JPS62130232A - Method and apparatus for manufacturing metallic magnesium - Google Patents

Abstract

PURPOSE:To inhibit the lowering of the internal temp. of a reducing furnace and the crushing of briquettes as starting material and to prolong the life of an apparatus by preheating the briquettes to a prescribed temp. when the briquettes are fed into the furnace. CONSTITUTION:Magnesium oxide is mixed with starting material contg. carbon, the mixture is briquetted and the resulting briquettes are preheated to 300-1,300 deg.C. The preheated briquettes are charged into a reducing furnace and reduced at 600-2,000 deg.C under 5-200Torr pressure to produce magnesium vapor. This magnesium vapor is cooled by the adiabatic expansion of the vapor.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method J3 for producing metallic magnesium and its production i.
i! ! Regarding the apparatus, in detail, it relates to a method J5 for producing metal magnesium by a carbon reduction method and an apparatus for producing the same.

[Prior Art] As a method for producing metallic magnesium using a carbon reduction method, for example, a method is disclosed in Japanese Patent Publication No. 185938/1983. This method will be explained with reference to the manufacturing apparatus shown in FIG. 3. Magnesium oxide, oxides such as calcium oxide and aluminum oxide, and carbon Nodular blinos 71 to 101 consisting of the following are charged from the hopper -102.

A cold JJI chamber 104 is connected to the 37 former furnace] 00 through a wide-end nozzle 103, and the cooling chamber 104 is depressurized by a vacuum pump 105.
A heater 106 is disposed inside the reduction furnace 100, and the inside of the reduction furnace 100 is kept at a pressure of 5 to 200 torr and a temperature of 1600°C or higher.

Then, the briquettes 101 react in accordance with the above conditions, and a reduction reaction occurs in the magnesium oxide to generate magnesium vapor and carbon monoxide gas. Then, the mixed gas is ejected from the divergent nozzle 103 into the cold JJJ chamber 104 while expanding adiabatically due to the pressure difference between the reduction furnace 100 and the cooling chamber 104, and is rapidly cooled/JIed. As a result, the magnesium vapor becomes crown-shaped metallic magnesium 108,
It is collected on the collection plate 107. Also, the carbon oxide gas is sucked into the vacuum pump 105 and discharged to the outside.

[Problems to be Solved by the Invention] In the example of the conventional method described above, cold briquettes at room temperature are suddenly supplied to a high-temperature reduction furnace. For this reason, the briquettes are rapidly heated and not only subjected to thermal shock, but also the moisture or volatile components contained within the briquettes rapidly evaporate, causing an explosive increase in volume within the briquettes. The briquettes may not be able to withstand the expansion force and break down into powder.

By the way, solid phase reaction <liquid-solid phase reaction depending on S combination) is
When each reaction raw material is in close contact with each other, the reaction rate increases by 1υ. Therefore, when the briquettes become powdered, not only does the reaction occur, but also the powdered reaction materials are easily carried by the airflow in the reaction chamber because they are turned on, so they are transferred from the wide-spread nozzle to the cooling chamber without reacting. There was a problem with dust accumulating inside the cooling chamber.

Further, there has been a problem in that the moisture that has entered the reduction furnace causes oxidation and corrosion of the furnace material.

Furthermore, since cold briquettes at room temperature are fed into the reduction furnace, the temperature inside the furnace may drop and the reaction may stop momentarily, or the generated magnesium vapor and carbon monoxide gas may be absorbed by the cold briquettes. However, there was also the problem that a reverse reaction occurred and magnesium oxide was produced.

The present invention has been made in view of these problems,
One object of the first invention is to prevent reverse reactions between magnesium vapor and carbon monoxide. Another object of the present invention is to provide a manufacturing method that prevents Blino knots from turning into powder and transferring to a cooling room unreacted. A second aspect of the present invention aims to provide a manufacturing apparatus that facilitates this manufacturing method.

[Means for Solving the Problems] The method for producing metallic magnesium, which is the first aspect of the present invention, involves mixing raw materials containing at least magnesium oxide and carbon to produce one culm. And 300~
A preheating process in which the briquettes are pre-boiled at a temperature of 1300°C, a redundant process in which the briquettes are heated under reduced F1 to generate magnesium gas, and the magnesium vapor is subjected to adiabatic expansion. The manufacturing method of the present invention is characterized in that it consists of a cooling process of using magnesium and cooling it to form metallic magnesium. A material containing at least magnesium oxide and carbon, such as magnesium oxide and carbon, or magnesium oxide, oxide, and carbon as disclosed in JP-A-57-185938, is used.The blending ratio of each component is exactly the same as before. It's good to be there.

In the mixing process, the above-mentioned raw materials are made into briquettes formed into nodules by a conventionally known method.

In this way, each component is brought into close contact with each other in the briquettes, solid phase or solid-liquid phase reactions occur efficiently, and scattering of raw material particles is prevented. The size of J3 briquettes is not particularly limited as long as it does not scatter and conducts heat efficiently, but it is generally 10 to 20III in diameter.
It is said to be granular.

The greatest feature of the present invention is the preheating step. That is, before the briquettes are fed to the reduction furnace, the briquettes are
It is characterized in that it is preheated at a temperature of ~1300°C. This adds heat to Brix1!
This is intended to reduce the impact of lithium, gently remove monochromatic light components such as moisture contained in the briquettes into the 11θ supplied to the reduction furnace, and prevent the temperature acid F in the reduction furnace to prevent reverse reactions. It is.

The carbon reduction reaction of magnesium oxide is 5 tor+・vI
It is known that this occurs at a temperature of 1350° C. or higher under a reduced pressure of 1 degree. Therefore, the temperature condition for preheating (fa) is 135
Although the temperature is lower than 0°C, it is preferable to keep it in the range of 300 to 1300°C.

If the preheating temperature is lower than 300℃, it will take a long time to remove moisture! In addition, the effect of preheating is small because it requires 5 hours, and if the temperature is higher than 1300°C, a reduction reaction may occur during the preheating of 1M, or the briquettes may be crushed due to thermal shock or rapid evaporation of water when charging. It is not desirable.

And to prevent thermal shock when supplied to the reduction furnace,
It is desirable that the temperature of the briquettes immediately before entering the reduction furnace is 700°C or higher.

Although the preheating step can be carried out under human pressure in a non-oxidizing atmosphere, it is preferable to carry out it under reduced pressure.

Heating under reduced pressure makes it easier to remove moisture and the like. Further, when the reduction furnace is under reduced pressure, the preheated briquettes can be promptly introduced into the reduction furnace without being cooled.

The reduction process is a process in which magnesium oxide is reduced to magnesium vapor and carbon monoxide gas, and as in the past, it is generally carried out at a pressure of 5 to 200 torr and 160 torr.
It is carried out under high temperature conditions of 0 to 2000°C. As for the heating method, either resistance heating or arc heating may be used40.

Cooling culm is a process in which metallic magnesium is obtained by rapidly cooling magnesium vapor generated by a reduction reaction. This rapid cooling must be carried out rapidly in order to prevent reverse reactions, and is carried out by utilizing adiabatic expansion using a wide-divergent nozzle, as in the past.

A manufacturing apparatus according to a second invention that can easily carry out the above-described manufacturing method will be described below.

This manufacturing equipment includes a hopper, a reduction furnace that communicates with the hopper and is maintained at a predetermined temperature, and a cooling furnace that communicates with the reduction furnace through a wide-spread nozzle and is reduced in pressure by a vacuum pump. Jl
The briquettes containing at least magnesium oxide and one wood shavings are supplied from the hopper to the reduction furnace to produce magnesium vapor, and the magnesium vapor is passed through the wide-spread nozzle into 1. h In a JTi apparatus configured to generate metallic magnesium by quenching it by blowing it out while expanding it adiabatically into a cooling chamber, the area between the hopper and the reduction furnace and at least the upper end of the hopper is It is recommended that one side be equipped with at least 6 preheating furnaces maintained at 300-1300°C.

The hopper is a device for temporarily storing briquettes, and a conventional one can be used as is.

The reduction furnace t is a reaction chamber for reducing magnesium oxide to produce magnesium vapor, and is formed by a heat-resistant furnace wall such as graph eye 1. This j
The heating means for the π-gen furnace can be constructed in the same manner as in the past, such as resistance heating or arc heating. and generally 160
Heated to 0-2000°C.

The pressure inside the reduction furnace is determined by the balance between the magnesium produced and the magnesium discharged from the nozzle. Also, the radius of the cooling chamber is determined by the stones flowing in from the nozzle and the displacement of the exhaust pump.

In order to perform sufficient adiabatic cooling, the pressure inside the reduction furnace must be 2 (3 or more, preferably 10 or more times) the pressure in the cooling chamber.
′! In general, a collection plate or the like is provided in the it° for collecting metallic magnesium in alignment with the diverging nozzle, as in the past.

A feature of the present invention is that it includes a preheating furnace.

This preheating furnace is provided between the hopper and the reduction furnace or at the upper end of the hopper (in this case, the preheating furnace, the hopper, and the i1 element 1 are connected in this order). Of course, both may be provided, or a plurality of preheating furnaces may be provided for each. It is preferable to arrange preheating furnaces having different temperatures so that the temperature increases toward the reduction furnace.

The fourth dimension of this r-thermal furnace is 300'-13 as mentioned in 11.
00°C. Further, it is desirable that the temperature of the briquettes immediately before entering the reduction furnace is set to 700°C.

(11) There is a shield (n1) that can be opened freely between each device (excluding the cold room 11), and it is desirable that each device is airtightly shut off.In the hopper and preheating furnace, It is necessary to temporarily store the briquettes in each case, and this is facilitated by the shielding member.Then, when necessary, by intervening the shielding member, briquettes can be supplied to other devices with which the hopper is connected. It is convenient because other equipment can be maintained at reduced pressure when briquettes are put into the reduction furnace.It is also possible to prevent magnesium gas generated in the reduction furnace from flowing back into the preheating furnace or hopper.

It is also preferable to connect a vacuum pump to the preheating furnace and hopper so that the pressure inside the furnace and hopper can be reduced. In this way, moisture vaporized in the preheating furnace can be thoroughly discharged without oxidizing and corroding the furnace material. Furthermore, by exhausting the atmosphere that has entered the hopper when briquettes are put into the hopper, it is possible to prevent the atmosphere from flowing out to other devices.

[Operations and Effects of the Invention] In the production method of the present invention, briquettes are supplied to a simulated reduction furnace that has been preheated in a preheating furnace. Therefore, the briquettes fed into the reduction furnace are sufficiently heated, preventing the temperature inside the furnace from decreasing and preventing reverse reactions. In addition, the thermal shock applied to the briquettes is alleviated and water etc. are sufficiently removed, so rapid evaporation does not occur when the briquettes are put into the reduction furnace, and the briquettes are prevented from being crushed 71, so one ricket is reduced to powder. This prevents dust from forming in the cold room. Moreover, since moisture is removed during preheating and hardly enters the reduction furnace, oxidation corrosion of the furnace wall is prevented and the life of the equipment is extended.

The manufacturing method according to the first invention can be easily carried out by the manufacturing apparatus according to the second invention.

[Example] Hereinafter, specific examples will be disclosed and explained in more detail.

(First Embodiment) FIG. 1 is a partially cutaway front view of a metal magnesium manufacturing apparatus used in one embodiment of the present invention.

The reduction furnace 1 is insulated from the outside by the heat insulating material 2, and the inside of the reduction furnace 4 is heated by the heat 33.

;! Motoshige nozzle 8 is located on the side wall of reduction furnace 1.
The cold PA chamber 9 is maintained at a predetermined reduced pressure state by a vacuum pump 10. In addition, a metal magnesium collection plate 11 is provided in the cold 2JImQ in alignment with the wide-spread nozzle 8, so that the vapor of metal magnesium generated in the reduction chamber 4 is adiabatically expanded by the wide-spread nozzle 8. It ejects and cools down, collides with the collection plate 11 at high speed, and collects the collection plate 11.
It is collected as a crown-shaped metal magnesium 12 on the top.

A preheating furnace 13 is provided upstream of the reduction furnace 1 and communicates with the reduction furnace 1 via a supply valve 7 that can be opened and opened. Supply valve 7
The reduction furnace 1 and the preheating furnace 13 can be shut off airtightly to some extent. A preheating chamber 14 of this preheating furnace 13 is heated by a heater 15 while being insulated from the outside of the furnace by a heat insulating material 16 . Further, a vacuum pump 18 is connected to the preheating furnace 13, and the preheating furnace 114 is maintained at a predetermined reduced pressure state.

A hopper 5 is provided on the −F side of the preheating furnace 13 and communicates with the preheating furnace 13 via an input valve 17 that can be opened and opened.

The charging valve 17 can airtightly shut off the preheating furnace 13 and the hopper 5. This hopper 5 is kept airtight by a lid 19 and can be reduced in pressure by a vacuum pump 20. Furthermore, since an argon gas cylinder 21 is connected, pressurization is also possible.

Next, the operation of the device configured as described above will be explained.

The hopper 5 is filled with briquettes, and the hopper 5, the preheating chamber 14 and the reduction chamber 4 are operated by a vacuum pump 20.18.10.
Assume that the system is under reduced pressure due to

・Prikera 1- filled in Topper 5 at substantially room temperature
By opening the input valve 17, a predetermined suspension is preheated.
Drop the drop at 4. Then, open the input valve 17 and briquette]・
6 is preheated until it reaches a predetermined temperature. Water vapor generated during this preheating is sucked out by the vacuum pump 18 and discharged.

To Briquette 1 where the temperature has reached a predetermined temperature and moisture etc. have been removed 6
opens the supply valve 7 (thereby falling into the reduction!4).

The supply valve 7 is closed, and the briquettes 6 undergo a reduction reaction in the reduction chamber 4 to produce a reaction gas consisting of magnesium vapor and carbon monoxide. Then, due to the pressure difference between the reduction chamber 4 and the cooling chamber 9, the reaction gas is ejected from the wide-spread nozzle 8, expands adiabatically, and is rapidly cooled, whereby metallic magnesium is collected on the collection plate 11.

, at the same time as the reduction step described in , or after the completion of the reaction, the input valve 1
After closing the valves of 7 and the vacuum pump 20 to cut off the connection between the hopper 5 and the preheating chamber 14, the cylinder 21 is opened and the hopper 5
Make the pressure inside equal to atmospheric pressure. Then, one lid is opened and new briquettes are put into the hopper 5. Thereafter, the cylinder 21 is empty, the pressure inside the hopper 5 is reduced by the vacuum pump 20, and the briquettes are introduced into the preheating chamber 14 by pressing the input valve 17.

According to the manufacturing apparatus configured in this way, the briquettes 6
After moisture has been removed and the mixture has been sufficiently heated, it is placed in the reduction chamber 4.
supplied to Therefore, the briquettes 6 will not be crushed due to rapid heating, and problems such as dust entering the cooling chamber 9 will be prevented.Furthermore, the briquettes 6 supplied into the first chamber 4 will be sufficiently heated. Therefore, the temperature of the reduction chamber 4 hardly decreases, and there is no problem such as a reverse reaction occurring.

Therefore, the reduction reaction can proceed smoothly, and
Effective use of energy can be achieved.

Using the above-mentioned apparatus, metallic magnesium was produced in the strip 1 shown in the table. Note that magnesium oxide, boron oxide, and carbon were used as raw materials in a weight ratio of 100:2:31.

Then, the skewers of raw material powder scattered into the cold FJl chamber 9 during production were measured, and the results are shown in the table. Note that the conventional Tl shown in FIG.
When manufactured by J Zosokon under the same conditions as the above example except that there was no preheating step, the proportion of scattering was about 20%.

As is clear from this result, according to the present invention, cold JJI
It is possible to significantly reduce the hanging of raw materials that scatter into the chamber. Note that the reason why the number of scattered v1 cases is higher in Example 3 than in Example 2 is thought to be because the preheating furnace temperature is as high as 1300° C., and there are raw materials that are crushed in the preheating furnace.

Further, conventionally, the life of the furnace material of the W1 furnace was about 50 hours, but when the operation continued under the conditions of Example 2, no problems appeared in the furnace material even after 300 hours had elapsed.

(Second Embodiment) FIG. 2 shows another example 7Il of the present invention! ! It is a hemostasis diagram partially cut away and showing the metal magnetic screw/comb manufacturing apparatus used in the example.

The reduction furnace 30 and the cold JII chamber 31 have the same configuration as in the first embodiment.

A hopper 33 is provided on the −F side of the reduction furnace 30 and communicates with the reduction furnace 30 via a supply valve 32 . A vacuum pump 34 is connected to this hopper 33 as in the first embodiment, and it is possible to reduce the pressure. Furthermore, since an inert gas cylinder 35 is connected, pressurization is also possible.

One end of a booth 37 is connected to one end of the hopper 33 via a charging valve 36 that can be opened and closed, and three preheating furnaces are connected to the other end of the booth 37 (through a charging valve 38 that can be opened and closed). The three preheating furnaces have the same structure as the first embodiment except that they have a raw material replenishment port 40 at the bottom and are not equipped with J'3 and a negative air pump. Inert gas cylinders 41 and 42 are connected to the lower part and the booth 37, respectively.

Next, the operation of the device configured in this way will be explained.

Arikera 1 to 50 are charged through the raw material replenishment port 40 of the P-thermal furnace 39, and are preheated while inert gas is flowed from the cylinder 41. Therefore, the generated water vapor and the like are efficiently (exhausted) to the outside through the exhaust port 43.

Next, the input valve 3B is opened, and the sufficiently preheated rickets 1-50 fall into the booth 37, are carried by the conveyor 44, and are input into the C hopper 33. Furthermore, booth 3
Since the inside of the container 7 is maintained in an inert gas atmosphere by the cylinder 42, the raw materials can be prevented from being burned out. If the temperature of the preheated briquettes 50 is lower than the burnout temperature of the raw material (usually 600° C. or lower), the atmosphere in the booth 37 can be set to atmospheric air.

After the input valve 36 is closed and the pressure inside the popper 33 is reduced as in the first embodiment, a predetermined amount of briquettes are supplied into the reduction furnace 30 by listening to the supply valve 32, and react to produce metallic magnesium. be captured.

Using the above-mentioned apparatus, the preheating furnace 39 was heated to 1 atm and a temperature of 900 DEG C. in a 1/2 rugon gas atmosphere, and the briquettes 50 formed from the same raw materials as in the first example were preheated for 1 hour. Then, we passed booth 37, which was roaring at 450 degrees Celsius, and about 40 degrees
Inside the hopper 33, which is at 0°C (maintained at a pressure of -5 torr or less for 30 minutes. After a), the temperature is 1800°C, approximately 5
The material was placed in a reduction furnace 30 maintained at torr conditions, and a reduction reaction was performed.

During the above reaction, in the first embodiment, the amount of raw material powder scattered into the cooling chamber 31 was measured, and it was found to be about 6%. Although the pressure fluctuation was slightly larger than that in Example 2 of the first embodiment, it was stable at only 1 t (compared to the conventional example shown in FIG. 3).

[Brief explanation of drawings]

Fig. 1 (4) is a partial cross-sectional front view of the metal magnesium manufacturing apparatus used in one embodiment of the present invention. It is a small J front view with a partial cross section. 3rd
The figure is a partially sectional front view of a conventionally used apparatus for producing genus A magnesium. 1.30.100...) ■1 Furnace 4,...5w All rooms 533.102...Hopper 6.50.101...Bricket 8.103...Wide end nozzle 9.31.104 ...Cooling chamber 1 1,'+07...Collection plate 12.108...Metal magnesium 13.39...Yp heat furnace 7.17.32.36.38.108...Valve No. 2 Amendment to figure procedure (spontaneous) December 1985 268 1. Indication of the case 1985 Patent Application No. 269839 2. Name of the invention Method for manufacturing metallic magnesium and its manufacturing device 3. Person making the amendment Relationship with the case Patent Applicant: 1 (320) Toyotacho, Toyota City, Aichi Prefecture - Yota Motors Co., Ltd. Representative: Kiyoshi Matsumoto 4, Agent: 3-3-4 Meieki, Nakamura-ku, Nagoya City, Aichi Prefecture 450 5, Pair of Amendments ♀ Scope of Claims in Specification 1, Detailed Description of the Invention 6, Contents of Amendment (1) The Claims column in the Description will be amended as shown in the attached sheet. ``The wide-end nozzle J in section (5) is referred to as ``nozzle.''
(2) "Reduction furnace 100
The phrase "A heater 106 is disposed within the wall," should be corrected to "A heater 106 is disposed within the container of the reduction furnace 100." (3) From line 15 to line 16 on page 9 of Mei 4I, [
Insert a nozzle, such as a straight shape nozzle. (4) Delete "Suehiro" from "Suehiro nozzle" on the second and sixth lines of page 10 of the specification. (5) Delete "Suehiro" from "Suehiro nozzle" on page 11, line 11 of the specification. (6) The table on page 18 of the specification will be amended as shown in the attached sheet. 7. List of attached documents (1) Attachment 111 copies of amended claims (2) Table on page 18 of attached specification 1. Claims (1) Containing at least magnesium oxide and carbon a preheating step of preheating the briquettes at a temperature of 300 to 1300°C; a reduction step of heating the briquettes under reduced pressure to produce magnesium vapor; A method for manufacturing magnesium metal, comprising: a cooling step of cooling vapor using adiabatic expansion to produce magnesium metal. (2) The reduction step is carried out at a pressure of 5 to 200 torr and 1
A method for producing metallic magnesium according to claim 1, which is carried out at a temperature of 600 to 2000°C. (3) The method for producing metal magnesium according to claim 1, wherein the preheating step includes preheating the briquettes to 700° C. or higher. (4) The method for producing metallic magnesium according to claim 1, wherein the preheating step is performed under reduced pressure. (5) It consists of a hopper, a reduction furnace that communicates with the hopper and is maintained at a predetermined temperature, and a cooling chamber that communicates with the reduction furnace through a nozzle and is depressurized by a vacuum pump, and contains magnesium oxide and Briquettes containing at least carbon are supplied from the hopper to the reduction furnace to produce magnesium vapor, and the magnesium vapor is adiabatically expanded and ejected into the cooling chamber via the nozzle to be rapidly cooled to produce metallic magnesium. In the manufacturing apparatus configured to do so, at least one preheating furnace maintained at a temperature of 300 to 1300° C. is provided between the hopper and the reduction furnace and at least one of the upper end of the hopper. Features: Magnesium oxide production equipment. (6) The metal magnesium manufacturing apparatus according to claim 5, wherein a shielding member that can be opened and closed is interposed at each boundary between the hopper, the preheating furnace, and the reduction furnace. (7) The reduction furnace has a pressure of 5 to 200 torr and 16
The magnesium metal according to claim 5, which has a temperature of oO to 2000°C! Ij33! i device. Attachment table

Claims (7)

[Claims] (1) A mixing step of mixing raw materials containing at least magnesium oxide and carbon to form briquettes, a preheating step of preheating the briquettes at a temperature of 300 to 1300°C, and heating the briquettes under reduced pressure. A method for producing metallic magnesium, comprising: a reduction step of producing magnesium vapor; and a cooling step of cooling the magnesium vapor using adiabatic expansion to produce metallic magnesium. (2) The reduction step is performed at a pressure of 5 to 200 torr and at a pressure of 16 torr.
The method for producing metallic magnesium according to claim 1, which is carried out at a temperature of 00 to 2000°C. (3) The method for producing metal magnesium according to claim 1, wherein the preheating step includes preheating the briquettes to 700° C. or higher. (4) The method for producing metallic magnesium according to claim 1, wherein the preheating step is performed under reduced pressure. (5) Consisting of a hopper, a reduction furnace that communicates with the hopper and is maintained at a predetermined temperature, and a cooling chamber that communicates with the reduction furnace through a wide-spread nozzle and is depressurized by a vacuum pump, The briquettes containing at least carbon and carbon are supplied from the hopper to the reduction furnace to produce magnesium vapor, and the magnesium vapor is adiabatically expanded and ejected into the cooling chamber through the diverging nozzle to rapidly cool the magnesium metal. In a manufacturing device configured to produce
An apparatus for producing magnesium oxide, comprising at least one preheating furnace maintained at a temperature of 300 to 1300° C. between the hopper and the reduction furnace and at least one of the upper end of the hopper. (6) The metal magnesium manufacturing apparatus according to claim 5, wherein a shielding member that can be opened and closed is interposed at each boundary between the hopper, the preheating furnace, and the reduction furnace. (7) The reduction furnace has a pressure of 5 to 200 torr and a pressure of 160 torr.
Claim 5, which is defined as a temperature of 0 to 2000°C
An apparatus for producing metal magnesium as described in 2.