JPH07207367A - Production of al or al alloy - Google Patents

Abstract

PURPOSE:To produce high purity Al or Al alloy having high electric conductivity by simultaneously removing V, Ti, Mn, Cr, Co, Ni, Na and Ca from molten Al or Al alloy. CONSTITUTION:Sulfur and/or a sulfate is added to molten Al or Al alloy contg. one or more kinds of impurities selected from among V, Ti, Mn, Cr, Co, Ni, Na and Ca to form sulfides of the impurities and these sulfides are separated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing Al or an Al alloy, and more particularly to impurities such as V, Ti, Mn, Cr, Co, Ni, which are contained in molten Al or Al alloy.
The present invention relates to a method for producing Al or Al alloy having good electric conductivity by removing Na and Ca.

[0002]

2. Description of the Related Art Al or Al alloys are used for power line applications because they are excellent in lightness, workability and surface beauty and have good electric conductivity. However, when the electric conductivity is lowered due to the mixing of the impurity element, there is a problem that heat generation loss occurs due to resistance during power transmission. In recent years, from the viewpoint of resource saving and energy saving, Al or Al
Although it is necessary to recycle alloy products, A can be obtained by recycling unless impurity elements are reduced as much as possible.
l or Al alloy becomes unusable.

Japanese Examined Patent Publication No. 58-24495 describes V and Ti.
Regarding the above, a method for producing an aluminum alloy for electroconductivity, which comprises removing these as boride, is disclosed, and these are known as boron treatment. But,
Other than V and Ti, Mn, Cr, Co, Ni, Na, C
If the impurity element such as a is dissolved in Al as a solid solution, the electric conductivity is lowered, and thus the boron treatment alone is insufficient. Further, some methods for removing the elements here have been disclosed, but there is a problem that the process is complicated.

[0004]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned problems of the prior art, and removes V from the molten Al or Al alloy.
Providing a method capable of removing Ti, Mn, Cr, Co, Ni, Na, and Ca at once, and having high purity and high electrical conductivity
Alternatively, it is intended to produce an Al alloy.

[0005]

Means for Solving the Problems Al or Al of the present invention
The method for producing the alloy is as follows: V, Ti, Mn, C as impurities
In an Al or Al alloy melt containing one or more impurities selected from the group consisting of r, Co, Ni, Na and Ca,
The gist is that it includes a step of adding S and / or sulfate to form a sulfide with impurities and separating this. A method of removing sulfides through a fireproof filter can also be preferably adopted.

[0006]

As a result of earnest studies by the present inventors, V, Ti, Mn, Cr, Co, Ni and N which adversely affect the electric conductivity.
The inventors of the present invention have found that a and Ca are present in the molten aluminum as sulfides in a crystallized or semi-molten state and can be separated and removed by filtration. Therefore, in the present invention, the addition of S element and / or sulfate as an S source to the molten aluminum is an essential requirement. As the sulfate, a potassium salt can be preferably used. It is preferable to add S in a stoichiometric amount or more capable of removing all the impurity elements in the molten metal as sulfides. However, if too much S is added, S may remain in the molten metal, which may lead to a deterioration in the performance of the obtained Al or Al alloy. Therefore, the upper limit of S is preferably about 3 times the stoichiometric equivalent capable of forming sulfide. More preferably, it is not more than twice the equivalent amount.

In the present invention, removal of the impurity element can be achieved by separating these sulfides from the molten Al or Al alloy melt. The method for removing sulfide is not particularly limited. Sulfide is considered to be heavier than Al or Al alloy, and it is possible to remove it by a method such as "melting the metal" by allowing the molten metal to stand and allowing the sulfide to settle, and then filtering the molten metal with a refractory porous filter. preferable. In addition, since many sulfides are suspended in the molten metal, nitrogen, argon, He,
A separation method in which an inert gas such as neon is blown into the molten metal in the form of fine bubbles, and the complex oxide is floated along with the floating of the bubbles to remove them, can also be preferably used. In this case, dehydrogenation can be achieved at the same time.

The melting temperature of Al or Al alloy in the present invention may be a usual temperature of 700 to 900 ° C. After forming sulfides and filtering, refining is carried out by a known method to obtain high purity Al. Alternatively, an Al alloy can be manufactured.

[0009]

The present invention will be described in more detail with reference to the following examples, but the following examples do not limit the present invention.
All modifications and implementations that do not depart from the spirit of the description below are included in the technical scope of the present invention.

V, Ti, Mn, Cr, Co, Ni, N
JIS 110 containing 500 ppm of a and Ca in total
Using pure Al-based scrap of 0 as the raw material, the melting temperature is 750
It was dissolved in the atmosphere in a reflection type melting furnace (boiled with heavy oil) of 20 tons at 0 ° C. 0.05% by weight of S alone was added, or 0.25% by weight of K ₂ SO ₄ was added to form a sulfide, and filtration was performed using a 16-piece cartridge of tubular filter (HD mesh) made by Mitsui Metals. Chlorine gas (100 l / min x
Refining for 10 minutes) was performed to semi-continuously cast a 300 mmφ ingot. The ingot obtained and 30 made from this ingot
The electrical conductivity of the mmφ bar was measured by the Fogster Sigmar test and is shown in Table 1.

[0011]

[Table 1]

It can be seen that the S treatment of the present invention exhibits electrical conductivity equal to or higher than that of the conventional boron treatment. The clogging of the filter was less in the method of the present invention.

[0013]

The present invention is constituted as described above, and A
l or impurities in Al alloy V, Ti, Mn, Cr, C
O, Ni, Na, and Ca could be efficiently removed at a low cost in a single step, and high-purity Al and Al alloy could be manufactured.

 ─────────────────────────────────────────────────── ─── Continued front page (72) Inventor Kiyomasa Oga 1-5-5 Takatsukadai, Nishi-ku, Kobe-shi, Hyogo Prefecture Kobe Steel Research Institute, Kobe Steel Co., Ltd. (72) Inventor Motohiro Arai Takatsuka, Nishi-ku, Kobe-shi, Hyogo Prefecture No. 1-5-5 Kobe Steel Works, Ltd., Kobe Research Institute (72) Inventor Minji Masuda 14-1, Chofu Minatomachi, Shimonoseki City, Yamaguchi Prefecture Kobe Steel Co., Ltd., Chofu Factory (72) Inventor Takayuki Kitano Yamaguchi 14-1 Chofu Minatomachi, Shimonoseki City, Shizuoka Prefecture Kobe Steel Co., Ltd. Chofu Works

Claims (2)

[Claims] 1. V, Ti, Mn, Cr, C as impurities
o, Ni, Na, Ca, S or / and sulfate is added to Al or Al alloy molten metal containing one or more impurities selected from the group consisting of Ca to form a sulfide with impurities. A method for producing Al or an Al alloy, comprising the step of separating. 2. The production method according to claim 1, wherein the sulfide in the molten Al or the molten Al alloy is removed through a refractory filter.