JPH03150326A - Method of manufacturing metals by reduction - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a method for producing metal by a reduction reaction of a metal halide, and more particularly to a continuous method for producing metal by flowing metal particles.

[Conventional technology]

Metal Ti is a typical metal produced by a reduction reaction of a metal halide. The production of metallic Ti by the reduction reaction of 7% metal halogenide is carried out industrially by the Kroll method, but this method is a batch method, and these days, when other metal production methods are continuous, it is difficult to produce Ti metal. Therefore, recently, the generation metal particles are fed into the reactor, and gaseous bodies of metal halide and reducing agent are blown up from below the particle group, thereby reducing the amount of metal particles. Japanese Unexamined Patent Publication No. 15339/1989 proposes 11 metal production methods using the so-called fluidization method, in which a group of particles is brought into a fluid state, and the produced metal is fixedly grown on the surface of the produced metal particles and extracted out of the reactor. When producing metallic Ti by the flow method, TiCj! . The metal Ti particles are blown up by the vapors of Mg and Mg to form a fluidized state, and TiCJ! , is reduced by Mg. The gold JiiTl generated by this reduction reaction adheres and accumulates on the surface of the metal Ti particles, thereby growing the metal Ti particles. Therefore, there are metal Ti particles and TiCj! in the reactor. a and Mg
While continuing to feed the respective vapors, the grown metal Ti
Metallic Ti is produced continuously by extracting particles from the reactor. The flow reaction in the reaction vessel is carried out at a temperature below the melting point of Ti, and with Mg and MgCl2. In order to prevent condensation of the reaction, it is said that it is necessary to conduct the reaction at a pressure lower than the vapor pressure of any substance at the reaction temperature. [Problem to be solved by the invention] The production method of metallic Ti using the fluidized bed method is a remarkable method in that it can be carried out continuously, but practical application on an industrial scale has not yet been realized. . This is because, in this method, the reaction in the reactor is a high-temperature reduction reaction, and extremely reduced pressure operation is forced to be performed in order to lower the reaction temperature from the apl due to the heat resistance of the reactor. That is, when the reaction temperature is suppressed below the heat resistance limit of the reactor, Mg and Mg as a reduction product are reduced at that temperature.
Cj! Conventionally, the reaction temperature was set at 1100°C and the reaction pressure was set at 5QTorr (0-065at
(2) Operating conditions are required, and it is extremely difficult to maintain the reduced pressure inside the reactor in such a continuous operating system that involves high temperatures. An even more fundamental problem is the fact that in a fluidized reduction reaction under reduced pressure, the rate of precipitation of reaction products decreases as the pressure decreases. Therefore, under extreme reduced pressure conditions such as 5 Q Torr, it is not possible to operate the system in an industrially profitable manner. The present invention has been made in view of the above circumstances, and its purpose is to provide a method for producing metal by reduction using a fluidized bed method, which is capable of stable operation even at relatively high reaction pressures, such as atmospheric pressure. be. Means for Solving Problem L} The first reaction condition required for producing metallic Ti by the flow method is to lower the reaction temperature below the melting point (1670° C.) of the produced Ti. However, since it is industrially difficult to conduct a fluidized reaction at a high temperature exceeding the melting point of Ti, this condition does not have much meaning industrially.The condition that has great industrial significance is the reaction pressure as the second condition. be. The reaction pressure as the second condition is such that MgCl2. and M as a reducing agent, under conditions that do not condense any of them.
The method disclosed in Japanese Patent No. 334 requires a reaction pressure lower than the vapor pressure of both the reduction product component and the reducing agent at the reaction temperature. However, as mentioned above, as long as this idea is followed, the pressure conditions will also be unrealistic like the temperature conditions. Therefore, in order to ease the reaction pressure conditions, the present inventors
The idea of partial pressure was introduced to the reaction pressure. Table 1 shows the effects of the gas pressures of MgCl2, which is produced by reduction, and Mg as a reducing agent, on the evaporation temperature and production rate when TiClx is reacted with Mg to produce metallic Ti. be. Comparing the evaporation temperature of MgClz and the evaporation temperature of Mg, we find that with a typical Mg input amount, at the same gas pressure, MgCl2. The evaporation temperature of MgC is higher, and the reaction temperature is higher than that of MgC.
l2. evaporation temperature. If the operating temperature is about 1100℃, Mg
Cl2. gas pressure of 0. O65ats (50 Torr
) The evaporation temperature of M g Cl * cannot be lowered unless , Also, according to this idea, a reactor with a heat-resistant temperature of 1250 ° C / or more is used,
Operating temperature 1250℃, production rate 218T/nr-H
Even if r can be secured, a reduced reaction pressure of 0°3at- is required. The inventors' thoughts regarding this are as follows. In order to suppress the condensation of M g Cl x under the conditions of the adopted temperature of 1250 ° C., it is not necessary to suppress the reaction pressure to L3at■, but it is sufficient to suppress the gas partial pressure of M g Cl t to 0.3 ats. gCj! Gas partial pressure of z is 0.3
It is possible to suppress the reaction pressure to ats even when the reaction pressure is lat-, and it is not very difficult. In other words, according to the inventors' idea, instead of lowering the reaction pressure, M g By lowering the partial pressure of C11H, the same effect as lowering the reaction pressure can be obtained, and as a result, stable operation without condensation of M g C1g becomes possible even under atmospheric pressure. M g CJ! As a means for lowering the partial pressure of z, it is advisable to use a heated inert gas in actual operation. The first ceremony is TiCj! A theoretical reaction formula for producing metal Ti by reacting x with Mg is shown. 7 iCl a is reduced with Mg to produce metal Ti and MgCIlt as a reduction product component. TiCJ other than Ti! a, Mg and MgCl2. is a gas. The reaction in actual operation is slightly different from the first equation, in which Mg is added in excess to ensure reaction stability, and the reaction equation is as shown in the second equation. If an inert gas is further introduced into the reaction system, the reaction equation changes as shown in the third equation. That is, MgCl2. The partial pressure of T i C a + 2 M g → T i + 2
M g C1m =・(1) T i C a + 2
．． 3Mg→Ti+2MgCj! 1+0.3Mg...(
2) T i Cj! a+2.3Mg-+Ti+2Mg
Clx+0.3Mg+xAr-(3) For example, if 4.4 mol of inert gas is introduced into the reaction system, the partial pressure of MgCl, even if the reaction pressure is fat, is 0.3
t-, and along with this, MgCl2. The evaporation temperature of is 1230°C. As a result, MgCl2. Stable operation with no condensation is achieved. 4
．． The addition of about 4 moles of inert gas has no adverse effect on the reaction system, either chemically or physically; rather, the following benefits can be obtained by using heated inert gas. . The heated inert gas is MgCl2. In addition to reducing the partial pressure of , it can function as a flow energy source for metal Ti particles, and can also function as a reaction heating source. In the flow method, the inside of the reactor is generally heated from the outside to maintain the reaction temperature, but compared to that case, when a heated inert gas is used as a heat source, the heat for the reaction is Energy transfer is direct and has excellent thermoeconomic efficiency. Plasma heating is a good method for heating inert gas.
By directly injecting inert gas into the reactor while heating it with plasma, the required temperature and amount of inert gas can be secured with simple installation. The present invention has been made based on the above, and is a method for producing metal by reduction in which metal is produced by a reduction reaction of a metal halide, the method comprising: feeding the produced metal particles into a reactor;
Gaseous bodies of metal halide, reducing agent, and heated inert gas are blown up from below the particle group to bring the particle group into a fluid state and maintain the reaction temperature below the melting point of the metal produced. In addition, the flow reaction pressure exceeds the vapor pressure of each reduction product component and reducing agent at the reaction temperature, and the gas partial pressure of each reduction product component and reducing agent is equal to or less than the vapor pressure at the reaction temperature. The gist of this invention is a method for producing metal by reduction, which is characterized in that the produced metal is fixedly grown on the surface of metal particles and extracted out of the reactor. [Example] Hereinafter, embodiments of the present invention will be described regarding the production of metal Ti. FIG. 1 is a flow sheet showing embodiment III of the present invention;
FIG. 2 is a sectional view showing the concept of a plasma heater. A distribution plate 2 is provided at the bottom of the reactor l. Fine metal Ti particles are continuously fed onto the dispersion plate 2 via a hopper 3. TiCJ! from below the dispersion plate 2 to above the dispersion plate 2! Each fraction of a and Mg is injected. Inert gas such as A gas is heated and blown into the lower part of the dispersion plate 2 from the side by the plasma heater 4. The nozzle 40 of the plasma heater 4 has a rod-shaped tungsten electrode 41 and a cylindrical W4 By passing a high-speed inert gas flow around the arc struck between the nozzle anodes 42, a plasma flow of inert gas is ejected from the nozzle 40. Inside the reaction vessel l. Above the dispersion plate 2, metal Ti particles are fluidized by an inert gas, TiCJ!, and Mg air to form a fluidized bed. In the fluidized bed, the reaction temperature is increased by the thermal energy of the inert gas. is maintained, and TiCj!a changes to Mg on the surface of the metal Ti particles.
will be reduced by The metal T1 generated by this reduction reaction adheres and accumulates on the surface of the metal Ti particles to grow the metal Ti particles. The Ti particles in the reactor 1 are continuously extracted to the side of the reactor 1. The remainder of Mg used in the fluid reduction reaction,
MgCj as a reduction product! Z and the inert gas used for heating and fluidization are discharged from the upper part of the reactor 1 to the outside of the reactor 1 and sent to the condenser 5. Mg and M g Cl condensed and separated in condenser 5! enters the electrolytic cell 8 through the insulating furnace 7, where Mg is separated,
The separated Mg is refluxed into the reaction vessel 1 through the heat insulating furnace 9 and reused. The inert gas is also refluxed into the reactor 1 through the pack filter 10 etc. for reuse. When producing metallic Ti using the production method of the present invention, the particle size of the Ti particles is preferably about 0.2 to 2 square centimeters. Mg stabilizes the reaction and MgCl4. From the viewpoint of reducing the gas partial pressure, it is better to use a surplus. Ar gas or He gas is usually used as the inert gas. The amount of inert gas to be added is appropriately determined based on the required gas partial pressure of MgCl4°, and the larger the amount, the more MgCl4. The partial pressure of the gas decreases, lowering its evaporation temperature. The reaction pressure is preferably atmospheric pressure, and may be higher or lower than this, but MgCffi at the reaction temperature. A reduced pressure condition in which the vapor pressure of either Mg or Mg is lowered is not adopted. According to the manufacturing method of the present invention, for example, by using 15% surplus Mn and 4.4 mol of Ar gas continuously heated by plasma, a reaction temperature of 1250°C is secured without external heating, and this Enables atmospheric pressure operation at temperatures. [Effects of the Invention] The method for producing metal by reduction according to the present invention can lower the reaction temperature without lowering the reaction pressure. It is also possible to lower the reaction pressure, in which case the reaction temperature can be significantly lowered. Therefore, the reaction conditions are significantly relaxed, the operation becomes easier, the reactor structure is simplified, and above all, the production rate can be greatly increased. When the production method of the present invention is applied to the production of metallic Ti, metallic Ti, which has been produced industrially only by the batch-type Kroll method, can be produced continuously by the flow method and under extremely mild conditions. It can be manufactured on a large scale with high efficiency and at low cost. In addition, when continuous plasma heating is used to heat inert gas, a large amount of high-temperature inert gas can be supplied, and the thermal efficiency is 6.
This makes it possible to reduce the gas partial pressure, promote fluidization, and use the inert gas as a heat source for the reaction. When heated inert gas is used as the reaction heat source, external heating means is not required, and heating efficiency is greatly improved.

[Brief explanation of the drawing]

FIG. 1 is a flow sheet showing an embodiment of the present invention; FIG.
The figure is a sectional view showing the concept of a plasma heater. 1: Reactor, 2: Dispersion plate, 4: Plasma heater, 5: Minil! 1 collection device. Applicant: Osaka Titanium Manufacturing Co., Ltd. Applicant: Toho Titanium Co., Ltd. Applicant: Showa Denko Co., Ltd. Applicant: Kobe Steel, Ltd. Applicant: Sumitomo Metal Industries, Ltd. Applicant: Nippon Steel Tube Co., Ltd. Figure 2

Claims (4)

[Claims] (1) A method for producing metal by reduction in which metal is produced by a reduction reaction of a metal halide, in which the produced metal particles are fed into a reactor, and the metal halide and reducing agent are added to each of the metal halide and reducing agent from below the particle group. Blowing up a gas body and a heated inert gas to bring the particle group into a fluid state,
The reaction temperature is maintained below the melting point of the metal produced, the flow reaction pressure exceeds the vapor pressure of both the reduction product component and the reducing agent at the reaction temperature, and the gas partial pressure of the reduction product component and the reducing agent is A method for producing a metal by reduction, characterized in that the produced metal is fixedly grown on the surface of the metal particles and extracted out of the reactor while keeping the vapor pressure at or below the respective vapor pressures at the reaction temperature. (2) The generated metal is Ti and the metal halide is TiCl_4
2. The method for producing metal by reduction according to claim 1, wherein the reducing agent is Mg. (3) The method for producing metal by reduction according to claim 1 or 2, wherein the heated inert gas is Ar gas or He gas that is continuously heated by plasma. (4) The method for producing metal by reduction according to any one of claims 1 to 3, wherein the inert gas is a reaction heat source heated to a temperature higher than the reaction temperature.