KR20160082948A - Manufacturemethod for titanium powder - Google Patents

Abstract

The present invention relates to a preparation method for a surface-modified titanium powder, wherein the preparation method comprises the followings: raw materials including titanium dioxide (TiO_2) and a metal reducing agent are subjected to self-propagating high temperature synthesis (SHS), to produce titanium (Ti); residues and chlorides of the metal reducing agent are removed therefrom through an acid leaching process; titanium sponges are broken down into pellet shapes to produce a titanium powder; the titanium powder, from which residues and chlorides of the metal reducing agent are removed, is heated to control the particle size of the titanium powder; and the titanium powder is surface-modified through one treatment method selected among electron beam melting, DC plasma treatment, RF plasma treatment and vacuum arc melting.

Description

TECHNICAL FIELD [0001] The present invention relates to a method for producing titanium powder,

The present invention relates to a method for producing titanium (Ti) powder, and more particularly, to a method for manufacturing a titanium (Ti) powder by a titanium oxide (TiO ₂ ) (Ti) powder.

Titanium powder is widely used as a material for various parts because of its excellent physical and chemical properties.

Generally, the titanium powder is produced by a Kroll process. In the crawling process, titanium oxide (Ti) in an oxide form is chlorinated and then pulverized into a tetrachloride (TiCl ₄ ) form. Titanium sponge and magnesium chloride (MgCl ₂ ), which is a byproduct of reaction, are produced by reducing the produced titanium tetrachloride (TiCl ₄ ) with molten magnesium (Mg). Next, magnesium chloride as a reaction by-product is removed by vacuum distillation, and a titanium (Ti) sponge is recovered. The recovered titanium (Ti) sponge is shredded and made of titanium (Ti) powder. However, in the case of the crawling process, since chlorination of titanium (Ti) and distillation for removing reaction by-products are performed, there is a disadvantage that the number of apparatuses for manufacturing is increased and the time required for manufacturing is increased.

Electrometallurgy processes have been proposed to solve the disadvantages of such a crawling process. In the electrolytic smelting process, distillation for removing reaction by-products is eliminated, and only titanium (Ti) is selectively recovered using the redox potential difference in the molten salt electrolyte. However, in the electrolytic smelting process, the disadvantage of the crawling process can be solved, but since the decomposition voltage of the water-based electrolyte is higher than the decomposition voltage of water, it must necessarily proceed in the molten salt electrolyte. Therefore, in the electrolytic smelting process, there is a disadvantage that the corrosion of the apparatus and the reaction atmosphere must be controlled.

In addition, the titanium (Ti) powder produced by the above processes has disadvantages such as high production cost and facility cost, rough surface, inconsistent particles, difficulty in continuous operation, low production efficiency, and impurities due to pulverization .

SUMMARY OF THE INVENTION The present invention has been made to solve the problems of the prior art as described above and it is an object of the present invention to provide a method of manufacturing a magnetic recording medium in which titanium (Ti) powder is subjected to electron beam melting, DC plasma treatment, RF Plasma Treatment) and vacuum arc melting (Vacuum Arc Melting).

In order to attain the above described object of the present invention, the present invention is titanium dioxide (TiO ₂₎ and rotating the raw material containing the metal reductant combustion synthesis reaction (SHS: self- Propagating High Temperature Synthesis ) and titanium (Ti) sponge, metal (2) in which the metal reducing agent oxide and the excess metal reducing agent produced in the step (1) are removed by an acid leaching process, the step (2) in which the reducing agent oxide and the excess metal reducing agent are produced, (3) in which the metal reducing agent oxide and the excess of the metal reducing agent are removed in the step (3) and the titanium (Ti) sponge is broken into the sintered body form to produce the titanium (Ti) ) Powder surface is subjected to any one of an electron beam melting method, a DC plasma treatment method, an RF plasma treatment method, and a vacuum arc melting method Titanium containing surface modification (4) steps is to provide a (Ti) powder production process.

More specifically, the metal reducing agent used in step (1) may be magnesium (Mg), aluminum (Al), carbon (C), or calcium (Ca).

Also, the titanium dioxide (TiO ₂ ) and the metal reducing agent are prepared by mixing each powder and in the form of a compacted compact. The compressed mixture may be self-standing inside the reactor during the reaction of the self-assembled combustion reaction.

In step (2) (S20), the metal reducing agent oxide and the excess metal reducing agent generated after the reduction of the titanium dioxide (TiO ₂ ) may be removed through an acid leaching process. Accordingly, only the titanium sponge can be selectively recovered by removing the metal reducing agent oxide and the surplus metal reducing agent.

Also, in the step (3) (S30), the titanium (Ti) sponge may be crushed to produce titanium (Ti) powder in the form of a sintered body.

Meanwhile, the size of the titanium (Ti) powder in the step (4) can be controlled by the heat generated during the surface modification process. In the step (4), the titanium (Ti) powder having a relatively small particle size may be relatively increased in comparison with the particle size of the titanium (Ti) powder before being condensed and surface modified in the course of surface modification.

In another embodiment of the present invention, the titanium (Ti) powder may have the same particle size of the initial powder and the same particle size after the surface modification.

The particle size of the titanium (Ti) powder before the surface modification according to the present embodiment is 0.1 to 200 μm, and the size of the particles of the titanium (Ti) powder after the surface modification can be 0.1 to 200 μm have.

The titanium (Ti) powder prepared by the manufacturing method of the above steps (1) to (4) can be used as a part manufacturing and 3D printing material using a metal powder injection molding process.

According to the method for producing titanium (Ti) powder according to the embodiment of the present invention, the following effects can be expected.

First, in the embodiment of the present invention, the particle size of the titanium (Ti) powder can be controlled by heat treatment.

Further, the titanium (Ti) powder whose particle size is adjusted may be surface-modified to have a smoother surface.

In addition, high purity titanium (Ti) powder can be produced by removing the impurities contained in the titanium (Ti) powder due to the high-density heat source treatment method.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a flow chart schematically illustrating a method for producing titanium (Ti) powder according to an embodiment of the present invention. FIG.
FIG. 2 is a photograph of a titanium (Ti) powder according to an embodiment of the present invention. FIG. 2 (a) is a photograph of titanium (Ti) powder before DC plasma treatment, Photo of titanium (Ti) powder.
FIG. 3 is a graph showing changes in reaction temperature and fraction of reaction products depending on the molar ratio of magnesium (Mg) as a metal reducing agent.
FIG. 4 is a graph showing the results of measuring the temperature change with the progress of the combustion wave in the reaction between titanium dioxide (TiO ₂ ) and magnesium (Mg) as a metal reducing agent during the reaction of the synthesis of the combustion.
5 is a graph showing the XRD (X-ray diffraction) analysis results of the surface-modified powder and the commercial titanium powder.

Hereinafter, a method for manufacturing titanium (Ti) powder according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a flow chart schematically showing a method for producing titanium (Ti) powder according to an embodiment of the present invention, and FIG. 2 is a photograph showing a surface modification process of titanium (Ti) powder according to an embodiment of the present invention FIG. 3 (a) is a photograph of titanium (Ti) powder before DC plasma treatment, (b) is a photograph of titanium (Ti) powder after DC plasma treatment, FIG. 4 is a graph showing the result of measuring the temperature change with the progress of the combustion wave in the reaction between titanium dioxide (TiO ₂ ) and magnesium (Mg) XRD (X-ray diffraction) analysis of surface-modified powder and commercial titanium powder.

Referring to FIG. 1, the present invention provides a method for producing a titanium sponge, comprising the steps of: (1) producing a titanium sponge; and (2) adding a metal reductant oxide and a surplus metal reductant, (2) step (S20), (3) step (S30) in which titanium (Ti) powder is produced, and surface modification step (S40) in which the titanium (Ti) (Ti) powder.

In the embodiment of the present invention, magnesium (Mg), calcium (Ca), aluminum (Al) or carbon (C) may be used as the metal reducing agent in the step (1) Aluminum (Al) is less reactive than magnesium (Mg) and calcium (Ca) is more reactive than magnesium (Mg), but calcium oxide (CaO) produced as a by-product of the reduction reaction is difficult to completely remove in the acid leaching process . The carbon (C) has a disadvantage of requiring a long heat treatment because of a high melting point. Therefore, magnesium (Mg) may preferably be used as the metal reducing agent in this embodiment. Such limitations are not absolute but refer to metal reducing agents mainly used in embodiments of the present invention. Accordingly, a metal reducing agent which is not melted at the reaction temperature of the embodiment of the present invention can be included in the metal reducing agent.

In an embodiment of the present invention, the step (S10) of the step (S10) comprises the steps of subjecting a raw material containing titanium dioxide (TiO ₂ ) and a metal reducing agent to self- .

More specifically, the titanium dioxide (TiO ₂ ) and the metal reducing agent are prepared as a mixture of compacts obtained by mixing each powder. The mixture of the molded bodies may be self-standing inside the reaction chamber.

Also, referring to FIG. 4, the reaction for the synthesis of the carbon-based combustion reaction may proceed at 1300 ° C to 1400 ° C, preferably at 1372.2 ° C.

In the above-mentioned self-propelled synthesis reaction, synthesis is carried out spontaneously by receiving heat by the continuous exothermic reaction of the reactants. That is, the rotating combustion synthesis reaction, in a reaction and character of titanium dioxide (TiO ₂₎ and then mixing the metal reducing agent to adjust the partial pressure of an inert gas such as argon (Ar) gas state, the titanium dioxide to the reaction (TiO ₂ ) And a metal reducing agent. After the ignition, heat is generated in the process of reacting the initial reactants, whereby heat is generated as the reaction of the reactants proceeds, so that the reaction can proceed without external heat supply.

In step (2) (S20), the metal reducing agent oxide and the excess metal reducing agent generated after the reduction of the titanium dioxide (TiO ₂ ) may be removed through an acid leaching process. At this time, the metal reducing agent oxide may be magnesia (MgO), calcia (CaO), aluminic acid (AlO ₃ ), and carbon dioxide (CO ₂ ). Accordingly, only the titanium sponge can be selectively recovered by removing the metal reducing agent oxide and the surplus metal reducing agent.

In an embodiment of the present invention, the acid leaching reaction may be an aqueous acid solution of acetic acid (CH ₃ COOH), hydrochloric acid (HCl), nitric acid (HNO ₃ ) or sulfuric acid (H ₂ SO ₄ ) It is not absolute but is a limitation on the acid used mainly in the embodiment of the present invention to remove reaction by-products. Therefore, no additional by-products are produced during the acid leaching reaction with the reaction by-products of the present invention, and all acids capable of removing all of the reaction by-products can be included in the reaction.

Also, in the step (3) (S30), the titanium (Ti) sponge may be crushed to produce titanium (Ti) powder in the form of a sintered body.

In the embodiment of the present invention, the step (4) is a method of surface-modifying the titanium (Ti) powder, and includes an electron beam melting method, a plasma treatment method and a vacuum arc melting method Can be applied.

Also, in the plasma treatment, DC plasma treatment and RF plasma treatment are available. Since RF plasma treatment is about 10 to 100 times faster than DC plasma treatment, the reaction proceeds relatively quickly. The present invention is not limited to such a treatment method, and a high-density heat source-related treatment method capable of surface modification of the titanium powder can be applied.

Therefore, in the embodiment of the present invention, the titanium (Ti) powder having a relatively small particle size due to the heat generated in the step (4) (S40) is condensed in the process of surface modification, Can be increased relative to the particle size of the titanium (Ti) powder before being reformed (see FIG. 2).

In another embodiment of the present invention, the titanium (Ti) powder may be surface-modified to have the same particle size as the particle size of the initial powder and the particle size after the surface modification.

In the embodiment of the present invention, the titanium (Ti) powder produced by the manufacturing method of the above (1) to (4) can be produced within the following range.

The size of the titanium (Ti) before the surface modification may be in the range of 0.1 to 200 mu m, and the size of the particles after the surface modification may be in the range of 0.1 to 200 mu m. When the size of the titanium (Ti) before and after the surface modification is less than 0.1 탆, there is a problem in that it is difficult to deal with oxidation prevention. When the size exceeds 200 탆, the titanium (Ti) powder is not surface- There is a problem that application is limited to manufacturing parts using powder metallurgy and addictive manufacturing.

Hereinafter, the present invention will be described in more detail with reference to Examples. It will be apparent to those skilled in the art that these embodiments are merely illustrative of the present invention and that the scope of the present invention is not limited to these embodiments.

< Example  1>

Synthesis reaction  Through titanium ( Ti ) Powder manufacturing

As a result of the thermodynamic calculations for the synthesis reaction using 'FactSage 7.0', as shown in FIG. 3, all the TiO ₂ participating in the reaction was reduced to Ti from the stoichiometric ratio of 2 Mg, and 2MgO, which is a reaction by- Respectively. In order to apply it to the experiment, TiO ₂ + As the reaction progresses, it can be seen that the reaction continuously occurs at 1372.2 ° C without a large temperature increase or decrease due to the continuous reaction heat of the reactants as shown in FIG.

< Example  2>

XRD  The prepared titanium ( Ti ) Powder analysis

As a result of XRD (X-ray diffraction) analysis of the titanium (Ti) powder of the present invention, it can be confirmed that it is a titanium (Ti) single phase having a hexagonal dense crystal structure as shown in FIG.

< Example  3>

DC plasma  By DC Plasma Treatment Surface modified titanium ( Ti ) Powder manufacturing

According to the stoichiometric ratio obtained through Example 1, TiO ₂ and 2Mg were mixed to carry out the reaction for the synthesis of the combustion reaction. After the reaction was completed, TiO ₂ was reduced to Ti and 2MgO, a byproduct of the reaction, was produced. Ti sponge was recovered through acid leaching process. The recovered Ti sponge was subjected to a mechanical pulverization process to produce a Ti powder having a d ₅₀ of 4.7 μm. The prepared Ti powder was subjected to DC plasma treatment under the conditions shown in Table 1 below to produce 31.8 μm Ti powder with a d ₅₀ (see FIG. 2).

In addition, observation of titanium powder through a scanning electron microscope (fe-SEM: Field Emission Scanning Electron Microscope) revealed that the surface of the Ti powder is constant and has a smooth surface.

Classification variable Power (kW) 9.0 Current (A) 300 Voltage (V) 30 30 Exhaust gas (L / min) Ar 15 Pressure (torr) 760 Supply (g / min) 1.0 Carrier gas (L / min) Ar 3

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the appended claims and their equivalents. .

Claims (10)

(1) a titanium (Ti) sponge and reaction by-products are produced by self-propagating high temperature synthesis (SHS) of a raw material containing titanium dioxide (TiO ₂ ) and a metal reducing agent;
(2) removing the metal reductant oxide and excess metal reducing agent, which are reaction byproducts, in the step (1) by an acid leaching process;
(3) the titanium (Ti) sponge in which the metal reducing agent oxide and the surplus metal reducing agent are removed in the step (2) is crushed into a sintered body to produce titanium (Ti) powder;
(4) The surface of the titanium (Ti) powder produced in the step (3) is subjected to an electron beam melting, a DC plasma treatment, an RF plasma treatment and a vacuum arc melting Arc Melting); (Ti) powder.
The method according to claim 1,
Wherein the particle size of the titanium (Ti) powder is controlled by the heat generated in the step (4).
3. The method of claim 2,
In the titanium (Ti) powder, the titanium (Ti) powder having a relatively small particle size in the step (4) has a particle size smaller than the particle size of the titanium (Ti) powder before being surface- (Ti) powder.
The method according to claim 1,
Wherein the titanium (Ti) powder is surface-modified to have a particle size equal to the particle size of the initial powder and the particle size after the surface modification.
5. The method according to any one of claims 1 to 4,
Wherein the titanium (Ti) powder before the surface modification step has a particle size of 0.1 mu m to 200 mu m.
5. The method according to any one of claims 1 to 4,
Wherein the titanium (Ti) powder after the surface modification step has a particle size of 0.1 mu m to 200 mu m.
The method according to claim 1,
Wherein the metal reducing agent is magnesium (Mg), aluminum (Al), carbon (C), or calcium (Ca).
The method according to claim 1,
Wherein the titanium oxide (Ti) and the metal reductant are mixed with each powder to produce a mixture of the powders, during the reaction (1).
9. The method of claim 8,
The method of manufacturing titanium (Ti) powder according to any one of the preceding claims, wherein the mixture of the shaped bodies in the self-standing synthesis reaction is self-standing inside the reactor.
A 3D printing material comprising titanium (Ti) powder produced by the method for producing a titanium (Ti) powder according to any one of claims 1 to 4 and 7 to 10.

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