Method for reducing slag rate on surface of lead alloy

Abstract

The invention relates to a method for reducing the surface slag rate of lead alloy, and belongs to the technical field of lead alloy. By optimizing the smelting temperature, adding a proper amount of specific auxiliaries and improving the casting process, formation of surface slag can be effectively reduced, and the surface quality and comprehensive performance of the lead alloy are improved; specifically, according to the method, in the production process of the lead alloy, the smelting temperature is controlled to be 560-600 DEG C, auxiliaries are added into molten lead liquid, the casting flow is controlled to be 100-105 kg / s, the auxiliaries comprise carbon powder, pulverized coal, coal cinder and wood chips, and the mass ratio of the auxiliaries to the molten lead liquid is (1-3): 1000. The production process comprises the following steps: heating the precipitated lead to the smelting temperature, refining and removing impurities to obtain the molten lead liquid, adding the alloy metal and the auxiliary agent, mixing, casting and cooling.

Description

Technical Field

[0001] This invention belongs to the field of lead alloy technology, specifically, it relates to a method for reducing the slag content on the surface of lead alloys. Background Technology

[0002] Lead alloys are alloy materials formed by adding elements such as tin and calcium to lead. They possess excellent corrosion resistance, chemical stability, and good machinability, and are widely used in battery manufacturing, radiation protection, soldering, cable sheathing, and electronic components. The performance of lead alloys is closely related to their purity and structural uniformity. If many impurities or inclusions are generated during the production process, it will not only affect the appearance of the product but also reduce its overall quality and shorten its service life.

[0003] In the production process of lead alloys, smelting and casting are the key steps that determine the final quality. During smelting, lead easily reacts with other alloy metals and oxygen to form slag. This slag is often less dense than the molten lead and floats on the surface, leading to metal loss, increased smelting costs, and defects such as voids and surface flaws in subsequent casting. Therefore, slag control is one of the core technical indicators in lead alloy production. However, existing research focuses mainly on the lead alloy slag ratio (the percentage of slag weight generated during smelting to the total weight of the metal put into smelting), lacking improvement and optimization of the lead alloy surface slag ratio (the percentage of slag weight on the lead alloy surface to the total weight of the lead alloy). Summary of the Invention

[0004] The purpose of this invention is to provide a method for reducing the slag content on the surface of lead alloys, so as to solve the problems existing in the background art.

[0005] To achieve the above objectives, the present invention provides the following solution: A method for reducing the surface slag rate of lead alloys, wherein during the production process of the lead alloy, the smelting temperature is controlled at 560-600℃, additives are added to the molten lead, and the casting flow rate is controlled at 100-105 kg / s.

[0006] As a preferred embodiment of the present invention, the additives include carbon powder, coal powder, coal slag and wood chips; the mass ratio of the carbon powder, the coal powder, the coal slag and the wood chips is 28-32:18-22:35:15-18.

[0007] As a preferred embodiment of the present invention, the production process includes the following steps: The precipitated lead is placed in a regenerator furnace and heated to the smelting temperature. The temperature is maintained, compressed air is introduced, and caustic soda flakes are added to the furnace surface. After the first stirring and mixing, the slag is skimmed off to obtain the molten lead liquid. The alloy metal and the additives are added, and the mixture is stirred and mixed a second time. Casting is then carried out according to the specified casting flow rate, followed by cooling, thus completing the production process. The alloy metal is selected according to the type of lead alloy to be produced. For example, tin ingots can be added when producing a lead-tin alloy; this is not a limitation.

[0008] Furthermore, the average grade of the precipitated lead is not less than 99.99%.

[0009] Furthermore, the heating rate is 5-15°C / min.

[0010] Furthermore, the mass ratio of the precipitated lead to the caustic soda flakes is 1000:0.3-0.5.

[0011] Furthermore, the first stirring and mixing refers to stirring for 30-40 minutes.

[0012] Furthermore, the chemical composition of the molten lead liquid meets the national standard for No. 1 lead ingots.

[0013] Furthermore, the mass ratio of the additive to the molten lead is 1-3:1000.

[0014] Furthermore, the second mixing refers to mixing for 30-40 minutes.

[0015] Furthermore, the cooling rate is 2-5°C / min.

[0016] Optimizing the melting temperature can effectively reduce the formation of surface slag and lower the slag rate of lead alloys. Excessively high melting temperatures can easily lead to oxidation during subsequent casting, forming new slag. Insufficiently low melting temperatures can cause the fluid viscosity to increase, resulting in poor fluidity and cold shuts during casting, leading to uneven mechanical properties of the finished product.

[0017] Introducing compressed air allows impurities such as As and Sb in the precipitated lead to be oxidized into their corresponding oxides, taking full advantage of the density difference to make them float on the surface. The addition of caustic soda will further react with them to generate slag such as Na2As2O4 and Na2Sb2O4.

[0018] Adding additives can inhibit the reaction of molten material with oxygen to form oxide slag.

[0019] A suitable casting flow rate ensures that the molten material fills the mold in a smooth, continuous, and near-laminar manner, avoiding turbulence and splashing, thereby preventing the entrainment of gas and impurities. Excessive casting flow rate can easily form subcutaneous pores or concentrated pores, and secondly, it will strongly scour the mold, easily forming sand holes or slag inclusions. Insufficient casting flow rate can easily form semi-solidified oxide wrinkles and flow marks, becoming extremely rough, and increasing internal defects.

[0020] The beneficial effects of this invention are: 1. This invention can effectively reduce the formation of surface slag and improve the surface quality and overall performance of lead alloys by optimizing the melting temperature, adding appropriate amounts of specific additives, and improving the casting process.

[0021] 2. This invention focuses on improving and optimizing the slag ratio (the percentage of the weight of the slag on the lead alloy surface to the total weight of the lead alloy), filling the gap in this part of the existing technology. Detailed Implementation

[0022] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0023] Example 1 A method for reducing the surface slag rate of lead alloys, wherein the method refers to controlling the smelting temperature at 560°C, adding additives to the molten lead liquid, and controlling the casting flow rate at 100 kg / s during the production process of the lead alloy.

[0024] The additives include carbon powder, coal powder, coal slag, and wood chips; the mass ratio of the carbon powder, coal powder, coal slag, and wood chips is 28:18:35:15.

[0025] The production process includes the following steps: The precipitated lead is placed in a regenerator furnace, heated to the smelting temperature, held at that temperature, and compressed air is introduced. Sodium hydroxide flakes are added to the furnace surface, and the mixture is stirred and mixed for the first time. The slag is skimmed off to obtain the molten lead liquid. Alloy metal and the additives are added, and the mixture is stirred and mixed for the second time. Casting is then carried out according to the specified casting flow rate, followed by cooling, thus completing the production process. Taking the production of lead-tin alloy as an example, the alloy metal added in this embodiment is tin ingot, and the final product (lead alloy) is tested to have a tin content of 2.0%.

[0026] The average grade of the precipitated lead is not less than 99.99%.

[0027] The heating rate is 5°C / min.

[0028] The mass ratio of the precipitated lead to the caustic soda flakes is 1000:0.3.

[0029] The first mixing refers to mixing for 30 minutes.

[0030] The chemical composition of the molten lead liquid meets the national standard for No. 1 lead ingots (GB / T 469-2023, Pb99.994).

[0031] The mass ratio of the additive to the molten lead is 1:1000.

[0032] The second mixing refers to mixing for 30 minutes.

[0033] The cooling rate is 2°C / min.

[0034] Example 2 A method for reducing the surface slag rate of lead alloys, wherein the smelting temperature is controlled at 600°C during the production process of the lead alloy, additives are added to the molten lead, and the casting flow rate is controlled at 105 kg / s.

[0035] The additives include carbon powder, coal powder, coal slag, and wood chips; the mass ratio of the carbon powder, coal powder, coal slag, and wood chips is 32:22:35:18.

[0036] The production process includes the following steps: The precipitated lead is placed in a regenerator furnace and heated to the smelting temperature. The temperature is maintained, compressed air is introduced, and caustic soda flakes are added to the furnace surface. After the first stirring and mixing, the slag is skimmed off to obtain the molten lead liquid. The alloy metal and the additives are added, and the mixture is stirred and mixed a second time. Casting is then carried out according to the specified casting flow rate, followed by cooling, thus completing the production process. Taking the production of lead-tin alloy as an example, the alloy metal added in this embodiment is tin ingot, and the final product (lead alloy) is tested to have a tin content of 2.7%.

[0037] The average grade of the precipitated lead is not less than 99.99%.

[0038] The heating rate is 15°C / min.

[0039] The mass ratio of the precipitated lead to the caustic soda flakes is 1000:0.5.

[0040] The first mixing refers to mixing for 40 minutes.

[0041] The chemical composition of the molten lead liquid meets the national standard for No. 1 lead ingots (GB / T 469-2023, Pb99.994).

[0042] The mass ratio of the additive to the molten lead is 3:1000.

[0043] The second mixing refers to mixing for 40 minutes.

[0044] The cooling rate is 5°C / min.

[0045] Example 3 A method for reducing the slag rate on the surface of lead alloys, wherein the smelting temperature is controlled at 580°C during the production process of the lead alloy, additives are added to the molten lead, and the casting flow rate is controlled at 103 kg / s.

[0046] The additives include carbon powder, coal powder, coal slag, and wood chips; the mass ratio of the carbon powder, coal powder, coal slag, and wood chips is 30:20:35:15.

[0047] The production process includes the following steps: The precipitated lead is placed in a regenerator furnace, heated to the smelting temperature, held at that temperature, and compressed air is introduced. Sodium hydroxide flakes are added to the furnace surface, and the mixture is stirred and mixed for the first time. The slag is skimmed off to obtain the molten lead liquid. Alloy metal and the additives are added, and the mixture is stirred and mixed for the second time. Casting is then carried out according to the specified casting flow rate, followed by cooling, thus completing the production process. Taking the production of lead-tin alloy as an example, the alloy metal added in this embodiment is tin ingot, and the final product (lead alloy) is tested to have a tin content of 1.5%.

[0048] The average grade of the precipitated lead is not less than 99.99%.

[0049] The heating rate is 10°C / min.

[0050] The mass ratio of the precipitated lead to the caustic soda flakes is 1000:0.4.

[0051] The first mixing refers to mixing for 30 minutes.

[0052] The chemical composition of the molten lead liquid meets the national standard for No. 1 lead ingots (GB / T 469-2023, Pb99.994).

[0053] The mass ratio of the additive to the molten lead is 2:1000.

[0054] The second mixing refers to mixing for 30 minutes.

[0055] The cooling rate is 4°C / min.

[0056] Comparative Example 1 A method for reducing the slag rate on the surface of lead alloys, wherein the smelting temperature is controlled at 550°C during the production process of the lead alloy, additives are added to the molten lead, and the casting flow rate is controlled at 103 kg / s.

[0057] The additives include carbon powder, coal powder, coal slag, and wood chips; the mass ratio of the carbon powder, coal powder, coal slag, and wood chips is 30:20:35:15.

[0058] The production process includes the following steps: The precipitated lead is placed in a regenerator furnace, heated to the smelting temperature, held at that temperature, and compressed air is introduced. Sodium hydroxide flakes are added to the furnace surface, and the mixture is stirred and mixed for the first time. The slag is skimmed off to obtain the molten lead liquid. Alloy metal and the additives are added, and the mixture is stirred and mixed for the second time. Casting is then carried out according to the specified casting flow rate, followed by cooling, thus completing the production process. Taking the production of lead-tin alloy as an example, the alloy metal added in this embodiment is tin ingot, and the final product (lead alloy) is tested to have a tin content of 1.5%.

[0059] The average grade of the precipitated lead is not less than 99.99%.

[0060] The heating rate is 10°C / min.

[0061] The mass ratio of the precipitated lead to the caustic soda flakes is 1000:0.4.

[0062] The first mixing refers to mixing for 30 minutes.

[0063] The chemical composition of the molten lead liquid meets the national standard for No. 1 lead ingots (GB / T 469-2023, Pb99.994).

[0064] The mass ratio of the additive to the molten lead is 2:1000.

[0065] The second mixing refers to mixing for 30 minutes.

[0066] The cooling rate is 4°C / min.

[0067] Comparative Example 2 A method for reducing the surface slag rate of lead alloys, wherein the smelting temperature is controlled at 610°C during the production process of the lead alloy, additives are added to the molten lead, and the casting flow rate is controlled at 103 kg / s.

[0068] The additives include carbon powder, coal powder, coal slag, and wood chips; the mass ratio of the carbon powder, coal powder, coal slag, and wood chips is 30:20:35:15.

[0069] The production process includes the following steps: The precipitated lead is placed in a regenerator furnace, heated to the smelting temperature, held at that temperature, and compressed air is introduced. Sodium hydroxide flakes are added to the furnace surface, and the mixture is stirred and mixed for the first time. The slag is skimmed off to obtain the molten lead liquid. Alloy metal and the additives are added, and the mixture is stirred and mixed for the second time. Casting is then carried out according to the specified casting flow rate, followed by cooling, thus completing the production process. Taking the production of lead-tin alloy as an example, the alloy metal added in this embodiment is tin ingot, and the final product (lead alloy) is tested to have a tin content of 1.5%.

[0070] The average grade of the precipitated lead is not less than 99.99%.

[0071] The heating rate is 10°C / min.

[0072] The mass ratio of the precipitated lead to the caustic soda flakes is 1000:0.4.

[0073] The first mixing refers to mixing for 30 minutes.

[0074] The chemical composition of the molten lead liquid meets the national standard for No. 1 lead ingots (GB / T 469-2023, Pb99.994).

[0075] The mass ratio of the additive to the molten lead is 2:1000.

[0076] The second mixing refers to mixing for 30 minutes.

[0077] The cooling rate is 4°C / min.

[0078] Comparative Example 3 A method for reducing the slag rate on the surface of lead alloys, wherein the smelting temperature is controlled at 580°C during the production process of the lead alloy, additives are added to the molten lead, and the casting flow rate is controlled at 103 kg / s.

[0079] The additives include carbon powder, coal powder, coal slag, and wood chips; the mass ratio of the carbon powder, coal powder, coal slag, and wood chips is 30:20:35:15.

[0080] The production process includes the following steps: The precipitated lead is placed in a regenerator furnace, heated to the smelting temperature, held at that temperature, and compressed air is introduced. Sodium hydroxide flakes are added to the furnace surface, and the mixture is stirred and mixed for the first time. The slag is skimmed off to obtain the molten lead liquid. Alloy metal and the additives are added, and the mixture is stirred and mixed for the second time. Casting is then carried out according to the specified casting flow rate, followed by cooling, thus completing the production process. Taking the production of lead-tin alloy as an example, the alloy metal added in this embodiment is tin ingot, and the final product (lead alloy) is tested to have a tin content of 1.5%.

[0081] The average grade of the precipitated lead is not less than 99.99%.

[0082] The heating rate is 10°C / min.

[0083] The mass ratio of the precipitated lead to the caustic soda flakes is 1000:0.4.

[0084] The first mixing refers to mixing for 30 minutes.

[0085] The chemical composition of the molten lead liquid meets the national standard for No. 1 lead ingots (GB / T 469-2023, Pb99.994).

[0086] The mass ratio of the additive to the molten lead is 0.8:1000.

[0087] The second mixing refers to mixing for 30 minutes.

[0088] The cooling rate is 4°C / min.

[0089] Comparative Example 4 A method for reducing the slag rate on the surface of lead alloys, wherein the smelting temperature is controlled at 580°C during the production process of the lead alloy, additives are added to the molten lead, and the casting flow rate is controlled at 103 kg / s.

[0090] The additives include carbon powder, coal powder, coal slag, and wood chips; the mass ratio of the carbon powder, coal powder, coal slag, and wood chips is 30:20:35:15.

[0091] The production process includes the following steps: The precipitated lead is placed in a regenerator furnace, heated to the smelting temperature, held at that temperature, and compressed air is introduced. Sodium hydroxide flakes are added to the furnace surface, and the mixture is stirred and mixed for the first time. The slag is skimmed off to obtain the molten lead liquid. Alloy metal and the additives are added, and the mixture is stirred and mixed for the second time. Casting is then carried out according to the specified casting flow rate, followed by cooling, thus completing the production process. Taking the production of lead-tin alloy as an example, the alloy metal added in this embodiment is tin ingot, and the final product (lead alloy) is tested to have a tin content of 1.5%.

[0092] The average grade of the precipitated lead is not less than 99.99%.

[0093] The heating rate is 10°C / min.

[0094] The mass ratio of the precipitated lead to the caustic soda flakes is 1000:0.4.

[0095] The first mixing refers to mixing for 30 minutes.

[0096] The chemical composition of the molten lead liquid meets the national standard for No. 1 lead ingots (GB / T 469-2023, Pb99.994).

[0097] The mass ratio of the additive to the molten lead is 3.2:1000.

[0098] The second mixing refers to mixing for 30 minutes.

[0099] The cooling rate is 4°C / min.

[0100] Comparative Example 5 A method for reducing the slag rate on the surface of lead alloys, wherein the smelting temperature is controlled at 580°C during the production process of the lead alloy, additives are added to the molten lead, and the casting flow rate is controlled at 95 kg / s.

[0101] The additives include carbon powder, coal powder, coal slag, and wood chips; the mass ratio of the carbon powder, coal powder, coal slag, and wood chips is 30:20:35:15.

[0102] The production process includes the following steps: The precipitated lead is placed in a regenerator furnace, heated to the smelting temperature, held at that temperature, and compressed air is introduced. Sodium hydroxide flakes are added to the furnace surface, and the mixture is stirred and mixed for the first time. The slag is skimmed off to obtain the molten lead liquid. Alloy metal and the additives are added, and the mixture is stirred and mixed for the second time. Casting is then carried out according to the specified casting flow rate, followed by cooling, thus completing the production process. Taking the production of lead-tin alloy as an example, the alloy metal added in this embodiment is tin ingot, and the final product (lead alloy) is tested to have a tin content of 1.5%.

[0103] The average grade of the precipitated lead is not less than 99.99%.

[0104] The heating rate is 10°C / min.

[0105] The mass ratio of the precipitated lead to the caustic soda flakes is 1000:0.4.

[0106] The first mixing refers to mixing for 30 minutes.

[0107] The chemical composition of the molten lead liquid meets the national standard for No. 1 lead ingots (GB / T 469-2023, Pb99.994).

[0108] The mass ratio of the additive to the molten lead is 2:1000.

[0109] The second mixing refers to mixing for 30 minutes.

[0110] The cooling rate is 4°C / min.

[0111] Comparative Example 6 A method for reducing the slag rate on the surface of lead alloys, wherein the smelting temperature is controlled at 580°C during the production process of the lead alloy, additives are added to the molten lead, and the casting flow rate is controlled at 110 kg / s.

[0112] The additives include carbon powder, coal powder, coal slag, and wood chips; the mass ratio of the carbon powder, coal powder, coal slag, and wood chips is 30:20:35:15.

[0113] The production process includes the following steps: The precipitated lead is placed in a regenerator furnace, heated to the smelting temperature, held at that temperature, and compressed air is introduced. Sodium hydroxide flakes are added to the furnace surface, and the mixture is stirred and mixed for the first time. The slag is skimmed off to obtain the molten lead liquid. Alloy metal and the additives are added, and the mixture is stirred and mixed for the second time. Casting is then carried out according to the specified casting flow rate, followed by cooling, thus completing the production process. Taking the production of lead-tin alloy as an example, the alloy metal added in this embodiment is tin ingot, and the final product (lead alloy) is tested to have a tin content of 1.5%.

[0114] The average grade of the precipitated lead is not less than 99.99%.

[0115] The heating rate is 10°C / min.

[0116] The mass ratio of the precipitated lead to the caustic soda flakes is 1000:0.4.

[0117] The first mixing refers to mixing for 30 minutes.

[0118] The chemical composition of the molten lead liquid meets the national standard for No. 1 lead ingots (GB / T 469-2023, Pb99.994).

[0119] The mass ratio of the additive to the molten lead is 2:1000.

[0120] The second mixing refers to mixing for 30 minutes.

[0121] The cooling rate is 4°C / min.

[0122] Detection of surface slag ratio The surface slag ratio of the lead alloys produced in Examples 1-3 and Comparative Examples 1-6 was tested. The test method was as follows: the lead alloy was heated from a solid state to a molten state, and the slag floating on the surface was removed manually with a slag scoop until a bright lead alloy melt was visible on the surface. The percentage of the weight of the removed slag to the weight of the lead alloy was the surface slag ratio.

[0123] Table 1. Detection of surface slag ratio This invention provides a method for reducing the surface slag rate of lead alloys. By optimizing the melting temperature, adding appropriate amounts of specific additives, and improving the casting process, the formation of surface slag can be effectively reduced, thereby improving the surface quality and overall performance of lead alloys.

[0124] In the description of this specification, the references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0125] The above description is merely an example and illustration of the concept of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described or use similar methods to replace them, as long as they do not deviate from the concept of the invention or exceed the scope defined in the claims, they should all fall within the protection scope of the present invention.

Claims

1. A method for reducing the slag content on the surface of lead alloys, characterized in that: The method refers to controlling the smelting temperature at 560-600℃ during the production process of the lead alloy, adding additives to the molten lead, and controlling the casting flow rate at 100-105kg / s.

2. The method for reducing the slag content on the surface of lead alloys according to claim 1, characterized in that: The additives include carbon powder, coal powder, coal slag, and wood chips; the mass ratio of the carbon powder, coal powder, coal slag, and wood chips is 28-32:18-22:35:15-18.

3. The method for reducing the slag content on the surface of lead alloys according to claim 1, characterized in that: The production process includes the following steps: The precipitated lead is placed into a regenerator furnace, heated to the smelting temperature, held at the temperature, and compressed air is introduced. Sodium hydroxide flakes are added to the inner surface of the furnace, and the mixture is stirred for the first time. The scum is skimmed off to obtain the molten lead liquid. Alloy metal and the additives are added, and the mixture is stirred for the second time. The mixture is then cast according to the casting flow rate and cooled to complete the production process.

4. The method for reducing the slag content on the surface of lead alloys according to claim 3, characterized in that: The average grade of the precipitated lead is not less than 99.99%.

5. The method for reducing the slag content on the surface of lead alloys according to claim 3, characterized in that: The heating rate is 5-15℃ / min.

6. The method for reducing the slag content on the surface of lead alloys according to claim 3, characterized in that: The mass ratio of the precipitated lead to the caustic soda flakes is 1000:0.3-0.

5.

7. The method for reducing the slag content on the surface of lead alloys according to claim 3, characterized in that: The first mixing refers to mixing for 30-40 minutes.

8. The method for reducing the slag content on the surface of lead alloys according to claim 3, characterized in that: The mass ratio of the additive to the molten lead is 1-3:1000.

9. A method for reducing the slag content on the surface of lead alloys according to claim 3, characterized in that: The second mixing refers to mixing for 30-40 minutes.

10. A method for reducing the slag content on the surface of lead alloys according to claim 3, characterized in that: The cooling rate is 2-5°C / min.

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