Carbon-free covering agent for smelting copper-iron alloy of heat type and its preparation method

Abstract

A covering agent for smelting carbon-free heat type copper-iron alloy, which is composed of the following components in mass percentage: 20-55% of calcium oxide, 15-30% of sodium carbonate, 4-14% of metallic aluminum, 0.5-4% of tricalcium diphosphide, 0.5-2% of magnesium oxide, 3-8% of lithium oxide, and the balance of silicon dioxide and inevitable impurities. The covering agent realizes the development of carbon-free material covering agent; the covering agent itself has the advantages of low melting point, suitable viscosity and the like, has good spreading performance after being added to the surface of alloy liquid, can be quickly and uniformly spread on the surface of copper liquid, and has uniform and stable slag melting; after long time covering, the molten slag does not have the phenomena of crust and lump. After use, the functions of anti-oxidation, slag absorption promotion, heat preservation and the like can be realized in the process of copper alloy smelting and casting, so as to ensure the smooth smelting and casting of copper-iron alloy under non-vacuum condition, and improve the finished product performance of copper-iron alloy.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of copper alloy smelting, in particular to a carbon-free heating type covering agent for copper-iron alloy smelting and a preparation method thereof. BACKGROUND

[0002] Copper-iron alloy (iron content of 5-50%) has excellent thermal conductivity and bending resistance, and has very excellent magnetic properties, electromagnetic shielding performance when the iron content is greater than 30%, and also has excellent low thermal expansion coefficient, wear resistance and other excellent properties, and has great application prospects in the fields of magnetic shielding, conductive and welding materials.

[0003] The non-vacuum smelting temperature of copper-iron alloy is about 1250-1550℃. The traditional smelting or ladle covering agent is by adding carbonaceous material in the compounded components, and the combustion and oxidation of the carbonaceous material is used to realize the heat preservation of the surface melt and promote the melting of the covering agent. However, the addition of carbonaceous material in the covering agent will cause the complex reaction between iron and carbon elements during the smelting process of copper-iron alloy, generating iron-carbon compounds, which will greatly affect the comprehensive performance of the finished copper-iron alloy. At the same time, since the smelting and casting of copper alloy are usually carried out in one smelting furnace, it is important to ensure the stability of the properties of the slag after absorbing iron oxides and prevent the formation of crust and clumps to ensure the covering effect. Therefore, how to design and prepare a covering agent without the conventional essential component carbonaceous material, which has good heating performance and good stability of copper-iron alloy material after use, and does not stick to the shell and clumps, is necessary for improving the smelting reliability and finished product performance of copper-iron alloy. SUMMARY

[0004] The technical purpose of the present application is to adjust the raw material components of the copper-iron alloy smelting covering agent and limit the process parameters, to prepare and provide a carbon-free heating type covering agent for copper-iron alloy smelting, which uses aluminum powder, calcium phosphide and metal oxide as the heat source, can be better used with low-melting-point copper-iron alloy, realizes the development of carbon-free material covering agent, and has the advantages of low melting point, appropriate viscosity and the like, and can realize the functions of anti-oxidation, slag absorption and heat preservation during the smelting and casting process of copper alloy, to ensure the smooth smelting and casting of copper-iron alloy under non-vacuum conditions and improve the finished product performance of copper-iron alloy.

[0005] The technical solution adopted by the present application to solve the above technical problems is: a carbon-free heating type covering agent for copper-iron alloy smelting, which is composed of the following components in mass percentage: 20-55% of calcium oxide, 15-30% of sodium carbonate, 4-14% of aluminum, 0.5-4% of calcium phosphide, 0.5-2% of magnesium oxide, 3-8% of lithium oxide, and the balance of silicon dioxide and unavoidable impurities.

[0006] Further, the covering agent is composed of the following components in mass percentage: 34% of calcium oxide, 18% of sodium carbonate, 5.5% of metallic aluminum, 1.4% of tricalcium diphosphide, 1% of magnesium oxide, 2% of lithium oxide, the rest being silicon dioxide and inevitable impurities.

[0007] Further, the total mass percentage of metallic aluminum and tricalcium diphosphide in the covering agent is ≥5.0%.

[0008] Further, the metallic aluminum is in powder structure, and the content of active aluminum in the metallic aluminum is >95%.

[0009] Further, the mass percentage of impurity iron oxide in the covering agent is <3%.

[0010] Further, after the covering agent is melted at a temperature of 1200℃, the isothermal viscosity of the molten slag within 20min is 0.6~2.0Pa.s.

[0011] Further, the covering agent is in granular form, and the mass percentage of the granules with a particle size of 0.20~1.0mm is 80~85%.

[0012] The preparation method of the carbon-free heat type copper-iron alloy smelting covering agent comprises the following steps: crushing each raw material in the covering agent, fully mixing and uniformly atomizing and granulating according to the mass percentage, then baking the obtained granules at a temperature of 65~90℃ for 2~4h to make the water content of the finished granules ≤0.5%, and obtaining the finished carbon-free heat type copper-iron alloy smelting covering agent.

[0013] Further, the particle size of the atomized and granulated granules is 0.20~1.0mm.

[0014] Beneficial effects:

[0015] 1. The carbon-free heat type copper-iron alloy smelting covering agent of the present application realizes the manufacture of the carbon-free heat type copper-iron alloy smelting covering agent, and the multiple components in the compound interact with each other and complement each other in the process of copper-iron alloy smelting through the adjustment of the formula components of the covering agent, so that the performance of the finished copper-iron alloy is significantly improved. On the one hand, the use of aluminum powder in the raw material formula of the covering agent makes the covering agent as a whole after being added to the surface of the copper liquid, the surface heat can be supplemented through the continuous and rapid heat release of the aluminum powder; on the other hand, the specially added calcium triphosphide in the raw material formula as an auxiliary combustion material can react at high temperature to generate calcium oxide and phosphorus oxide, and these compounds will not react with the copper solution. The addition of calcium triphosphide not only effectively reduces the use of aluminum heat generating material, but also greatly reduces the residual amount of aluminum in the copper liquid, thereby reducing the cost and improving the purity and comprehensive performance of the finished copper-iron alloy.

[0016] 2. The carbon-free heat type copper-iron alloy smelting covering agent of the present application uses sodium carbonate and lithium oxide with a specific component ratio as a solvent, which significantly reduces the melting point of the slag, ensures the melting performance and high temperature viscosity rationality of the slag, and realizes the purpose of spreading well on the solution surface and fully covering the solution.

[0017] 3. The carbon-free heat type copper-iron alloy smelting covering agent of the present application, due to the use of 3-8% mass percentage of lithium oxide in the slag, ensures that the melting point and viscosity performance of the slag change stably after absorbing the iron oxide in the alloy solution, realizes the use effect of long-time covering without shell and good covering, thereby reducing the loss of alloy elements in the solution and improving the yield.

[0018] 4. The preparation process of the carbon-free heat type copper-iron alloy smelting covering agent provided by the present application is simple in steps and convenient to operate, and the finished covering agent prepared has excellent performance, can realize the purposes of oxidation prevention, slag absorption promotion and heat preservation during the copper alloy smelting and casting process, and can better ensure the smooth smelting and casting of copper-iron alloy under non-vacuum conditions. DETAILED DESCRIPTION

[0019] In order for those skilled in the art to better understand the technical solutions provided by the present application, the technical solutions of the present application will be further described and explained in detail below in combination with specific embodiments. The purpose of disclosing the present application is to protect all variations and improvements within the scope of the present application, and the present application is not limited to the following embodiments.

[0020] The carbon-free heat type copper-iron alloy smelting covering agent is composed of the following components in percentage by mass: 20-55% of calcium oxide, 15-30% of sodium carbonate, 4-14% of metallic aluminum, 0.5-4% of diphosphine tricalcium, 0.5-2% of magnesium oxide, 3-8% of lithium oxide, and the balance of silicon dioxide and inevitable impurities.

[0021] Further, the total mass percentage of the metallic aluminum and the diphosphine tricalcium in the covering agent is ≥5.0%.

[0022] Further, the metallic aluminum is in a powder structure, and the content of active aluminum in the metallic aluminum is >95%.

[0023] Further, the mass percentage of the impurity iron oxide in the covering agent is <3%.

[0024] Further, the covering agent has a constant-temperature viscosity of 0.6-2.0 Pa.s of the molten slag after being melted at 1200°C for 20 min.

[0025] Further, the covering agent is in a granular form, and the mass percentage of the particles with a particle size of 0.20-1.0 mm is 80-85%.

[0026] The preparation method of the carbon-free heat type copper-iron alloy smelting covering agent comprises the following steps: crushing each raw material in the covering agent, fully mixing according to the mass percentage, atomizing and granulating into particles with a particle size of 0.20-1.0 mm, and then baking the particles at a temperature of 65-90°C for 2-4 h to make the water content of the finished particles ≤0.5%, thereby obtaining the finished carbon-free heat type copper-iron alloy smelting covering agent.

[0027] The covering agent has two main features: carbon-free heat material and low melting temperature, and stable properties after absorbing iron oxide. The covering agent uses metallic aluminum powder, diphosphine tricalcium and metallic oxide as a heat source to realize the carbon-free heat material in the covering agent. By adding sodium carbonate and lithium oxide, the melting temperature of the molten slag is reduced, and when the molten slag absorbs a certain amount of iron oxide, the melting temperature and viscosity of the molten slag do not change significantly, ensuring the use effect (no crust, full coverage), and realizing the purpose of preventing oxidation, promoting slag absorption and heat preservation during the copper alloy smelting and casting process, so as to ensure the smooth smelting and casting of copper-iron alloy under non-vacuum conditions.

[0028] Example 1

[0029] The carbon-free heat type copper-iron alloy smelting covering agent prepared in the embodiment is composed of the following components in percentage by mass: calcium oxide 34%, sodium carbonate 18%, metal aluminum powder 5.5%, tricalcium diphosphide 1.4%, magnesium oxide 1.0%, lithium oxide 2.0%, and the balance of silicon dioxide and unavoidable impurities.

[0030] The specific preparation process of the carbon-free heat type copper-iron alloy smelting covering agent is as follows: after the raw materials are respectively taken according to the above-mentioned ratio and fully crushed, they are uniformly doped and mixed, and then atomized and granulated into particles with a particle size of 0.20-1.0 mm. The obtained particles are baked at a temperature of 65℃ for 4h, and the moisture content is controlled to be ≤0.5%, thereby obtaining the finished heat type copper-iron alloy smelting covering agent.

[0031] The covering agent prepared in the embodiment has good spreadability and can be uniformly spread on the surface of copper liquid. The slag is uniformly and stably melted, and there is no phenomenon such as clumping.

[0032] It is determined that, after the covering agent prepared in the embodiment is melted at 1200℃, the viscosity of the molten slag is 0.95 Pa.s within 20 min; the water-quenched slag melting temperature test value is 1010℃; and the viscosity after adding 5% of the mass of diiron trioxide is 1.1 Pa.s.

[0033] Example 2

[0034] The carbon-free heat type copper-iron alloy smelting covering agent prepared in the embodiment is composed of the following components in percentage by mass: calcium oxide 40%, sodium carbonate 23%, metal aluminum 4.5%, tricalcium diphosphide 2.0%, magnesium oxide 1.0%, lithium oxide 3.0%, and the balance of silicon dioxide and unavoidable impurities.

[0035] The specific preparation process of the carbon-free heat type copper-iron alloy smelting covering agent is as follows: after the raw materials are respectively taken according to the above-mentioned ratio and fully crushed, they are uniformly doped and mixed, and then atomized and granulated into particles with a particle size of 0.20-1.0 mm. The obtained particles are baked at a temperature of 90℃ for 2h, and the moisture content is controlled to be ≤0.5%, thereby obtaining the finished heat type copper-iron alloy smelting covering agent.

[0036] The covering agent prepared in the embodiment has good spreadability and can be uniformly spread on the surface of copper liquid. The slag is uniformly and stably melted, and there is no phenomenon such as clumping.

[0037] It is determined that, after the covering agent prepared in the embodiment is melted at 1200℃, the viscosity of the molten slag is 1.2 Pa.s within 20 min; the water-quenched slag melting temperature test value is 1025℃; and the viscosity after adding 5% of the mass of diiron trioxide is 1.35 Pa.s.

[0038] Example 3

[0039] The carbon-free heat type copper-iron alloy smelting covering agent prepared in the embodiment is composed of the following components in mass percentage: calcium oxide 20%, sodium carbonate 25%, metallic aluminum 11%, tricalcium diphosphide 0.5%, magnesium oxide 2.0%, lithium oxide 6.0%, and the balance being silicon dioxide and unavoidable impurities.

[0040] The specific preparation process of the carbon-free heat type copper-iron alloy smelting covering agent is as follows: after the raw materials are respectively taken according to the above-mentioned ratio and fully crushed, they are uniformly doped and mixed, and then atomized and granulated into particles with a particle size of 0.20-1.0 mm. The obtained particles are baked at a temperature of 70℃ for 3h, and the moisture content is controlled to be ≤0.5%, thereby obtaining the finished heat type copper-iron alloy smelting covering agent.

[0041] The covering agent prepared in the embodiment has good spreadability and can be uniformly spread on the surface of copper liquid. The slag is uniformly and stably melted, and there is no phenomenon such as clumping.

[0042] It is determined that, after the covering agent prepared in the embodiment is melted at 1200℃, the viscosity of the molten slag at a constant temperature within 20 min is 1.4 Pa.s; the water-quenched slag melting temperature test value is 1030℃; and the viscosity after adding 5% of the mass of diiron trioxide is 1.7 Pa.s.

[0043] Example 4

[0044] The carbon-free heat type copper-iron alloy smelting covering agent prepared in the embodiment is composed of the following components in mass percentage: calcium oxide 31%, sodium carbonate 30%, metallic aluminum 4%, tricalcium diphosphide 4%, magnesium oxide 0.5%, and lithium oxide 4.0%, and the balance being silicon dioxide and unavoidable impurities.

[0045] The specific preparation process of the carbon-free heat type copper-iron alloy smelting covering agent is as follows: after the raw materials are respectively taken according to the above-mentioned ratio and fully crushed, they are uniformly doped and mixed, and then atomized and granulated into particles with a particle size of 0.20-1.0 mm. The obtained particles are baked at a temperature of 70℃ for 2.5h, and the moisture content is controlled to be ≤0.5%, thereby obtaining the finished heat type copper-iron alloy smelting covering agent.

[0046] The covering agent prepared in the embodiment has good spreadability and can be uniformly spread on the surface of copper liquid. The slag is uniformly and stably melted, and there is no phenomenon such as clumping.

[0047] It is determined that, after the covering agent prepared in the embodiment is melted at 1200℃, the viscosity of the molten slag at a constant temperature within 20 min is 1.4 Pa.s; the water-quenched slag melting temperature test value is 1030℃; and the viscosity after adding 5% of the mass of diiron trioxide is 1.7 Pa.s.

[0048] Example 5

[0049] The carbon-free heating type copper-iron alloy smelting covering agent prepared in the embodiment is composed of the following components in mass percentage: calcium oxide 55%, sodium carbonate 15%, metallic aluminum 14%, tricalcium diphosphide 0.5%, magnesium oxide 1.5%, lithium oxide 8%, and the balance of silicon dioxide and unavoidable impurities.

[0050] The specific preparation process of the carbon-free heating type copper-iron alloy smelting covering agent is as follows: the raw materials are fully crushed according to the above-mentioned ratio, then uniformly mixed, and then atomized and granulated into particles with a particle size of 0.20-1.0 mm, and then the obtained particles are baked at 80℃ for 2h, and the moisture content is controlled to be ≤0.5%, and the finished product of the heating type copper-iron alloy smelting covering agent is obtained.

[0051] The covering agent prepared in the embodiment has good spreadability and can be uniformly spread on the surface of the copper liquid, and the slag is uniformly and stably melted without agglomeration and other phenomena.

[0052] It is determined that the slag of the covering agent prepared in the embodiment has a constant temperature viscosity of 0.90 Pa.s within 20 min after melting at 1200℃, the water-quenched slag melting temperature test value is 1010℃, and the viscosity after adding 5% of the covering agent by mass of ferric sesquioxide is 1.1 Pa.s.

Claims

1. A covering agent for smelting of carbon-free heat-generating copper-iron alloy, characterized by comprising: a fluxing agent; and a slag forming agent. The covering agent is composed of the following components in mass percentage: 20-55% of calcium oxide, 15-30% of sodium carbonate, 4-14% of metallic aluminum, 0.5-4% of tricalcium diphosphide, 0.5-2% of magnesium oxide, 3-8% of lithium oxide, the balance of silicon dioxide and inevitable impurities. The metallic aluminum is in a powder structure, and the content of active aluminum in the metallic aluminum is > 95%.

2. The carbon-free heat-generating copper-iron alloy smelting covering agent according to claim 1, characterized in that: The total mass percentage of the metallic aluminum and the tricalcium diphosphide in the covering agent is ≥ 5.0%.

3. The carbon-free heat-generating copper-iron alloy smelting covering agent according to claim 1, characterized in that: The mass percentage of the impurity iron oxide in the covering agent is < 3%.

4. The carbon-free heat-generating copper-iron alloy smelting covering agent according to claim 1, characterized in that: After the covering agent is melted at a temperature of 1200℃, the isothermal viscosity of the molten slag within 20 min is 0.6-2.0 Pa.s.

5. The carbon-free heat-generating copper-iron alloy smelting covering agent according to claim 1, characterized by: The covering agent is in a granular form, and the mass percentage of the granules with a particle size of 0.20-1.0 mm is 80-85%.

6. The method of producing a covering agent for smelting a carbon-free heat-type copper-iron alloy according to any one of claims 1 to 5, characterized by, The method comprises the following steps: crushing each raw material in the covering agent respectively, atomizing and granulating after fully mixing the raw materials according to the mass percentage, and then baking the obtained granules at a temperature of 65-90℃ for 2-4 h to make the water content of the finished granules ≤ 0.5%, thereby obtaining the finished carbon-free heat-generating copper-iron alloy smelting covering agent.

7. The method for preparing a carbon-free exothermic covering agent for smelting copper-iron alloys according to claim 6, characterized in that: The particle size of the atomized and granulated granules is 0.20-1.0 mm.