Manufacturing process for producing casting silicon-aluminum alloy by recycling waste glass

Abstract

The invention discloses a manufacturing process for producing a silicon-aluminum alloy for casting by recycling waste glass. The manufacturing process comprises the following steps: (a) respectively preparing dried waste glass, waste aluminum, aluminum ash and a carbonaceous reducing agent into centimeter-level blocks or granular briquettes of 40-80 meshes; (b) respectively calculating the proportions of the raw materials required in production according to the content requirements of aluminum and silicon components required in the predetermined target aluminum-silicon alloy; (c) heating the smelting furnace to the temperature of # imgabs0 #, and then adding the waste glass blocks, the waste aluminum, the aluminum ash blocks and the carbonaceous reducing agent into the furnace; and (d) increasing the temperature of the smelting furnace to 1500 DEG C or above, smelting for 2-6 hours, discharging, and pouring into a casting mold to cast an aluminum-silicon alloy ingot. Waste utilization is achieved, production of the silicon-aluminum alloy can be completed at a time, the technology is simple, the machining time is short, and a large amount of energy can be saved.

Description

Technical field:

[0001] The invention relates to the field of smelting technology, and more specifically to a process for producing silicon-aluminum alloy for casting by recycling waste glass. Background technology:

[0002] Cast aluminum alloy has good fluidity and can be made into parts with complex shapes. It has the advantages of saving metal, reducing costs, and reducing working hours. It is widely used in various industrial fields. In particular, aluminum alloy has a low density and can produce lightweight structures. Therefore, it has unique advantages in the manufacture of transportation vehicles such as airplanes, cars, trains and ships.

[0003] In recent years, the growth rate of aluminum used in the manufacture of transportation vehicles has remained above 10%, which is one of the fastest growing areas of aluminum alloy in various industries. At present, aluminum alloy and its casting are the pillars of the non-ferrous metal casting industry and have become an important emerging industry supporting the development of the national economy. Since 2009, my country's aluminum alloy parts production has accounted for more than 30% of the global production, and exceeded 40% in 2019. my country has become the center of the international aluminum alloy casting industry.

[0004] Among cast aluminum alloys, aluminum-silicon alloys account for the largest proportion. On the one hand, this is because aluminum-silicon alloys have good fluidity and can be used to manufacture parts with complex shapes. On the other hand, aluminum-silicon alloys have small solidification shrinkage, fewer shrinkage cavities in castings, and better performance consistency. At present, the manufacture of aluminum-silicon alloys mainly uses liquid aluminum and solid silicon to diffuse to obtain aluminum-silicon alloys. The general process is to melt silicon and aluminum together in a melting furnace at a temperature of 500-900°C, and then add other alloying elements such as copper, magnesium, manganese, and chromium to melt together. Because the melting point of aluminum is about 660°C, aluminum is first melted into liquid, and then silicon is melted to form aluminum alloy liquid, which is then tested and cast into aluminum alloy ingots. Since the melting point of silicon is 1440°C and the diffusion rate is slow, the manufacturing process takes a long time and consumes a lot of energy. In addition, in the process of manufacturing the alloy, oxides (SiO 2 ), which will further reduce the diffusion of silicon, and also make the silicon consumption rate as high as 10% to 20%, seriously affecting production efficiency and cost. It has problems such as high cost and difficulty in impurity control. Therefore, how to reduce costs and control impurities has become an effective way to improve product competitiveness.

[0005] In recent years, some people have used silica ore and bauxite (containing Al 2 O 3The raw materials of the electrothermal method are bauxite, kaolinite and sillimanite, etc. The main control is the aluminum-silicon ratio in the raw materials. If you want to make an aluminum-silicon alloy containing 70% aluminum, the aluminum-silicon ratio of the raw materials should be 2-3. If this requirement cannot be met, it needs to be adjusted. It is generally believed that the aluminum content in the aluminum-silicon alloy is 70% to 72% most suitable. If it is too high, Al will appear. 4 C 3 . Lignite, peat coke, etc. are used as reducing agents in smelting. The purpose of batching is to accurately mix the reducing agent and the aluminum-silicon ratio. Excessive reducing agent will generate carbides, reduce the resistance of the charge, and cause the furnace bottom to grow higher. On the contrary, the amount of slag will increase, resulting in original product loss and mechanical loss of the product. For powder materials, the powder needs to be made into agglomerates in advance. The purpose of agglomeration is to enable the CO gas produced by the reaction to be discharged smoothly. The requirements for agglomerates are: (1) high reducing ability and speed, and sufficient porosity; (2) large resistivity and strength of the agglomerates; (3) the melting point of the four-piece material must be higher than the reduction temperature; (4) the water content of the agglomerates should be less than 1%. Smelting is generally carried out in an electric furnace. Under normal circumstances, the furnace can be divided into a charge preheating zone, a solidification zone, a reaction zone, an arc zone, and an aluminum-silicon alloy zone. Nowadays, electric furnaces for electrothermal smelting of aluminum-silicon alloys are getting larger and larger, and three-phase furnaces reach 25,000 to 30,000 kW. The power consumption of an arc furnace decreases with the increase of power. Therefore, electrothermal melting of aluminum-silicon alloys has become increasingly popular. At present, how to further reduce product costs is still very attractive.

[0006] In recent years, as environmental awareness has increased, people have realized the importance of waste utilization. Collecting materials that would otherwise be discarded and making them into new products can reduce the production of garbage and the consumption of raw materials, and can greatly reduce the impact of waste on the environment. In order to realize waste resource utilization, many countries have adopted a series of policies and measures to encourage the direct and effective use of waste.

[0007] Glass is a material commonly used in modern human life. It can be made into various utensils, containers, flat glass, etc. The main component of ordinary glass is silicon dioxide (SiO 2 , which is the main component of quartz sand). Sodium carbonate (Na 2 CO 3 , i.e. soda) and potassium carbonate (K 2 CO 3, potash) to lower the process temperature. Because the amount of glass used is large, there is also a lot of waste. For the sustainable use of resources, the discarded glass and products can be collected to turn harm into benefit and turn waste into treasure. There are several types of recycling of glass products: as a casting flux, transformation utilization, remelting, raw material recovery and reuse. Although these applications are very successful, the added value of the recycled products is low. At present, how to further increase the added value of recycled products is very attractive.

[0008] Similarly, scrap aluminum is also a commonly used waste material. A large number of abandoned cars, beverage cans, etc. contain a large amount of aluminum. During the recycling process, aluminum will oxidize and produce certain products such as aluminum ash. Generally speaking, aluminum ash contains 15% to 30% of metallic aluminum, which is discarded because of its low grade and is not worth further extraction of aluminum. Therefore, it is very promising to use appropriate methods to reuse these materials to produce high value-added products.

[0009] Therefore, the market needs technological advances to use waste glass, waste aluminum and aluminum ash to produce high value-added products, especially aluminum-silicon alloys with broad market value. Summary of the invention:

[0010] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a process for producing silicon-aluminum alloy for casting by recycling waste glass. The silicon-aluminum alloy can be made from waste glass, waste aluminum ash and waste aluminum. The recycled aluminum alloy has high added value, is simple in process and easy to manufacture.

[0011] The solution of the present invention to solve the technical problem is:

[0012] A process for producing silicon-aluminum alloy for casting by recycling waste glass, comprising the following steps:

[0013] (a) Dry waste glass, waste aluminum, aluminum ash and carbonaceous reducing agent are respectively made into centimeter-sized blocks or granular blocks with a size of 40 to 80 meshes;

[0014] (b) calculating the proportions of the raw materials required for production according to the required aluminum and silicon content in the predetermined target aluminum-silicon alloy;

[0015] (c) Heat the smelting furnace to The temperature is then increased, and waste glass blocks, waste aluminum and aluminum ash blocks, and carbonaceous reducing agent are added into the furnace;

[0016] (d) Raise the temperature of the smelting furnace to above 1500°C and smelt for 2 to 6 hours before taking out of the furnace and pouring into a casting mold to cast an aluminum silicon alloy ingot.

[0017] The reaction principle is Al 2 O 3 +SiO 2+5C→2Al+Si+5CO.

[0018] The silicon content in the aluminum-silicon alloy ingot is 5% to 25%.

[0019] The waste glass is ordinary glass, and its main component is silicon dioxide.

[0020] The scrap aluminum is recycled industrial aluminum material or recycled aluminum material commonly used in daily life.

[0021] The waste aluminum ash contains metallic aluminum and aluminum oxide.

[0022] In the step (a), the dried waste glass, waste aluminum and aluminum ash, and carbonaceous reducing agent are respectively made into granular briquettes with a size between 40 and 80 meshes.

[0023] The aluminum-silicon alloy ingot is in the shape of blocks, rods, strips, particles or crushed pieces.

[0024] Carbonaceous reducing agent is an indispensable raw material. The carbonaceous reducing agent can be any carbonaceous material. However, the more ideal carbonaceous materials include coke, petroleum coke, coal, etc.

[0025] The ratio of silicon to aluminum in silicon-aluminum alloy can be adjusted arbitrarily according to the needs of different uses. According to the general requirements of cast aluminum alloys, it is better to control the silicon content between 5% and 25%.

[0026] Waste glass, waste aluminum and aluminum ash, and carbon materials can be directly added to the melting furnace in the form of lumps, or these materials can be pulverized and then pressed into lumps before being added to the melting furnace.

[0027] Liquid silicon-aluminum alloy can be used directly as the final product, or other elements can be added to produce multi-component aluminum-silicon alloy that meets national or international standards.

[0028] Liquid silicon-aluminum alloy can be cast into solid shapes such as blocks, strips, granules, and crushed pieces.

[0029] The outstanding effects of the present invention are:

[0030] Compared with the existing technology, it can make silicon-aluminum alloy from waste glass, waste aluminum ash and waste aluminum, and its reuse added value is high;

[0031] It completes the production of silicon-aluminum alloy in one step, simplifies the complicated process of smelting two minerals separately, saves a lot of energy and reduces costs. When the silicon-aluminum alloy made by the present invention is used as the raw material for producing aluminum alloy ingots, because the melting point of silicon-aluminum alloy is much lower than that of silicon, it can save the melting time of aluminum alloy ingots, improve the recovery rate of silicon, and save materials. Specific implementation method:

[0032] Embodiment: produce one ton of silicon-aluminum alloy containing silicon (20%) and aluminum (80%).

[0033] Waste glass (mainly containing SiO 2 ) and containing Al 2 O 3 The waste aluminum ash blocks, waste aluminum blocks, and carbonaceous reducing agents (coke, petroleum coke, coal, etc.) are preheated first.

[0034] The silicon dioxide in the glass is controlled to be 560 kg, the aluminum ash is 1000 kg, the waste aluminum (Al, 600 kg), and the coke is measured at 3-4% of the total input.

[0035] Then add them together into the melting furnace. Raise the melting furnace temperature to 1500-1900°C. After several hours (2 to 6 hours), liquid silicon and aluminum are formed and directly mixed into liquid silicon-aluminum alloy.

[0036] Then it is sent to the batching furnace for heat preservation and standing, and other alloy elements are added as needed, and slag remover and appropriate gas are added to remove impurities, oxides and harmful gases.

[0037] Then, take samples for inspection to see if the proportion of each element meets the production requirements. Casting can be carried out after it meets the production requirements. If the content ratio does not meet the requirements, you can add more elements to adjust it to meet the requirements. Pay special attention to the fact that the proportion of silicon and aluminum in the cast silicon-aluminum alloy can be adjusted arbitrarily according to the feed amount, and the range is very large. Other elements can also be adjusted in the melt. Then casting can be carried out.

[0038] After casting, the liquid alloy is rapidly cooled in the metal mold to form an ingot.

[0039] The silicon aluminum alloy produced by this embodiment can be processed into solid shapes such as blocks, strips, granules, and crushed shapes by adjusting the composition according to user needs. This embodiment completes the manufacturing of the entire cast silicon aluminum alloy at one time, and the consumption rate of silicon (Si) can be greatly reduced to less than 5%, thereby improving the recovery rate of silicon, and the process is simple, which can save a lot of energy, fuel and production costs.

[0040] Table 1 below shows the alloys produced using this technology.

[0041] Table 1 Chemical composition of aluminum alloy

[0042]

[0043] Finally, the above implementation modes are only used to illustrate the present invention, and are not intended to limit the present invention. Ordinary technicians in the relevant technical field may make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, all equivalent technical solutions also belong to the scope of the present invention. The scope of patent protection of the present invention should be defined by the claims.

Claims

1. A process for producing silicon-aluminum alloy for casting by recycling waste glass, which has the following characteristics: it includes the following steps: (a) Dry waste glass, waste aluminum, aluminum ash and carbonaceous reducing agent are respectively made into centimeter-sized blocks or granular blocks with a size of 40 to 80 meshes; (b) calculating the proportions of the raw materials required for production according to the required aluminum and silicon content in the predetermined target aluminum-silicon alloy; (c) Heat the smelting furnace to The temperature is then increased, and waste glass blocks, waste aluminum and aluminum ash blocks, and carbonaceous reducing agent are added into the furnace; (d) Raise the temperature of the smelting furnace to above 1500°C and smelt for 2 to 6 hours before taking out of the furnace and pouring into a casting mold to cast an aluminum silicon alloy ingot.

2. The process for producing silicon-aluminum alloy for casting by recycling waste glass according to claim 1, characterized in that: The silicon content in the aluminum-silicon alloy ingot is 5% to 25%.

3. The process for producing silicon-aluminum alloy for casting by recycling waste glass according to claim 2, characterized in that: The waste glass is ordinary glass, and its main component is silicon dioxide.

4. The process for producing silicon-aluminum alloy for casting by recycling waste glass according to claim 1, characterized in that: The scrap aluminum is recycled industrial aluminum material or recycled aluminum material commonly used in daily life.

5. The process for producing silicon-aluminum alloy for casting by recycling waste glass according to claim 1, characterized in that: The waste aluminum ash contains metallic aluminum and aluminum oxide.

6. The process for producing silicon-aluminum alloy for casting by recycling waste glass according to claim 1, characterized in that: In the step (a), the dried waste glass, waste aluminum and aluminum ash, and carbonaceous reducing agent are respectively made into granular briquettes with a size between 40 and 80 meshes.

7. The process for producing silicon-aluminum alloy for casting by recycling waste glass according to claim 1, characterized in that: The aluminum-silicon alloy ingot is in the shape of blocks, rods, strips, particles or crushed pieces.

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