Method for preparing silicon-aluminum alloy mixed plate by using coal gangue

Abstract

A method for preparing a silicon-aluminum alloy mixed plate from coal gangue comprises the following steps that firstly, the coal gangue washed and selected by a coal washing plant is collected, the aluminum oxide content and the heat value of the coal gangue are detected after smashing and sorting are conducted, and it is guaranteed that the aluminum oxide content is higher than 70%, and the heat value is higher than 3000 kilocalories; 2, adding water, stirring, and kneading; 3, manufacturing a strip-shaped blank through an extruder; 4, conveying to a drying furnace for drying; 5, the strip-shaped blanks obtained in the step 4 are conveyed to a tunnel type gasification furnace and a heating pipeline to be used for heating the gasification furnace, the temperature of the gasification furnace is 1500 DEG C, and semi-melting of the blanks is completed through a gasification tunnel kiln; and 7, after the semi-molten state is achieved, multi-pass rolling is conducted in the atmosphere environment, and the silicon-aluminum alloy sheet is obtained. The coal gangue is fully utilized, dependence on natural resources is reduced, the influence of accumulation of waste on the environment is reduced, and sustainable utilization of resources is achieved.

Description

Technical Field

[0001] The invention belongs to the field of coal gangue recycling in coal washing plants, and specifically relates to a method for preparing a silicon-aluminum alloy mixed plate material by utilizing coal gangue. Background Art

[0002] Coal gangue is a solid waste discharged during coal mining and subsequent fine processing. It is a kind of black-gray rock with low carbon content and harder than coal that accompanies coal seams during the coal formation process. It includes excavation gangue during tunnel excavation, gangue mined from the roof, floor and interlayer during mining, and washed gangue picked out during coal washing. Its main components are aluminum oxide and silicon dioxide. At present, in order to recycle coal gangue as solid waste, it is generally reused as filler or raw material for the production of building materials. However, although the carbon content in coal gangue is low, it still has a certain amount of carbon. Therefore, it has calorific value and cannot be recycled directly as filler or raw material for the production of building materials. Summary of the invention

[0003] The invention provides a method for preparing a silicon-aluminum alloy mixed plate material by using coal gangue, so as to solve the defects in the prior art.

[0004] The present invention is achieved through the following technical solutions:

[0005] A method for preparing a silicon-aluminum alloy hybrid plate using coal gangue comprises the following steps:

[0006] Step 1: Collect the coal gangue after washing in the coal washing plant, crush and sort it, and then test the alumina content of the coal gangue. If the alumina content is lower than 70%, add bauxite with a content higher than 70% until the alumina content of the mixture is higher than 70%, and then test the calorific value of the mixture; if the alumina content is higher than 70%, directly test the calorific value. If the calorific value test result is lower than 3000 kcal, add coal powder until the calorific value of the mixture is higher than 3000 kcal. If the calorific value is higher than 3000 kcal, directly carry out the subsequent operation;

[0007] Step 2: adding water to the gangue powder or mixture obtained in step 1, stirring and kneading;

[0008] Step 3: Extruding the mixture obtained in step 2 into a strip-shaped blank;

[0009] Step 4: The strip blank obtained in step 3 is transported to a drying furnace for drying;

[0010] Step 5: The strip billet obtained in step 4 is transported to a tunnel-type gasifier. The gasified gases are mainly hydrogen, carbon monoxide and methane. These combustible gases are burned in the pipeline in the gasifier to heat the pipeline and heat the gasifier. The temperature of the gasifier is 1500°C. After passing through the gasification tunnel kiln, the billet is semi-melted.

[0011] Step 7: After reaching a semi-molten state, multiple rolling passes are performed in an atmosphere environment to obtain a silicon-aluminum alloy sheet.

[0012] In the method for preparing silicon-aluminum alloy hybrid plate material using coal gangue as described above, the alumina content and calorific value detection technology of the coal gangue in step 1 is any one of laser Raman and near-infrared spectroscopy.

[0013] In the method for preparing silicon-aluminum alloy hybrid plate using coal gangue as described above, in step 1, the particle size of the coal gangue after sorting is 20-80 mm, and the particle size after crushing is 1-5 mm.

[0014] In the method for preparing a silicon-aluminum alloy hybrid plate material using coal gangue as described above, the moisture content of the mixed material after kneading in step 2 is not greater than 15%.

[0015] In the method for preparing a silicon-aluminum alloy mixed plate material using coal gangue as described above, the moisture content of the strip blank after drying in step 4 is no more than 3%.

[0016] In the method for preparing silicon-aluminum alloy hybrid plate using coal gangue as described above, in the step 5, the strip billet is formed by vacuum hollow or solid extrusion, and the extrusion pressure is not less than 3MPa.

[0017] In the method for preparing silicon-aluminum alloy hybrid plate using coal gangue as described above, the first 3-5 rolling passes in step 6 are vertical double-sided rolling, and the subsequent rolling passes are converted to flat rolling.

[0018] In the method for preparing silicon-aluminum alloy mixed plate using coal gangue as described above, double-sided surface heating is performed before each rolling process in step six.

[0019] As described above, in a method for preparing silicon-aluminum alloy mixed plate using coal gangue, the double-sided surface heating adopts a graphite rectangular frame set in front of the rolling mill, and a medium-frequency induction heating is set outside the frame. The billet passes through the rectangular graphite frame and is heated to maintain a temperature of 1500°C.

[0020] In the method for preparing a silicon-aluminum alloy hybrid plate using coal gangue as described above, the atmosphere in step seven is vacuum or inert gas is introduced.

[0021] In the method for preparing a silicon-aluminum alloy mixed plate using coal gangue as described above, the thickness of the silicon-aluminum alloy thin plate in step seven is 1 mm-5 mm.

[0022] The advantages of the present invention are:

[0023] 1. In the present invention, coal gangue is crushed and then tested for alumina content and calorific value before being mixed with water to form blanks. Since the calorific value of the final blank is greater than 3000 kcal, combustible gas can be generated through gasification during heating in a gasifier. The gas burns in a combustion tube in the gasifier cavity. The combustion tube continues to heat up and is used to heat materials in the gasifier tunnel, thereby achieving energy self-sustainability.

[0024] 2. The present invention can be a continuous production process, rather than the intermittent production of traditional smelting.

[0025] 3. The present invention does not separate elemental silicon and aluminum, and produces them together with some impurities, which reduces product performance but significantly reduces costs.

[0026] 4. The present invention uses multiple melting and rolling under atmosphere control, and only processes 1 mm of the surface each time, thereby reducing energy consumption and process complexity.

[0027] 5. The present invention can make full use of wastes such as gangue from coal washing plants, reduce dependence on natural resources, reduce the impact of waste accumulation on the environment, and achieve sustainable utilization of resources.

[0028] 6. The present invention reduces the production cost of silicon aluminum alloy materials by optimizing the process route and utilizing waste raw materials. Compared with traditional preparation methods, it reduces the raw material procurement cost and part of the energy consumption, and improves the economic benefits of the enterprise.

[0029] 7. The present invention adopts a variety of advanced process technologies and strict quality control measures, such as specific sorting, atmosphere control, multi-pass rolling and surface heating, which effectively reduces the impurity content in the plate and improves the purity and quality stability of the product. The product can meet the performance requirements of silicon aluminum alloy materials in different fields and has a wider market application prospect.

[0030] 8. The present invention integrates a variety of innovative processes, including sorting process, gasification process, surface heating degassing modification rolling under multi-pass atmosphere environment, etc., to form a unique comprehensive preparation process with high technical content, providing new ideas and methods for the development of the industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0032] Figure 1 It is one of the production process schematic diagrams of the present invention;

[0033] Figure 2 This is the second schematic diagram of the production process of the present invention;

[0034] Figure 3 It is the third schematic diagram of the production process of the present invention. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are 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 creative work are within the scope of protection of the present invention.

[0036] like Figure 1-3 As shown, a method for preparing a silicon-aluminum alloy hybrid plate using coal gangue comprises the following steps:

[0037] Step 1: Collect the coal gangue after washing in the coal washing plant, crush and sort it, and then test the alumina content of the coal gangue. If the alumina content is lower than 70%, add bauxite with a content higher than 70% until the alumina content of the mixture is higher than 70%, and then test the calorific value of the mixture; if the alumina content is higher than 70%, directly test the calorific value. If the calorific value test result is lower than 3000 kcal, add coal powder until the calorific value of the mixture is higher than 3000 kcal. If the calorific value is higher than 3000 kcal, directly carry out the subsequent operation;

[0038] Step 2: adding water to the gangue powder or mixture obtained in step 1, stirring and kneading;

[0039] Step 3: Extruding the mixture obtained in step 2 into a strip-shaped blank;

[0040] Step 4: The strip blank obtained in step 3 is transported to a drying furnace for drying;

[0041] Step 5: The strip billet obtained in step 4 is transported to a tunnel-type gasifier. The gasified gases are mainly hydrogen, carbon monoxide and methane. These combustible gases are burned in the pipeline in the gasifier to heat the pipeline and heat the gasifier. The temperature of the gasifier is 1500°C. After passing through the gasification tunnel kiln, the billet is semi-melted.

[0042] Step 7: After reaching a semi-molten state, multiple rolling passes are performed in an atmosphere environment to obtain a silicon-aluminum alloy sheet.

[0043] Preferably, the alumina content and calorific value detection technology of the coal gangue in step 1 is any one of laser Raman and near-infrared spectroscopy.

[0044] Specifically, in step 1 of this embodiment, the particle size of the coal gangue after sorting is 20-80 mm, and the particle size after crushing is 1-5 mm.

[0045] In the method for preparing a silicon-aluminum alloy hybrid plate material using coal gangue as described above, the moisture content of the mixed material after kneading in step 2 is not greater than 15%.

[0046] Specifically, in step 4 of this embodiment, the moisture content of the strip blank after drying is no more than 3%.

[0047] More specifically, in the process of making the strip-shaped blank in step five described in this embodiment, the blank is formed by vacuum hollow or solid extrusion, and the extrusion pressure is not less than 3 MPa.

[0048] More specifically, in step six described in this embodiment, the first 3-5 rolling passes are vertical double-sided rolling, and the subsequent rolling passes are converted to flat rolling.

[0049] Furthermore, in step six described in this embodiment, double-sided surface heating is used before each rolling pass.

[0050] Furthermore, the double-sided surface heating described in this embodiment adopts a graphite rectangular frame set in front of the rolling mill, and a medium-frequency induction heater is set outside the frame. The billet passes through the rectangular graphite frame and is heated to maintain a temperature of 1500°C.

[0051] Furthermore, the atmosphere in step seven of this embodiment is vacuum or an inert gas is introduced.

[0052] Furthermore, in step seven of this embodiment, the thickness of the silicon aluminum alloy sheet is 1 mm-5 mm.

[0053] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing a silicon-aluminum alloy hybrid plate using coal gangue, characterized in that: The steps include: Step 1: Collect the coal gangue after washing in the coal washing plant, crush and sort it, and then test the alumina content of the coal gangue. If the alumina content is lower than 70%, add bauxite with a content higher than 70% until the alumina content of the mixture is higher than 70%, and then test the calorific value of the mixture; if the alumina content is higher than 70%, directly test the calorific value. If the calorific value test result is lower than 3000 kcal, add coal powder until the calorific value of the mixture is higher than 3000 kcal. If the calorific value is higher than 3000 kcal, directly carry out the subsequent operation; Step 2: adding water to the gangue powder or mixture obtained in step 1, stirring and kneading; Step 3: Extruding the mixture obtained in step 2 into a strip-shaped blank; Step 4: The strip blank obtained in step 3 is transported to a drying furnace for drying; Step 5: The strip billet obtained in step 4 is transported to a tunnel-type gasifier. The gasified gases are mainly hydrogen, carbon monoxide and methane. These combustible gases are burned in the pipeline in the gasifier to heat the pipeline and heat the gasifier. The temperature of the gasifier is 1500°C. After passing through the gasification tunnel kiln, the billet is semi-melted. Step 7: After reaching a semi-molten state, multiple rolling passes are performed in an atmosphere environment to obtain a silicon-aluminum alloy sheet.

2. The method for preparing a silicon-aluminum alloy hybrid plate material using coal gangue according to claim 1, characterized in that: In the step 1, the particle size of the coal gangue after sorting is 20-80 mm, and the particle size after crushing is 1-5 mm.

3. The method for preparing a silicon-aluminum alloy hybrid plate material using coal gangue according to claim 1, characterized in that: In the step 2, the moisture content of the mixed material after kneading is not more than 15%.

4. The method for preparing a silicon-aluminum alloy hybrid plate material using coal gangue according to claim 1, characterized in that: In the step 4, the moisture content of the strip blank after drying is not more than 3%.

5. The method for preparing a silicon-aluminum alloy hybrid plate material using coal gangue according to claim 1, characterized in that: In the process of making the strip blank in step 5, the blank is formed by vacuum hollow or solid extrusion, and the extrusion pressure is not less than 3MPa.

6. The method for preparing a silicon-aluminum alloy hybrid plate material using coal gangue according to claim 1, characterized in that: In the step 6, the first 3-5 rolling passes are vertical double-sided rolling, and the subsequent rolling passes are converted to flat rolling.

7. The method for preparing a silicon-aluminum alloy hybrid plate material using coal gangue according to claim 1, characterized in that: In the step six, double-sided surface heating is adopted before each rolling.

8. The method for preparing a silicon-aluminum alloy hybrid plate material using coal gangue according to claim 7, characterized in that: The double-sided surface heating adopts a graphite rectangular frame arranged in front of the rolling mill, and a medium-frequency induction heating is arranged outside the frame. The billet passes through the rectangular graphite frame and is heated to maintain a temperature of 1500°C.

9. The method for preparing a silicon-aluminum alloy hybrid plate material using coal gangue according to claim 1, characterized in that: The atmosphere in step seven is vacuum or an inert gas is introduced.

10. The method for preparing a silicon-aluminum alloy hybrid plate material using coal gangue according to claim 1, characterized in that: In the step seven, the thickness of the silicon aluminum alloy sheet is 1mm-5mm.

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