JPH06122906A - Method for supplying chloride and production of magnetic metal powder - Google Patents

Abstract

PURPOSE:To supply a metal chloride to a magnetic metal powder producing device without the stable supply of the metal chloride vapor being obstructed by an oxide and to produce the magnetic metal powder. CONSTITUTION:Cobalt chloride or nickel chloride is supplied to a device for producing a magnetic metal powder by reducing the metal chloride vapor contg. at least one kind between cobalt and nickel in the vapor phase. In this case, granular metallic cobalt or metallic nickel is allowed to react with a chlorine- contg. gas, and the cobalt chloride or nickel chloride vapor formed by the chlorination reaction is directly supplied to the device. The cobalt chloride or nickel chloride vapor is reduced in the vapor phase by a reducing gas in this device to produce a magnetic metal powder contg. cobalt or nickel.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for supplying chloride vapor to an apparatus for producing metal magnetic powder by reducing metal chloride in a gas phase with a reducing gas, and a method for producing metal magnetic powder.

[0002]

2. Description of the Related Art Metallic magnetic powder containing nickel or cobalt obtained by vapor-phase reducing a metal chloride vapor containing at least one of nickel and cobalt with a reducing gas has high coercive force and high saturation magnetization. It has, and is being developed as a medium that enables high-density magnetic recording.

As a method of supplying nickel chloride or cobalt chloride to the apparatus for producing metal magnetic powder when producing metal magnetic powder by this method, for example, the following method is adopted. One is to charge anhydrous chloride powder into the raw material hopper, replace it with an inert gas, and then quantitatively cut it out with a device such as a table feeder, and in a crucible placed in the evaporator, at a temperature of 800 ° C or higher. This is a method of heating and volatilizing at a temperature and supplying an inert gas as a carrier gas to the reactor. Others use 80% of anhydrous metal chloride cut out from the raw material hopper.
It is a method of melting in a crucible in an evaporator at a temperature of 0 ° C. or higher, blowing an inert gas into the crucible, and controlling the evaporation amount of a metal chloride by the flow rate and temperature of the inert gas and supplying it to the reactor. .

[0004]

However, in these conventional methods of supplying nickel chloride or cobalt chloride, when the raw material hopper is charged with anhydrous chloride, the anhydrous chloride comes into contact with the atmosphere and absorbs moisture. During heating, the absorbed moisture reacts with chloride to form an oxide, which accumulates in the crucible or adheres to the crucible or the piping on the outlet side of the evaporator, which hinders the stable supply of metal chloride vapor. There's a problem.

Further, since anhydrous chloride is temporarily stored and supplied in the raw material hopper, in order to stably supply it, one having very small particle size or bulk density cannot be used, and metal chloride produced by an aqueous solution reaction cannot be used. It is customary to use anhydrous metal chloride prepared by a wet method, which is produced by dehydrating and drying the hydrate. However, the anhydrous metal chloride obtained by the wet method contains a few percent of oxides, which also causes the above problems. The present invention has been made in view of the above circumstances, and a method for supplying chloride to a magnetic metal powder manufacturing apparatus in which oxide does not hinder stable supply of metal chloride vapor, and such chloride. It is an object of the present invention to provide a method for producing metal magnetic powder, which adopts the above-mentioned supply method.

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention aims to solve the above-mentioned problems by subjecting a metal chloride vapor containing at least one of cobalt and nickel to a gas phase reduction with a reducing gas. A method of supplying a chloride containing cobalt chloride or nickel chloride to an apparatus for producing a metal chloride, comprising reacting a granular metal cobalt or a granular metal nickel with a chlorine-containing gas to form a chloride produced by the chlorination reaction. Provided is a method for supplying chloride, which comprises directly supplying cobalt vapor or nickel chloride vapor to a metal magnetic powder production apparatus.

Further, the particulate metal cobalt or the particulate metal nickel is reacted with a chlorine-containing gas, and the metal chloride vapor generated there is directly introduced into a reduction furnace to reduce the metal chloride vapor in the gas phase with the reducing gas. Thus, there is provided a method for producing a metal magnetic powder, which comprises obtaining a metal magnetic powder containing cobalt or nickel.

As described above, the granular metal cobalt or nickel is reacted with the chlorine-containing gas, and the vapor of cobalt chloride or nickel chloride produced by the chlorination reaction is directly supplied to the apparatus for producing metal magnetic powder. Prevents the stable supply of cobalt chloride or nickel chloride to the metal magnetic powder production equipment from being hindered by oxides that are generated due to moisture absorption of substances and oxides that are inevitably mixed during the production of anhydrous chloride. In addition, it is possible to solve the problem of restriction in use due to powder properties such as particle size or bulk density of anhydrous cobalt chloride or nickel chloride.

In the present invention, the metal cobalt or metal nickel particles used as a raw material preferably have a particle size of 5 mm or less. If the particle size exceeds 5 mm, the contact area with the chlorine-containing gas becomes small, the reaction amount is small, and it is necessary to enlarge the apparatus, which is not practical.

The reaction temperature of the metal cobalt particles or metal nickel particles and the chlorine-containing gas is preferably 850 to 950 ° C. In this temperature range, the vapor pressure of cobalt chloride or nickel chloride is large, and the reaction rate of the chlorination reaction is proportional to the partial pressure of chlorine gas. It is possible to control the amount of steam generated. When the reaction temperature is 850 ° C. or lower, chloride due to evaporation delay coats the metal particles and the reaction becomes difficult to proceed. On the other hand, at a temperature of 950 ° C. or higher, the metal particles are sintered during the reaction,
The reaction area decreases and the reaction rate cannot be kept constant.

As the chlorine-containing gas used as the reaction gas, a mixed gas of chlorine and an inert gas or pure chlorine gas is used. It is necessary to dehydrate in advance by passing through sulfuric acid.

In the present invention, it is important to suppress the residual chlorine concentration after the reaction to such an extent that it does not affect the production of the metal magnetic particles, and for that reason, the layer thickness of the metal cobalt or nickel particles in the crucible which causes the chlorination reaction. Needs to be held constant. Also, the chlorination reaction of metallic cobalt or nickel can be performed under reduced pressure.

The cobalt chloride vapor or nickel chloride vapor thus produced is directly supplied to the apparatus for producing magnetic metal powder. Then, by supplying a reducing gas such as hydrogen gas into the apparatus for producing metal magnetic powder, the supplied chloride is gas-phase reduced to produce metal magnetic powder.

[0014]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a diagram showing an example of a reaction apparatus for carrying out the present invention. In FIG. 1, reference numeral 1 is a reaction tube in which a crucible 2 is arranged. The crucible 2 has a supply port 2 for supplying granular metal as a raw material to the upper end thereof.
a is formed, a gas introduction port 2c for introducing the chlorine-containing gas through the gas supply pipe 9 is formed in the bottom of the a, and a gas dispersion plate 2b is provided therein.

A hopper 5 for storing granular metallic cobalt or granular metallic nickel 3 is provided above the reaction tube 1. The bottom of the hopper 5 is supplied to the supply port 2a of the crucible 2 in the reaction tube 1. The pipe 6 is connected. Further, a gas supply port 8 for supplying a metal chloride gas into a metal magnetic powder manufacturing apparatus described later is formed on the upper side wall of the reaction tube 1. The hopper 5 is configured to supply a certain amount of granular metallic cobalt or granular metallic nickel 3 consumed by the chlorination reaction, and keeps the layer thickness of the metallic particles in the crucible 2 constant to keep the reaction amount constant. It is like this.

Inert gas supply pipes 10a and 10b are connected to the hopper 5 and the supply pipe 6, respectively, so that the vapor of cobalt chloride or nickel chloride is prevented from being mixed and blocked. There is.

Further, an inert gas supply pipe 10c is connected to the bottom of the reaction tube 1, and when the heat generation during the chlorination reaction in the crucible 2 is remarkable, the inert gas is supplied to bring the reaction temperature to a predetermined value. It is supposed to be maintained. Around the reaction tube 1, a heater 7 is provided, which is divided into several stages and is capable of independent temperature control.

In such an apparatus, the heater 7 is set to a predetermined temperature, and a certain amount of granular metal cobalt or granular metal nickel 3 is fed from the hopper 5 into the crucible 2 through the feed pipe 6 and then downward. A chlorine-containing gas is supplied to the granular metal 3 in the crucible 2 through the gas inlet 2b and the dispersion plate 2c. As a result, a chlorination reaction occurs to generate cobalt chloride or nickel chloride vapor, and this vapor is supplied into the metallic magnetic powder manufacturing apparatus through the gas supply port 8. As described above, the granular metal cobalt or nickel 3 and the chlorine-containing gas are supplied in a constant amount into the crucible 2, and the layer thickness of the metal particles in the crucible 2 is kept constant to cause a chlorination reaction. The chlorine-containing gas consumed in the crucible 2 is prevented from coming into contact with the reaction tube 1 at a high temperature portion, and the chlorine-containing gas is mixed with the chloride vapor of cobalt or nickel supplied to the metal magnetic powder production apparatus. Is prevented.

The reaction residue 4 is fed to the reaction tube 1 when the gas flow rate decreases at the supply port 2a of the crucible 2 (that is, the chloride outlet).
It falls to the bottom of the stack and is deposited and removed by regular cleaning.

Next, a metal magnetic powder production apparatus for producing metal magnetic powder from the chloride supplied from the reactor will be described with reference to FIG. In FIG. 2, reference numeral 11 is a reactor, and an inlet pipe 12 for introducing the vapor of cobalt chloride or nickel chloride produced in the above-mentioned reactor from above the reactor 11 is inserted into the reaction vessel 11. The introduction pipe 12 has, for example, a T shape as shown in the drawing, and can supply a plurality of gases.

A hydrogen gas supply pipe 17 is connected to an upper portion of a side wall of the reactor 11, and preheated hydrogen gas as a reducing gas is supplied into the reactor 11 through the supply pipe 17. Further, an exhaust pipe 24 is connected to the lower portion of the side wall thereof, and a powder collector 25 is provided in the exhaust pipe 24. Reference numeral 23 is a flange for opening the reactor 11 at the time of cleaning.

A water cooling jacket 20 to which a cooling water supply pipe 21 and a discharge pipe 22 are connected is provided on the outer wall of the reactor 11. Further, a solenoid coil 19 is provided around the reactor 11, and a magnetic field is formed in the reactor 11 by supplying an electric current thereto.

In such an apparatus, vapor of cobalt chloride or nickel chloride is directly introduced into the reactor 11 through the supply pipe 12, and hydrogen gas is introduced through the hydrogen gas supply pipe 17. As a result, in the reaction part 8, a reduction reaction occurs between the cobalt chloride or nickel chloride vapor and the hydrogen gas, and the magnetic metal powder magnetized by the solenoid coil 19 is generated. The gas in which the generated magnetic metal powder is suspended is cooled by the cooling water flowing in the water cooling jacket 20, passes through the exhaust pipe 24 and reaches the powder collector 25, where only the magnetic metal powder is separated. It Thus, the magnetic metal powder is manufactured.

Next, a specific example in which cobalt chloride is actually supplied to the apparatus for producing metal magnetic powder by using the apparatus shown in FIG. 1 will be described. Cobalt particles having a particle size of 0.5 mm obtained by pulverizing electrolytic cobalt having a purity of 98% or more are supplied from the hopper 5,
A mixed gas of N ₂ : 90 vol% -Cl: 10 vol% was supplied from the supply pipe 9 at a flow rate of 3.5 Nl / min, and chlorination was performed in the reaction pipe 1 under normal pressure at 900 ° C.

After the reaction for 2 hours, the cobalt particles were 240
g was consumed, and the gas was sampled at the outlet of the reaction tube 1, and the chlorine concentration in the gas was measured. As a result, it was stable at 5 to 15 ppm during the reaction time.

After the experiment, scale-like blue crystals were adhered to the inner wall of the crucible 2 and the inner wall of the reaction tube 1. It was discolored and reddish when contacted with the atmosphere, and as a result of analysis by X-ray diffraction, it was confirmed to be anhydrous cobalt chloride. That is, it was confirmed that no oxide was generated.

[0028]

EFFECTS OF THE INVENTION According to the present invention, anhydrous nickel chloride or anhydrous cobalt chloride can be supplied to the apparatus for producing metal magnetic powder without absorbing temperature due to contact with the atmosphere. It is possible to provide a method for supplying a chloride to a device for producing a metal magnetic powder which is not hindered by the above, and a method for producing a metal magnetic powder adopting such a method for supplying a chloride. Further, since it is possible to directly supply by steam, it is possible to solve the problem of powder property required for anhydrous cobalt chloride powder or anhydrous nickel chloride powder.

[Brief description of drawings]

FIG. 1 is a diagram showing a reactor for carrying out a method for supplying chloride according to the present invention.

FIG. 2 is a view showing a metal magnetic powder production apparatus for producing metal magnetic powder from cobalt chloride or nickel chloride vapor supplied from the apparatus of FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Reaction tube, 2 ... Crucible, 3 ... Granular metal cobalt or granular metal nickel, 5 ... Hopper, 6 ... Supply pipe, 7 ... Heater, 8 ... Gas supply port, 9 ... Gas supply pipe, 11 ... Reactor,
12 ... Introduction pipe, 17 ... Hydrogen gas supply pipe, 18 ... Reaction part,
19 ... Solenoid coil, 24 ... Exhaust pipe, 25 ... Powder collector.

Claims (3)

[Claims] 1. A chloride for supplying a chloride containing cobalt chloride or nickel chloride to an apparatus for producing a metal magnetic powder by vapor-phase reducing a metal chloride vapor containing at least one of cobalt and nickel with a reducing gas. A method for supplying a substance, comprising reacting granular metal cobalt or granular metal nickel with a chlorine-containing gas, and directly supplying the cobalt chloride vapor or nickel chloride vapor produced by this chlorination reaction to a metal magnetic powder manufacturing apparatus. A method for supplying chloride, which is characterized in that: 2. The reaction of the granular metallic cobalt or granular metallic nickel with a chlorine-containing gas is performed at 850 ° C. to 950 ° C.
The method for supplying chloride according to claim 1, wherein the method is performed at the temperature of. 3. A granular metal cobalt or granular metal nickel is reacted with a chlorine-containing gas, and the metal chloride vapor produced there is directly introduced into a reduction furnace to reduce the metal chloride vapor in a gas phase with a reducing gas. And a metal magnetic powder containing cobalt or nickel is obtained.