Rare earth zinc-aluminum alloy ingot intermediate frequency furnace smelting method

Abstract

The invention belongs to the technical field of aluminum alloy ingot production, and particularly discloses a rare earth zinc-aluminum alloy ingot intermediate frequency furnace smelting method which comprises the following steps: firstly, independently melting an aluminum ingot by using a furnace A at the melting temperature of 1000-1100 DEG C, then pouring molten aluminum into a furnace B, then adding lanthanum-cerium rare earth and metal silicon into the furnace B, heating the furnace B to 1100-1200 DEG C, keeping the temperature for 2-3 hours, and cooling to room temperature to obtain the rare earth zinc-aluminum alloy ingot intermediate frequency furnace. And after the lanthanum cerium rare earth and the metal silicon are completely melted, zinc ingots are added into the furnace B in batches, the melting temperature is 630-670 DEG C, after the zinc ingots in the furnace B are completely melted, furnace shutdown refining is carried out, after refining is completed, slag fishing and sampling are carried out, and finally discharging and casting are carried out. The problems that in the melting process of an intermediate frequency furnace, production efficiency is low, and production cost is increased are solved. By adopting the A furnace and B furnace smelting process, the daily production efficiency of rare earth zinc-aluminum alloy ingot products is improved, and production pauses caused by waiting for molten aluminum melting or molten zinc vaporization and the like are reduced.

Description

Technical Field

[0001] The invention relates to the technical field of aluminum alloy ingot production, and in particular to a medium frequency furnace smelting method for rare earth zinc-aluminum alloy ingots. Background Art

[0002] With the development of science and technology and modern industry, people have put forward higher requirements on the performance of hot-dip galvanized layer. Exploring low-cost, high-performance special hot-dip galvanized alloys has always been the goal of most steel companies. Adding aluminum, silicon, magnesium or rare earth elements to hot zinc liquid to improve the corrosion resistance of the coating and improve the bonding strength between the coating and the substrate has been the direction that hot-dip galvanizing workers in various countries have been working on for many years. The main raw materials used in the production of rare earth zinc-aluminum alloy ingots are zinc ingots, aluminum ingots, lanthanum-cerium rare earth alloys and metal silicon.

[0003] In order to reduce procurement costs, it is now necessary to use a medium frequency furnace to melt aluminum alloys. The medium frequency furnace is a power supply device that converts industrial frequency 50Hz alternating current into medium frequency (above 300Hz to 1000Hz), rectifies the three-phase industrial frequency alternating current into direct current, and then converts the direct current into adjustable medium frequency alternating current to supply the medium frequency alternating current flowing through the capacitor and induction coil, generates high-density magnetic lines in the induction coil, and cuts the metal material contained in the induction coil, generates large eddy currents in the metal material, and uses the principle of electromagnetic induction to heat the metal and melt it into liquid.

[0004] However, during the melting process using a medium frequency furnace, since the melting points of lanthanum-cerium rare earth alloy are 900°C and metallic silicon is 1410°C, in order to ensure that the lanthanum-cerium rare earth alloy and metallic silicon are completely melted and dissolved, the temperature of the metal liquid in the medium frequency furnace must be raised to above 1100°C. However, the boiling point of zinc ingots is 907°C. Continuous heating will vaporize the zinc liquid, thereby increasing production costs. In addition, during the melting of zinc ingots, it is necessary to wait for the aluminum liquid to melt, which causes production pauses and leads to low production efficiency. Summary of the invention

[0005] The purpose of the present invention is to provide a medium frequency furnace smelting method for rare earth zinc-aluminum alloy ingots to solve the problem that zinc liquid is easily vaporized during the melting process using a medium frequency furnace and it is necessary to wait for aluminum liquid to melt, thereby causing production pauses, resulting in low production efficiency and increased production costs.

[0006] To achieve the above object, the basic scheme provided by the present invention is: a medium frequency furnace smelting method of rare earth zinc-aluminum alloy ingots, comprising the following steps:

[0007] S1, first use furnace A to melt aluminum ingots alone, the melting temperature is 1000-1100℃;

[0008] S2, pouring the molten aluminum into furnace B, then adding lanthanum, cerium, rare earth and metallic silicon into furnace B, and heating furnace B to 1100-1200°C;

[0009] S3, when lanthanum, cerium, rare earth and metal silicon are completely melted, zinc ingots are added to furnace B in batches, and the melting temperature is 630℃-670℃;

[0010] S4, when the zinc ingot in furnace B is completely melted, the furnace is stopped for refining;

[0011] S5, after refining is completed, slag removal is performed on the surface of the zinc-aluminum alloy solution in the B furnace;

[0012] S6, after the scum on the surface of the zinc-aluminum alloy solution in the B furnace is removed and cleaned, sampling is performed;

[0013] S7, after sampling, the casting is carried out.

[0014] The beneficial effects of the present invention are: 1. By melting the aluminum ingot separately, the unnecessary waiting of the zinc ingot while waiting for the aluminum ingot to melt is avoided when the aluminum ingot and the zinc ingot are melted in the same furnace at the same time, thereby effectively shortening the smelting cycle and improving production efficiency.

[0015] ② By adding zinc ingots in batches, the melting process of the zinc liquid can be better controlled to avoid adding a large number of zinc ingots at one time, which would cause the problem of zinc liquid vaporization, thereby further improving the continuity of the entire smelting process and reducing production downtime.

[0016] ③ Through the form of A furnace + B furnace, the energy waste caused by the low melting point of zinc ingots when melting aluminum ingots and zinc ingots in the same furnace can be avoided, thereby saving electricity consumption and reducing production costs.

[0017] Option 2 is the preferred basic option. The total weight of the ingredients in furnace B is 700±50kg, of which aluminum ingots account for 24%-26%, lanthanum, cerium and rare earth account for 0.05%-0.08%, metallic silicon account for 0.5%-0.8% and zinc ingots account for 74%-76%. The more metal materials are added to the furnace of the medium frequency furnace and the denser they are, the easier it is to melt the metal materials and the higher the efficiency. Therefore, the melting efficiency can be improved by setting a reasonable ratio to increase the material density.

[0018] Option 3 is the preferred option of the basic option. In S1, the power supply to furnace A is controlled to be 50%-60% of the total power of the equipment. This power supply control method can meet the melting demand of aluminum ingots while avoiding the problem of energy waste and increased power consumption caused by excessive power supply.

[0019] Scheme 4 is the preferred option of the basic scheme. In S3, 40-55% of zinc ingots are added to furnace B for the first time. After the zinc ingots added for the first time are melted, 25-35% of zinc ingots are added to furnace B for the second time. After the zinc ingots added for the second time are melted, 10-25% of zinc ingots are added to furnace B for the third time. By adding zinc ingots to furnace B three times in different proportions, the temperature of furnace B can be effectively lowered, thereby reducing the risk of zinc liquid vaporization and improving product quality.

[0020] Option 5 is the preferred basic option. In S3, during the process of adding zinc ingots, power needs to be continuously supplied to furnace B. This can prevent the temperature of furnace B from being lost after adding zinc ingots, which may cause solidification of aluminum liquid.

[0021] Scheme 6 is the preferred basic scheme. In S4, during refining, 1% zinc refining agent is added to furnace B, and nitrogen is blown into the zinc-aluminum alloy solution in furnace B. The addition of zinc refining agent can react with impurities to remove impurities. By blowing in nitrogen, the zinc-aluminum alloy solution can be stirred to allow the refining agent to fully contact and react with impurities. In addition, the nitrogen itself plays a protective role to prevent the solution from being oxidized during the refining process, thereby further improving product quality.

[0022] Option 7 is the preferred option of Option 6. The pressure of nitrogen blown into furnace B is 0.1-0.15MPa. Controlling the pressure of nitrogen blown into furnace B at 0.1-0.15MPa can ensure that nitrogen produces a proper stirring effect in the solution, so that the refining agent can be more evenly distributed in the zinc-aluminum alloy solution. At the same time, the appropriate pressure can also avoid the problem of solution splashing due to excessive pressure or failure to achieve good stirring due to too low pressure while ensuring the refining effect. DETAILED DESCRIPTION

[0023] The present invention is further described in detail below through specific embodiments:

[0024] Example 1

[0025] A medium frequency furnace smelting method for rare earth zinc-aluminum alloy ingots comprises the following steps:

[0026] S1, first use furnace A to melt aluminum ingots alone, control the power supply of furnace A to 50%-60% of the total power of the equipment, and make the melting temperature 1000℃;

[0027] S2, pouring the molten aluminum into furnace B, then adding lanthanum, cerium, rare earth and metallic silicon into furnace B, and heating furnace B to 1100°C;

[0028] S3, when lanthanum, cerium, rare earth and metal silicon are completely melted, zinc ingots are added to furnace B in batches. 40% of zinc ingots are added to furnace B for the first time. After the first zinc ingot is melted, 35% of zinc ingots are added to furnace B for the second time. After the second zinc ingot is melted, 25% of zinc ingots are added to furnace B for the third time. During the process of adding zinc ingots, power needs to be continuously supplied to furnace B until the temperature is raised to 630°C.

[0029] S4, when the zinc ingot in furnace B is completely melted, the furnace is stopped for refining. During refining, 1% zinc refining agent is first added to furnace B, and nitrogen is blown into the zinc-aluminum alloy solution in furnace B. The nitrogen pressure is 0.1MPa. The total weight of the ingredients in furnace B is 700kg, of which aluminum ingot is 24%, lanthanum, cerium and rare earth are 0.05%, metal silicon is 0.5%, and zinc ingot is 76%;

[0030] S5, after refining is completed, slag removal is performed on the surface of the zinc-aluminum alloy solution in the B furnace;

[0031] S6, after the scum on the surface of the zinc-aluminum alloy solution in the B furnace is removed and cleaned, sampling is performed;

[0032] S7, after sampling, the casting is carried out.

[0033] In the A furnace + B furnace smelting process, using the above data, it can be obtained that the smelting time of one furnace is 40 minutes, the daily output of rare earth zinc-aluminum alloy ingots can reach 30 tons, and the production efficiency is improved by 67%. In addition, the use of two medium frequency furnaces for smelting can reduce power consumption, thereby reducing production costs. Through calculation, the production cost is reduced by 288 yuan / ton.

[0034] Example 2

[0035] A medium frequency furnace smelting method for rare earth zinc-aluminum alloy ingots comprises the following steps:

[0036] S1, first use furnace A to melt aluminum ingots alone, control the power supply of furnace A to 55% of the total power of the equipment, and make the melting temperature 1050℃;

[0037] S2, pouring the molten aluminum into furnace B, then adding lanthanum, cerium, rare earth and metallic silicon into furnace B, and heating furnace B to 1150°C;

[0038] S3, when lanthanum, cerium, rare earth and metal silicon are completely melted, zinc ingots are added to furnace B in batches. 45% of zinc ingots are added to furnace B for the first time. After the first zinc ingot is melted, 32% of zinc ingots are added to furnace B for the second time. After the second zinc ingot is melted, 23% of zinc ingots are added to furnace B for the third time. During the process of adding zinc ingots, power needs to be continuously supplied to furnace B until the temperature is raised to 650°C.

[0039] S4, when the zinc ingot in furnace B is completely melted, the furnace is stopped for refining. During refining, 1% zinc refining agent is first added to furnace B, and nitrogen is blown into the zinc-aluminum alloy solution in furnace B. The nitrogen pressure is 0.8MPa. The total weight of the ingredients in furnace B is 730kg, of which aluminum ingot is 25%, lanthanum, cerium and rare earth are 0.06%, metal silicon is 0.65%, and zinc ingot is 75%;

[0040] S5, after refining is completed, slag removal is performed on the surface of the zinc-aluminum alloy solution in the B furnace;

[0041] S6, after the scum on the surface of the zinc-aluminum alloy solution in the B furnace is removed and cleaned, sampling is performed;

[0042] S7, after sampling, the casting is carried out.

[0043] In the A furnace + B furnace smelting process, using the above data, it can be obtained that the smelting time of one furnace is 30 minutes, the daily output of rare earth zinc-aluminum alloy ingots can reach 45 tons, and the production efficiency is improved by 89%. In addition, the use of two medium frequency furnaces for smelting can reduce power consumption, thereby reducing production costs. Through calculation, the production cost is reduced by 292 yuan / ton.

[0044] Example 3

[0045] A medium frequency furnace smelting method for rare earth zinc-aluminum alloy ingots comprises the following steps:

[0046] S1, first use furnace A to melt aluminum ingots alone, control the power supply of furnace A to 50%-60% of the total power of the equipment, and make the melting temperature 1100℃;

[0047] S2, pouring the molten aluminum into furnace B, then adding lanthanum, cerium, rare earth and metallic silicon into furnace B, and heating furnace B to 1200°C;

[0048] S3, when lanthanum, cerium, rare earth and metal silicon are completely melted, zinc ingots are added to furnace B in batches. 55% of the zinc ingots are added to furnace B for the first time. After the first zinc ingot is melted, 35% of the zinc ingots are added to furnace B for the second time. After the second zinc ingot is melted, 25% of the zinc ingots are added to furnace B for the third time. During the process of adding zinc ingots, power needs to be continuously supplied to furnace B until the temperature is raised to 670°C.

[0049] S4, when the zinc ingot in furnace B is completely melted, the furnace is stopped for refining. During refining, 1% zinc refining agent is first added to furnace B, and nitrogen is blown into the zinc-aluminum alloy solution in furnace B. The nitrogen pressure is 0.15MPa. The total weight of the ingredients in furnace B is 750kg, of which aluminum ingot is 26%, lanthanum, cerium and rare earth are 0.08%, metal silicon is 0.8%, and zinc ingot is 74%;

[0050] S5, after refining is completed, slag removal is performed on the surface of the zinc-aluminum alloy solution in the B furnace;

[0051] S6, after the scum on the surface of the zinc-aluminum alloy solution in the B furnace is removed and cleaned, sampling is performed;

[0052] S7, after sampling, the casting is carried out.

[0053] In the A furnace + B furnace smelting process, using the above data, it can be obtained that the smelting time of one furnace is 29 minutes, the daily output of rare earth zinc-aluminum alloy ingots can reach 36 tons, and the production efficiency is improved by 85%. In addition, the use of two medium frequency furnaces for smelting can reduce power consumption, thereby reducing production costs. Through calculation, the production cost is reduced by 124 yuan / ton.

[0054] In summary, by adopting the data of Example 2 for smelting, the smelting time is short, the smelting cycle is effectively shortened, the production efficiency is improved, the production efficiency is increased to 89%, and the production downtime is reduced, so that the daily output is increased to 40 tons. At the same time, through the form of A furnace + B furnace, electricity consumption is saved, and the production cost per ton is the lowest.

[0055] The above is only an embodiment of the present invention, and the common knowledge such as the known specific structure and characteristics in the scheme is not described in detail here. It should be pointed out that for those skilled in the art, several deformations and improvements can be made without departing from the structure of the present invention, which should also be regarded as the protection scope of the present invention, and these will not affect the effect of the implementation of the present invention and the practicality of the patent. The scope of protection required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.

Claims

1. A medium frequency furnace smelting method for rare earth zinc-aluminum alloy ingots, characterized in that: The following steps are involved: S1, first use furnace A to melt aluminum ingots alone, the melting temperature is 1000-1100℃; S2, pouring the molten aluminum into furnace B, then adding lanthanum, cerium, rare earth and metallic silicon into furnace B, and heating furnace B to 1100-1200°C; S3, when lanthanum, cerium, rare earth and metal silicon are completely melted, zinc ingots are added to furnace B in batches, and the melting temperature is 630℃-670℃; S4, when the zinc ingot in furnace B is completely melted, the furnace is stopped for refining; S5, after refining is completed, slag removal is performed on the surface of the zinc-aluminum alloy solution in furnace B; S6, after the scum on the surface of the zinc-aluminum alloy solution in the B furnace is removed and cleaned, sampling is performed; S7, after sampling, the casting is carried out.

2. A medium frequency furnace smelting method for rare earth zinc-aluminum alloy ingots according to claim 1, characterized in that: The total weight of the ingredients of furnace B is 700±50kg, of which aluminum ingots account for 24%-26%, lanthanum, cerium and rare earth account for 0.05%-0.08%, metallic silicon account for 0.5%-0.8% and zinc ingots account for 74%-76%.

3. A medium frequency furnace smelting method for rare earth zinc-aluminum alloy ingots according to claim 1, characterized in that: In S1, the power supply to furnace A is controlled to be 50%-60% of the total power of the equipment.

4. A medium frequency furnace smelting method for rare earth zinc-aluminum alloy ingots according to claim 1, characterized in that: In S3, 40-55% of zinc ingots are added to furnace B for the first time. After the first added zinc ingots are melted, 25-35% of zinc ingots are added to furnace B for the second time. After the second added zinc ingots are melted, 10-25% of zinc ingots are added to furnace B for the third time.

5. The medium frequency furnace smelting method of rare earth zinc-aluminum alloy ingots according to claim 1, characterized in that: In S3, during the process of adding zinc ingots, power needs to be continuously supplied to furnace B.

6. A medium frequency furnace smelting method for rare earth zinc-aluminum alloy ingots according to claim 1, characterized in that: In S4, during refining, 1% zinc refining agent is added to furnace B, and nitrogen is blown into the zinc-aluminum alloy solution in furnace B.

7. A medium frequency furnace smelting method for rare earth zinc-aluminum alloy ingots according to claim 6, characterized in that: The pressure of nitrogen blown into furnace B is 0.1-0.15MPa.