Metallurgical furnace with aluminum refining function and aluminum liquid refining method

Abstract

The present invention relates to a metallurgical furnace with aluminum refining function and a refining method, the metallurgical furnace comprises a furnace body, the furnace body has an inner cavity for retaining aluminum liquid, the furnace body is provided with a furnace eye connected with the inner cavity; the inner cavity has a first bottom surface and a second bottom surface adjacent to the first bottom surface, the first bottom surface is parallel to the horizontal plane, the second bottom surface is annular, and the cross-sectional area of ​​the space surrounded by the second bottom surface gradually decreases from top to bottom; a plurality of first porous bricks and a plurality of second porous bricks are provided in the wall of the furnace body, the top surface of the first porous brick is connected with the first bottom surface, the bottom of the first porous brick is connected with a first gas distribution pipe, the top surface of the second porous brick is connected with the second bottom surface, the bottom of the second porous brick is connected with a second gas distribution pipe, and the first porous brick and the second porous brick are both located between the central axis of the furnace body and the furnace eye. The present invention has the advantages of low operating cost, good refining effect, high utilization rate of refining medium, etc.

Description

Technical Field

[0001] The invention relates to a metallurgical furnace with an aluminum refining function and a method for refining aluminum liquid. Background Art

[0002] Steel pipe refining is one of the common methods of aluminum refining. It achieves refining by injecting the refining medium gas into the aluminum melt through a steel pipe. When this technology is implemented, the refining medium has large bubbles, short contact time with the aluminum liquid, poor mixing uniformity with the aluminum liquid, poor degassing effect, and high labor intensity.

[0003] In order to overcome the above problems, researchers have done a lot of improvement work. For example, at present, in foreign aluminum smelting and casting industries, porous air-permeable bricks and corresponding gas distribution and adjustment systems have been widely installed at the bottom of various furnaces for orderly bottom blowing and stirring, which can overcome the problems of large bubbles, short contact time, poor uniformity, etc. Chinese patent specification CN110079688A discloses a method for automatic refining treatment of aluminum liquid insulation bricks, which is to arrange multiple porous bricks at the bottom of the furnace, use porous bricks to fully disperse the refining gas, expand the contact area with aluminum liquid and prolong the time, which is conducive to ensuring that the inert gas fully absorbs the impurities. However, in order to ensure that the aluminum liquid in various parts of the furnace is fully in contact with the inert gas, the number of porous bricks required to be arranged is large, and there are many leakage points, which increases the construction and maintenance costs of the furnace, and the amount of inert gas required is also large, which increases the operating cost. Summary of the invention

[0004] One of the purposes of the present invention is to provide a metallurgical furnace with aluminum refining function to reduce the refining cost; the second purpose of the present invention is to provide a refining method for molten aluminum to achieve aluminum refining simply and efficiently.

[0005] The technical solution of the present invention is as follows:

[0006] A metallurgical furnace with aluminum refining function comprises a furnace body, the furnace body having an inner cavity for retaining aluminum liquid, the furnace body being provided with a furnace eye connected to the inner cavity; the inner cavity having a first bottom surface and a second bottom surface adjacent to the first bottom surface, the first bottom surface being parallel to the horizontal plane, the second bottom surface being annular, and the cross-sectional area of ​​the space enclosed by the second bottom surface gradually decreases from top to bottom; a plurality of first porous bricks and a plurality of second porous bricks are provided in the wall of the furnace body, the top surface of the first porous brick is connected to the first bottom surface, the bottom of the first porous brick is connected to a first gas distribution pipe, the top surface of the second porous brick is connected to the second bottom surface, the bottom of the second porous brick is connected to a second gas distribution pipe, and the first porous brick and the second porous brick are both located between the central axis of the furnace body and the furnace eye.

[0007] In this way, porous bricks are only arranged near the furnace eye, and inert gas and / or active gas can be introduced into the metallurgical furnace through the first porous brick and / or the second porous brick during the aluminum liquid transfer in or out process. During the introduction process, the gas is refined into millimeter-level bubbles by the porous bricks, generating a large amount of gas-liquid contact surface, thereby capturing harmful gas inclusions in the aluminum melt, improving the purity of the melt, and achieving the purpose of automatic and efficient purification; at the same time, the composition of the melt is made more uniform. The present invention only arranges porous bricks in a part of the furnace bottom area, realizes melt purification in the process of the converter, can effectively reduce equipment investment, reduce potential leakage points of the metallurgical furnace, and has a high utilization rate of the introduced gas, which can effectively reduce the overall cost.

[0008] In the present invention, the wall of the furnace body may generally refer to the outer shell of the furnace body, and may be a side wall or a bottom wall.

[0009] Furthermore, the minimum distance between the top surface of the first porous brick and the second bottom surface is 0-30 cm; the minimum distance between the top surface of the second porous brick and the first bottom surface is 0-30 cm.

[0010] Preferably, the minimum distance between the top surface of the first porous brick and the second bottom surface is 5-20 cm; the minimum distance between the top surface of the second porous brick and the first bottom surface is 5-20 cm.

[0011] Furthermore, the plane passing through the central axis of the furnace body and bisecting the furnace eye is recorded as a bisecting plane; the minimum distance between the top surface of the first porous brick and the bisecting plane is 0-30 cm, and the minimum distance between the top surface of the second porous brick and the bisecting plane is 0-30 cm.

[0012] Furthermore, the minimum distance between the top surface of the first porous brick and the bisecting plane is 0-20 cm, and the minimum distance between the top surface of the second porous brick and the bisecting plane is 0-20 cm.

[0013] The porous bricks are placed just below the flow path of the molten aluminum when it flows out of the metallurgical furnace, so that the molten aluminum can fully contact with the inert gas or active gas to ensure the refining effect.

[0014] Furthermore, the number of the first porous bricks is 1-3 pieces; the number of the second porous bricks is 1-3 pieces.

[0015] Furthermore, the number of the first porous bricks is 2; the number of the second porous brick is 1, the two first porous bricks are symmetrically distributed on both sides of the bisecting plane, and the second porous brick is bisected by the bisecting plane.

[0016] Furthermore, the angle between the first bottom surface and the second bottom surface is 15-25°, further 18-22°.

[0017] Furthermore, the metallurgical furnace is a smelting furnace or a holding furnace.

[0018] Based on the same inventive concept, the present invention also provides a method for refining molten aluminum, wherein a metallurgical furnace containing molten aluminum is tilted toward the direction of a furnace eye, so that the molten aluminum in the metallurgical furnace gathers toward the furnace eye and flows out through the furnace eye; at the same time, an inert gas and / or an active gas is introduced through the first gas distribution pipe and / or the second gas distribution pipe.

[0019] In this way, over-flow refining is formed, that is, inert gas or active gas is introduced while over-flowing near the furnace eye to remove impurities such as hydrogen or harmful metals such as K, Na, and Ca in the aluminum melt. The converter process and refining process are integrated, simplifying the process.

[0020] Furthermore, the inert gas is argon; and the active gas is chlorine or carbon tetrachloride.

[0021] Compared with the prior art, the present invention has the following advantages:

[0022] 1. Fewer porous bricks are required, fewer potential leakage points, and lower operating costs.

[0023] 2. The porous bricks are set near the furnace eye to ensure that all the molten aluminum can come into contact with the gas, resulting in a good refining effect.

[0024] 3. High degree of automation, can be completed during the normal converter process.

[0025] 4. High utilization rate of refining medium. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a cross-sectional view of a metallurgical furnace with aluminum refining function according to the present invention (non-converter state).

[0027] Figure 2 It is a cross-sectional view of a metallurgical furnace with an aluminum refining function according to the present invention (converter state one: rotated 5° clockwise).

[0028] Figure 3 It is a cross-sectional view of a metallurgical furnace with an aluminum refining function according to the present invention (converter state two: rotated 20° clockwise). DETAILED DESCRIPTION

[0029] The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments. It should be noted that the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict. For the convenience of description, if the words "upper", "lower", "left" and "right" appear in the following, they only indicate that the upper, lower, left and right directions are consistent with the drawings themselves, and do not limit the structure.

[0030] See also Figure 1-Figure 3A metallurgical furnace with aluminum refining function comprises a furnace body, the furnace body having an inner cavity 1 for retaining aluminum liquid, and a furnace eye 2 connected to the inner cavity 1 is provided on the furnace body; the inner cavity 1 has a first bottom surface 101 and a second bottom surface 102 adjacent to the first bottom surface 101, the first bottom surface 101 is parallel to the horizontal plane, the second bottom surface 102 is annular, and the cross-sectional area of ​​the space surrounded by the second bottom surface 102 gradually decreases from top to bottom; a plurality of first porous bricks 4 and a plurality of second porous bricks 3 are embedded in the wall of the furnace body, the top surface of the first porous brick 4 is connected to the first bottom surface 101, the bottom of the first porous brick 4 is connected to the first gas distribution pipe 6, the top surface of the second porous brick 3 is connected to the second bottom surface 102, the bottom of the second porous brick 3 is connected to the second gas distribution pipe 5, and the first porous brick 4 and the second porous brick 3 are both located between the central axis 8 of the furnace body and the furnace eye 2.

[0031] The minimum distance between the top surface of the first porous brick 4 and the second bottom surface is 5 cm; the minimum distance between the top surface of the second porous brick 3 and the first bottom surface is 5 cm.

[0032] The number of the first porous brick 4 is 1; the number of the second porous brick 3 is 1; the plane passing through the central axis 8 of the furnace body and bisecting the furnace eye 2 is recorded as a bisecting plane; the bisecting plane bisects the first porous brick, and the bisecting plane bisects the second porous brick 3. Optionally, as another embodiment, the number of the first porous brick 4 is 2; the number of the second porous brick 3 is 1, the two first porous bricks 4 are symmetrically distributed on both sides of the bisecting plane, and the second porous brick 3 is bisected by the bisecting plane.

[0033] The included angle between the first bottom surface 101 and the second bottom surface 102 is 22°.

[0034] The porous brick is made of high temperature porous ceramic material, such as corundum alumina-chromium. Optionally, the porous brick is conical. The porous brick is wrapped with a stainless steel shell or a nickel-chromium alloy shell (shell), the shell is only open at the top, and the gas distribution pipe is connected to the bottom of the shell.

[0035] A method for refining aluminum liquid, wherein a metallurgical furnace containing aluminum liquid is tilted toward a furnace eye so that the aluminum liquid in the metallurgical furnace is gathered toward the furnace eye and flows out through the furnace eye; at the same time, an inert gas and / or an active gas is introduced through a first gas distribution pipe 6 and / or a second gas distribution pipe 5;

[0036] Among them, the rate of aluminum liquid flowing out of the furnace eye is 100-800kg / min; the gas flow rate of a single porous brick is 5-20L / min;

[0037] The inert gas is argon; the active gas is chlorine or carbon tetrachloride.

[0038] The contents explained in the above embodiments should be understood as these embodiments are only used to more clearly illustrate the present invention, and are not used to limit the scope of the present invention. After reading the present invention, various equivalent forms of modifications to the present invention by those skilled in the art all fall within the scope defined by the claims attached to this application.

Claims

1. A method for refining molten aluminum, characterized in that: The metallurgical furnace containing the aluminum liquid is tilted toward the furnace eye so that the aluminum liquid in the metallurgical furnace is gathered toward the furnace eye and flows out through the furnace eye; at the same time, an inert gas and / or an active gas is introduced through the first gas distribution pipe (6) and / or the second gas distribution pipe (5) to form a flow-through refining; The metallurgical furnace comprises a furnace body, the furnace body having an inner cavity (1) for retaining aluminum liquid, and the furnace body is provided with a furnace eye (2) connected to the inner cavity (1); the inner cavity (1) has a first bottom surface (101) and a second bottom surface (102) adjacent to the first bottom surface (101), the first bottom surface (101) is parallel to a horizontal plane, the second bottom surface (102) is annular, and the cross-sectional area of ​​the space enclosed by the second bottom surface (102) gradually decreases from top to bottom; a plurality of first porous bricks (4) and A plurality of second porous bricks (3), wherein the top surface of the first porous brick (4) is connected to the first bottom surface (101), the bottom of the first porous brick (4) is connected to a first gas distribution pipe (6), the top surface of the second porous brick (3) is connected to the second bottom surface (102), the bottom of the second porous brick (3) is connected to a second gas distribution pipe (5), and the first porous brick (4) and the second porous brick (3) are both located between the central axis (8) of the furnace body and the furnace eye (2); the number of the first porous bricks (4) is 1 to 3; the number of the second porous bricks (3) is 1 to 3.

2. The refining method according to claim 1, characterized in that: The minimum distance between the top surface of the first porous brick (4) and the second bottom surface is 0-30 cm; the minimum distance between the top surface of the second porous brick (3) and the first bottom surface is 0-30 cm.

3. The refining method according to claim 2, characterized in that: The minimum distance between the top surface of the first porous brick (4) and the second bottom surface is 5-20 cm; the minimum distance between the top surface of the second porous brick (3) and the first bottom surface is 5-20 cm.

4. The refining method according to claim 1, characterized in that: A plane passing through the central axis (8) of the furnace body and bisecting the furnace eye (2) is recorded as a bisecting plane; the minimum distance between the top surface of the first porous brick (4) and the bisecting plane is 0-30 cm, and the minimum distance between the top surface of the second porous brick (3) and the bisecting plane is 0-30 cm.

5. The refining method according to claim 4, characterized in that: The minimum distance between the top surface of the first porous brick (4) and the bisecting plane is 0-20 cm, and the minimum distance between the top surface of the second porous brick (3) and the bisecting plane is 0-20 cm.

6. The refining method according to claim 4, characterized in that: The number of the first porous bricks (4) is 2; the number of the second porous brick (3) is 1, the two first porous bricks (4) are symmetrically distributed on both sides of the bisecting plane, and the second porous brick (3) is bisected by the bisecting plane.

7. The refining method according to any one of claims 1 to 6, characterized in that: The included angle between the first bottom surface (101) and the second bottom surface (102) is 15-25°.

8. The refining method according to claim 1, characterized in that: The inert gas is argon; the active gas is chlorine or carbon tetrachloride.

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