Device and method for cyclone centrifugal separation and purification of metal melt

Abstract

The invention discloses a device and method for cyclone centrifugal separation and purification of metal melt. The device is composed of a fluid power unit, a centrifugal separation unit and a heat preservation unit. A rotational flow centrifugal mechanical effect is innovatively combined with a metal melt purification process, and in-situ continuous separation of impurity phases is realized based on density difference under the action of a centrifugal field by regulating and controlling key parameters such as the flow of a melt pump, structural parameters of a rotational flow device and the diameter of an underflow opening. The method for separating and purifying the metal melt by using the device comprises the following steps: (1) starting the heating device to preheat the cyclone centrifugal separator; (2) a melt pump is adopted to input metal melt into a rotational flow centrifugal separator at a high speed through a feeding port; and (3) the purified metal melt is output through an overflow port, the melt enriched with the impurity phase is discharged through an underflow port, and the whole process is continuously carried out. The technology breaks through the limitation of a traditional intermittent purification process, has the full-process continuous operation characteristic and is suitable for large-scale application of metal melt purification.

Description

Technical Field

[0001] This invention belongs to the field of high-purity metal preparation and metal secondary resource recycling, and specifically relates to a metal melt purification technology, namely a device and method for purifying metal melts by cyclone centrifugal separation. Background Technology

[0002] Metallic materials occupy a vital position in modern industry. The purification and recycling of primary metals such as copper, aluminum, silicon, lead, and tin, as well as secondary metal resources, are of great significance for promoting green and sustainable development. These metals, due to their excellent electrical and thermal conductivity, mechanical strength, and corrosion resistance, are widely used in aerospace, construction, transportation, electronics and communications, and defense industries. However, with the increasing depletion of natural resources and the intensification of environmental problems, traditional primary metal production methods face challenges such as limited resources, high energy consumption, and severe pollution. Therefore, the recycling and purification of secondary metal resources has become a key path to achieving the goals of "carbon peaking" and "carbon neutrality."

[0003] Taking aluminum as an example, as the second largest metallic material after steel, its recycling research has received widespread attention. Similarly, other metals such as copper, silicon, lead, and tin also face the same resource and environmental challenges. Scrap metals often contain various impurity phases, including metallic impurities (such as iron) and non-metallic impurities (such as nitrides, oxides, slag / molten salts, etc.). These impurities seriously affect the physical and chemical properties of the metals, reducing their application value. Currently, traditional impurity removal methods mainly rely on dilution and gravity sedimentation, but both methods suffer from resource waste and low efficiency, making it difficult to meet the modern society's demands for high efficiency, energy saving, and environmental protection.

[0004] Therefore, how to reduce the resistance to impurity phase aggregation, shorten separation time, improve the continuous energy efficiency of the device, reduce energy consumption in the recovery process, and achieve high-quality, rapid, large-scale, low-energy-consumption preparation of various metals through technological innovation has become an urgent problem to be solved by those skilled in the art. A device and method for purifying molten metals by cyclone centrifugal separation has emerged, aiming to provide an effective solution for the purification of primary metals such as copper, aluminum, silicon, lead, and tin, as well as the purification and regeneration of secondary metal resources, thus promoting the green development of the metal industry. Summary of the Invention

[0005] This invention provides an apparatus and method for purifying molten metal by cyclone centrifugal separation. This method minimizes separation time, improves separation efficiency, enhances continuous separation efficiency, and achieves continuous removal of impurity phases, thereby achieving the purpose of impurity removal from waste aluminum.

[0006] According to the technical solution provided by this invention: a device and method for purifying molten metal by cyclone centrifugal separation, characterized in that the components include a fluid power unit, a centrifugal separation unit, and a heat preservation unit. The fluid power unit is a melt pump, providing flow power to the molten aluminum; the centrifugal separation unit is a cyclone centrifugal separator, enabling the molten aluminum to separate from impurity phases under cyclone action; the heat preservation unit is an electric furnace, ensuring that the operating temperature of the centrifugal separation unit is higher than the melting point of metallic aluminum.

[0007] As a further improvement of the present invention, the waste aluminum used as raw material includes primary metal melt prepared by mineral smelting, metal melt after remelting secondary metal resources, and metal melt after mixed remelting of primary metal and secondary metal resources.

[0008] As a further improvement of the present invention, the apparatus for preparing recycled aluminum alloy by separating impurity phases from waste aluminum by cyclone centrifugation is characterized in that the heat-insulating electric furnace is a box furnace with a heat-insulating lining on the inner wall of the furnace, and the furnace top can be flipped open for taking out and installing the cyclone centrifuge. The heating method includes resistance heating and electromagnetic induction heating; the melt pump includes an electromagnetic pump or a mechanical pump.

[0009] Furthermore, the temperature of the melt is 10-300℃ higher than the melting point of the waste aluminum, and the transmission speed of the aluminum melt is 1-15m / s.

[0010] As a further improvement of the present invention, the structure of the cyclone centrifugal separator includes a feed pipe, a cyclone column section, a cyclone cone section, an overflow pipe, and an underflow pipe.

[0011] Preferably, the diameter of the cyclone column section of the cyclone centrifugal separator is 0.05-0.5m.

[0012] Preferably, the height of the cyclone column section of the cyclone centrifugal separator is 0.7-2.0 times the diameter of the cyclone column section.

[0013] Preferably, the cone angle of the cyclone centrifugal separator's cyclone cone section is 3-16°.

[0014] Preferably, the length-to-width ratio of the feed pipe of the cyclone centrifuge is 1.5:1-4:1.

[0015] Preferably, the equivalent diameter of the feed pipe of the cyclone centrifuge is 0.13-0.29 times the diameter of the cyclone column section.

[0016] Preferably, the diameter of the overflow pipe of the cyclone centrifugal separator is 0.2-0.4 times the diameter of the cyclone column section.

[0017] Preferably, the overflow pipe of the cyclone centrifugal separator is inserted into the cyclone column section to a depth of 0.2-1.0 times the diameter of the cyclone column section.

[0018] Preferably, the wall thickness of the overflow pipe of the cyclone centrifugal separator is 0.002-0.02 times the diameter of the cyclone column section.

[0019] Preferably, the diameter of the underflow pipe of the cyclone centrifugal separator is 0.1-0.2 times the diameter of the cyclone column section.

[0020] Furthermore, the manufacturing methods of the cyclone centrifugal separator include two types: integral molding and segmented molding followed by assembly. The materials used include any one or more combinations of silicon carbide, silicon nitride, graphite, magnesium-aluminum refractory materials, steel, cast iron, and multi-element alloys.

[0021] Furthermore, the underflow split ratio of the cyclone centrifugal separator is 1%-50%.

[0022] According to the technical solution provided by the present invention: a device and method for purifying molten metal by cyclone centrifugal separation, characterized by comprising the following steps:

[0023] (1) Start the heat preservation electric furnace 2 to preheat the cyclone centrifuge to 10-300℃ higher than the melting point of the waste aluminum;

[0024] (2) Start the melt pump 1 and pump the molten metal into the cyclone centrifugal separator 7. The transfer speed of the molten metal is 1-15 m / s.

[0025] (3) In the cyclone centrifuge 7, the molten metal and the impurity phase are separated under the action of cyclone. The purified molten metal flows out from the overflow port 5, which is the high-quality purified molten metal. The impurity phase flows out from the underflow port 4 along with a small part of the underflow molten metal. The underflow molten metal rich in impurity phase is recycled as residual material.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] (1) The present invention provides a device and method for purifying molten metal by cyclone centrifugation, which overcomes the continuous application of multiple units such as melt melting, melt transportation and online feeding. The method has the advantages of high efficiency, continuity, short distance and low cost, and is easy to realize the stable, efficient and continuous preparation of high-quality purified molten metal.

[0028] (2) The present invention provides a device and method for purifying molten metal by cyclone centrifugation, which accelerates the separation of impurity phase from molten metal by applying strong centrifugal force, thereby achieving efficient removal of impurities from molten metal and overcoming the common problems of long time, low efficiency and incomplete removal of impurities in the process of removing impurities by current industrial technologies such as gravity sedimentation and electromagnetic enhanced sedimentation. Attached Figure Description

[0029] Figure 1This is a schematic diagram of the cyclone centrifugal separator proposed in this invention.

[0030] Among them: 1-melt pump; 2-holding electric furnace; 3-heating element; 4-underflow pipe; 5-overflow pipe; 6-feed pipe; 7-cyclone centrifuge; 8-furnace top cover.

[0031] Figure 2 This is a schematic diagram of the core structure of the cyclone centrifugal separator proposed in this invention.

[0032] Wherein: 1-Inlet; 2-Overflow pipe; 3-Swirl column section; 4-Swirl cone section; 5-Underflow pipe.

[0033] D - Column section diameter; α - Long side of feed pipe; b - Short side of feed inlet; d0 - Overflow pipe diameter; L0 - Overflow pipe insertion depth; du - Underflow pipe diameter; θ - Cone angle. Detailed Implementation

[0034] Unless otherwise specified, the experimental methods described in the following examples are conventional methods; unless otherwise specified, the reagents and materials are commercially available.

[0035] The following examples illustrate how the effects of the present invention can be verified. However, these examples are merely illustrative of the present invention and are not intended to limit the scope of the invention.

[0036] Example 1:

[0037] (1) The iron content is 1.2% and the non-metallic impurity content is 9210mm. 2 / kg of scrap aluminum is completely melted;

[0038] (2) Start the electromagnetic pump and pump the aluminum melt from step (1) into a cyclone separator with a diameter of 0.20m, an equivalent diameter of the feed pipe, an overflow pipe, and an underflow pipe that are 0.2, 0.2, and 0.1 times the diameter of the cyclone column, and a cone angle of 10° at a speed of 8m / s.

[0039] (3) After centrifugal separation, it enters the overflow molten pool to obtain a purified aluminum melt with an iron content of 0.12% and a non-metallic impurity removal rate of 92.3%.

[0040] Example 2:

[0041] (1) The iron content is 1.8% and the non-metallic impurity content is 3560mm. 2 / kg of scrap aluminum is completely melted;

[0042] (2) Start the electromagnetic pump and pump the aluminum melt from step (1) into a cyclone separator with a diameter of 0.25m, an equivalent diameter of the feed pipe, an overflow pipe, and a bottom flow pipe that are 0.2, 0.3, and 0.15 times the diameter of the cyclone column, and a cone angle of 8° at a speed of 5m / s.

[0043] (3) After centrifugal separation, it enters the overflow molten pool to obtain a purified aluminum melt with an iron content of 0.18% and a non-metallic impurity removal rate of 87.8%.

[0044] Example 3:

[0045] (1) The iron content is 0.9% and the non-metallic impurity content is 5310 mm. 2 / kg of silicon waste is completely melted;

[0046] (2) Start the electromagnetic pump and pump the silicon melt from step (1) into a cyclone separator with a diameter of 0.15m, an equivalent diameter of the feed pipe, an overflow pipe, and an underflow pipe that are 0.25, 0.4, and 0.15 times the diameter of the cyclone column, and a cone angle of 6° at a speed of 10m / s.

[0047] (3) After centrifugal separation, it enters the overflow molten pool to obtain a purified silicon melt with an iron content of 0.09% and a non-metallic impurity removal rate of 86.3%.

[0048] Example 4:

[0049] (1) The iron content is 1.3% and the non-metallic impurity content is 4930 mm. 2 / kg of scrap aluminum is completely melted;

[0050] (2) Start the mechanical pump and pump the aluminum melt from step (1) into a cyclone separator with a diameter of 0.4m, an equivalent diameter of the feed pipe, an overflow pipe, and an underflow pipe that are 0.22, 0.4, and 0.2 times the diameter of the cyclone column, and a cone angle of 5° at a speed of 12m / s.

[0051] (3) After centrifugal separation, it enters the overflow molten pool to obtain a purified aluminum melt with an iron content of 0.15% and a non-metallic impurity removal rate of 87.7%.

[0052] Example 5:

[0053] (1) The iron content is 1.1% and the non-metallic impurity content is 2420 mm. 2 / kg of scrap copper is completely melted;

[0054] (2) Start the mechanical pump and pump the copper melt from step (1) into a cyclone separator with a diameter of 0.35m, an equivalent diameter of the feed pipe, an overflow pipe, and an underflow pipe that are 0.2, 0.2, and 0.18 times the diameter of the cyclone column, and a cone angle of 9° at a speed of 6m / s.

[0055] (3) After centrifugal separation, it enters the overflow molten pool to obtain a purified copper melt with an iron content of 0.17% and a non-metallic impurity removal rate of 89.3%.

[0056] Comparative Example 1

[0057] This comparative example provides a method for iron removal in the recycling of waste aluminum. The method adopts the method disclosed in Example 1 of CN117051248A, and specifically includes the following steps:

[0058] (1) First, 20 tons of scrap aluminum are heated in the melting and holding furnace to form aluminum melt and the temperature of the aluminum melt reaches 700-750℃. This temperature is the operating temperature of the aluminum melt in the iron removal process in the melting and holding furnace.

[0059] (2) Then, magnesium oxide with an iron content 2.148 times that in the aluminum melt is introduced into the aluminum melt by compressed air; the amount of magnesium oxide is 429.6 kg; magnesium oxide reacts with Fe and other elements in the liquid to form a composite oxide; the compressed air is supplied to the aluminum melt for the first 30 min at a rate of 20-50 L / min; the compressed air promotes the formation of Fe3O4 in the aluminum melt, which is carried out of the aluminum melt by the composite oxide and removed by flotation filtration.

[0060] (3) 0.1-0.2% of KCL-based refining agent is introduced into the aluminum melt by nitrogen gas, wherein the nitrogen gas is supplied to the aluminum melt for 30 minutes at a rate of 10-20 L / min; nitrogen gas and refining agent can remove hydrogen gas and inclusions in the aluminum melt.

[0061] (4) Finally, the aluminum melt is filtered using a ceramic filter to separate the intermetallic compounds from the aluminum melt; the filtered aluminum melt can be directly used for casting aluminum materials such as aluminum rods.

[0062] Compared to Example 1, this comparative example requires an additional filtration step, which increases the processing cost. Although the recycled aluminum prepared achieves iron removal, it is far inferior to that of Example 1, and there is still considerable room for improvement.

[0063] Therefore, the method provided by this invention overcomes the matching and connection problems of multiple units such as melt melting, melt transportation, online feeding, and melt impurity removal, and realizes the efficient, stable and continuous preparation of high-purity metal materials.

[0064] The applicant declares that the above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. An apparatus and method for purifying molten metal by hydrocyclone centrifugal separation, the apparatus comprising a fluid power unit, a centrifugal separation unit, and a heat preservation unit, wherein the fluid power unit uses a melt pump to drive the flow of molten metal, the centrifugal separation unit achieves dynamic separation of impurity phases from the molten metal under the action of fluid mechanics through a hydrocyclone centrifugal separator, and the heat preservation unit maintains the stability of the system temperature field through a heating device. This innovatively combines the hydrocyclone centrifugal mechanics effect with the molten metal purification process, and by controlling key parameters such as the melt pump flow rate, hydrocyclone structural parameters, and underflow diameter, enables the impurity phase to achieve in-situ continuous separation based on density difference under the action of a centrifugal field. The method for separating and purifying molten metal using the aforementioned apparatus includes the following steps: (1) Start the heating device to preheat the cyclone centrifuge; (2) The molten metal is fed into the cyclone centrifugal separator at high speed through the feed port using a melt pump; (3) The purified molten metal is output through the overflow port, while the melt enriched with impurity phases is discharged through the underflow port. The whole process is carried out continuously.

2. The apparatus and method for purifying molten metal by cyclone centrifugal separation according to claim 1, characterized in that, The insulated electric furnace mentioned in step (1) is a box furnace with an insulated lining on the inner wall. The top of the furnace can be flipped open to remove and install the cyclone centrifuge. The heating methods include resistance heating and electromagnetic induction heating.

3. The apparatus and method for purifying molten metal by cyclone centrifugal separation according to claim 1, characterized in that, The metal melt mentioned in step (2) includes primary metal melt prepared by mineral smelting, metal melt after remelting secondary metal resources, and metal melt after mixed remelting of primary metal and secondary metal resources.

4. The apparatus and method for purifying molten metal by cyclone centrifugal separation according to claim 1, characterized in that, The melt pump mentioned in step (2) includes one of the following: electromagnetic pump, gear pump, centrifugal pump, and peristaltic pump.

5. The apparatus and method for purifying molten metal by cyclone centrifugal separation according to claim 1, characterized in that, The structure of the cyclone centrifuge described in step (3) includes a feed pipe, a cyclone column section, a cyclone cone section, an overflow pipe, and an underflow pipe. Preferably, the diameter of the cyclone column section of the cyclone centrifugal separator is 0.05-0.5m. Preferably, the height of the cyclone column section of the cyclone centrifugal separator is 0.7-2.0 times the diameter of the cyclone column section. Preferably, the cone angle of the cyclone centrifugal separator's cyclone cone section is 3-16°. Preferably, the length-to-width ratio of the feed pipe of the cyclone centrifuge is 1.5:1-4:

1. Preferably, the equivalent diameter of the feed pipe of the cyclone centrifuge is 0.13-0.29 times the diameter of the cyclone column section. Preferably, the diameter of the overflow pipe of the cyclone centrifugal separator is 0.2-0.4 times the diameter of the cyclone column section. Preferably, the overflow pipe of the cyclone centrifugal separator is inserted into the cyclone column section to a depth of 0.2-1.0 times the diameter of the cyclone column section. Preferably, the wall thickness of the overflow pipe of the cyclone centrifugal separator is 0.002-0.02 times the diameter of the cyclone column section. Preferably, the diameter of the underflow pipe of the cyclone centrifugal separator is 0.1-0.2 times the diameter of the cyclone column section.

6. The apparatus and method for purifying molten metal by cyclone centrifugal separation according to claim 1, characterized in that, The manufacturing methods of the cyclone centrifuge in step (3) include one-piece molding and segmented molding and reassembly. The materials used include any one or more combinations of silicon carbide, silicon nitride, graphite, magnesium aluminum refractory materials, steel cast iron, and multi-element alloys.

7. The apparatus and method for purifying molten metal by cyclone centrifugal separation according to claim 1, characterized in that, The aluminum melt in step (2) has a transmission speed of 1-15 m / s, a melt temperature 10-300℃ higher than the melting point of waste aluminum, and an underflow split ratio of 1%-50% for the cyclone centrifuge.

8. The apparatus and method for purifying molten metal by cyclone centrifugal separation according to claim 1, characterized in that, The aforementioned apparatus and method are used to recover high-purity metals, including aluminum, iron, chromium, manganese, copper, magnesium, potassium, sodium, calcium, strontium, barium, lead, zinc, tin, cobalt, nickel, antimony, cadmium, bismuth, gold, silver, platinum, ruthenium, palladium, lithium, beryllium, titanium, zirconium, vanadium, gallium, indium, thallium, germanium, lanthanum, cerium, neodymium, scandium, and silicon; the operating process temperature is 10-300℃ higher than the melting point of the metal.

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