Multi-effect composite aluminum alloy fluxing medium containing rare earth and preparation method of multi-effect composite aluminum alloy fluxing medium

Abstract

The invention belongs to the technical field of alloy smelting, and discloses a rare earth-containing multi-effect composite aluminum alloy fluxing medium and a preparation method thereof in order to solve the technical problem that in the prior art, an aluminum or aluminum alloy fluxing medium cannot efficiently remove inclusions in aluminum melt. The raw materials comprise potassium chloride, sodium chloride, magnesium chloride, sodium carbonate, calcium fluoride, sodium hexafluoroaluminate, potassium fluoroborate, nano silicon dioxide, nano aluminum oxide, borax and a rare earth compound. The preparation method comprises the following steps: (1) pretreating the raw materials; (2) mixing the raw materials; (3) melting; (4) cooling and crushing; and (5) screening. The preparation method is simple, effective, low in use cost, wide in application, environmentally friendly and recyclable in development.

Description

Technical Field

[0001] The invention belongs to the technical field of alloy smelting, and particularly relates to a rare earth-containing multi-effect composite aluminum alloy slagging agent and a preparation method thereof. Background Art

[0002] Prior to the present invention, aluminum ash treatment in the aluminum alloy smelting field mainly involved direct storage or landfill of the remaining aluminum ash after aluminum recovery. In terms of the use of slag removers, there were few specific existing technical solutions and the preparation method was cumbersome. This existing treatment method has the following defects and shortcomings:

[0003] Serious waste of resources: About 2.5wt% of slag (aluminum ash) is produced during the aluminum alloy production process. After aluminum is recycled, the remaining aluminum ash is directly stored or landfilled. It may also contain other usable substances that have not been fully recycled, resulting in waste of resources.

[0004] Environmental pollution problem: Aluminum ash is included in the "National List of Hazardous Wastes". Direct storage or landfill will pollute the soil, water sources, etc. and damage the ecological environment.

[0005] Lack of efficient slag removers: Existing aluminum or aluminum alloy slag removers are insufficient and cannot efficiently remove inclusions from the aluminum melt, and cannot meet the demand for improved melt purity during aluminum alloy smelting.

[0006] Chinese patent application CN117418130A discloses an aluminum alloy deslagging agent and its preparation method. The agent comprises the following raw materials in parts by weight: Glauber's saltpeter, sodium chloride, potassium fluorosilicate, potassium nitrate, calcium fluoride, and boron-coated sodium fluoroaluminate. The deslagging agent is suitable for low-temperature smelting, effectively removing impurities and resolving pipe blockage caused by powder injection.

[0007] Chinese patent application document CN117380712A discloses a method for preparing a slag-removing agent by sintering dust-collecting material using aluminum ash fire method, comprising the following steps:

[0008] 1. First, make the aluminum ash into pulp and react it with alkali solution, and collect the filter residue after solid-liquid separation.

[0009] 2. Add a mixture containing sodium carbonate, sodium oxide and other raw materials to the filter residue, stir and crush to obtain raw material slurry.

[0010] 3. Atomize and spray the raw material slurry into the rotary kiln for sintering, and control the process parameters of the kiln tail flue gas.

[0011] 4. Use a cyclone dust collector to screen out large-sized smoke dust particles, return them to the kiln for sintering after water quenching, and use an electrostatic dust collector to collect small-sized particles to obtain aluminum ash pyrometallurgical sintering dust collection material.

[0012] 5. Finally, the dust collected is granulated to obtain a slagging agent.

[0013] The first kind of slagging agent has the following problems: the raw material potassium nitrate is dangerous, high-temperature operation is easy to cause safety accidents, the composition is fixed, and the adaptability to complex aluminum alloy melt and the impurity removal effect are limited; the second kind of slagging agent has the problems of long production cycle and high equipment requirement, multi-step operation from aluminum ash slurry to final agent not only consumes time and energy, but also requires professional equipment.

[0014] The disclosure of the above background art is only used to assist in understanding the inventive concept and technical solutions of the present application, and does not necessarily belong to the prior art of the present patent application. In the absence of explicit evidence that the above content has been disclosed on the filing date of the present patent application, the above background art should not be used to evaluate the novelty and inventiveness of the present application. SUMMARY

[0015] The present application mainly aims to provide a rare earth-containing multi-effect composite aluminum alloy slagging agent and a preparation method thereof, so as to solve the technical problems that the existing aluminum or aluminum alloy slagging agent cannot efficiently remove inclusions in the aluminum melt.

[0016] In order to achieve the above technical purposes, the technical solutions adopted by the present application are as follows:

[0017] A rare earth-containing multi-effect composite aluminum alloy slagging agent, in terms of mass parts, comprises the following raw materials: potassium chloride 24-32 parts, sodium chloride 25-35 parts, magnesium chloride 2-7 parts, sodium carbonate 4-6 parts, calcium fluoride 5-10 parts, sodium hexafluoroaluminate 3-8 parts, potassium fluoroborate 2-8 parts, nano silicon dioxide 2-6 parts, nano aluminum oxide 4-9 parts, borax 2-4 parts, and rare earth compound 8-17 parts.

[0018] Preferably, the rare earth-containing multi-effect composite aluminum alloy slagging agent comprises the following raw materials in terms of mass parts: potassium chloride 30 parts, sodium chloride 30 parts, magnesium chloride 5 parts, sodium carbonate 5 parts, calcium fluoride 8 parts, sodium hexafluoroaluminate 5 parts, potassium fluoroborate 5 parts, nano silicon dioxide 4 parts, nano aluminum oxide 7 parts, borax 3 parts, and rare earth compound 12 parts.

[0019] Preferably, the rare earth compound is composed of lanthanum oxide, praseodymium oxide, and rubidium oxide in a mass ratio of (3-7):(1-2):(2-4).

[0020] Preferably, the rare earth compound is composed of lanthanum oxide, praseodymium oxide, and rubidium oxide in a mass ratio of 6:1.4:3.

[0021] The present application also provides a preparation method of the rare earth-containing multi-effect composite aluminum alloy slagging agent, comprising the following steps:

[0022] (1) Raw material pretreatment: the potassium chloride, sodium chloride, magnesium chloride, sodium carbonate, calcium fluoride, sodium hexafluoroaluminate, potassium fluoroborate, nano silicon dioxide, nano aluminum oxide, borax, rare earth compounds are respectively dried to remove the water in the raw materials; then the dried raw materials are respectively crushed;

[0023] (2) Raw material mixing: the pretreated raw materials are weighed according to the mass fraction ratio, and are put into a mixing machine to mix, to obtain a mixture;

[0024] (3) Melting: the mixture is put into a melting furnace and is mixed under the protection of inert gas, and is kept at the melting temperature after reaching the melting temperature, so that the raw materials are fully fused;

[0025] (4) Cooling and crushing: the mixed material after melting is taken out, naturally cooled to room temperature, and then crushed;

[0026] (5) Screening: the crushed material is screened, and finally sealed and stored to obtain the finished product of the multi-effect composite aluminum alloy deslagging agent containing rare earth.

[0027] Preferably, the drying temperature in step (1) is 105-152℃, the drying time is 1.5-3.5h, and the crushing particle size is 60-90 mesh.

[0028] Preferably, the mixing speed in step (2) is 300-500r / min, and the mixing time is 25-50min.

[0029] Preferably, the inert gas in step (3) is nitrogen, argon or helium.

[0030] Preferably, the melting temperature in step (3) is 760-810℃, the heating rate is 12-18℃ / min, and the holding time is 2-4h.

[0031] Preferably, the crushing particle size in step (4) is 20-50 mesh.

[0032] Preferably, the crushed material is screened in step (5), and the particle size of 20-50 mesh is selected, and finally sealed and stored.

[0033] Compared with the prior art, the present application has the following technical advantages:

[0034] (1) High deslagging efficiency and good purification effect

[0035] The slag removal efficiency of the slag removal agent of the present application is high, mainly due to the synergistic effect of rare earth elements and other raw materials and the optimized formula design. The high chemical activity of rare earth elements enables them to react with various impurities in the aluminum liquid, and the generated compounds form low-melting-point and low-viscosity slag under the action of chlorides and fluorides, which is easy to separate from the aluminum liquid. At the same time, the multi-component complex effect expands the removal range of different types of impurities, whether it is metal oxides, non-metallic inclusions or gas impurities, which can be effectively removed. Compared with the slag removal agent with good slag removal effect in the prior art, the scrap rate of aluminum alloy castings is reduced by more than 10% under the same use conditions.

[0036] (2) significantly improve the mechanical properties and corrosion resistance of aluminum alloy

[0037] The addition of rare earth elements is a key factor in improving the performance of aluminum alloy. Lanthanum oxide, praseodymium oxide and rubidium oxide can enter the aluminum alloy melt at high temperature, form stable compounds with impurities in the aluminum liquid, and at the same time, adsorb on the grain boundaries to hinder the growth of the grains, playing a role in refining the grains. The refined grains can significantly improve the mechanical properties of the aluminum alloy. In addition, rare earth elements can also form a dense oxide film on the surface of the aluminum alloy, enhancing the corrosion resistance of the aluminum alloy. The slag removal agent of the present application is particularly suitable for aluminum alloy products with high requirements for mechanical properties and corrosion resistance, such as aerospace, automobile manufacturing and other fields.

[0038] (3) excellent environmental performance and meets the requirements of green production

[0039] The present application fully considers the environmental factors in the selection of raw materials and preparation process. The selected raw materials are low-toxicity or non-toxic substances, avoiding the use of raw materials containing toxic ingredients. In the preparation process, by inert gas protection, the reaction of raw materials with air is reduced, and the generation of harmful gases is reduced. When used, the compounds generated by the reaction of the slag removal agent with impurities have good stability and are not easy to decompose to produce toxic gases, and the generated slag is easy to collect and process, and will not cause secondary pollution to the environment, fully meeting the national environmental protection standards. This not only protects the health of the operating personnel, but also meets the development trend of modern industrial green production, and is conducive to the realization of sustainable development of enterprises.

[0040] (4) wide application range and good versatility

[0041] The slagging agent of the present application has a wide range of application through reasonable formula design and process optimization. Whether it is pure aluminum smelting or the production of aluminum alloy castings and deformed aluminum alloys (such as 6061, 7075, etc.), the slagging agent of the present application can exhibit good results. In different aluminum alloy systems, its slag removal, purification and performance improvement can be effectively played. This is mainly because the slagging agent of the present application has strong adaptability, can adjust its reaction mode with impurities according to the composition characteristics of different aluminum alloys, and ensure that the desired treatment effect is achieved. Compared with the existing slagging agent which is only suitable for specific aluminum alloys, the universality of the present application enables it to be applied in different production scenarios, reducing the cost and trouble of replacing the slagging agent due to changes in product types, improving the flexibility and adaptability of production.

[0042] (5) High cost-effectiveness and good economy

[0043] The slagging agent of the present application has good cost-effectiveness while ensuring high performance. The selected raw materials are all conventional chemical raw materials easily available on the market, and the price is relatively low. By optimizing the amount ratio of each raw material in the formula, the use amount of high-priced raw materials is reduced under the premise of ensuring the effect. The preparation process is simple and does not require special high-end equipment, which is easy to realize industrial production, has high production efficiency, and further reduces the production cost. Compared with the existing high-performance slagging agent, the production cost of the present application is reduced by more than 10%, while the use of the slagging agent of the present application can improve the qualified rate and performance of aluminum alloy products, and increase the added value of products. In summary, the slagging agent of the present application can bring significant economic benefits to enterprises, and has high popularization and application value. BRIEF DESCRIPTION OF DRAWINGS

[0044] Figure 1 is the formula of FY-01 slagging agent;

[0045] Figure 2 is the formula of AJ-101A slagging agent;

[0046] Figure 3 is the formula of AJ-01C slagging agent;

[0047] Figure 4 is the schematic diagram of rod length influence factor and crack position influence factor;

[0048] Figure 5 is the hot crack rod sample diagram without slagging agent;

[0049] Figure 6 is the hot crack rod sample diagram of FY-01 slagging agent;

[0050] Figure 7 is the hot crack rod sample diagram of AJ-101A slagging agent;

[0051] Figure 8 This is a picture of the hot cracking rod sample with AJ-01C slag agent;

[0052] Figure 9 This is a picture of a hot cracking rod sample of the new formula slag beating agent in Example 2;

[0053] Figure 10 This is the heat tendency coefficient diagram after treatment with different slagging agents;

[0054] Figure 11 This is the burnout rate diagram after treatment with different slagging agents;

[0055] Figure 12 This is the hardness diagram after treatment with different slag agents;

[0056] Figure 13 This is the conductivity diagram after treatment with different slag agents;

[0057] Figure 14 This is the density diagram after treatment with different slag agents. DETAILED DESCRIPTION

[0058] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the preferred examples. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0059] In an embodiment of the present invention, a multi-effect composite aluminum alloy slag breaker containing rare earths includes the following raw materials, in parts by mass: 24-32 parts of potassium chloride, 25-35 parts of sodium chloride, 2-7 parts of magnesium chloride, 4-6 parts of sodium carbonate, 5-10 parts of calcium fluoride, 3-8 parts of sodium hexafluoroaluminate, 2-8 parts of potassium borofluoride, 2-6 parts of nano-silicon dioxide, 4-9 parts of nano-alumina, 2-4 parts of borax, and 8-17 parts of rare earth compounds.

[0060] The rare earth compound is composed of lanthanum oxide, praseodymium oxide and rubidium oxide in a mass ratio of (3-7): (1-2): (2-4).

[0061] The preparation method of the rare earth-containing multi-effect composite aluminum alloy slag remover comprises the following steps:

[0062] (1) Raw material pretreatment: Potassium chloride, sodium chloride, magnesium chloride, sodium carbonate, calcium fluoride, sodium hexafluoroaluminate, potassium borofluoride, nano-silica, nano-alumina, borax, and rare earth compounds are dried separately at a drying temperature of 105-152° C. for 1.5-3.5 hours to remove moisture from the raw materials; the dried raw materials are then crushed to a particle size of 60-90 mesh;

[0063] (2) raw material mixing: according to the mass fraction of the pretreated raw materials, put into the mixing machine for mixing, the mixing speed is 300-500r / min, the mixing time is 25-50min, the mixture is obtained;

[0064] (3) melting: the mixture is put into the melting furnace, and is mixed under the protection of inert gas, the melting temperature is 760-810℃, the heating rate is 12-18℃ / min, after reaching the melting temperature, the temperature is kept for 2-4h, so that the raw materials are fully fused, and the inert gas is nitrogen, argon or helium;

[0065] (4) cooling and crushing: the melted and mixed material is taken out, naturally cooled to room temperature, and then crushed to a particle size of 20-50 mesh;

[0066] (5) screening: the crushed material is screened, and the particle size of 20-50 mesh is selected, and finally sealed and stored, to obtain the finished product of the multi-effect composite aluminum alloy slagging agent containing rare earth.

[0067] The technical principle of the application is:

[0068] 1, the role of each raw material

[0069] Potassium chloride (24-32 parts): as a fluxing agent, it can reduce the melting point of the slagging agent, enhance its fluidity in the aluminum liquid, help the slagging agent to diffuse more uniformly, thereby improving the contact efficiency with the oxidized slag and inclusions, and promoting the deslagging process.

[0070] Sodium chloride (25-35 parts): cooperates with potassium chloride to further reduce the melting temperature of the slagging agent and improve its fluidity. At the same time, sodium chloride can react with some metal oxides in the aluminum liquid to form compounds that are easy to separate from the aluminum liquid, assisting in deslagging.

[0071] Magnesium chloride (2-7 parts): has good adsorption performance, can adsorb fine inclusions in the aluminum liquid, increase the impurity particles, and make them more easily removed. In addition, magnesium chloride can also improve the stability of the slagging agent and reduce the decomposition of the slagging agent at high temperature.

[0072] Sodium carbonate (4-6 parts): Adding sodium carbonate in the flux, it will react with aluminum melt and release heat. This part of heat will increase the local temperature, on the one hand, it will help to destroy the large size colloid of sodium hexafluoroaluminate in the aluminum melt, so that sodium hexafluoroaluminate is dispersed in the aluminum melt in the form of small size colloid, and then promote the dissolution ability of sodium hexafluoroaluminate to alumina, and enhance its ability to capture alumina inclusions; on the other hand, the elevated temperature can also promote the decomposition and reaction of high melting point components. In addition, the non-hydrogen gas produced by the reaction of sodium carbonate and aluminum melt can remove the dissolved hydrogen in the aluminum melt and the floating fine inclusions in the process of foaming and floating, further purifying the aluminum melt.

[0073] Calcium fluoride (5-10 parts): It can react with alumina and other oxidized slag in the aluminum liquid to form low-melting-point compounds, making it easier for oxidized slag to aggregate and separate. Moreover, calcium fluoride can improve the refractoriness of the slag remover, preventing it from melting too quickly in the high-temperature aluminum liquid.

[0074] Sodium hexafluoroaluminate (3-8 parts): It can reduce the surface tension of the aluminum liquid, making it easier for oxidized slag and inclusions to detach from the surface of the aluminum liquid and improving the efficiency of slag removal. At the same time, it can also refine the grains of aluminum alloy and improve its mechanical properties.

[0075] Potassium fluoroborate (2-8 parts): It has good deoxidizing and desulfurizing effects, can remove impurities such as oxygen and sulfur in the aluminum liquid, and improve the purity of aluminum alloy. In addition, potassium fluoroborate can also synergize with rare earth elements to further improve the performance of aluminum alloy.

[0076] Nano-silicon dioxide (2-6 parts): It has a large specific surface area and surface activity, can adsorb small inclusions in the aluminum liquid, and improve the slag removal effect. At the same time, nano-silicon dioxide can enhance the high-temperature stability of the slag remover and prolong its service life.

[0077] Nano-alumina (4-9 parts): It can refine the grains of aluminum alloy, improve its strength and hardness. In addition, nano-alumina can also synergize with other raw materials to enhance the slag removal capacity of the slag remover.

[0078] Borax (2-4 parts): It will melt and form a glassy substance at high temperatures, which can encapsulate the oxidized slag and inclusions in the aluminum liquid, preventing them from re-entering the aluminum liquid and improving the completeness of slag removal. At the same time, borax can also improve the welding performance of aluminum alloy.

[0079] Rare earth compounds (8-17 parts): Composed of lanthanum oxide, praseodymium oxide, and rubidium oxide in a specific ratio, it can refine the grains of aluminum alloy, significantly improve its mechanical properties such as strength, hardness, and toughness, and improve its corrosion resistance. Rare earth elements can also react with impurities in the aluminum liquid to reduce the harm of impurities.

[0080] 2. Synergistic effect between raw materials

[0081] Chlorides such as potassium chloride and sodium chloride and fluorides such as calcium fluoride and sodium hexafluoroaluminate synergize to not only reduce the melting point of the slagging agent and the surface tension of the aluminum liquid, but also to chemically react with the oxidized slag to form easily separable compounds, greatly improving the efficiency of slag removal.

[0082] Rare earth compounds (lanthanum oxide, praseodymium oxide, rubidium oxide) synergize with fluorides (calcium fluoride, etc.), and the rare earth elements preferentially react with impurities such as oxygen and sulfur in the aluminum liquid, and the generated compounds are more easily dissolved in the molten slag under the action of fluorides, thereby improving the purification efficiency. At the same time, fluorides can promote the dispersion of rare earth elements in the aluminum liquid, enhancing their effect of refining grains.

[0083] Borax synergizes with rare earth compounds (lanthanum oxide, praseodymium oxide, rubidium oxide) to refine grains, and borax can reduce the grain growth rate of aluminum alloys, while rare earth elements can hinder the nucleation and growth of grains. The combined action of the two makes the grain refinement effect more significant, improving the microstructure and mechanical properties of aluminum alloys.

[0084] The glassy substance formed by borax can encapsulate the oxidized slag and inclusions separated by chlorides, fluorides, etc., preventing their re-dissolution into the aluminum liquid, and synergizing with other slag removal components to ensure the stability of the slag removal effect.

[0085] In addition, all raw materials form an organic whole during the melting process, with each component interacting and complementing each other, resulting in a comprehensive improvement in the performance of the slagging agent in terms of slag removal, deoxidation, desulfurization, grain refinement, etc., thereby achieving the effect of multiple effects. The synergistic effect not only improves the overall performance of the slagging agent, but also reduces the use of single components, reducing costs and potential negative impacts.

[0086] 3. Specific role of each preparation step

[0087] Raw material pretreatment: drying treatment can remove water from the raw materials, avoiding the generation of bubbles due to water evaporation during subsequent melting, which affects the quality of the slagging agent. Crushing treatment crushes the raw materials to a specific particle size, facilitating the thorough mixing of the raw materials in the mixing step and improving the mixing uniformity.

[0088] Raw material mixing: mix the pretreated raw materials according to the proportion to ensure uniform distribution of each raw material, creating good conditions for subsequent melting and ensuring that each raw material can fully integrate.

[0089] Melting: under the protection of inert gas, melt the mixed materials to allow each raw material to fully integrate, forming a uniform melt, enhancing the synergistic effect between the components of the slagging agent, and ensuring the stability of the performance of the slagging agent.

[0090] Cooling and crushing: After the molten material is cooled to room temperature, it is crushed to form particles of a certain size, making it easier to sieve and use later. Controlling the crushing size has an important influence on the diffusion and reaction speed of the slag remover in the aluminum liquid.

[0091] Sieving: Selecting materials of a specific particle size ensures that the particle size of the slag remover is uniform, allowing it to function stably when used and avoiding fluctuations in slag removal due to uneven particle size.

[0092] 4. Reasons for not being able to exchange steps

[0093] Raw material pretreatment must be done before mixing the raw materials. If drying and crushing are done after mixing, it will cause uneven heating of the mixed raw materials during drying, incomplete water removal, and uneven particle size of the crushed raw materials, affecting the subsequent mixing effect.

[0094] Melting needs to be done after the raw materials are mixed. Only by mixing the raw materials uniformly can we ensure that each component is in contact during melting. If melting is done first and then mixing, it is impossible to achieve uniform fusion of the raw materials, which will result in unstable performance of the slag remover.

[0095] Cooling and crushing after melting is to convert the molten melt into solid particles to prepare for sieving. If the order is reversed, crushing first and then melting, the crushed raw materials will be unevenly distributed during melting, affecting the melting effect.

[0096] Sieving is the last step, used to select products that meet the particle size requirements. If sieving is done before crushing, the desired particle size cannot be obtained, and the stability of product quality cannot be guaranteed.

[0097] 5. Necessity, importance and unexpected technical effects of optimizing process parameters

[0098] Drying temperature and time: Optimizing the drying temperature (105-152℃) and time (1.5-3.5h) is to completely remove the water in the raw materials while avoiding decomposition or deterioration of the raw materials due to high temperature. If the temperature is too low or the time is too short, the water will not be completely removed, which will produce bubbles during melting, affecting the quality of the slag remover; if the temperature is too high or the time is too long, it will damage the structure and performance of the raw materials. Optimized parameters not only effectively remove water, but also maintain the good activity of the raw materials, unexpectedly improving the effect of the raw materials during melting.

[0099] Crushing particle size: crushing the raw materials to 60-90 mesh to facilitate subsequent uniform mixing; crushing the cooled material to 20-50 mesh to facilitate the rapid diffusion and reaction of the slagging agent in the aluminum liquid. If the particle size is not controlled properly, it will lead to uneven mixing and insufficient reaction if it is too coarse, or it will increase the crushing cost and may be lost in use if it is too fine. The optimized particle size parameters unexpectedly improve the storage stability of the slagging agent, which is not easy to absorb moisture and cake.

[0100] Mixing speed and time: the optimization of mixing speed (300-500 r / min) and time (25-50 min) is to ensure uniform mixing of raw materials. If the speed is too low or the time is too short, the mixing will not be sufficient; if the speed is too high or the time is too long, it will lead to excessive wear and heating of the raw materials. The optimized parameters greatly improve the uniformity of the raw material mixing, unexpectedly enhancing the synergistic effect of the components of the slagging agent, further improving the deslagging efficiency.

[0101] Melting temperature, heating rate and holding time: the optimization of melting temperature (760-810℃), heating rate (12-18℃ / min) and holding time (2-4h) can ensure the complete fusion of the raw materials. If the temperature is too low, the raw materials cannot be completely melted; if the temperature is too high, it will lead to volatilization and decomposition of the raw materials. If the heating rate is too fast, the material will not be evenly heated; if it is too slow, it will prolong the production time. If the holding time is insufficient, the melting will not be sufficient; if it is too long, it will increase the energy consumption. The optimized parameters not only ensure the performance of the slagging agent, but also unexpectedly reduce the energy consumption during production, improving the production efficiency.

[0102] Inert gas protection: selecting nitrogen, argon or helium as the inert gas can prevent the raw materials from being oxidized during melting, ensuring the purity of the slagging agent. If there is no inert gas protection, the raw materials will react with oxygen in the air to generate impurities, affecting the performance of the slagging agent. The optimized inert gas protection process unexpectedly reduces the generation of harmful gases during melting, which is more in line with environmental protection requirements.

[0103] In order to make the disclosure more complete, the following will further illustrate the present application with specific examples.

[0104] I. Examples

[0105] Example 1

[0106] A multi-effect composite aluminum alloy slagging agent containing rare earth, in mass parts, includes the following raw materials: potassium chloride 25 parts, sodium chloride 28 parts, magnesium chloride 2 parts, sodium carbonate 4 parts, calcium fluoride 6 parts, sodium hexafluoroaluminate 4 parts, potassium fluoroborate 2 parts, nano silicon dioxide 2 parts, nano aluminum oxide 4 parts, borax 2 parts, rare earth compound 9 parts.

[0107] The rare earth compound is composed of lanthanum oxide, praseodymium oxide and rubidium oxide in a mass ratio of 3:1:2.

[0108] The preparation method of the rare earth-containing multi-effect composite aluminum alloy slagging agent comprises the following steps:

[0109] (1) Raw material pretreatment: dry the potassium chloride, sodium chloride, magnesium chloride, sodium carbonate, calcium fluoride, sodium hexafluoroaluminate, potassium fluoroborate, nano silicon dioxide, nano aluminum oxide, borax and rare earth compound respectively at an oven drying temperature of 108°C for 3.4h to remove the water in the raw materials; then crush the dried raw materials to a particle size of 60 mesh;

[0110] (2) Raw material mixing: weigh the pretreated raw materials according to the mass fraction ratio, and put them into a mixing machine to mix at a mixing speed of 300r / min for 50min to obtain a mixture;

[0111] (3) Melting: put the mixture into a melting furnace and melt and mix under the protection of an inert gas, the melting temperature is 765°C, the heating rate is 12°C / min, and the temperature is kept for 4h after reaching the melting temperature to make the raw materials fully fuse, and the inert gas is nitrogen, argon or helium;

[0112] (4) Cooling and crushing: take out the melt-mixed material, cool it to room temperature naturally, and then crush it to a particle size of 20 mesh;

[0113] (5) Screening: screen the crushed material, select the particle size of 20 mesh, and finally seal and store to obtain the rare earth-containing multi-effect composite aluminum alloy slagging agent finished product.

[0114] Example 2

[0115] A rare earth-containing multi-effect composite aluminum alloy slagging agent, in mass parts, comprises the following raw materials: potassium chloride 30 parts, sodium chloride 30 parts, magnesium chloride 5 parts, sodium carbonate 5 parts, calcium fluoride 8 parts, sodium hexafluoroaluminate 5 parts, potassium fluoroborate 5 parts, nano silicon dioxide 4 parts, nano aluminum oxide 7 parts, borax 3 parts, and rare earth compound 12 parts.

[0116] The rare earth compound is composed of lanthanum oxide, praseodymium oxide and rubidium oxide in a mass ratio of 6:1.4:3.

[0117] The preparation method of the rare earth-containing multi-effect composite aluminum alloy slagging agent comprises the following steps:

[0118] (1) raw material pretreatment: the potassium chloride, sodium chloride, magnesium chloride, sodium carbonate, calcium fluoride, sodium hexafluoroaluminate, potassium fluoroborate, nano silicon dioxide, nano aluminum oxide, borax, rare earth compound are respectively dried at 130℃ for 2.6h to remove water in the raw materials; then the dried raw materials are respectively crushed to 80 mesh;

[0119] (2) raw material mixing: the pretreated raw materials are weighed according to the mass fraction ratio, and put into a mixer for mixing at a speed of 400r / min for 40min to obtain a mixture;

[0120] (3) melting: the mixture is put into a melting furnace and melted under the protection of inert gas, the melting temperature is 780℃, the heating rate is 15℃ / min, and the temperature is kept for 3h after reaching the melting temperature to make the raw materials fully fused, and the inert gas is nitrogen, argon or helium;

[0121] (4) cooling and crushing: the melted and mixed material is taken out, naturally cooled to room temperature, and then crushed to 40 mesh;

[0122] (5) screening: the crushed material is screened, and the 40 mesh product is selected and sealed for storage to obtain the finished product of the rare earth-containing multi-effect composite aluminum alloy slagging agent.

[0123] Example 3

[0124] A rare earth-containing multi-effect composite aluminum alloy slagging agent, in mass parts, comprises the following raw materials: potassium chloride 28 parts, sodium chloride 27 parts, magnesium chloride 3 parts, sodium carbonate 4.3 parts, calcium fluoride 6 parts, sodium hexafluoroaluminate 4 parts, potassium fluoroborate 5 parts, nano silicon dioxide 2.4 parts, nano aluminum oxide 5 parts, borax 2.2 parts, and rare earth compound 10 parts.

[0125] The rare earth compound is composed of lanthanum oxide, praseodymium oxide and rubidium oxide in a mass ratio of 4:1.2:3.

[0126] The preparation method of the rare earth-containing multi-effect composite aluminum alloy slagging agent comprises the following steps:

[0127] (1) raw material pretreatment: the potassium chloride, sodium chloride, magnesium chloride, sodium carbonate, calcium fluoride, sodium hexafluoroaluminate, potassium fluoroborate, nano silicon dioxide, nano aluminum oxide, borax, rare earth compound are respectively dried at 130℃ for 2.6h to remove water in the raw materials; then the dried raw materials are respectively crushed to 80 mesh;

[0128] (2) Raw material mixing: the pretreated raw materials were weighed according to the mass fraction ratio, and were put into a mixer for mixing at a mixing speed of 300 r / min for 50 min to obtain a mixture;

[0129] (3) Melting: the mixture was put into a melting furnace and was subjected to melting mixing under the protection of an inert gas, the melting temperature was 790 DEG C, the heating rate was 13 DEG C / min, and after reaching the melting temperature, the mixture was kept for 3.5 h to make the raw materials fully fused, and the inert gas was nitrogen, argon or helium;

[0130] (4) Cooling and crushing: the melted and mixed material was taken out, naturally cooled to room temperature, and then was crushed to a particle size of 40 mesh;

[0131] (5) Screening: the crushed material was screened, and a particle size of 40 mesh was selected, and finally was sealed and stored to obtain the finished product of the rare earth-containing multi-effect composite aluminum alloy slagging agent.

[0132] Example 4

[0133] A rare earth-containing multi-effect composite aluminum alloy slagging agent, in mass parts, comprises the following raw materials: potassium chloride 31 parts, sodium chloride 32 parts, magnesium chloride 6 parts, sodium carbonate 6 parts, calcium fluoride 10 parts, sodium hexafluoroaluminate 7 parts, potassium fluoroborate 8 parts, nano silicon dioxide 5 parts, nano aluminum oxide 9 parts, borax 4 parts, and rare earth compound 16 parts.

[0134] The rare earth compound is composed of lanthanum oxide, praseodymium oxide and rubidium oxide in a mass ratio of 7:2:4.

[0135] The preparation method of the rare earth-containing multi-effect composite aluminum alloy slagging agent comprises the following steps:

[0136] (1) Raw material pretreatment: the potassium chloride, sodium chloride, magnesium chloride, sodium carbonate, calcium fluoride, sodium hexafluoroaluminate, potassium fluoroborate, nano silicon dioxide, nano aluminum oxide, borax and rare earth compound were subjected to drying treatment at a drying temperature of 150 DEG C for 1.6 h to remove the water in the raw materials, and then the dried raw materials were crushed to a particle size of 90 mesh;

[0137] (2) Raw material mixing: the pretreated raw materials were weighed according to the mass fraction ratio, and were put into a mixer for mixing at a mixing speed of 500 r / min for 25 min to obtain a mixture;

[0138] (3) Melting: the mixture was put into a melting furnace and was subjected to melting mixing under the protection of an inert gas, the melting temperature was 800 DEG C, the heating rate was 18 DEG C / min, and after reaching the melting temperature, the mixture was kept for 2.2 h to make the raw materials fully fused, and the inert gas was nitrogen, argon or helium;

[0139] (4) Cooling and crushing: the molten mixed material is taken out, naturally cooled to room temperature, and then crushed to a particle size of 50 mesh;

[0140] (5) Screening: the crushed material is screened, and the particle size of 50 mesh is selected, and finally sealed and stored to obtain the finished product of the rare earth-containing multi-effect composite aluminum alloy slagging agent.

[0141] II. Experimental test

[0142] The advantages of the present application are embodied by comparing experimental data. The experiment is divided into five groups, and the experimental materials are respectively: (A) 40% waste aluminum chips + 60% 6016Al; (B) FY-01 slagging agent; (C) AJ-101A slagging agent; (D) AJ-01C slagging agent; (E) new formula slagging agent (slagging agent of example 2). The formula of FY-01 slagging agent, AJ-101A slagging agent and AJ-01C slagging agent is as shown in Table 1. Figure 1-Figure 3

[0143] Experimental group:

[0144] 1 2 3 4 5 A A+0.3%B A+0.3%C A+0.3%D A+0.3%E

[0145] Experimental group 1: the waste aluminum chips are cleaned with an organic solvent to remove oil, then dried and pressed into a cake by a hydraulic machine for standby, and the required weight for the experiment is weighed according to the proportion of 40% waste aluminum chips + 60% 6016Al. First, put the 6016Al block into the crucible and put it into the melting Lu furnace at a temperature of 750℃ until it is melted, then add 40% waste aluminum chips, and after the whole is melted, heat preservation for 10 min, stirring for 1 min, and finally casting into a regenerated aluminum block. After cooling, a 12mmx12mm sample is cut by wire cutting.

[0146] Experimental group 2: the waste aluminum chips are cleaned with an organic solvent to remove oil, then dried and pressed into a cake by a hydraulic machine for standby, and the required weight for the experiment is weighed according to the proportion of 40% waste aluminum chips + 60% 6016Al. First, put the 6016Al block into the crucible and put it into the melting Lu furnace at a temperature of 750℃ until it is melted, then add 40% waste aluminum chips, and after the whole is melted, heat preservation for 10 min, stirring for 1 min, and finally casting into a regenerated aluminum block. After cooling, a 12mmx12mm sample is cut by wire cutting.

[0147] ​Experimental group 3: The waste aluminum chips are cleaned with an organic solvent to remove oil, then dried and pressed into a cake by a hydraulic machine for standby. The required weight for the experiment is weighed according to the proportion of 40% waste aluminum chips + 60% 6016Al. First, put the 6016Al block into the crucible and put it into the smelting Lu furnace at a temperature of 750°C until it melts. Then add 40% waste aluminum chips and wait for it to melt completely. After 10 minutes of heat preservation, stir for 1 minute. Then wrap the added slagging agent (0.3% AJ-101A slagging agent) with aluminum foil and stir for 30 seconds. After 5 minutes of heat preservation, stir for 1 minute, then heat preservation for 5 minutes, and then stir for 30 seconds for slagging. Finally, cast the recycled aluminum block, and after cooling, cut a 12mm x 12mm sample with a wire cutter.

[0148] Experimental group 4: The waste aluminum chips are cleaned with an organic solvent to remove oil, then dried and pressed into a cake by a hydraulic machine for standby. The required weight for the experiment is weighed according to the proportion of 40% waste aluminum chips + 60% 6016Al. First, put the 6016Al block into the crucible and put it into the smelting Lu furnace at a temperature of 750°C until it melts. Then add 40% waste aluminum chips and wait for it to melt completely. After 10 minutes of heat preservation, stir for 1 minute. Then wrap the added slagging agent (0.3% AJ-01C slagging agent) with aluminum foil and stir for 30 seconds. After 5 minutes of heat preservation, stir for 1 minute, then heat preservation for 5 minutes, and then stir for 30 seconds for slagging. Finally, cast the recycled aluminum block, and after cooling, cut a 12mm x 12mm sample with a wire cutter.

[0149] Experimental group 5: The waste aluminum chips are cleaned with an organic solvent to remove oil, then dried and pressed into a cake by a hydraulic machine for standby. The required weight for the experiment is weighed according to the proportion of 40% waste aluminum chips + 60% 6016Al. First, put the 6016Al block into the crucible and put it into the smelting Lu furnace at a temperature of 750°C until it melts. Then add 40% waste aluminum chips and wait for it to melt completely. After 10 minutes of heat preservation, stir for 1 minute. Then wrap the added slagging agent (0.3% new formula slagging agent) with aluminum foil and stir for 30 seconds. After 5 minutes of heat preservation, stir for 1 minute, then heat preservation for 5 minutes, and then stir for 30 seconds for slagging. Finally, cast the recycled aluminum block, and after cooling, cut a 12mm x 12mm sample with a wire cutter.

[0150] From Figure 4-Figure 14 It can be seen that the recycled 6016 aluminum alloy treated by the slagging agent of example 2 has better performance in terms of hot cracking tendency coefficient, burning loss rate, hardness, electrical conductivity and density compared to other slagging agents on the market. It proves that it can effectively remove inclusions and improve the performance of aluminum alloy.

[0151] 1. Better slagging and purification effect

[0152] Hot cracking tendency coefficient and reduction of burning loss rate: the hot cracking tendency of the alloy is evaluated by hot cracking bar method, mainly considering the following three factors, i.e. the length of the bar generating hot cracks, the position of the hot cracks and the size of the hot cracks, and each influencing factor is divided into different levels for comprehensive consideration. The calculation method of hot cracking tendency is: HCS =∑(flength·flocation·wcrack), wherein HCS represents the hot cracking tendency coefficient (Hot Cracking Susceptibility), flength is the bar length influencing factor, according to the difficulty of hot cracking, the bar length parameter factor is shown in the following table: Figure 4 The left figure is: the longest bar is 4, the second longest bar is 8, the shorter bar is 16, and the shortest bar is 32. flocation is the crack position influencing factor, and the parameter is shown in the following table: Figure 4 The right figure shows that the crack is most likely to occur at the root, and the parameter is 1, at the ball end, the parameter is 2, and in the middle, it is the least likely to break, and the parameter is wcrack is the crack size factor, breakage is 4, half breakage is 3, crack is 2, and half crack is 1.

[0153] Figure 10 It is shown that the hot cracking tendency coefficient of the recycled 6016 aluminum alloy treated by the slagging agent of example 2 is 208, which is lower than that after treatment by other slagging agents, such as 312 after treatment by FY-01 slagging agent.

[0154] Burning loss rate calculation formula:

[0155]

[0156] Figure 11 It is shown that the burning loss rate of the recycled 6016 aluminum alloy treated by the slagging agent of example 2 is 21.08%, which is lower than that after treatment by other slagging agents, such as 24.13% after treatment by AJ-101A slagging agent. This is due to the synergistic effect of the composition of the slagging agent, which effectively removes impurities while reducing the loss of aluminum and improving the utilization rate of aluminum.

[0157] 2. Improve the performance of aluminum alloy

[0158] Improve hardness: the hardness of the alloy is measured by HV-1000TPTA type Vickers microhardness tester according to GB / T4340.1 standard, the sample is polished to mirror surface after sanding, and the experimental surface of the sample is parallel to the supporting surface, and finally the sample surface impurities are removed by anhydrous ethanol. The pressure head adopts a right tetrahedral pyramid pressure head with a diagonal line of 136°, and the calculation method is:

[0159]

[0160] The test load is 200g, and the load time is 15s. 20 points on the front and back of the sample are measured, and the truncated average value is taken as the hardness value of the sample. In the formula, HV is the microhardness, kgf / mm 2 ; F is the experimental force applied to the sample, kgf; θ is the diamond pyramid edge angle, 136°; D is the length of the indentation diagonal, mm; S is the indentation surface area, mm 2 .

[0161] Figure 12 It is shown that the hardness of the aluminum alloy treated by the slagging agent of Example 2 is 77Hv, which is higher than that of the untreated and other slagging agents. This is because the rare earth atoms refine the grain and enhance the structural strength of the aluminum alloy, so that the hardness is improved, and the use performance of the aluminum alloy is improved.

[0162] Optimization of electrical conductivity and density: The electrical conductivity test is carried out according to GB / T12966 standard by using Sigma2008 type digital conductivity meter. The sample is tested, and the surface of the sample is polished smooth before testing, and the instrument is calibrated. After turning on the instrument, the sample and the instrument are placed in an environment of 20℃, and the test is carried out and recorded when the instrument displays that the temperature is stable at 20℃. The electrical conductivity of 9 points on the front and back of the sample is measured, and the truncated average value is taken as the final electrical conductivity of the sample.

[0163] The density test is based on the principle of Archimedes drainage method, and is completed by using MAY-124SD type solid density tester. The whole test process strictly follows GB / T1423-1996 standard. The test steps are as follows: 1. The mass of the sample in the air is weighed by the balance, and the value is recorded by clicking “print”. 2. The sample is placed in water, and the mass of the sample in water is weighed, and the value is recorded again by clicking “print”. The value calculated automatically by the instrument is the density of the sample. Repeat three times, and take the average value.

[0164] Figure 13 and Figure 14 The data shows that the electrical conductivity of the aluminum alloy treated by the slagging agent of Example 2 is 20.123 (s / SW), and the density is 2.7362g / cm 3 , which is better than that of the aluminum alloy treated by other slagging agents in terms of electrical conductivity and density. It is shown that the slagging agent of the application has a positive effect on the physical properties of the aluminum alloy while purifying the aluminum alloy, and meets the different industrial application requirements.

Claims

1. A multi-effect composite aluminum alloy slag remover containing rare earth, characterized in that: The raw materials include, in parts by mass: 24-32 parts of potassium chloride, 25-35 parts of sodium chloride, 2-7 parts of magnesium chloride, 4-6 parts of sodium carbonate, 5-10 parts of calcium fluoride, 3-8 parts of sodium hexafluoroaluminate, 2-8 parts of potassium borofluoride, 2-6 parts of nano-silicon dioxide, 4-9 parts of nano-alumina, 2-4 parts of borax, and 8-17 parts of rare earth compounds.

2. The multi-effect composite aluminum alloy slag remover containing rare earth according to claim 1, characterized in that: The raw materials are as follows, in parts by mass: 30 parts of potassium chloride, 30 parts of sodium chloride, 5 parts of magnesium chloride, 5 parts of sodium carbonate, 8 parts of calcium fluoride, 5 parts of sodium hexafluoroaluminate, 5 parts of potassium borofluoride, 4 parts of nano-silicon dioxide, 7 parts of nano-alumina, 3 parts of borax, and 12 parts of rare earth compounds.

3. The rare earth-containing multi-effect composite aluminum alloy slag remover according to claim 1 or 2, characterized in that: The rare earth compound is composed of lanthanum oxide, praseodymium oxide and rubidium oxide in a mass ratio of (3-7): (1-2): (2-4).

4. The multi-effect composite aluminum alloy slag remover containing rare earth according to claim 3, characterized in that: The rare earth compound is composed of lanthanum oxide, praseodymium oxide and rubidium oxide in a mass ratio of 6:1.4:

3.

5. A method for preparing the rare earth-containing multi-effect composite aluminum alloy slag-breaking agent according to any one of claims 1 to 4, characterized in that: The following steps are involved: (1) Raw material pretreatment: Potassium chloride, sodium chloride, magnesium chloride, sodium carbonate, calcium fluoride, sodium hexafluoroaluminate, potassium borofluoride, nano-silicon dioxide, nano-alumina, borax, and rare earth compounds are dried to remove moisture from the raw materials; the dried raw materials are then crushed; (2) Raw material mixing: weigh the pre-treated raw materials according to the mass ratio, put them into a mixer and mix them to obtain a mixed material; (3) Melting: Place the mixed materials into a melting furnace and melt and mix them under the protection of inert gas. After reaching the melting temperature, keep the temperature to allow the raw materials to fully blend; (4) Cooling and crushing: The melted and mixed materials are taken out, cooled naturally to room temperature, and then crushed; (5) Screening: The crushed material is screened and finally sealed and stored to obtain a finished product of a multi-effect composite aluminum alloy slag breaker containing rare earth.

6. The method for preparing the rare earth-containing multi-effect composite aluminum alloy slag-breaking agent according to claim 5, characterized in that: In step (1), the drying temperature is 105-152° C., the drying time is 1.5-3.5 h, and the powder is crushed to a particle size of 60-90 mesh.

7. The method for preparing the rare earth-containing multi-effect composite aluminum alloy slag-breaking agent according to claim 5, characterized in that: In step (2), the mixing speed is 300-500 r / min and the mixing time is 25-50 min.

8. The method for preparing the rare earth-containing multi-effect composite aluminum alloy slag-breaking agent according to claim 5, characterized in that: The inert gas described in step (3) is nitrogen, argon or helium.

9. The method for preparing the rare earth-containing multi-effect composite aluminum alloy slag-breaking agent according to claim 5, characterized in that: In step (3), the melting temperature is 760-810° C., the heating rate is 12-18° C. / min, and the holding time is 2-4 h.

10. The method for preparing the rare earth-containing multi-effect composite aluminum alloy slag-breaking agent according to claim 5, characterized in that: In step (4), the particles are crushed to a particle size of 20-50 mesh.

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