Magnesium alloy melt multi-stage liquid level difference filtering-purifying impurity removal system and magnesium alloy melt multi-stage liquid level difference filtering-purifying impurity removal method

Abstract

The invention discloses a magnesium alloy melt multistage liquid level difference filtering-purifying impurity removal system and method, the system mainly comprises a smelting and impurity removal unit and a filtering system, and three different smelting furnaces of the smelting and impurity removal unit and three different filter screens of the filtering system act together; a multi-stage gradient is formed between every two adjacent smelting furnaces through the liquid level difference (100-300 mm), and under the action of purifying agents and inert gas with different masses, different impurities are classified, purified in a graded mode and removed; and the filter screens with different materials and different mesh numbers can be used for grading and filtering impurities in a melt flowing process in a classified manner. And sediments in each detachable impurity retention area can be detached and cleaned after the cast rolling work is completed. The device integrates smelting, filter screen filtration, purifying agent purification and gas impurity removal, is particularly suitable for a magnesium alloy cast-rolling production line, and has positive effects of removing inclusions in magnesium melt, improving the purity of the melt and improving the quality of magnesium alloy cast-rolling forming parts.

Description

Technical Field

[0001] The invention relates to the technical field of magnesium alloy casting and rolling, and in particular to a magnesium alloy melt multi-stage liquid level difference filtering-purification and impurity removal system and method. Background Art

[0002] As the lightest metal material, magnesium alloy has been widely used in recent years. However, impurities in magnesium alloy cast-rolled plates have limited the application and development of magnesium alloys to a certain extent. Therefore, removing impurities in magnesium melt before casting is the primary task to obtain high-quality magnesium alloy cast-rolled plates.

[0003] In order to eliminate impurities in magnesium alloy melts, industry insiders have been studying magnesium alloy impurity removal and purification process methods and devices. For example, the Chinese invention patent with the authorization announcement number CN 102296184 B and the invention name "A solvent-free magnesium alloy purification method" achieves the purpose of removing impurities by cooling and remelting the alloy liquid that has been modified and has the required composition, but the cooling and heating processes require a lot of time costs; the Chinese invention patent with the authorization announcement number CN 110724843B and the invention name "A method for removing magnesium oxide inclusions in magnesium or magnesium alloy melts" achieves the purpose of removing small-sized impurities by adding metal elements to the melt, but the impurity removal and purification effect on the casting and rolling production line where different impurities coexist is limited; the application publication number is CN 116162798 A. The Chinese invention patent named "A multifunctional magnesium alloy melt purification device and purification method" requires that the purification device of the invention be placed in a high-temperature melt for sufficient stirring. The melt after stirring also needs to be fully allowed to stand and cool down before artificial slag removal, so the device is not particularly suitable for continuous casting and rolling production lines; it is common to use foam ceramic filters to purify the melt, but the ceramic itself is brittle and easy to break. The impact of impurities during the filtering and impurity removal process will cause tiny ceramic fragments to enter the melt and pollute the melt. Summary of the invention

[0004] The purpose of the present invention is to address the deficiencies of the above-mentioned prior art and to provide a magnesium alloy melt multi-stage liquid level difference filtration-purification and impurity removal system and method, which can grade and classify impurities of different sizes and weights through the multi-stage liquid level difference generated by multiple smelting furnaces. During the flow of the molten metal, multiple filter screens also simultaneously filter different impurities. The system and method integrate smelting, precipitation and filtration, and have a significant effect on improving the purity of the melt and the quality of cast and rolled parts.

[0005] The objective of the present invention is achieved through the following technical scheme: a magnesium alloy melt multi-stage liquid level difference filtration-purification and impurity removal system and method; the system consists of a smelting and impurity removal unit consisting of a first smelting furnace, a second smelting furnace, a third smelting furnace, etc. and a filtration system consisting of a first filter screen, a second filter screen and a third filter screen.

[0006] Before the start of casting and rolling work, the melt is injected into the first smelting furnace through the feed port, and the melt flows through the second smelting furnace and the third smelting furnace in turn for smelting; during the operation of the first smelting furnace and the second smelting furnace, purifiers of different masses are added through the feed port 1 and the feed port 2 to purify the melt, and during the operation of the second smelting furnace and the third smelting furnace, inert gases of different masses are blown into the second smelting furnace through the blowing port 1 and the blowing port 2 to prevent the oxidation of the melt and make the inclusions in the melt float and settle; during the flow of the melt, it is filtered through the first filter screen, the second filter screen and the third filter screen in turn, and the pure melt after filtering and impurity removal enters the casting and rolling unit through the discharge port 3 for subsequent casting and rolling work.

[0007] . Further, the height difference between the feed port and the discharge port of the first smelting furnace is greater than 100 mm, the height difference between the feed port and the discharge port of the second smelting furnace is greater than 200 mm, and the height difference between the feed port and the discharge port of the third smelting furnace is greater than 300 mm.

[0008] This is because, as the purification work proceeds, from the first smelting furnace to the third smelting furnace, the volume of impurities and the amount of precipitation gradually decrease, and the types of impurities that need to be removed are constantly changing. The first smelting furnace mainly removes large-volume impurities, so the height difference between the feed port and the discharge port should be the smallest. The third smelting furnace mainly uses inert gas to make tiny inclusions float to the surface of the melt with bubbles, so the height difference between the feed port and the discharge port of the first smelting furnace should be the largest.

[0009] Furthermore, the first filter is a detachable stainless steel filter with a mesh size less than 250 meshes; the second filter is a detachable titanium alloy filter with a mesh size of 250-400 meshes; and the third filter is a detachable titanium alloy filter with a mesh size greater than 400 meshes.

[0010] This is because, as the purification and impurity removal work proceeds, the number of impurities will become less and less, and the volume of impurities will become smaller and smaller, so the small mesh filter is used to filter large impurities, and the large mesh filter is used to filter small impurities. The first filter has the largest filtration capacity, so the material is relatively cheap stainless steel.

[0011] Furthermore, the discharge port of the first smelting furnace is aligned with the feed port of the second smelting furnace, and the discharge port of the second smelting furnace is aligned with the feed port of the third smelting furnace.

[0012] Furthermore, the first and second feeding ports, the first and second blowing ports are all arranged above each smelting furnace.

[0013] Furthermore, the first filter screen and the second filter screen are connected to the inner walls of two adjacent smelting furnaces at an angle of 45° to 90°, and the third filter screen is connected to the side wall of the third smelting furnace at an angle of 45° to 90°.

[0014] Furthermore, the first smelting furnace, the second smelting furnace and the third smelting furnace are respectively provided with a first impurity retention zone, a second impurity retention zone and a third impurity retention zone at the bottom, and each impurity retention zone is detachable.

[0015] The advantages and positive effects of the multi-stage liquid level difference filtering-purification and impurity removal system and method described in the present invention include at least: three different smelting furnaces and three different filter screens interact with each other, integrating smelting, filter screen filtering, purifier purification and gas impurity removal, which is particularly suitable for casting and rolling production lines, and has better filtering and impurity removal effects; a multi-level gradient is formed by the liquid level difference (100~300mm) between adjacent smelting furnaces, and under the action of purifiers of different qualities, it is ensured that impurities with larger volumes are precipitated first and impurities with smaller volumes are precipitated later. At the same time, the inert gas introduced into the melt can prevent the oxidation of the melt and cause impurities in the melt to float and settle; the entire filtering-purification and impurity removal process is carried out in a relatively closed environment, which can avoid temperature loss and prevent external impurities from contaminating the melt. The sediment in each detachable impurity retention area can be cleaned after the casting and rolling work is completed. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is an isometric view of a multi-stage liquid level difference filtration-purification and impurity removal system; Figure 2 It is a schematic diagram of a multi-stage liquid level difference filtration-purification and impurity removal system and method. DETAILED DESCRIPTION

[0017] The following is a non-limiting and clear description of the system and method of the present invention in conjunction with preferred embodiments and the accompanying drawings.

[0018] See also Figure 1 The isometric view of the magnesium alloy multi-stage liquid level difference filtration-purification and impurity removal system consists of two major parts: a smelting and impurity removal unit consisting of a first smelting furnace 11, a second smelting furnace 12, a third smelting furnace 13, etc., and a filtration system consisting of a first filter screen 21, a second filter screen 22, and a third filter screen 23.

[0019] See also Figure 2Schematic diagram of a magnesium alloy multi-stage liquid level difference filtration-purification and impurity removal system and method, wherein the discharge port 112 of the first smelting furnace 11 is aligned with the feed port 121 of the second smelting furnace 12, and the discharge port 122 of the second smelting furnace 12 is aligned with the feed port 131 of the third smelting furnace 13; the first feeding port 112, the second feeding port 122, the first blowing port 125, and the second blowing port 135 are all arranged above each smelting furnace; in order to increase the filtration area, the first filter screen 21 and the second filter screen 22 are connected to the inner walls of the two adjacent smelting furnaces at an angle of 45° to 90°, and the third filter screen 23 is connected to the side wall of the third smelting furnace at an angle of 45° to 90°; the first smelting furnace, the second smelting furnace, and the third smelting furnace are respectively provided with an impurity retention zone 1, an impurity retention zone 2, and an impurity retention zone 3 at the bottom, and each impurity retention zone is detachable.

[0020] See also Figure 1 , Figure 2 The multi-stage liquid level difference filtering-purification and impurity removal method is as follows: before the casting and rolling work begins, the melt is injected into the first smelting furnace 11 from the feed port 111, and a large amount of purifier is added from the feed port 112 at the same time. After the melt reacts with the purifier, the large volume of impurities is precipitated to the impurity retention area 114 by relying on their own weight and the impact force given by the fluid. Because this smelting furnace is the first furnace passed through in the purification process and produces the largest number of impurities, the height difference between the feed port 111 and the discharge port 112 is the smallest.

[0021] The melt purified by the first smelting furnace 11 enters the second smelting furnace 12 through the first detachable filter screen 21 with a mesh size less than 250. The height difference between the feed port 121 and the discharge port 122 of the second smelting furnace 12 is greater than 200 mm. The first filter screen 21 has the largest amount of impurities filtered, so the filter screen material is relatively cheap stainless steel. A small amount of purifier is added to the second inlet 122, and a large amount of inert gas is blown into the additional blowing port 125 to precipitate or separate the impurities from the melt.

[0022] The melt purified by the second smelting furnace 12 enters the third smelting furnace 13 through the removable second filter screen 22 with mesh size between 250 and 400 and made of titanium alloy. When the melt flows through the first smelting furnace 11 and the second smelting furnace 12, large-volume impurities and a part of tiny impurities have been filtered out. The third smelting furnace 13 only needs to blow a small amount of inert gas into the second blowing port 135 to separate the remaining tiny impurities from the melt with the bubbles generated by the inert gas. Therefore, the height difference between the feed port 131 and the discharge port 132 of the third smelting furnace 13 is the largest, which is more than 300 mm.

[0023] The melt in the third smelting furnace 13 is filtered through a detachable titanium alloy third filter screen 23 with a mesh size greater than 400 meshes, and then flows out from the third discharge port 132, and the multi-stage liquid level difference filtration-purification and impurity removal is completed.

[0024] The melt after filtration, purification and impurity removal enters the casting and rolling unit (not shown) for subsequent casting and rolling work.

[0025] It should be noted that the embodiments described in the present invention are not all embodiments. The words "connected", "connected" and similar words used in the present invention include but are not limited to connections made by welding, riveting, screw threads and the like; the words "first", "second" and similar words used in the present invention do not indicate the importance of the contents described, but are only used to distinguish different parts or contents.

[0026] It should also be noted that, without any creative work, other embodiments obtained by ordinary technicians in this field based on the spirit of the present invention should fall within the protection scope of the present invention.

Claims

1. A magnesium alloy melt multi-stage liquid level difference filtration-purification and impurity removal system, characterized by: The invention is composed of two major parts: a smelting and impurity removal unit composed of a first smelting furnace (11), a second smelting furnace (12), a third smelting furnace (13), etc., and a filtration system composed of a first filter screen (21), a second filter screen (22), and a third filter screen (23); a multi-stage liquid level difference filtration-purification and impurity removal system is applied. Before the casting and rolling work begins, the melt is injected into the first smelting furnace (11) through the feed port (111), and under the auxiliary effect of the gas pressure of the inert gas, the melt flows through the second smelting furnace (12) and the third smelting furnace (13) in sequence for smelting; during the operation, the first smelting furnace (11) and the second smelting furnace (12) are charged with purifiers of different masses through the charging port 1 (112) and the charging port 2 (122) to purify the melt; during the operation, the second smelting furnace (12) and the third smelting furnace (13) are blown with inert gases of different masses through the blowing port 1 (125) and the blowing port 2 (135) to prevent the melt from oxidation and to make the impurities in the melt float and settle; during the flow of the melt, the melt is filtered through the first filter screen (21), the second filter screen (22) and the third filter screen (23) in sequence, and the pure melt after filtering and impurities removal enters the casting and rolling unit (not shown) through the discharge port 3 (132) for subsequent casting and rolling work.

2. A magnesium alloy melt multi-stage liquid level difference filtration-purification and impurity removal system according to claim 1, characterized in that: The height difference between the feed port (111) and the discharge port (112) of the first smelting furnace (11) is greater than 100 mm, the height difference between the feed port (121) and the discharge port (122) of the second smelting furnace (12) is greater than 200 mm, and the height difference between the feed port (131) and the discharge port (132) of the third smelting furnace (13) is greater than 300 mm.

3. A magnesium alloy melt multi-stage liquid level difference filtration-purification and impurity removal system according to claim 1, characterized in that: The first filter screen (21) is a detachable stainless steel filter screen with a mesh size of less than 250 meshes; the second filter screen (22) is a detachable titanium alloy filter screen with a mesh size of 250-400 meshes; and the third filter screen (23) is a detachable titanium alloy filter screen with a mesh size of more than 400 meshes.

4. A magnesium alloy melt multi-stage liquid level difference filtration-purification and impurity removal system according to claim 1, characterized in that: The discharge port (112) of the first smelting furnace (11) is aligned with the feed port (121) of the second smelting furnace (12), and the discharge port (122) of the second smelting furnace (12) is aligned with the feed port (131) of the third smelting furnace (13).

5. The multi-stage liquid level difference filtration-purification and impurity removal system for magnesium alloy melt according to claim 1, characterized in that: The first feeding port (112), the second feeding port (122), the first blowing port (125), and the second blowing port (135) are all arranged above each smelting furnace.

6. The magnesium alloy melt multi-stage liquid level difference filtration-purification and impurity removal system according to claim 1, characterized in that: The first filter screen (21) and the second filter screen (22) are connected to the inner walls of two adjacent smelting furnaces at an angle of 45° to 90°, and the third filter screen (23) is connected to the side wall of the third smelting furnace (13) at an angle of 45° to 90°.

7. The magnesium alloy melt multi-stage liquid level difference filtration-purification and impurity removal system according to claim 1, characterized in that: A first impurity retention zone (114), a second impurity retention zone (124), and a third impurity retention zone (134) are respectively arranged at the bottom of the first smelting furnace (11), the second smelting furnace (12), and the third smelting furnace (13), and each impurity retention zone is detachable.

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