JPH0633154A - Melting and separating method of metal - Google Patents

Abstract

PURPOSE:To completely separate a metal of a low sp.gr. and high m.p. and a metal of a high sp.gr. and low m.p. in the form of solid and molten metals by melting a mixture composed of the both metals and cooling the melts to the temp. between the m.p. of the two metals. CONSTITUTION:The metal mixture composed of, for example, Fe and Cu, varying in the sp.gr. and the m.p. is charged into a melting furnace 1 and a high-frequency induction heating coil 2 on the side wall of the melting furnace 1 is energized to melt the metal mixture composed of the Fe and the Cu. The molten metal 4 of the Cu having the large sp.gr. settles in the lower part and the molten metal 3 of the Fe having the small sp.gr. floats in the upper part. The molten metal in the mixed state of the Fe and the Cu exists in the intermediate part thereof. The current of the high-frequency induction heating coil 2 is then gradually decreased to slowly cool the two molten metal layers 3, 4. The layers are thus cooled to, for example, 1200 deg.C intermediate temp. of 1083 deg.C which is the m.p. of the Cu and 1540 deg.C which is the m.p. of the C and the Fe. The Fe 3 having the high m.p. is solidified to the solid Fe which floats on the molten metal 4 of the Cu of the low m.p. The Fe in the intermediate part of both solidifies as well and floats on the molten Cu 4, by which the Fe is separated. An ejection port 6 in the bottom of the melting furnace 1 is opened to discharge the Cu in the molten state which is thus separated from the Fe 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for melting and separating a metal by melting the metal and taking out one of the dissimilar metals separated by the difference in specific gravity.

[0002]

2. Description of the Related Art Conventionally, a method of separating molten metal by the difference in specific gravity has been such that metals having different specific gravities are melted and separated by a crucible or the like, then cooled and taken out as a solid for separation.

[0003]

In the conventional method in which metals having different specific gravities are melted, separated by the difference in specific gravities and then cooled and taken out as a solid, the metal taken out as a solid is
Since dissimilar metals are mixed at the boundary, they cannot be separated and a means such as mechanical cutting is required.

The present invention is intended to provide a method for dissolving and separating a metal which can solve the above problems.

[0005]

A method for melting and separating metals according to the present invention is to melt metals having different specific gravities into molten metal, and after the molten metals are separated into upper and lower parts due to the difference in specific gravity, the temperature of the molten metal is changed to a low melting point metal. It is characterized in that the temperature is lowered to a temperature slightly higher than the melting point, and only the metal having the low melting point is taken out as a molten metal in a state where the metal having the high melting point is solidified and the metal having the low melting point is molten.

[0006]

In the present invention, metals having different specific gravities that are melted and mixed to form a molten metal are separated into upper and lower parts by the difference in specific gravities in the molten metal state, and then this molten metal is melted with the melting point of a metal having a low melting point. Cool to an intermediate temperature of the melting point of the high metal. As a result, the metal having a high melting point is solidified and the metal having a low melting point is kept in a molten state, so that the separation accuracy is improved. The metal having a low melting point and separated with high accuracy is taken out as a molten metal, and the two metals are separated. Various shapes can be obtained by injecting the extracted metal having a low melting point into a mold.

[0007]

EXAMPLE An example of the present invention used for separating iron and copper will be described with reference to FIG. FIG. 1 is a vertical sectional view showing the overall structure of a melting furnace for separation used in this example.

A mixture of iron (high melting point, low specific gravity) and copper (low melting point, high specific gravity) is charged into a melting furnace 1 having a spout 6 at the bottom, and the side wall of the melting furnace 1 is connected to a power source (not shown). By energizing the high-frequency heating coil 2 arranged so as to surround it, the mixture of iron and copper is heated and melted.

By maintaining this state, the iron in the molten metal of the molten iron and copper has a small specific gravity and thus floats above the molten metal, while the copper in the molten metal has a large specific gravity. They are separated downward, and in the middle part they are still mixed in the molten state.

Then, the high frequency output to the heating coil 2 is gradually lowered so that the temperature of the molten metal of the mixture in the melting furnace 1 is higher than the melting point of copper (1083 ° C.) and the melting point of iron (154).
The temperature is lowered to about 1200 ° C, which is lower than 0 ° C).

In the process of lowering the temperature, the iron that has floated upward starts solidification, and the iron mixed in the molten state in the intermediate portion locally starts solidification selectively, and the solidified iron moves upward due to the difference in specific gravity. It floats and is gradually separated from the molten copper.

At the place where the temperature of the molten metal in the melting furnace 1 reaches about 1200 ° C. due to the progress of the temperature decrease, the iron 3 and the copper 4 are vertically separated in the melting furnace 1 as shown in FIG. The iron 3 is solid and the copper 4 is present in a molten liquid state, and both are vertically separated. In this case, since iron having a high melting point is solidified and separated from copper in a molten state, iron and copper are separated from each other in a highly accurate state without being mixed.

In this way, the iron 3 is solidified and floats upward, and the copper 4 is melted and is present below.
When the lid 5 at the lower spout is removed, only the copper 4 at the bottom of the melting furnace 1 can be taken out as a molten metal.

Further, after the copper is taken out in the molten state, the iron remaining in the melting furnace 1 can be easily taken out as a molten iron by heating the melting furnace 1 again by the high frequency heating coil 5. .

If the cooling rate after melting the mixture is large, it becomes difficult to separate it, and it is advantageous that the cooling rate is small. However, this cooling rate is set to an appropriate value in view of the operating time and the life of the furnace. In the separation of iron and copper in this example, 10
A temperature decrease rate of about -15 ° C / min was suitable.

In this embodiment, the heating method is high frequency, but it is also possible to use other heat sources (for example, gas heating or electric heating).

[0017]

Industrial Applicability According to the present invention, metals having different specific gravities are melted to form a molten metal, and the molten metal is separated into upper and lower parts by the difference in specific gravities.
The metal can be reliably separated by the difference in specific gravity, and
By lowering the temperature of the molten metal to an intermediate temperature between the melting points of the metal having a low melting point and the metal having a high melting point and solidifying the metal having a high melting point, it is possible to accurately separate the two metals, and Only low metals can be taken out in the state of molten metal (liquid). Therefore, according to the present invention, metals having different specific gravities can be accurately separated by a simple method.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing an overall configuration according to a first embodiment of the invention of a melting furnace used in one embodiment of the present invention.

[Explanation of symbols]

 1 melting furnace 2 high frequency heating coil 3 iron 4 copper 5 spout lid 6 spout

Claims (1)

[Claims] 1. A molten metal obtained by melting metals having different specific gravities,
After the molten metal is separated into upper and lower due to the difference in specific gravity, the temperature of the molten metal is lowered to an intermediate temperature between the melting points of the low melting point metal and the high melting point metal, the high melting point metal solidifies and the low melting point metal melts. A method for melting and separating metals, characterized in that only the metal having a low melting point is taken out as molten metal in the state of being present.