is provided for moving reagents through (317). Section (317) has an outlet (319) for gases used in the reactor and any gaseous by-products formed as a result of the process and leaving the reactor. The reactor also includes a chamber or chambers (320) for collecting by-products from the gas stream. Section (317) also includes means (321) for moving powder from (312) into the reactor.

At the end outlet for the product, one or more openings (322) are provided for introducing an inert gas and gaseous precursor materials. An outlet opening (323) for the product and a chamber (324) for collecting the product are also provided.

It is preferable that section (317) and all internal walls located inside this section are maintained at a temperature higher than the boiling temperature(s) or the sublimation temperature(s) of the by-products. Section (317) has a minimum temperature _T2 at the powder inlet through (321), increasing to a temperature _Tmax at the level of (325) and then decreasing to room temperature at the powder product outlet level. Temperatures _T2 and _Tmax depend on the materials being processed. _T2 and _Tmax are controlled by heating/cooling means (not shown). T2 is preferably higher than the sublimation temperature(s) of the by-products. The minimum temperature _T2 is preferably about 200°C.

As discussed previously, T _max is preferably below 1100°C, more preferably below 1000°C, and even more preferably below 900°C. After the reactor section, at T _max , the products advance to the powder outlet, where they are cooled to room temperature and discharged. For example, when nickel chlorides are reduced using Al, the maximum temperature T1 in the reduction stage (301) is set to 500°C, the minimum temperature _T2 in the purification stage is preferably set to 200°C, and T _max is set in the range from 850°C to 950°C.

The configuration in Fig. 7 is intended to illustrate the functionality of the continuous reactor only, and some auxiliary devices that form part of the reactor system are not shown, including containers for storing solid reactants in an inert atmosphere, auxiliary devices for feeding powder, and powder mixers.

For the reactor configuration shown in Fig. 7, the precursor materials to be reduced in (305), (306), and (307) are fed separately into a continuous premixer (302) and then into the reactor (301), mixed in situ, and heated at a temperature of between 160°C and 660°C. As the materials react, they form an intermediate product of an alloy of the base metals and the remaining unreacted materials, and this product is then processed through a condenser (311). A portion of the resulting mixture is returned to the premixer as a control powder. It should be noted that some initial amount of control powder used at the beginning of the operation may be required.

As the products from the reduction stage pass through the reactor section (317), any remaining unreacted materials react or vaporize. An external gas stream is introduced into the reactor through a gas inlet (322) in the direction opposite to the flow of the solid reactants. The external gas stream helps displace byproducts from the reactor for the purification stage. The reacting materials in section (317) are continuously mixed to maximize the contact surface area between the reactants and to complete the reduction reactions of the residual unreacted reactants. Product formation occurs through the formation of fine submicron-sized particles, followed by sintering and agglomeration of the particles, resulting in products with larger particle sizes. The residence time of the materials in the reactor influences this agglomeration/sintering process, and therefore the method includes a step of adjusting the residence time to achieve the desired particle size distribution and degree of agglomeration.

In a preferred embodiment, the heating/cooling means in sections (301), (311), and (317) control the heat flow in the reactor and maintain the temperature profile required for processing in both stages, but especially in the reduction stage. As can be seen from Table 1, for all base metals covered by this description, the reactions between the chlorides of the base precursor metals and the Al reduction alloy are highly exothermic. However, some portions of the reactor vessel may need to be heated first to reach a threshold temperature sufficient to initiate the reaction, but the reactor may then need to be cooled to maintain the threshold temperature and prevent overheating.

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Examples

The following examples illustrate the preparation of alloys and compounds from base metals in accordance with embodiments of the present invention.

Example 1. Fe-Al-Cr alloy._____________________________________________________________

Element The original chemical substance Ms (mg) % mass. SG СгС1 ₃ 473 16.80 Fe FeCl ₃ 2362 81.24 Al A1C1 ₃ 490 1.96

Ms: mass of starting chemicals (mg).

Me: mass of elemental base metal in the final product (mg) example 1: Fe-Al-Cr alloy.

Control powder: Fe-Al-Cr alloy.

Total final products: ~825 mg.

The following method was used for testing in the examples listed below. Ecka A1 powder with a grain size of 4 µm was used for all tests unless otherwise noted.

a) The chlorides of the main precursor metals were first thoroughly mixed to obtain a homogeneous mixture of the chlorides of the main metals (Mx1).

b) Al was mixed with AlCl ₃ to obtain an Al-AlCl ₃ mixture with a mass equal to that of the base metal chloride mixture (Mx2). This last step is intended to: (i) improve the contact between the base metal chlorides and the Al reducing agent when mixed during reduction; and (ii) use AlCl ₃ as a cooling agent in the reduction step.

c) 100 mg Mx1 is mixed with a certain amount of Mx2 (100 Mx2/Mx1) and the resulting mixture is introduced into a quartz tube under Ar at 1 atm.

d) The mixture is heated at 500°C while rotating the quartz tube to ensure adequate mixing of the reactants. In the first stage, without the control powder, the reaction occurs explosively, causing the powder to be ejected from the bottom of the tube. It is then collected and heated again to complete the reaction between Mx1 and the Al reducing agent; the intermediate products at this stage are designated Pd1.

e) Removal of by-products.

f) Pd1 is mixed with certain amounts of Mx1 and Mx2 (Pd1 > Mx1 + Mx2). The amounts of Mx1 and Mx2 are increased after each cycle as the experiment progresses and more products are obtained.

g) Go to d).

h) Continue until all precursor materials have been used.

i) The mixture is then heated from 500°C to 1000°C in 100°C increments for 10 minutes at each step.

j) The powder is then discharged, washed, dried and analyzed.

Example 2. Ni powder___________________________________________________________

Element The original chemical substance Ms (mg) Me (mg) % mass. Ni NiCl ₂ 4920 2080 100 Al Al 720 0 0

Control powder: Ni.Al powder is mixed with 1.740 g AlCl ₃ .

Total final products: ~ 2 g.

The reduction process was carried out as described above for Example 1. The resulting powder consisted of agglomerated, irregular, spongy grains with a broad size distribution. The powder was analyzed using X-ray diffractometry (XRD), X-ray luminescence (XRF), and inductively coupled plasma (ICP). The X-ray diffraction pattern is shown in Fig. 8, where peaks corresponding to pure Ni are shown. ICP analysis revealed that the Al content was less than 0.1 wt%.

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Example 3. Fe powder.

Element The original chemical substance Ms (mg) Me (mg) % mass. Fe FeCl ₃ 5814 2000 100 Al Al 966 0 0

Control powder: Fe. Al powder is mixed with 1.940 g of AlCl3.

Total final products: ~ 1.8 g.

The recovery process is carried out as described above for example 1.

The powder was analyzed using XRD, XRF, and ICP. The XRD pattern is shown in Fig. 9, where peaks corresponding to pure Fe are shown. ICP analysis showed that the Al content was less than 0.1 wt%.

Example 4. SS316.__________________________________________________________________________

Element The original chemical substance Ms (mg) Me (mg) % mass. Fe FeCl ₃ 19767 6800 68 Ni NiCl ₂ 2838 1200 12 Cr CrCl ₃ 4784 1700 17 Mo MoCl ₅ 855 300 3 Al A1C1 ₃ 4625 0 0

Control powder: semi-processed intermediate products from the reduction stage. Al powder is mixed with 9.25 g of AlCl ₃ .

Products: ~ 9.6 g.

The reduction process is carried out as described previously for Example 1. The powder consists of irregular agglomerated particles. The XRD pattern is shown in Fig. 10. The ICP and XRF analysis data show that the Al content is on the order of 0.7 wt%, while the Cr content is about 12.7 wt%, which is below the target value (17 wt%). This discrepancy is likely due to the batch operation of the test tubular reactor with ineffective mixing and no recirculation. Since CrCl _x is more stable than other chloride reactants, elemental Cr tends to reduce FeCl _x , NiCl ₂ , and MoCl _x . Since CrCl ₂ is quite stable, it can only be reduced by direct contact with Al. Two remedies were developed to address this difficulty. First, the reduction/recirculation time was increased and mixing was improved. Second, the limited reactivity of CrCl _x was compensated for by using more CrCl ₃ in the starting precursors.

Example 5. INCONEL 718._______________________________________________________

Element The original chemical substance Ms (mg) Me (mg) % mass. Ni NiCl ₂ 6300 2660 53.26 Fe FeCl ₃ 2689 925 18.5 Cr CrCl ₃ 2617 930 18.6 Mo MoCl ₅ 442 155 3.1 Nb NbCl ₅ 728 250 5 Ti TiCl ₃ 145 45 0.9 Mn MnCl ₂ 23 10 0.2 C c 2 2 0.04 Al A1C1 ₃ 2039 20 0.4

Control powder: semi-processed INCONEL-AlCl ₃ powder from the reduction stage. Ecka A1 powder is mixed with 4.434 g of AlCl ₃ .

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Products: ~4.85 g.

The reduction process was carried out as described above for Example 1. The XRD pattern is shown in Fig. 11, showing peaks consistent with Inconel 718. The ICP and XRF analyses confirmed that the content was Al 0.4 wt.%, Ti 0.2 wt.%, Mn 0.1 wt.%, Mo 3.4 wt.%, Nb 5.6 wt.%, Cr 13.6 wt.%, Fe 19.4 wt.%, and the balance was Ni.

Example 6. MAR-M-509.__________________________________________________________

Element The original chemical substance Ms (mg) Me (mg) % mass. So СоС1 ₂ 6054 2745 54.9 Ni NiCl ₂ 1183 500 10 SG СгС1 ₃ 3293 1170 23.4 That's it TaS1 ₅ 347 175 3.5 W WC1 ₆ 620 350 7 Ti TiCl ₃ 40 12.5 0.25 Zr ZrCl ₃ 45 17.5 0.35 WITH C-A1C1 ₃ 300 30 0.6 Al A1C1 ₃ 1676 0 0

Control powder: semi-processed MAR-M-509 - AlCl ₃ from the reduction stage. C is introduced as crushed graphite, 1 part graphite - 9 parts AlCl ₃ . Al is introduced as Al-AlCl ₃ 1 part Al 3 parts AlCl ₃ . Al powder is mixed with 4.265 g AlCl ₃ .

Products: ~ 4.8 g.

The reduction process is carried out as described above for Example 1. The XRD pattern in Fig. 12 corresponds to known alloy structures. ICP analysis shows that the Al content is below 500 ppm.

Example 7. Obtaining Ta from TaCl ₅ .____________________________________________________

Element The original chemical substance Ms (mg) Me (mg) % mass. That's it TaS1 ₅ 10400 5000 100 A1 A1C1 ₃ 1243 0 0

TaC1 ₅ + 1.666 A1 = Ta + 1.666 A1C1 ₃

Ecka Al (grain size = 4 µm) is mixed with AlCl ₃ (weight ratio 1:2); total: 3.730 g.

The amount of TaCl ₅ is 5% higher than the stoichiometric amount to compensate for losses associated with manual material handling. Excess tantalum chlorides are removed during the purification stage.

Control powder: Ta.

Total final products: ~4.77 g.

The recovery process is carried out as follows.

The oven is set to 500°C.

Step 1: 100 mg TaCl ₅ + 33 mg Al-AlCl ₃ are introduced into a quartz tube.

Step 2: The quartz tube is placed in a furnace; when the reaction occurs, the by-products of aluminum chloride + some TaCl ₅ evaporate and precipitate on the cold part of the tube.

The tube is removed from the oven.

Scrape by-products + residues back into the reaction zone at the bottom of the tube.

The resulting mixture is used as a control powder for the next reaction cycle.

Step 3: Add another 50 mg of TaCl ₅ than in step 1 and triple the amount of TaCl ₅ for Al-AlCl ₃ .

Mix with the control powder already in the tube.

Stage 2 is carried out.

Continue the process until all TaCl ₅ is used.

Add the remaining Al-AlCl ₃ and proceed to step 2.

Mix the products with collected by-products + residues.

Heat at 500°C for 10 minutes.

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Collect by-products + residues.

Mix the products with collected by-products + residues.

Heat at 500°C for 10 minutes. Collect and remove the resulting byproducts.

It is heated in a rotating quartz tube at a temperature from 500°C to 1000°C in 100°C increments at a rate of 10°C per minute.

The product is collected, washed and dried.

Analysis: Figure 13 shows the XRD data of the obtained materials, which are consistent with pure Ta. ICP analysis shows that the Al concentration in the sample is about 530 ppm.

Example 8. SMA - FeNiCoAlTaB powder,________________________________________

Element The original chemical substance Ms (mg) Me (mg) % mass. Fe FeCl ₃ 1329 457 41.5 So СоС1 ₂ 442 200 18.2 Ni NiCl ₂ 689 291 26.5 That's it TaS1 ₅ 179 90.5 8.2 IN IN oh, and oh, and 0.01 A1 A1 445 62.1 5.6

The initial precursor of boron is powder B. Ecka Al (4 μm) mixed with 1.555 g AlCl ₃ .

The process is carried out as described in Example 1. ~0.92 g of powder is collected. The XRD spectra are shown in Fig. 14. ICP and XRF analyses indicate that the composition matches the target.

Example 9. AlCoCrCuFeNi powder HEA._____________________________________________

Element Original Ms (mg) Me (mg) % mass. chemical substance So СоС1 ₂ 1300 589 18.64 Ni NiCl ₂ 1230 520 16.46 SG СгС1 ₂ 1652 587 18.58 Si SiS1 ₂ 1346 636 2011 Fe FeCl ₃ 1625 559 1767 Al Al 1350 270 8.54

Control powder: AlCoCrCuFeNi HEА. Ecka Al powder (grain size = 4 μm) is mixed with _AlCl3 (weight ratio 1:2); total: 4.050 g.

Total final products: ~ 3 g.

The restoration process is carried out in two stages.

First, the procedures described for Example 1 are used throughout the reduction stage to obtain an approximate composition equivalent to CoCrCuFeNi.

The remaining A1 is then added gradually using the same procedure as in Example 1.

The resulting materials are then processed in a purification stage to remove residual chlorides and coarsen the powder products.

The X-ray diffraction patterns of the obtained powder products are shown in Fig. 15.

The products were analyzed using XRF and ICP and the results were consistent with the expected composition.

Example 10. Skeletal Co catalyst,_______________________________________________

Element The original chemical substance Ms (mg) Me (mg) % mass. So СоС1 ₂ 1299 589 81 A1 A1 990 0 19

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Chlorides of the main metals are mixed with 2.7 g of AlCl ₃ .

Ecka Al (4 µm) is mixed with AlCl ₃ (weight ratio 1:2); total: 2970 mg.

The recovery process is carried out in two stages.

First, the procedures used in Example 1 for MAR-M-509 are used throughout the reduction step to obtain an approximate composition equivalent to Co.

The remaining Al is then added gradually using the same procedure as in Example 1.

The resulting materials are then processed in a purification stage to remove residual chlorides and coarsen the powder products.

The X-ray diffraction patterns of the obtained powder products are shown in Fig. 16.

A 1 g sample of Co-Al powder was washed (for 2 h) in 60 ml H ₂ O plus 10 ml NaOH (50 mol%). The powder was then washed in distilled water until the pH became neutral. The X-ray diffraction pattern of the obtained materials is shown in Fig. 17. The absence of significant peaks is noted due to the hyperfine structure of the obtained skeletal structure.

The present method can be used to produce alloys and compounds of various compositions, including compounds of pure metals, oxides and nitrides of Al, Zn, V, Cr, Co, Sn, Ag, Ta, Ni, Fe, Nb, Cu, Pt, W, Pd and Mo, including alloying additives as described above. Modifications, variations, products and the use of said products, as is obvious to a person skilled in the art, are considered to be within the scope of the present invention.

Materials obtained using the present invention possess unique characteristics that cannot be achieved using prior art. The present invention extends to materials that can be manufactured using the present invention and materials, without being limited to the examples provided in this description by way of illustration. Specific properties include the ability to produce nanostructured and/or complex compositions that may be unattainable using conventional powder production technologies.

In the following claims and in the preceding description of embodiments, except where the context otherwise requires because of the express language or the necessary meaning, the words include (and comprise) and variations such as includes or including (and contains or comprising) are used in an inclusive sense to indicate the presence of the claimed features, but not to exclude the presence or to exclude the addition of additional features in various embodiments of the invention.

Furthermore, it will be apparent to those skilled in the art that many modifications can be made without departing from the spirit and scope of the invention; in particular, it will be apparent that certain features of the embodiments of the invention can be used to form additional embodiments.

Claims (12)

1. A method for the controlled exothermic reduction of a chloride of one or more base metals selected from Zn, V, Cr, Co, Sn, Ag, Ta, Ni, Fe, Nb, Cu, Pt, W, Pd and Mo using an Al reducing agent, comprising contacting said one or more metal chlorides, a control powder and an Al reducing agent, which are in the form of fine powder particles with an average particle size of less than 500 μm in at least one dimension, at temperatures from 160 to 600°C in a reduction step in which at least 50% of the chlorine contained in the original chloride of the base metal is removed, and a cleaning step at temperatures above the sublimation/evaporation temperature of the chlorides of the base metal and below the maximum temperature T _max with the formation of a powder product of a metal or metal alloy and a by-product including aluminum chloride; and wherein the purification step serves to purify the powder product and complete the reduction reaction resulting in the formation of a solid powder product and a gaseous by-product; and separating the by-products from the metal or metal alloy powder product; wherein the control powder comprises one or more metals selected from Zn, V, Cr, Co, Sn, Ag, Ta, Ni, Fe, Nb, Cu, Pt, W, Pd and Mo, or an alloy or compound thereof, and serves to control the exothermic release of heat during the reduction reaction, thereby maintaining the reaction temperature below Tmax; _Tmax is between 400 and 1100°C, which is below the melting point of the base metal or metal alloy product, and the reaction is controlled such that the heat released by the reaction does not increase the reaction temperature by more than 200°C. 2. The method according to claim 1, wherein T _max is higher than the sublimation/evaporation temperature of one or more metal chlorides. 3. The method according to any one of claims 1 or 2, wherein in the first step said metal chlorides are metal chlorides that are mixed and reacted with said con- - 25 050552 with a trol powder, and then the obtained intermediate products are subjected to interaction with a powdered Al reducing agent. 4. The method according to claim 1 or 3, in which the control powder is introduced in an amount sufficient to absorb the heat released by exothermic reactions and to limit the increase in the reaction temperature to a value less than ΔT=200°C, and where the amount of control powder per 1 kg of metal chlorides is from M _c /100 to M _c ; and where Tmin Tr, and the ratio of the chlorides of the main metals to the control powder is from 0.03:1 to 100:1 by weight, and where _Tr is the threshold reaction temperature, C _p-b is the specific heat capacity of the main metals, _Mb is the mass of the product _Mb per 1 mol of _the initial chlorides of the main metals _{MbCl x} , and _MaiCi3 and C _p- Aia3 are, respectively, the mass and specific heat capacity of the resulting by-product aluminum chloride per 1 mol MbCl _x . 5. The method according to any one of the preceding claims, wherein the control powder further comprises aluminum chloride. 6. A method according to any one of the preceding claims, comprising providing a first stream of materials comprising one or more metal chlorides and, optionally, precursor alloying additives; obtaining a second stream of materials including an Al reducing agent; and obtaining a third stream of materials including a control powder; feeding the said flows into the reaction zone and mixing and interaction of the said flows at temperatures from 25 °C to T _max ; where T _max is between 400 and 1100°C; Al reducing agent is in the form of powder, flakes or fine particles made from pure Al-based element, alloy or compound; the base metal is one or more metals selected from Zn, V, Cr, Co, Sn, Ag, Ta, Ni, Fe, Nb, Cu, Pt, W, Pd and Mo; and the precursor materials for the alloying additive precursors include one or more pure elements, chlorides, oxides, nitrides and any other compound or alloy or intermetallic compound containing the element. 7. The method of claim 6, comprising continuously feeding and mixing materials from said streams at temperatures increasing from T ₀ to T 1 for a first residence time and then at temperatures between T ₂ and T _max for a second residence time; where T ₀ is between 160 and 600°C, T 1 is below 660°C, T ₂ is between 200 and 700°C and T _max is between 400 and 1100°C; and where the first residence time is sufficient to reduce all of the original base metal chlorides to a chlorine content of less than 50% of the chlorine content of the original base metal chloride. 8. The method according to any one of the preceding claims, wherein the metal chloride comprises one or more metal chlorides selected from ZnCl ₂ , VCl( ₂ , ₃ , ₄ ), CrCl( ₂ , ₃ ), CoCl ₂ , SnCl( ₂ , ₄ ), AgCl, TaCl( ₄ , ₅ ), NiCl ₂ , FeCl( ₂ , ₃ ), NbCl ₅ , CuCl( 1, ₂ ), PtCl( ₄ , ₃ , ₂ ), WCl( ₄ , ₅ , ₆ ), PdCl ₂ and MoCl ₅ , and wherein the reactions between the metal chlorides and the Al reducing agent are exothermic at temperatures below 500°C and the energy released is greater than 10 kJ per 1 mole of said metal chloride. 9. The method according to claim 1, wherein the metal chloride reacts with the control powder by chlorine substitution reactions and/or single substitution reactions to form intermediate reducible substances. 10. The method of claim 1 for producing an alloy, compound or catalyst, comprising performing the method of claim 1 to produce a product from a metal alloy containing one or more metals selected from Zn, V, Cr, Co, Sn, Ag, Ta, Ni, Fe, Nb, Cu, Pt, W, Pd and Mo, and containing more than 10 wt.% Al; and an additional second step of removing Al by dissolving it in an alkali metal hydroxide or in an acid. 11. The method of claim 1, wherein the metal chloride comprises TaCl ₅ , NbCl ₅ , MoCl ₅ , FeCl ₃ , WCl( ₄ , _{5 or} 6), VCl( _{3 or 4} ) or SnCl ₄ , and wherein the method comprises the main step of reducing the metal chloride to obtain an intermediate product comprising TaCl(0, 2, 3 or 4), NbCl(0, 2, 3 or 4), MoCl^, 2, 3 or 4), FeCl(0 or 2), W ^Cl (0, 2, 3, 4 or 5), ^VCl (0, 2 or 3) ^{or SnCl} 2 12. The method of claim 1, wherein the metal chloride comprises TaCl ₅ , NbCl ₅ , MoCl ₅ , FeCl ₃ , WCl( ₄ , 5 _or 6), VCl(3 _or 4) or SnCl ₄ , and wherein the method comprises the steps of - 26 050552 interaction of a metal chloride with a control powder and an Al reducing agent in a reaction zone at temperatures from 160 to 600°C to obtain a mixture of a metal or metal alloy, an Al or Al alloy and metal subchlorides; and condensation of the metal chlorides evaporated from the reaction zone and their return to the said reaction zone, wherein the condensed metal chlorides are in the form of a solid powder or in liquid form; and processing the resulting mixture of a metal or metal alloy, an Al or Al alloy and metal subchlorides to obtain an alloy from the base metal.