JPH0288727A - Production of metal titanium - Google Patents

Abstract

PURPOSE:To enable continuous operation and to drastically improve recovery efficiency of a titanium by suitably extracting molten titanium alloy and supplying Mg and TiCl4 and molten metal. CONSTITUTION:Mg and the molten metal are charged into a reaction vessel 10 at each single body or under beforehand making the alloying state. Successively, the reaction vessel 10 is heated and held to the temp. for melting the charging material, to make the molten alloy. Under this condition, the molten alloy surface is positioned to lower side than a magnesium chloride discharging pipe 10c. Then, supplying of TiCl4 from an introducing hole 12b is started. TiCl4 blown into the molten alloy is reduced with Mg in the molten alloy to produce metal Ti, and immediately the molten metal and the molten alloy of Zn, etc., are formed. The produced metal titanium alloy is suitably extracted under molten state, and molten alloy is replenished, and by supplying TiCl4 of the raw material, semi-continuous or continuous operation can be executed.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a method for manufacturing titanium metal.

Titanium, which is a high-melting-point, high-toughness material, is mainly produced by reduction of chloride with magnesium, the so-called Kroll process. The present invention provides a manufacturing method suitable for continuous manufacturing of titanium metal based on the Kroll method.

[Prior art and its problems]

The manufacturing method of metallic titanium using the crawl method has conventionally been carried out using a batch method, but there have been problems such as low production efficiency and increased equipment size. Therefore, several continuous manufacturing methods have been proposed to solve this problem. For example, US Pat. No. 2,826,492 proposes a method of heating produced titanium above its melting point and continuously extracting it as a melt. Also, in US Pat. No. 4,390,365, Ti
F4 is reduced with Al-Zn alloy to obtain Ti-Zn alloy,
A method for decomposing and collecting this as a melt is disclosed.

However, the former method is difficult to implement because there is no refractory material that can withstand the melting of titanium, and the latter method
The formation of a Ti-Zn-Al ternary alloy cannot be avoided, and since Al has a strong affinity with Ti, it is extremely difficult to separate the two.

Based on the above technical background, the present inventors have determined that by using a metal that forms a molten alloy with titanium and is easy to separate from titanium, such as Zn, Pb, Cu, etc. A method was developed in which titanium produced by reduction with magnesium is captured by the above metal, converted into a molten alloy, and continuously recovered, and this method was disclosed in JP-A-60-89592 (hereinafter referred to as "prior application").

In the method of the prior application, the magnesium and the molten metal are each charged into the furnace as a single molten body, and are separated into layers due to the difference in specific gravity. When liquid TiCl4 is supplied to the surface of metallic magnesium, TiCl4 is reduced by magnesium to produce metallic titanium, which settles to the lower molten metal layer due to the difference in specific gravity, where the molten titanium alloy and will be collected as appropriate. Further, MgC1□ produced as a by-product accumulates between the molten metal layer and the metal magnesium layer, and is extracted as appropriate.

According to the above method, it is possible to operate semi-continuously or continuously by extracting the molten titanium alloy appropriately and supplying magnesium, TiCl4, and molten metal.

Further, it has many practical advantages, such as easy separation and purification of titanium and the fact that Y and M are omitted.

However, although the production method of the above-mentioned prior application allows continuous operation, the reaction rate cannot exceed 1 ct compared to the conventional batch method.

[Structure of the invention]

The present invention further improves the above-mentioned method of the prior application, and by changing the bath composition, the recovery efficiency of titanium is greatly improved, and a production method that enables stable continuous operation has been achieved.

According to the present invention, in a method for producing titanium in which titanium metal is obtained by reducing titanium tetrachloride with magnesium, an alloy of magnesium and a metal that forms a molten alloy with titanium and is separable from titanium at the reduction temperature is prepared in advance. charging a reaction vessel as a molten alloy, supplying titanium tetrachloride into the alloy bath;
There is provided a method for producing titanium metal, characterized in that a reduction reaction is carried out in the alloy bath, and the produced titanium is taken out from the reaction zone as a molten alloy.

In the present invention, an alloy of the above-mentioned molten metal (M) and Mg is charged into a furnace as a molten alloy in advance, and T is added to the Mg-M alloy bath.
Supply iCl4. The molten metal is a metal that forms a molten alloy with titanium at a reduction temperature and is separable from titanium, such as Zn, Pb, Ni, Cu, Sn, Bi.
is preferably used. When supplying TiCl4, it is preferred to insert a supply pipe into the alloy bath and blow gaseous TiCl, into the bath.

The reduction reaction in the alloy bath is extremely rapid and stable due to the stirring effect of gas injection, and no unreacted titanium tetrachloride or lower chlorides of titanium are produced, and the produced titanium is quickly removed. to form a molten alloy. In a steady state, this molten titanium alloy naturally contains magnesium as a reducing agent, but this magnesium content, which is approximately equal to the amount of Mg in the Mg-M bath, is 1% by weight or less, Kg can be easily removed from the recovered titanium alloy by vacuum distillation or molten salt electrolysis.

In addition, in order for the above reduction reaction to proceed stably, Mg -M
It is preferable that the amount of Mg in the bath is 0.5% by weight or more.

The method of the present invention is a semi-continuous method or a continuous method, and the raw materials are charged intermittently or continuously, but the titanium produced is a melt at the reaction temperature and can be taken out continuously.

Magnesium chloride, a by-product, floats on the bath surface and can also be taken out continuously.

Titanium is separated from the extracted titanium alloy by vacuum distillation of the alloy metal, electrolysis, etc. Magnesium is recovered from the recovered magnesium chloride by molten salt electrolysis.

Next, the present invention will be described in detail with reference to the drawings.

The accompanying drawings are conceptual diagrams showing an example of an apparatus used to carry out the method of the present invention.

The apparatus consists of a reaction vessel 10 and a heating furnace 20 that accommodates the reaction vessel 10. The furnace is made of refractory and insulating material and is internally equipped with suitable heating means, usually electrical resistance heating means 21.

The reaction vessel 10 is provided with an upper lid 12, a discharge pipe 10b for the produced titanium alloy, and a discharge pipe 10c for the by-product magnesium chloride. The valves provided in these discharge pipes are heat-resistant valves using heat-resistant gaskets made of ordinary asbestos, carbon, etc., and are commercially available. The reaction vessel is also provided with a flange 10a that serves as a support when placed in the heating furnace 20.

The lid of the reaction vessel has inlet ports 12a and 12a' for supplying magnesium and alloy metals, and an inlet port 12b for titanium tetrachloride.
, an opening 12c used for introducing an inert gas such as argon and measuring pressure.

Of these inlets, 12a is a valve similar to the above for charging magnesium or alloy metal in the form of a melt, and 12a' is a comparative valve equipped with a slide tamper for charging in the solid state. It is a large opening.

By cooling the opening, the titanium tetrachloride vapor can be refluxed so that the opening can be opened and the solid material can be charged.

The actually manufactured device has an inner diameter of 484 mm and a height of 625 mm.
■, thickness 12mm 5US304 (18-8Cr-N
i steel) It was made of steel plate, but Mo like SUS 316
It may be roughly manufactured using Cr-Ni containing steel or carbon steel. Depending on the type of alloy metal used, if these materials are insufficient, a material lined with oxide refractory material or carbon stamp material may be used. As mentioned above, it is possible to use a large device with a refractory lining containing magnesia.

The method of the invention is carried out as follows.

When the above-mentioned apparatus is first put into operation, magnesium and molten metal are charged into a container, either alone or in a pre-alloyed state. These materials are usually supplied in a molten state through the inlet, but in some cases it is preferable to charge alloy metal or metallic magnesium in a solid state to control (cool) the temperature of the reaction system after the reaction has started. . The container is heated and maintained at a temperature at which the charge melts (around 750° C.) to form an alloy bath. In this state, the liquid level of the molten alloy is located below the magnesium chloride discharge pipe 10c. At this point, the supply of titanium tetrachloride is started from the inlet 12b. -Once the reaction starts, it is an exothermic reaction, so
The temperature of the reaction system rises and reaches a steady state of 900-1000°C. If this happens, there is no need for external heating.

TiC1, injected into the molten alloy bath, is reduced by Mg in the bath to become metallic titanium, which is immediately converted into Z
form a molten alloy with a molten metal such as n.

The generated metallic titanium alloy is appropriately extracted in a molten state,
Semi-continuous or continuous operation is possible by replenishing the molten alloy bath and supplying the raw titanium tetrachloride.

〔Effect of the invention〕

The method of the present invention has the following advantages over conventional methods.

(1) Unlike conventional batch furnaces, there is no need for incidental equipment for product separation, making it possible to increase the size of the furnace and shift to mass production methods such as copper smelting.

(2) Products and by-products are automatically discharged, and there is no heating/cooling cycle, so there is little wear and tear on the equipment. Therefore, there is a patent that features an inner wall of the reaction vessel, which allows operation at high temperatures without worrying about the formation of Fe--Ti alloys, as is the case with conventional iron reaction vessels.

(3) In the conventional batch method, only a certain amount of magnesium is charged at the beginning, and as titanium is produced, magnesium is physically captured and precipitated together, and is retained in the spongy titanium. Although the amount of effective magnesium decreases and the reaction rate decreases as the amount of magnesium decreases, the method of the present invention can maintain the highest production rate because raw materials can be continuously supplied, and the production rate is much higher than that of the batch method. High efficiency.

(4) In addition, in the batch method, a large amount of unreacted Mg and by-product MgC1□ remain in the titanium sponge produced, so the purification process to separate and remove these is a heavy burden, but in the method of the present invention, the Kg content is is suppressed to 0.5 to 1% by weight, reducing the burden on the purification process.

(5) In the method of the present invention, TiCl4 is fed directly into the reducing alloy bath, preferably in gaseous form, so that Ti
Since a large number of small bubbles of C1 are dispersed in the bath and the reaction area is greatly increased, the production efficiency is improved by about three times compared to the method of the previous application.

Example 1 First, 120 kg of zinc and 2 kg of magnesium were added to the above reactor.
1 kg of each solid was charged and heated to 750°C to dissolve. After that, Mg-Zn is introduced through the introduction pipe 12b.
Blowing of TiCl4 into the molten alloy was started. When the supply of titanium tetrachloride was started, the temperature inside the reaction vessel rose to 90%
The temperature reached 0°C to 1000°C. The feed rate of titanium tetrachloride was initially 200 m/min, and was gradually increased to 840 m/min after 10 minutes, and this feed rate was then maintained. After one hour, 42 kg of by-product magnesium chloride was discharged, and at the same time, 70 kg of Ti alloy produced was extracted.

The extracted Ti alloy has a composition of 13.6% Ti and 1 Mg.
．． 2% (residual Zn). Immediately after that, take 60% zinc.
11 kg of solid Mg and 11 kg of Mg were supplied, and the supply of titanium tetrachloride was continued. 42 in the same manner at 30 minute intervals thereafter.
kg of magnesium chloride and 70 kg of Ti alloy were extracted.
Immediately, the operation of replenishing 60 kg of zinc and 11 kg of magnesium was repeated. Such semi-continuous operation was continued for 10 hours to obtain a total amount of 1550 kg of Ti alloy. The composition of the Ti alloy extracted each time was Ti12-15%, Mg0.5-1
．． It was 2% (residual Zn). In addition, the supply rate of titanium tetrachloride was approximately 840 m12/min during the 10-hour operation time.
was able to be maintained constant.

The Ti alloy thus obtained was heated at 1000°C, 10-
'n.

Vacuum distillation was performed under Hg conditions to separate and remove zinc and magnesium to obtain spongy pure titanium. The impurities in the obtained titanium were as follows.

c: o, oos% H,: 0.001%0
: 0.040% N2: 0.001% C1
: 0.01% Mg: 0°02% Mn: 0
．． 021% Ni: 0.001% Zn:
0.01% (wt%) Example 2 The same equipment as in Example 1 was used and the reaction was initiated in the same manner. The supply speed of TiC1 is 840m+lI/mi
n, and the Mg-Zn molten alloy was blown into the Mg-Zn molten alloy through the introduction pipe 12b. After one hour, 42 kg of MgCl2 was discharged, and thereafter, continuous operation was started. That is, while continuously charging the =12-Zn-15%Mg alloy prepared in advance with a solution at a rate of 156 kg/hr, on the other hand, TiCl4 was supplied and the produced Ti alloy and by-product MgCl were maintained at 840 mΩ/min. , were discharged at 3θ minute intervals, 70 kg and 42 kg, respectively. Continuous operation like this for 24
Although the reaction continued for a long time, the reaction was extremely stable, and the internal pressure did not increase due to unreacted TiC 1°, and the discharged M
No lower Ti chloride was observed in gC1□. The average composition of the discharged Ti alloy is Ti14.2%, Mg0
．． It was 8%.

This Ti alloy was vacuum separated under the same conditions as in Example 1, and
23 kg of Ti sponge was obtained. The analysis value of Ti was almost the same as in Example 1.

Example 3 Using the same apparatus as in Example 1, titanium was produced using Cu as the alloy metal. Initially, 150 kg of a Cu-24% Ti alloy (containing 1% Mg) was charged into a reaction vessel in advance and a molten alloy was prepared at 900° C., and then TiCl was blown into the molten alloy. At the same time as starting TiCl4 introduction, molten alloy of Cu-25%Mg was introduced from the inlet 12a at 92°C.
It was continuously charged at a rate of kg/hr. TiCl4
The feed rate was kept constant at 840 m12/min.

91kg/hr of Ti alloy produced after 30 minutes
is continuously discharged from the discharge port 10b at a rate of
gC1□ was also discharged from the discharge port 10c at a rate of 87 kg/hr.

Continuing this continuous operation for 12 hours, Ti-Cu
1083 kg of alloy was obtained.

This Ti-Cu alloy is electrolytically refined in a molten salt bath mainly composed of NaCl-KCI, and the cathode contains dendrite-like Ti.
I got it. After washing this with ion-exchanged water, it was dried and analyzed, and the results were as follows.

Fe: 0.008% 0: 0.035
%Cu: 0.012% N: 0.00
2%Mn: 0.03%C: 0.002
%C1: 0.027% H: 0.001%
10b, 10cm discharge pipe 12a, 12a', 12b-inlet 20...heating furnace 12...lid 12c...opening 21...heating means

Claims (1)

[Scope of Claims] 1. In a titanium production method in which titanium metal is obtained by reducing titanium tetrachloride with magnesium, an alloy of magnesium and a metal that forms a molten alloy with titanium and is separable from titanium at the reduction temperature is provided. Charge the reaction vessel as a molten alloy in advance,
A method for producing titanium metal, which comprises supplying titanium tetrachloride into the alloy bath, causing a reduction reaction in the alloy bath, and removing the produced titanium from the reaction zone as a molten alloy. 2. The alloying elements that form the molten alloy with titanium are Zn and P.
2. The method of claim 1, wherein the material is selected from the group consisting of: b, Ni, Cu, Sn, Bi. 3. An alloy of metal and magnesium that forms a molten alloy with titanium and is separable from titanium is continuously introduced into a reaction vessel, and the titanium alloy produced as a result of the reaction and magnesium chloride as a by-product are continuously discharged. The method of claim 1. 4. The magnesium content in the alloy bath is 0.5 to 1.
3. The method of claim 3, wherein the weight percentage is % by weight.