JPS621223Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an apparatus for obtaining high purity aluminum by separately solidifying molten aluminum using the principle of fractional crystallization.

As is well known, aluminum obtained by electrolytically smelting alumina using a molten salt bath has a purity of about 99.9% at most. In recent years, with the development of the electronics industry, the demand for aluminum materials with higher purity has increased, and high purity (refined) aluminum with a purity of 99.99% or more is produced by refining aluminum using methods such as three-layer electrolysis. Supplied. Apart from such electrolytic refining methods, various methods using the principle of fractional crystallization have been proposed and developed for the purpose of providing high-purity aluminum (for example, Japanese Patent Publication No. 49-5806; -20536, JP-A-55-89439, JP-A-55-89440, etc.).

However, these purification methods require considerably high equipment costs, and in addition, their productivity is unexpectedly low, so that they are not necessarily satisfactory as industrial purification methods.

One such cause is the solidification form when molten aluminum solidifies. That is, dendrites of aluminum precipitated from crystal nuclei or solidified solid phase surfaces extend into the molten aluminum phase, and crystals grow. During this time, the molten aluminum phase containing concentrated impurities is not sufficiently diffused into the remaining liquid phase in the dendrite gaps, is restrained without achieving uniform purity, and is incorporated into the highly pure solid phase aluminum. solidification, resulting in an unexpectedly low average purity of solid state aluminum.

Knowing this phenomenon, the inventors of the present invention first discovered that by rotating a container containing molten aluminum, which is a raw material during fractional crystallization, it is possible to obtain highly purified aluminum with high purification efficiency, and developed a method for purifying the same. A patent application was filed for the same (Patent Application No. 57494-1983).

The present invention is intended to provide a specific apparatus for carrying out such a method for refining aluminum.

In other words, the present invention consists of a molten aluminum holding container with a lid that can be opened and closed and has heat retention properties, and a rotatable pedestal on which the container is placed and fixedly held, and which has a passage space for a cooling medium inside. , a heating holding area having a function of surrounding the container, a rotational force transmission mechanism for transmitting rotational force to the pedestal, and a drive device, and the pedestal is connected to the rotational force transmission mechanism. It also has a downwardly extending shaft section inside which has a passage space that communicates with the cooling medium passage space of the pedestal and the external cooling medium. The present invention provides a fractional solidification apparatus for fractional crystallization of molten aluminum with controlled movement.

Hereinafter, the present invention will be explained in detail using the drawings.

FIG. 1 shows an embodiment of the present invention. In the figure, reference numeral 1 denotes an iron container with a lid, and the iron container is lined at least inside with refractory bricks 2, and furthermore, the outside is covered with a heat-retaining material such as castable.

5 is a furnace configured to surround a melting vessel;
The inner wall has a heat-retaining heater 4 that can arbitrarily adjust the temperature inside the furnace, and the molten aluminum 3 inside the container
This is a function that can be controlled so that coagulation does not proceed preferentially from the top and sides of the container.

Reference numeral 6 denotes a pedestal on which a heat-insulating container of molten aluminum is placed, and a cooling medium passage space 8 is bored in the lower part of the pedestal 6. Further, on the upper part of the pedestal, there is a suitable fixing and holding means 7 to prevent the container 1 placed thereon from moving.
It is effective and appropriate to provide

The pedestal 6 is rotatably supported by a shaft 9, and by rotating a bevel gear 12 fixed to a drive device 13, a bevel gear 11 fixed to the shaft 9 is rotated.
The rotational force is transmitted to the pedestal 6, which has the function of rotating the pedestal 6.

A cooling medium passage space 10 is bored inside the shaft 9, and the cooling medium is introduced from the end of the shaft 9 (not shown), and is introduced into the passage space 8 below the pedestal 6 through the passage space 10. , has a mechanism to cool the bottom of the container.

The heating and insulating furnace 5 having the heat insulating heater 4 shown in FIG.
and can run on the track 16, with a pedestal 6
After moving to the top of the container placed above, the front door is closed and the container is surrounded to form a heating and heat-insulating atmosphere. However, if a crane or the like is installed on the ceiling, the upper part of the heating and heat-insulating furnace 5 may be lifted up. Either make it into a box shape and cover it from the top of the container, or furthermore, place a heating insulation furnace whose ceiling can be opened and closed on the pedestal 6 in advance, and insert the molten aluminum holding container from the open ceiling of the heating insulation furnace. It is also possible to adopt a method in which the ceiling is closed after being placed.

In applying the device of the present invention, raw molten aluminum is introduced into a heat-insulating holding container placed on a pedestal 6, and after the lid is closed, it is surrounded by a heating and insulating furnace, and priority is given to the top and sides of the container. The drive device 13 is operated while heating the bevel gear 1 to prevent coagulation from proceeding.
The pedestal 6 is rotated by the rotational force transmission mechanism 1 and 12. The rotation of the container may include a drive device and a rotational force transmission mechanism that give the container continuous positive rotation, but a drive device and/or that has variable rotation speed, intermittent rotation, and even reversal function may be used. Application of rotational force transmission mechanism is recommended.

Although a bevel gear is shown as an example of the rotational force transmission mechanism in FIG. 1, it is of course possible to apply a known method such as a chain system or a rack and pinion system as long as it has the function of rotating the container holder.

Prior to the rotation of the container or after the start of rotation, a cooling medium such as water is supplied to the passage space bored at the bottom of the shaft 9 and the pedestal 6 to cool the bottom of the container, thereby promoting the crystallization of primary aluminum from the molten aluminum. .

The cooling medium is not limited to water, and known cooling media such as oil, compressed air, etc. can also be used.

In addition, in order to reduce the load on the shaft 9 and the load on the rotational force transmission mechanism and drive device, a rotatable jig 14 is installed at the bottom of the pedestal 6 as shown in FIG. It can also be loaded on.

Although not shown in the drawings, in the present invention, a baffle plate made of a material that has corrosion resistance against molten aluminum, such as a ceramic material such as graphite or aluminum nitride, and a separate stirrer may be installed in the container. .

According to the fractional solidification apparatus for fractional crystallization of molten aluminum of the present invention described in detail above, it is possible to obtain highly purified aluminum with extremely simple operations and purification efficiency, so its industrial value is extremely large. It is something.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing an example of the fractional solidification apparatus for fractional crystallization of molten aluminum according to the present invention, in which 1 is an iron container with a lid, 2 is a refractory brick, 3 is molten aluminum, and 4 is a heat insulator. heating heater, 5
is a heating and insulating furnace; 6 is a pedestal; 7 is a container holding means; 8
and 10 is a passage space, 9 is an axis, 11 and 12
13 is a bevel gear, 13 is a drive device, 14 is a rotatable jig, 15 is a wheel, and 16 is a track.

Claims (1)

[Scope of utility model registration request] A holding container made of molten aluminum with a lid that can be opened and closed and has heat retention properties, a rotatable pedestal on which the container is placed and held fixedly, and a passage space for a cooling medium is bored inside; The heating holding area has a function of enclosing the area, a rotational force transmission mechanism for transmitting rotational force to the pedestal, and a drive device, and the pedestal engages with the rotational force transmission mechanism and has a downwardly extending shaft portion with a passage space that communicates with the cooling medium passage space of the pedestal and the external cooling medium, and rotates the pedestal and controls the heat transfer from the bottom of the molten aluminum holding container. Fractional solidification equipment for fractional crystallization of aluminum.