JPS60190534A - Apparatus for continuous production of high-purity aluminum - Google Patents

Abstract

PURPOSE:To discharge smoothly aluminum oxide in the stage of crystallizing molten aluminum in plural crucibles arrayed into one row by positioning a receiving spout, connecting spouts and discharge spout for the molten metal on the straight line parallel with the straight line connecting the centers of the crucibles. CONSTITUTION:Plural crucibles 2A-2E are arrayed in one row and the molten Al from a melting furnace 1 is supplied via a receiving spout 6 to the crucible 2a where the molten Al is stirred by a stirrer 3. The molten Al is then fed succcessively via connecting spouts 5 to the crucibles 2B-2E and high-purity Al is crystallized by rotary cooling bodies 4. The molten Al is discharged from a discharge spout 7. The receiving spout 6, the connecting spouts 5 and the discharge spout 7 are positioned on the straight line shifted toward left from the straight line connecting the centers of the crucibles 2B-2E while the bodies 4 rotate clockwise when viewed from the plane. The Al oxide generated in the molten Al is then passed through the spouts 5 and the spout 7 by the centrifugal force of the bodies 4 and is thus smoothly removed.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for continuously producing high-purity aluminum using segregation solidification.

The present applicant previously proposed an aluminum refining method that utilizes the principle of segregation solidification in order to produce high-purity aluminum. In this refining method, after melting the aluminum to be refined, the molten aluminum is always heated and maintained at a temperature exceeding its solidification temperature, and a cooling body is immersed in the heated molten aluminum. By maintaining the surface temperature of the body below the solidification temperature and rotating this cold body to disperse and mix the impurities discharged near the solidification interface, the impurity concentrated layer near the solidification interface in the liquid phase is It is characterized by crystallizing high-purity aluminum on the surface of the cooling body while reducing the thickness and thereby steepening the temperature gradient in the liquid phase in the impurity-concentrated layer.
JP-A-1J) No. 57-82437).

An object of the present invention is to provide an apparatus capable of efficiently removing aluminum oxide generated during refining when high-purity aluminum is continuously produced using the above-described method.

In this specification (■), forward and backward refers to the direction in which the molten aluminum advances in the melting furnace (right side of Figure 1), and backward refers to the direction in which the molten aluminum advances in the melting furnace. It shall point to the side. In addition, left and right mean forward.

The continuous VC manufacturing apparatus for high-purity aluminum according to the present invention includes a plurality of crucibles arranged in a line following a melting furnace for melting aluminum, one crucible in each crucible, and It is equipped with a rotary cooling body for crystallizing high-purity aluminum that can be moved up and down, and adjacent crucibles are connected in a continuous manner by a connecting gutter at the upper end, so that the upper end of the crucible that is the fastest to move from the melting furnace A molten metal discharge gutter is attached to the melting furnace, and the connecting gutter J3 and the molten metal discharge gutter are located on a straight line parallel to the straight line connecting the centers of the crucibles when viewed from the plane, and melting is carried out in the crucible closest to the melting furnace. Molten aluminum is fed into the furnace from a furnace.

The rotary cooling body is used to crystallize high-purity aluminum on its circumferential surface. That is, after the molten metal is poured into each crucible, the rotary cooling body is lowered and immersed in the molten metal,
When the rotary cooling body is rotated, high-purity primary aluminum crystallizes on the circumferential surface of the rotary cooling body, and impurities are discharged into the liquid phase. A relative movement occurs between the two, and the impurity concentrated layer formed near the solidification interface by the ejected impurities is effectively stirred and mixed with most of the other liquid phase, and the impurity concentrated layer is The impurities are dispersed throughout the liquid phase, and the thickness of the impurity-concentrated layer becomes very thin as a result. Therefore, high purity aluminum can be obtained with high purification efficiency. As this rotary cooling body, a cylindrical one or a Taber cylindrical one whose diameter becomes gradually smaller toward the bottom are used. It is more preferable to use a tapered cylindrical cooling body as this makes it easier to recover high-purity aluminum crystallized on the circumferential surface of the cooling body.

The cooling body is cooled by feeding a cold IJI body such as air, argon gas, nitrogen gas, or a mixed liquid of air and water into the cooling body. increasing the infusion delivered to the molten aluminum in the crucible by heating from an external heat source;
Moreover, if a large amount of heat is removed by cooling the molten aluminum with the cooling body, the solidification rate will decrease, and the heat flow between the cooling body and the molten aluminum will increase, increasing the temperature gradient in the liquid phase near the solidification interface. growing. Therefore, the effect of the rotation of the cooling body mentioned above and the effect of obtaining high-purity aluminum are further improved.

The connecting gutter and the discharge gutter are designed so that when the molten aluminum advances forward, the rotating cooling body rotates in the direction of
When the rotary cooling body is rotated counterclockwise when viewed from a plane, it is placed to the left of the straight line connecting the centers of the crucibles, and to the right of the DI line connecting the centers of the crucibles. It is placed in a position that is biased towards. Therefore, the aluminum oxide generated during the production of high-purity aluminum due to the centrifugal force generated by the rotation of the rotary cooling body flows through the connecting gutter to the crucible before passing through the JJI tap and is smoothly removed. Ru.

In such a manufacturing apparatus for 1OIIIi degree aluminum, the cold body is raised in advance, molten aluminum is supplied from the melting furnace to the crucibles, and the amount of molten metal in each crucible becomes equal, and then the cooling body is lowered. Immerse it in molten metal and avoid rotating it. Then, the molten metal supply ffi d5 and the discharge chamber are adjusted so that the molten metal (1) in each crucible remains unchanged during operation, and the aluminum stones crystallized on the circumferential surface of each cooling body are adjusted to be equal. The amount of aluminum crystallized on the circumferential surface of the cooling body can be changed as appropriate depending on the temperature of the molten metal, the rotational speed of the cooling body, the cooling capacity, and the oil immersion time. The impurity 1I11 degree in the molten metal in each crucible increases successively from the one closest to the melting furnace to the further away from the melting furnace. The total amount of aluminum recovered by each cold body ii1'7'i1, the total amount of molten metal fed into the
By changing the ratio to aluminum (hereinafter referred to as recovery rate), the average impurity concentration in the total aluminum can be changed, and the smaller the recovery rate, the lower the above average impurity concentration. Therefore, by setting the above-mentioned recovery rate to a predetermined value, it is possible to obtain a higher IT! 1. It is possible to produce 1 g of ff aluminum. Furthermore, if the recovery rate is kept constant, high purity aluminum can be obtained with a large number of crucibles.

” - As mentioned above, according to the high-purity aluminum continuous VJ production apparatus of the present invention, all the connection gutter and molten metal discharge gutter are on a straight line parallel to the straight line connecting the centers of the crucible when viewed from the plane. Since the aluminum oxides generated in the molten aluminum in each crucible during the refining work are also passed through the connection gutter J3J and the outlet gutter 171 by the centrifugal force generated by the rotation of the rotating cold fJI body. It can be removed smoothly. If the connecting gutter and the discharge gutter are on a straight line connecting the centers of the crucibles, the aluminum oxide will not flow forward smoothly, and if the connecting gutter Cm is on the tangent line common to two adjacent crucibles when viewed from the plane. In some cases, there is a backflow of something flowing into the crucible at one end in front. According to the device of the present invention, the molten aluminum melted in the melting furnace and supplied to the crucible at the rear end can be smoothly sent to the crucible at the front by the centrifugal force generated by the rotation of the cold body of the rotor. This makes it possible to continuously and efficiently produce high-purity aluminum.

This invention will be explained below with reference to the drawings.

The continuous production equipment for high-purity aluminum consists of a melting furnace (1) that melts aluminum, five crucibles (2Δ) to (2E) lined up next to each other, and a stirring pot located in the crucible (2Δ) at the rear end. machine (3) and the other four crucibles (2B) ~ (
2[E], and rotary cooling bodies (4) for crystallizing high-purity aluminum, which are movable up and down.

Adjacent crucibles (2A) to (2[) are connected in a communicating manner by a connecting gutter (5) at the upper end, and the melting furnace (1) supplies full miniram molten metal to the crucible (2A) at the rear end. A receiving gutter (6) is installed to receive the melted slag discharge side (7) at the upper end of the crucible (213) at the front end.
Connecting gutter (5), receiving gutter (
6) and molten metal discharge 1iffi (7) are located on a straight line with a sharp hh (-) parallel to the straight line connecting the centers of the crucibles (2Δ) to (211= ) when viewed from the plane. .

On the peripheral wall of each crucible (2△) to (2E), from the upper edge ()
A shaped notch (8) is formed, and a recess (9) is provided in the outer surface of the peripheral wall on the lower side J3 and on the right side of the portion around this notch (8). The connecting gutter (5) is arranged so that the notches (8 pieces) of the adjacent corners (2A) to (2E) communicate with each other.The connecting gutter (5) has a cross section ()
In shape, both front and rear ends are round (2Δ) ~ (2I:3)
J along the outer circumferential surface of the sea urchin is rounded.

In addition, there are notches (8
) The human part (1o) that can be inserted into the middle part (1o) is accented in a protruding manner. The connecting gutter (5) is connected to the insertion part (1o)
is fitted into the notch (8), and the lower and right parts are fitted into the recess (9).
'c It is fixed at Ruppo (2Δ) ~ (2E). Crucible of receiving gutter (6) and discharge gutter (7) (2A>(2E)
The connecting end to the connecting tilfi (5) has the same shape as the connecting trough (5), and the crucible (2A>(2E)
is fixed.

The rotary cooling body (4) has a hollow tapered cylindrical shape that gradually becomes thinner toward the bottom and is closed at both ends, and is made of graphite, shiramix, or the like. In addition, the rotary cooling body (4)
is attached to the lower end of the hollow rotating shaft (12), and cooling fluid is supplied to the inside thereof from a cooling fluid supply pipe (not shown) arranged inside the hollow rotating shaft (12). ing.

In the continuous manufacturing apparatus for high-purity aluminum having such a configuration, refined rivet aluminum melted in the melting furnace (1) is fed into each of the crucibles (2Δ) to (2[). This molten aluminum contains Fe, Si, Ctll.
In addition to eutectic impurities such as MCI, if impurities that form peritectics with aluminum such as Zr are included (hereinafter referred to as peritectic impurities), the leftmost crucible (2A
), add boron to the molten metal and stir with the stirrer (3)] 1! When covered, boron reacts with peritectic impurities such as Ti1 and Zr to form insoluble metal borides such as TtB2, VB2 and ZrB2.

Each crucible (2B)” (2E) kl: #4
:J'Z>When the molten metal m reaches a predetermined amount, the cooling body (
4) is lowered ten times and immersed in the molten metal, and is rotated while supplying cooling fluid to the inside. Then, the rotating cooling body (
4) High-grade aluminum crystallizes on the surrounding surface. The eutectic impurities and the excess boron added in the crucible (2A) on the left end are ejected into the liquid phase and are removed from the cooling body (4) by the centrifugal horn generated by the rotation of the cooling body (4). 1. Metal borides contained in the molten aluminum are also moved away from the rotary cooling body (4) by the centrifugal force generated by the rotation of the rotary cooling body (4), so that the metal borides contained in the molten aluminum are moved away from the rotary cooling body (4), so that they are The crystallized "aluminum" no longer contains metal borides. In this way, aluminum of higher purity than the original purified aluminum supplied from the melting furnace (1) is obtained.

In addition, due to the centrifugal force generated by the rotation of the rotary cooling body (4), each crucible (2B) to (2F) is
) is smoothly sent to the front end crucible (2F) through the connecting trough (5) and removed through the JJI outlet (7).

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is a vertical longitudinal cross-sectional view, FIG. 2 is a partially omitted plan view, FIG. 3 is a partially enlarged view of FIG. 2, and FIG. 4 is an IV view of FIG. 3. FIG. 5 is an exploded perspective view showing the state of connection between the crucible and the connecting gutter. (1)... Melting furnace, (2B) to (2E)... Crucible, (4)... 1 rotating cold moon, (5)... Connecting gutter, (
7)...Discharge gutter. that's all

Claims (1)

[Claims] A melting furnace (1) for melting aluminum is followed by a plurality of crucibles (2B) to (2[3) arranged in a row, and one crucible is placed in each crucible (2B) to (2F). It is equipped with a rotary cooling 2J body (4) for crystallizing high-purity aluminum that can be moved up and down, and adjacent crucibles (2B) to (2F) are connected to each other at their upper ends. (through 5) and are connected in a continuous manner through the melting furnace (
Molten metal jJl is placed at the upper end of the crucible (2F) farthest from 1).
The outlet (7) has been removed and all connecting gutters (5) have been removed.
J3 and the molten metal discharge gutter (7) are connected to the crucible (2) when viewed from above.
The crucible (2B) that is located on a straight line parallel to the straight line connecting the centers of
) is a continuous production T made of high-purity aluminum, into which molten aluminum is fed from a melting furnace (1);
1 device.