KR19990048242A - Method for producing pure titanium powder from titanium oxide using self-burning reaction - Google Patents

Abstract

A method of producing pure titanium (Ti) powder from titanium oxide (TiO ₂ ) powder by using a self-propagating high-temperature synthesis is disclosed. According to the present invention, titanium oxide (TiO ₂ ) and magnesium (Mg) are mixed at a molar ratio of 1: (2 to 2.5), and then compacted by applying a molding pressure of 4 to 14 tons to form pellets. Next, the pellets are charged into the self-combustion reactor and ignited and burned in the self-combustion reactor under an argon (Ar) gas atmosphere. The resulting combustion product is taken out of its own combustion reactor and leached using nitric acid (HNO ₃ ) diluted 5-50%. Thereafter, the leachate is filtered using a filter paper, and the filtrate is washed and dried to obtain pure titanium (Ti). Pure titanium (Ti) thus obtained shows high purity of 99.93% or more.

Description

Method for producing pure titanium powder from titanium oxide using self-burning reaction

The present invention relates to a method for producing pure titanium (Ti) powder from titanium oxide (TiO ₂ ) powder by using a self-propagating high-temperature synthesis (hereinafter referred to as SHS), in particular magnesium ( Mg) powder is used as a reducing agent to reduce titanium oxide (TiO ₂ ) powder, and magnesium oxide (MgO) obtained as a by-product is leached with nitric acid (HNO ₃ ) to prepare pure titanium (Ti) powder. It is about.

In general, pure titanium (Ti) is a metal material which is light, excellent in corrosion resistance and excellent in properties at relatively high temperatures. In particular, due to its high tensile strength ratio, it is suitable as an aircraft material that requires light weight and strength. It is expected that the demand will increase as a new industrial material.

As such, pure titanium (Ti) is a very excellent material, but since it is a chemically strong metal, special care is required in its manufacture. In order to produce a titanium (Ti), ores (原鑛) of Ilmenite (ilmenite; FeO · TiO ₂₎ or rutile (rutile; TiO ₂₎ and then subjected to the pretreatment for concentrating the in TiO _2, carbon (C) Is added and chlorine (Cl ₂ ) is blown into the reactor to form titanium tetrachloride (TiCl ₄ ) as an intermediate raw material. At this time, according to the Kroll method, one of the methods for producing pure titanium (Ti), argon (Ar), helium (He), etc. by distilling and purifying titanium tetrachloride (TiCl ₄ ) as shown in the following reaction formula (I). Is reduced to magnesium (Mg) in an inert gas atmosphere to form sponge titanium, a sponge-like metal mass.

TiCl ₄ + 2Mg → Ti + 2MgCl ₂ ----------- (Ⅰ)

On the other hand, according to the Hunter method, one of the methods for producing pure titanium (Ti), sponge tetrazide titanium is reduced by distilling and purifying titanium tetrachloride (TiCl ₄ ) to sodium (Na) in an inert gas atmosphere. You can also make it. In addition, pure titanium (Ti) can also be produced by molten salt electrolysis or pyrolysis of titanium oxide. Among the methods for producing titanium (Ti) as mentioned above, only the Kroll method has been developed and industrialized.

However, in order to perform such a Kroll method, complicated facilities are required, and manufacturing costs are high.

The present invention has been made to solve the conventional problems as described above, an object of the present invention is to reduce the titanium oxide (TiO ₂ ) powder as a raw material powder using magnesium (Mg) powder as a reducing agent in the self-combustion reaction method. Thereafter, magnesium oxide (MgO) obtained as a by-product is leached using nitric acid (HNO ₃ ) to provide a method of producing pure titanium (Ti) powder.

1 is a manufacturing process chart of the pure titanium (Ti) powder according to the present invention.

2 is a diagram schematically showing the configuration of a self-burning reactor used to carry out the present invention.

Figure 3 is a graph showing the X-ray diffraction results of the reaction product obtained by the self-burn reaction of a powder mixed with titanium oxide (TiO ₂ ) and magnesium (Mg) in a molar ratio of 1.0: 2.0 according to a preferred embodiment of the present invention . And

FIG. 4 shows the results of X-ray diffraction after leaching a reaction product obtained by self-combustion of a powder mixed with titanium oxide (TiO ₂ ) and magnesium (Mg) in a molar ratio of 1.0: 2.0 according to a preferred embodiment of the present invention. The graph shown.

<Explanation of symbols for main parts of drawing>

10: preheat 12: green pellets

14: Thermocouple 16: Data Collector

20 computer 22 tungsten (W) filament

24: power supply 26: heat-resistant glass

28 vacuum pump 30 inert gas supply source

32: vent 34: cooling device

36: infrared thermometer 100: self-burning reactor

102: reactor chamber

In order to achieve the above object, the present invention,

Mixing titanium oxide (TiO ₂ ) and magnesium (Mg) at a constant ratio (S1);

Molding the mixture formed in the step (S1) into pellets (S2);

Charging said pellets into a self-combustion reactor (S3);

Combusting the pellets in the self-burning reactor (S4);

Taking out the combustion product made in the step (S4) from the self-combustion reactor (S5);

Leaching the combustion product with nitric acid (HNO ₃ ) (S6);

Filtering the leachate leaching in step S6 (S7); And

It provides a method of producing a pure titanium powder comprising the step (S8) of washing the titanium (Ti) powder filtered in the step (S7).

Preferably, the pure titanium powder manufacturing method, after the step (S8), further comprises a step (S9) of drying the washed titanium (Ti) powder.

The titanium oxide (TiO ₂ ) and the magnesium (Mg) are mixed in a molar ratio of 1: (2 to 2.5). Preferably, the purity of the titanium oxide (TiO ₂ ) is 98.56% or more.

In the reactor chamber, a vacuum atmosphere or an argon (Ar) gas atmosphere is formed.

As mentioned above, in the method for producing pure titanium powder according to the present invention, magnesium oxide (MgO) obtained as a by-product after reducing titanium oxide (TiO ₂ ) powder using magnesium (Mg) powder as a reducing agent Pure titanium (Ti) powder is prepared by leaching with nitric acid (HNO ₃ ).

Hereinafter, the manufacturing process of the pure titanium (Ti) powder according to the present invention with reference to the accompanying drawings in more detail.

First, FIG. 2 is a diagram schematically showing the configuration of a self-burning reactor used to carry out the present invention. Referring to FIG. 2, the self-burning reactor 100 mainly consists of the reactor chamber 102 and its peripheral devices. The self-burning reactor 100 may have any structure as long as it can create a vacuum or inert gas atmosphere in the reactor chamber 102 and ignite the specimen located in the reactor chamber 102.

The preheating furnace 10 is located in the center of the reactor chamber 102 of the self-burning reactor 100. Preferably, the preheating furnace 10 has a cylindrical shape of 30 cm in diameter and 40 cm in length. In the preheating furnace 10, a green pellet 12 made of titanium oxide (TiO ₂ ) and magnesium (Mg) is located. One side of the preheating furnace 10 is equipped with a thermocouple 14 for measuring the temperature of the green pellet 12 to be burned in the preheating furnace 10. Thermocouple 14 is electrically connected to computer 20 via data collector 16.

Within the reactor chamber 102, tungsten filaments 22 for igniting the green pellets 12 located in the preheater 10 are located just above the preheater 10. Tungsten filament 22 receives current from a power source 24 located outside the reactor chamber 102. On one side wall of the reactor chamber 102 is a heat-resistant glass 26 of a disc shape that can be opened and closed. The heat-resistant glass 26 performs the inlet and outlet of the green pellet 12 while opening and closing as needed, and allows the operator to check the combustion state of the green pellet 12 with the naked eye through the heat-resistant glass 26. .

At the bottom of the reactor chamber 102 is connected a vacuum hose 29 for establishing a vacuum in the reactor chamber 102. The vacuum hose 29 extends to a vacuum pump 28 located outside the reactor chamber 102. The vacuum pump 28 draws air in the reactor chamber 102 as needed to create a vacuum. In addition, an inert gas supply hose 31 for introducing an inert gas into the reactor chamber 102 is connected to a lower end of the reactor chamber 102. The inert gas supply hose 31 extends to an inert gas supply source 30 located outside the reactor chamber 102. Inert gas source 30 provides inert gas, such as hydrogen (H ₂ ) or argon (Ar), into reactor chamber 102 as needed. In addition, the vent 32 formed on one side of the lower end of the reactor chamber 102 maintains a constant pressure in the reactor chamber 102 or discharges the pressure in the reactor chamber 102 to the outside when the heat-resistant glass 26 is opened. Let's do it.

Cooling devices 34 for maintaining a constant temperature in the reactor chamber 102 are installed in the upper and lower portions of the reactor chamber 102. Above the outer side of the reactor chamber 102, a vacuum instrument panel 36 is provided for notifying the vacuum state formed in the reactor chamber 102.

A process of manufacturing pure titanium (Ti) powder using the self-burning reactor 100 having the configuration as described above will be described.

In the present invention, titanium oxide (TiO ₂ ) and magnesium (Mg) are mixed in a constant molar ratio to obtain titanium (Ti) and magnesium oxide (MgO) by SHS and leaching it with nitric acid (HNO ₃ ) to magnesium oxide (MgO). ) To remove pure titanium (Ti). In general, the SHS used in the present invention is a self-combustion reaction method in which a chemical reaction between a solid and a solid is an exothermic reaction and synthesizes a material using its own heat of chemical reaction after ignition of the material without supplying energy from the outside.

As the raw material powder used in the present invention, titanium oxide (TiO ₂ ) having a particle size of 0.3 μm and magnesium (Mg) having a particle size of 10 to 100 μm are employed. At this time, the purity of the titanium oxide (TiO ₂ ) of the raw material powder is closely related to the purity of the pure titanium (Ti) powder to be obtained in the present invention. That is, as the purity of titanium oxide (TiO ₂ ) is increased, the purity of pure titanium (Ti) is increased. Preferably, the purity of titanium oxide (TiO ₂ ) is 98.56%, its chemical composition is shown in Table 1 below.

Table 1

Element (weight%) TiO ₂ Fe ₂ O ₃ H ₂ O K ₂ O P ₂ O ₅ SO ₃ Cr ₂ O ₃ MnO CdO ZnO 98.56 0.054 0.22 0.36 0.2 0.1 0.0003 0.00023 0.00018 a very small amount

After preparing titanium oxide (TiO ₂ ) and magnesium (Mg) having the chemical composition, titanium oxide (TiO ₂ ) and magnesium (Mg) are uniformly mixed in a molar ratio of 1: 2 or 1: 2.5. Next, the mixture of titanium oxide (TiO ₂ ) and magnesium (Mg) is compressed by applying a predetermined molding pressure. Preferably, it compresses by applying molding pressure of 4-14t. This is because, when a molding pressure of 4t or less is applied, the pellet is easily broken due to the low pressure, and when the molding pressure of 14t or more is applied, the pellet does not ignite well.

After compressing the mixture of titanium oxide (TiO ₂ ) and magnesium (Mg), the heat-resistant glass 26 of the self-combustion reactor 100 is opened and the green pellet 12 composed of titanium oxide (TiO ₂ ) and magnesium (Mg) ) Into the reactor chamber 102. That is, the green pellet 12 is located in the preheating furnace 10. Under this condition, after closing the heat-resistant glass 26, the vacuum pump 28 is operated to create a vacuum in the reactor chamber 102, or the inert gas source 30 is operated to inert gas, into the reactor chamber 102, Preferably argon (Ar) gas is introduced. After that, the heat-resistant glass 26 is closed, and the green pellet 12 is ignited and burned by applying a current from the power supply source 24 to the tungsten filament 22.

At this time, the process of forming titanium (Ti) and magnesium oxide (MgO) using the SHS is shown in the following scheme (II).

TiO ₂ + 2Mg → Ti + 2MgO ---------- (II)

After obtaining titanium (Ti) and magnesium oxide (MgO) from a green pellet (12) consisting of titanium oxide (TiO ₂ ) and magnesium (Mg), the mixture was leached with nitric acid (HNO ₃ ) to oxidize as shown in the following reaction formula (III). Magnesium (MgO) is removed to obtain pure titanium (Ti).

Ti + 2MgO + (HNO ₃ ) (ℓ) → Ti ↓ + (2MgO + HNO ₃ ) (ℓ) ----------- (Ⅲ)

At this time, nitric acid (HNO ₃ ) is used for a solution diluted to about 5 to 50%, it is carried out for 0.5 to 5 hours at a temperature of about 50 ~ 70 ℃. Thus precipitated titanium (Ti) powder is recovered using a filter paper and washed several times to remove impurities remaining in the titanium (Ti) powder, and then dried in a dryer to a temperature of about 70 ℃ to pure titanium ( Ti).

Pure titanium (Ti) prepared according to the present invention, since impurities are volatilized and dissolved by nitric acid (HNO ₃ ) during the combustion process, the final product exhibits a high purity of 99.93% or more.

Hereinafter, a preferred embodiment of the present invention will be briefly described.

Example

Titanium oxide (TiO ₂ ) (a prototype of Titanium Powder Co., Ltd.) and magnesium (Mg) are added to a ball mill in a molar ratio of 1: 2 or 1: 2.5, respectively, and mixed for at least 5 hours as a raw material powder. Next, the mixed powder is applied with a pressure of 4 to 14 tons to form pellets having a diameter of 20 mm and a height of 15 to 20 mm. The pellets thus formed are sufficiently dried in a dryer at a temperature of about 60 ° C., and then ignited and burned in an argon (Ar) gas atmosphere in a self-combustion reactor. Thereafter, the generated sample is analyzed using X-ray diffraction (hereinafter referred to as XRD).

Figure 3 is a graph showing the X-ray diffraction results of the reaction product obtained by the self-burn reaction of a powder mixed with titanium oxide (TiO ₂ ) and magnesium (Mg) in a molar ratio of 1.0: 2.0 according to a preferred embodiment of the present invention . Referring to FIG. 3, it can be seen that titanium (Ti) and magnesium oxide (MgO) are produced.

Alternatively, the pellets are ignited and burned to leach the reaction product produced by nitric acid (HNO ₃ ) diluted to about 5-50%, and then the precipitated titanium (Ti) is recovered using a filter paper. . Then, several times the titanium (Ti) is washed and sufficiently dried in a dryer at a temperature of 60 ~ 70 ℃ and analyzed by XRD.

FIG. 4 shows the results of X-ray diffraction after leaching the reaction product obtained by self-combustion of a powder mixed with titanium oxide (TiO ₂ ) and magnesium (Mg) in a molar ratio of 1.0: 2.0 according to a preferred embodiment of the present invention. The graph shown. Referring to FIG. 4, it can be seen that magnesium oxide (MgO) shown in FIG. 3 is removed by leaching and only pure titanium (Ti) is present as a final product. In addition, the final product was measured by atomic absorption spectrometer, it was confirmed that the high purity powder of 99.93% or more.

As mentioned above, in the method for producing pure titanium powder according to the present invention, magnesium oxide (MgO) obtained as a by-product after reducing titanium oxide (TiO ₂ ) powder using magnesium (Mg) powder as a reducing agent Pure titanium (Ti) powder is prepared by leaching with nitric acid (HNO ₃ ). Therefore, the high temperature reactor required by the conventional titanium (Ti) manufacturing method becomes unnecessary, and the manufacturing process is simplified. In addition, since the combustion reaction of the reactant proceeds automatically by the self-heating amount, the energy efficiency is high, and the purity of the product is higher than that of the reactant.

Although described above with reference to a preferred embodiment of the present invention, those skilled in the art will be variously modified and changed within the scope of the invention without departing from the spirit and scope of the invention described in the claims below. I can understand that you can.

Claims (9)

Mixing titanium oxide (TiO ₂ ) and magnesium (Mg) at a constant ratio (S1); Molding the mixture formed in the step (S1) into pellets (S2); Charging said pellets into a self-combustion reactor (S3); Combusting the pellets in the self-burning reactor (S4); Taking out the combustion product made in the step (S4) from the self-combustion reactor (S5); Leaching the combustion product (S6); Filtering the leachate leaching in step S6 (S7); And Method of producing a pure titanium powder comprising the step (S8) of washing the titanium (Ti) powder filtered in the step (S7). The method of claim 1, further comprising drying the washed titanium (Ti) powder (S9) after the step (S8). The method of claim 1, wherein the titanium oxide (TiO ₂ ) and the magnesium (Mg) are mixed in a molar ratio of 1: (2 to 2.5). The method for producing pure titanium powder according to claim 1 or 3, wherein the purity of the titanium oxide (TiO ₂ ) is 98.56% or more. The method of claim 1, wherein in the step (S2), the mixture is compressed by applying a molding pressure of 4 to 14 tons to form the pellets. The method of claim 1, wherein a vacuum atmosphere is formed in the reactor chamber. The method of claim 1, wherein an inert gas atmosphere is formed in the reactor chamber. 8. The method for producing pure titanium powder according to claim 7, wherein the inert gas atmosphere is made of argon (Ar) gas atmosphere. The method of claim 1, wherein in the step S6, the combustion product is leached using nitric acid (HNO ₃ ) diluted to 5 to 50%.