A borax-type slag cleaning agent and its application in brass smelting

Abstract

The present invention discloses a borax-type drossing agent and its application in brass smelting. The borax-type drossing agent includes borax, boron ore, fluorite powder, carbon powder, and soda ash. When using the borax-type drossing agent of the present invention to smelt brass, the metal content in the furnace ash decreases, the copper ash becomes fluffy, reducing the loss of valuable metals and lowering the production cost.

Description

Technical Field

[0001] The present invention relates to the technical field of dross removers, and in particular to a borax-based dross remover and its application in brass smelting. Background Art

[0002] Brass is a type of copper alloy composed of copper and zinc. Various profiles such as brass bars, brass strips, brass tubes, brass wires, and brass plates are widely used in consumer electronics, electrical appliances, plumbing and sanitary ware, molds, aerospace, ocean liners, etc. The application forms include connectors, frames, gaskets, castings, bushings, wires, etc. All forms of end products have a lifespan and will be scrapped at the end of their life. The scrap and recycled materials from processing need to be remelted in the furnace. During the remelting process, oxidation and slag formation will occur. The generation of slag not only causes the burning loss of valuable metals, but also causes mechanical entrapment of granular copper alloy in the copper ash, resulting in an increase in the cost of valuable metal loss.

[0003] Solving the problems of serious burning loss of valuable metals and a large amount of mechanical entrapment of copper particles in the furnace ash is an urgent task for foundry workers. At present, the content of copper particles is mainly reduced by repeatedly vibrating a conventional funnel spoon, and at the same time, a conventional dross remover is added to the melt. However, the oxidation of zinc is serious, the copper content in the copper ash remains high, and the production cost is high. Summary of the Invention

[0004] The purpose of the present invention is to provide a borax-based dross remover and its application in brass smelting for the deficiencies in the prior art.

[0005] To achieve the above purpose, the technical solution adopted by the present invention is:

[0006] In the first aspect of the present invention, a borax-based dross remover is provided, which includes borax, borax ore, fluorite powder, carbon powder, and soda ash.

[0007] After being baked and dehydrated, borax becomes sodium tetraborate and decomposes into boric anhydride at high temperatures. It is extremely easy to form a fluffy complex salt with metal oxides. In addition, the fine silica sand and alumina in the copper ash can also react with soda ash to form slag floating on the surface of the copper melt. The fluorite powder plays a role in dispersing the slag and increasing fluidity. Through the comprehensive action, the fluffy slag can make the copper particles with a larger density sink into the copper melt. The fluorite powder CaF2 belongs to a viscosity regulator, which mainly combines with borates and aluminates to form some low-melting-point solutes to prevent the slag from being too viscous.

[0008]

[0009]

[0010] ZnO + C → Zn + CO2

[0011] Na2O.B2O3+CaF2→ Na2O.B2O3.CaF2

[0012] Reference Figure 1 The formation of furnace ash will prevent copper particles from re-entering the copper melt. The thickness and particle size of the furnace ash will form different mechanical resistances. By using a certain flux to change the physical properties of the furnace ash slag, making the furnace ash form a fluffy flocculent shape and reducing the amount of furnace ash, the copper content in the furnace ash can be reduced. For example, when the weight of the copper particles is greater than the resistance given by the slag, the copper particles slide into the copper melt and melt. The fluffy slag is beneficial to reducing this resistance. When the copper particles in the copper ash decrease, the copper content in the fished-out copper ash slag will naturally decrease. At the same time, after borax melts, it will form an oil film protection layer on the surface of the melt to prevent the oxidation of zinc and reduce the generation of furnace ash.

[0013] Preferably, the borax-based slag cleaning agent comprises the following components in percentage by weight: borax Na2B4O7·10H2O, 20% - 50%; boron gangue B2O3, 5% - 15%; fluorite powder CaF2, 2% - 10%; soda ash Na2CO3, 10% - 15%; carbon powder, 20% - 50%; the balance being other components brought in by the raw materials.

[0014] More preferably, the borax-based slag cleaning agent comprises the following components in percentage by weight: borax Na2B4O7·10H2O, 30% - 50%; boron gangue B2O3, 5% - 10%; fluorite powder CaF2, 2% - 10%; soda ash Na2CO3, 10% - 15%; carbon powder, 20% - 40%; the balance being other components brought in by the raw materials.

[0015] Even more preferably, the borax-based slag cleaning agent comprises the following components in percentage by weight: borax Na2B4O7·10H2O, 30% - 40%; boron gangue B2O3, 5% - 10%; fluorite powder CaF2, 5% - 10%; soda ash Na2CO3, 10% - 15%; carbon powder, 30% - 40%; the balance being other components brought in by the raw materials.

[0016] Borax Na2B4O7·10H2O, 30% - 40%; when it is less than 30%, some oxides cannot be completely compounded, and the surface of the melt is not fully covered; when it is higher than 40%, it will increase the viscosity of the molten slag, and too many vitreous oxides are not conducive to the fluidity of the molten slag. At the same time, the slag caking is serious, which is not conducive to smooth production.

[0017] Boron gangue B2O3, 5% - 10%; when it is higher than 10%, boron gangue and materials such as corundum, magnesia, and bauxite reduce their melting points and generate a liquid phase, acting as a sintering promoter and causing the problem of furnace ash caking. At the same time, it increases the risk of furnace wall corrosion; when it is less than 5%, the overall melting point of the slag does not decrease significantly, which is not conducive to the fluidity of the molten slag.

[0018] Fluorite powder CaF2, 5% - 10%; if higher than 10%, the excessive corrosiveness will erode the furnace wall and the furnace, and at the same time, the volatilized fluorides have health impacts; if lower than 5%, it is not sufficient to reduce the melting point of the furnace ash, resulting in caking problems.

[0019] Soda ash Na2CO3, 10% - 15%; if higher than 15%, it will increase the amount of furnace ash in the slag; if lower than 10%, it is not conducive to the formation of complex salts, resulting in poor fluffiness of the melt and serious caking.

[0020] The second aspect of the present invention is to provide the application of the above-mentioned borax-type slag cleaning agent in brass melting, including the following steps:

[0021] Step 1: After melting the first part of the production return materials, add the first part of the borax-type slag cleaning agent, evenly sprinkle it on the surface of the ash slag, stir evenly, let it stand, and clean up the ash slag; add the second part of the production return materials into the furnace, stir evenly, let it stand, and clean up the ash slag.

[0022] Step 2: Control the temperature in the furnace at 1080°C - 1100°C, add the second part of the borax-type slag cleaning agent, stir evenly, let it stand, and clean up the ash slag.

[0023] The present invention adopts the above technical solutions. Compared with the prior art, it has the following technical effects:

[0024] When melting brass with the borax-type slag cleaning agent of the present invention, the metal content in the furnace ash decreases, the copper ash becomes fluffy, reducing the loss of valuable metals and lowering the production cost. Description of the Drawings

[0025] Figure 1 It is a schematic diagram of the existence forms of copper and copper ash during the melting process. Detailed Embodiments

[0026] The following further describes the present invention with reference to the drawings and specific embodiments, but it is not a limitation of the present invention. It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments can be combined with each other. Embodiment

[0027] The borax-type slag cleaning agent provided in this embodiment includes the following components in weight percentage:

[0028] Borax Na2B4O7·10H2O, 40%; boron gangue B2O3, 5%; fluorite powder CaF2, 10%; soda ash Na2CO3, 10%; carbon powder, 35%. The addition amount of the slag cleaning agent is 0.3% of the total mass of the furnace charge.

[0029] Melting raw materials: Production return materials (sawing materials, scrapped materials) 100%, copper rice, 0# zinc.

[0030] The above slag cleaning agent was used for tests in the production of H62 billets in a 5t industrial frequency furnace. The melting process is as follows:

[0031] Step 1: After the first part of the melting raw materials (2.5t) was melted (when adding the raw materials, the raw materials were compacted to facilitate full and efficient melting), 5kg of the slag cleaning agent was added. The slag cleaning agent was evenly sprinkled on the surface of the slag using an iron shovel, stirred evenly, left standing for 10 minutes, the slag was completely fished out, and then the second part of the melting raw materials (2.3t) was added to the furnace (the raw materials were compacted to facilitate full and efficient melting), stirred evenly, left standing for 10 minutes, and the slag was completely fished out;

[0032] Step 2: After small-scale spouting and the voltage was adjusted to 320V, the temperature in the furnace was controlled at 1080°C - 1100°C. 8kg of the slag cleaning agent was added. In a sprinkling manner, the slag skimmer was used for stirring to fully mix the slag cleaning agent and the furnace slag. Stirring was carried out for 1 - 3 minutes. After stirring was completed, left standing for 10 minutes, and then the slag was fished out;

[0033] Step 3: The voltage of the electric furnace was raised to 340V, the temperature was maintained at about 1000°C, samples were taken, and spectral tests were carried out. Casting could be carried out if the composition was qualified.

[0034] Spectral composition of H62: Sn 0.0006, Pb 0.00062, Al 0.0001, Si 0.001, Fe 0.061, Ni 0.0021, Mn 0.0011, Cu 60.9, Cr 0.00015, Bi 0.0010, Zn balance.

[0035] The copper content in the slag was 8.5% (10kg of slag, 0.85kg of copper sand).

[0036] After the above slag was cleaned, there was basically no visible copper, only copper particles in a dust-like form. Example

[0037] The borax-type slag cleaning agent provided in this example includes the following components by weight percentage:

[0038] Borax Na2B4O7·10H2O, 35%; boron ore B2O3, 5%; fluorite powder CaF2, 10%; soda ash Na2CO3, 10%; carbon powder, 40%. The addition amount of the slag cleaning agent was 0.3% of the total mass of the furnace charge.

[0039] Melting raw materials: 100% production return materials (sawed materials, scrapped materials), copper rice, 0# zinc.

[0040] Tests were carried out in the production of H62 billets in a 5t industrial frequency furnace, and the melting process was the same as that described in Example 1.

[0041] H62 spectral composition: Sn 0.0004, Pb 0.00052, Al 0.0004, Si 0.003, Fe 0.051, Ni 0.0031, Mn 0.0021, Cu 61.2, Cr 0.0005, Bi 0.0015, balance Zn.

[0042] The copper content in the slag is 10% (10 kg of furnace ash, 1 kg of copper sand).

[0043] In this comparative example, ordinary sodium carbonate 50% + sodium chloride 50% was used as the slag cleaning agent. The raw materials were mixed together, wrapped in a packaging bag and reserved for use. The addition amount of the slag cleaning agent was 0.3% of the total mass of the furnace charge.

[0044] Melting raw materials: 100% production return materials (sawing materials, scrapped materials), copper rice, 0# zinc.

[0045] Tests were carried out on the production of H62 billets in a 5t industrial frequency furnace, and the melting process was the same as that described in Example 1.

[0046] H62 spectral composition: Sn 0.0008, Pb 0.00012, Al 0.0004, Si 0.002, Fe 0.071, Ni 0.0021, Mn 0.0011, Cu 61.1, Cr 0.0015, Bi 0.0025, balance Zn.

[0047] The copper content in the slag is 37% (10 kg of furnace ash, 3.7 kg of copper particles).

[0048] In this comparative example, zinc oxide powder was used as the slag cleaning agent, and the addition amount of the slag cleaning agent was 0.3% of the total mass of the furnace charge.

[0049] Melting raw materials: 100% production return materials (sawing materials, scrapped materials), copper rice, 0# zinc.

[0050] Tests were carried out on the production of H62 billets in a 5t industrial frequency furnace, and the melting process was the same as that described in Example 1.

[0051] H62 spectral composition: Sn 0.0007, Pb 0.00011, Al 0.0003, Si 0.001, Fe 0.051, Ni 0.0011, Mn 0.0021, Cu 60.8, Cr 0.0015, Bi 0.0025, balance Zn

[0052] The copper content in the slag is 27% (10 kg of furnace ash, 2.7 kg of copper particles).

[0053] The above are only the preferred embodiments of the present invention, and thus do not limit the implementation manners and protection scope of the present invention. For those skilled in the art, it should be realized that all the solutions obtained by equivalent substitution and obvious changes made by using the content of the specification and illustrations of the present invention should be included within the protection scope of the present invention.

Claims

1. A borax-type slag cleaning agent, characterized in that, It comprises components in the following weight percentages: borax Na2B4O7·10H2O, 20% - 50%; boron ore B2O3, 5% - 15%; fluorite powder CaF2, 2% - 10%; soda ash Na2CO3, 10% - 15%; carbon powder, 20% - 50%; the balance being impurities.

2. The borax-based slag cleaning agent according to claim 1, wherein The borax - type dross - cleaning agent comprises components in the following weight percentages: borax Na2B4O7·10H2O, 30% - 50%; boron ore B2O3, 5% - 10%; fluorite powder CaF2, 2% - 10%; soda ash Na2CO3, 10% - 15%; carbon powder, 20% - 40%; the balance being impurities.

3. The borax-based slag cleaning agent according to claim 2, wherein The borax - type dross - cleaning agent comprises components in the following weight percentages: borax Na2B4O7·10H2O, 30% - 40%; boron ore B2O3, 5% - 10%; fluorite powder CaF2, 5% - 10%; soda ash Na2CO3, 10% - 15%; carbon powder, 30% - 40%; the balance being impurities.

4. Application of the borax - type dross - cleaning agent according to any one of claims 1 - 3 in brass smelting.

5. The application according to claim 4, wherein It includes the following steps: Step 1: After melting the first part of the smelting raw materials, add the borax - type dross - cleaning agent in the first part, evenly sprinkle it on the surface of the slag, stir evenly, let it stand, and clean up the slag; add the second part of the smelting raw materials into the furnace, stir evenly, let it stand, and clean up the slag. Step 2: Control the temperature in the furnace at 1080°C - 1100°C, add the borax - type dross - cleaning agent in the second part, stir evenly, let it stand, and clean up the slag.

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