A method for preparing vitrified bond grinding wheel by geopolymerization reaction using coal gangue

Abstract

The present invention relates to the technical field of preparation of ceramic bond grinding wheels, and specifically to a method for preparing ceramic bond grinding wheels by using coal gangue through geopolymerization reaction. The main raw material of the ceramic bond used is coal gangue, and the porosity and surface activity of the material are greatly improved by mechanical-thermal activation of the coal gangue. Various mineral powders, alkaline solutions, water glass and other gelling agents are added to the activated coal gangue. After mixing, the dissolved aluminum silicon complex diffuses from the particle surface to the particle gap, and polymerization occurs between the silicate solution and the aluminum silicon complex, thereby obtaining a new type of geopolymer gelling material with high strength, good chemical resistance and thermal stability. Then, a ceramic bond grinding wheel is prepared by adding various supplementary materials. The grinding wheel has uniform pore distribution, a hardness grade of M grade or above, high flexural strength and tensile strength, and excellent grinding performance. It can save costs to a certain extent, reduce sintering temperature, and save energy and resources.

Description

Technical Field

[0001] The invention relates to the technical field of preparation of vitrified bond grinding wheels, and in particular to a method for preparing vitrified bond grinding wheels by utilizing coal gangue through geopolymerization reaction. Background Art

[0002] Gangue is a solid waste generated during coal mining, washing, and processing. Large-scale storage of gangue not only wastes land resources but also poses serious environmental risks, including spontaneous combustion, rain damage, and mudification. Furthermore, gangue contains certain combustible materials that, under suitable conditions, can spontaneously combust, emitting harmful gases such as sulfur dioxide, nitrogen oxides, carbon oxides, and smoke, polluting the atmosphere.

[0003] The activity of coal gangue refers to its ability to form gelling components with other substances in alkaline aqueous solutions. To effectively utilize coal gangue and address related issues, it needs to be modified to enhance its activity. Gangue activity is influenced not only by its particle size but also by its chemical properties. Therefore, mechanical activation and thermal activation are common methods for modifying coal gangue. Mechanical activation involves the use of mechanical forces to physically act on the gangue, dispersing and reorganizing its physical structure. Mechanical activation refines the kaolin particles in the gangue, disrupting its crystal structure and causing hydroxyl group cleavage (O~H, Al~OH, Al~O~Si, Si~O, etc.), increasing porosity, increasing active surface area, and improving reactivity. Mechanical treatment of coal gangue is typically performed using equipment such as ball mills and high-pressure roller mills. Although mechanical ball milling can increase the surface area and number of active sites in coal gangue, its adsorption capacity is still limited by the influence of organic and inorganic impurities in the gangue. It also suffers from disadvantages such as weak reducibility and a short lifespan. Therefore, to further maximize the resource utilization value of coal gangue and improve its adsorption capacity, thermal activation is necessary after mechanical activation. Thermal activation involves subjecting the gangue to a high-temperature oxidation reaction at a specific temperature using air or gas as an oxidant. The high temperature causes the particles in the gangue to undergo intense thermal motion, removing bound water from the minerals. Cations such as calcium, magnesium, and iron then reselect interstitial locations, preventing the silicon-oxygen tetrahedra and aluminum-oxygen triangular structures from fully polymerizing into long chains, resulting in a large number of free-end breakpoints. The particles can no longer arrange themselves in a regular pattern, forming a thermodynamically unstable glassy phase structure. After calcination, the gangue contains a large amount of active silicon oxide and aluminum oxide, which alters its physical and chemical properties, further increasing the material's porosity and surface activity, and improving its active surface area and reactivity. After thermal activation treatment, the organic matter and inorganic impurities in the gangue can be removed, their impact can be reduced, the porosity and specific surface area can be increased, and at the same time, the reducibility of the gangue can be enhanced and its life can be extended, so as to better play its role and provide strong support for environmental governance and utilization.

[0004] Geopolymers are a new type of high-performance inorganic polymer material, typically made from metakaolin or other silico-aluminous materials primarily composed of silicon, aluminum, and oxygen, and alkaline (or acidic) active substances. The preparation process involves adding various mixed mineral powders to the metakaolin. The mineral powders are dissolved in an alkaline solution, and then a gelling agent such as water glass is added. The dissolved aluminum-silicon complex diffuses from the surface of the solid particles into the interparticle spaces, forming a gel phase. Polymerization occurs between the silicate solution and the aluminum-silicon complex. As the gel phase gradually expels excess water, the gel solidifies and hardens into a geopolymer block, resulting in a new type of gelling material with properties similar to ceramics. These materials possess the advantages of organic polymers, ceramics, and cement, resulting in high strength, good chemical resistance, low carbon emissions, and thermal stability. They also offer advantages such as a wide range of raw material sources, simple processing, low energy consumption, and minimal environmental impact. The addition of suitable fiber materials can further enhance the performance of geopolymers. Summary of the Invention

[0005] In response to the annual increase in coal gangue stocks, the present invention aims to provide a method for preparing vitrified bond grinding wheels using coal gangue through geopolymerization. This method prepares a vitrified bond using a geopolymer gelling material prepared from coal gangue after mechanical and thermal composite activation. This method effectively utilizes the excellent properties of coal gangue and geopolymer, thereby imparting to the vitrified bond higher strength, good chemical resistance, and thermal stability.

[0006] To achieve the above object, the present invention is implemented through the following technical solutions:

[0007] The vitrified bond grinding wheel is composed of diamond abrasive, vitrified bond and temporary binder in a mass ratio of 60:15:1.

[0008] Furthermore, the ceramic binder is prepared from the following raw materials in parts by weight: 10-12 parts of coal gangue; 0.7-1.1 parts of sodium hydroxide; 2.8-3.3 parts of silicon dioxide; 0.9-1.2 parts of sodium oxide; 30-31.1 parts of deionized water; 20.4-21 parts of anhydrous ethanol; 11-12.5 parts of ethyl orthosilicate; 22-24 parts of aluminum nitrate nonahydrate; 0.4-0.5 parts of sodium nitrate; 1.41-1.68 parts of potassium nitrate; 4.1-4.5 parts of boric acid; 0.7-0.8 parts of lithium nitrate; 5.8-6.1 parts of magnesium nitrate; and 4-6 parts of nitric acid.

[0009] Furthermore, the ceramic binder is prepared from the following raw materials in parts by weight: 12 parts of coal gangue; 1 part of sodium hydroxide; 3.3 parts of silicon dioxide; 0.9 part of sodium oxide; 31.1 parts of deionized water; 21 parts of anhydrous ethanol; 12.5 parts of ethyl orthosilicate; 24 parts of aluminum nitrate nonahydrate; 0.45 parts of sodium nitrate; 1.68 parts of potassium nitrate; 4.5 parts of boric acid; 0.8 part of lithium nitrate; 6.1 parts of magnesium nitrate; and 5 parts of nitric acid.

[0010] Furthermore, the abrasive is diamond, CBN or silicon carbide, and the temporary binder is polyethylene glycol or dextrin.

[0011] A method for preparing a vitrified bond grinding wheel by geopolymerization using coal gangue comprises the following steps:

[0012] Step 1: Mechanical and thermal composite activation of coal gangue; first, the raw coal gangue is mechanically activated and placed in a planetary ball mill for ball milling. After mechanical ball milling, the kaolin particles in the coal gangue are refined; the coal gangue powder is thermally activated and calcined in a box-type high-temperature furnace to obtain activated coal gangue powder; the calcined coal gangue is sieved to obtain coal gangue powder of the desired mesh size;

[0013] Step 2: Preparation of geopolymer material; adding sodium hydroxide powder to deionized water and stirring thoroughly to dissolve to obtain a sodium hydroxide solution for later use; adding silicon dioxide powder and sodium oxide powder to deionized water, stirring and mixing uniformly to obtain a water glass suspension; adding the sodium hydroxide solution to the water glass suspension, stirring uniformly to obtain an alkali activator for coal gangue; adding the alkali activator to the sieved coal gangue, stirring uniformly to obtain a geopolymer gelling material; curing the geopolymer gelling material under a temperature and humidity environment, avoiding exposure to sunlight and maintaining ventilation;

[0014] Step 3: Preparation of a ceramic binder system; deionized water and anhydrous ethanol are uniformly mixed, ethyl orthosilicate is added to the mixed solution, and the solution is uniformly stirred with a magnetic stirrer at room temperature to prepare solution A; aluminum nitrate nonahydrate, sodium nitrate, potassium nitrate, boric acid, lithium nitrate, and magnesium nitrate are sequentially added to the mixed solution of deionized water and anhydrous ethanol, stirred uniformly, and prepared as solution B; solution A and solution B are mixed, magnetically stirred uniformly, nitric acid is added to adjust the pH, and mixed uniformly to obtain a sol; the sol is stirred under constant temperature and drying conditions until it gels, aged at room temperature, placed in a planetary ball mill, and sieved; the sieved gel powder is mixed with activated coal gangue powder, and stirred uniformly to obtain a ceramic binder;

[0015] Step 4: Preparation of diamond ceramic bond grinding wheel; diamond abrasive grains, ceramic bond and temporary binder are mixed evenly, placed in a mold and pressed into a grinding wheel shape; the pressed grinding wheel is sintered, kept warm and finally cooled to room temperature to obtain a ceramic bond grinding wheel prepared by coal gangue through geopolymerization reaction.

[0016] Furthermore, the components of the gangue in step 1 are 62% silicon dioxide, 30% aluminum oxide, 1% sodium oxide, 3% potassium oxide, 1% calcium oxide, 2% magnesium oxide, and 1% impurities, where % is the mass fraction;

[0017] Furthermore, the gangue is mechanically activated, specifically: the gangue is placed in a planetary ball mill for mechanical ball milling, the ball milling speed is 480~500r / min, and the ball milling time is 25~30min; the gangue powder is thermally activated, specifically: the gangue powder is calcined in a box-type high-temperature furnace, the heating rate is 5℃ / min, the calcination temperature is 750~850℃, and the calcination time is 2~2.5h; the sieving mesh size is 250 mesh.

[0018] Furthermore, the concentration of the sodium hydroxide solution obtained in step 2 is 8-10 mol / L; the geopolymer cementitious material is cured, specifically: cured at a temperature of 25-30° C. and a humidity of 65-75% for 24-36 hours.

[0019] Furthermore, in step 3, the speed of magnetic stirring is 300-350 r / min, and the temperature is room temperature; nitric acid is added to adjust the pH range to 3-5, the temperature of the sol constant temperature drying is 70-90°C, the time is 24-36 hours, and the aging time is 18-24 hours; the speed of the sol ball milling is 450-500 r / min, the time is 20-25 minutes, and the mesh size of the sieve is 250 mesh;

[0020] Furthermore, in step 4, the pressure for pressing into the grinding wheel shape is 15-25 MPa; the sintering temperature is 600-650° C., the heating rate is 5° C. / min, and the holding time is 2 h.

[0021] Furthermore, the weight proportions of the components in the ceramic binder are: 10-12 parts of coal gangue; 0.7-1.1 parts of sodium hydroxide; 2.8-3.3 parts of silicon dioxide; 0.9-1.2 parts of sodium oxide; 30-31.1 parts of deionized water; 20.4-21 parts of anhydrous ethanol; 11-12.5 parts of ethyl orthosilicate; 22-24 parts of aluminum nitrate nonahydrate; 0.4-0.5 parts of sodium nitrate; 1.41-1.68 parts of potassium nitrate; 4.1-4.5 parts of boric acid; 0.7-0.8 parts of lithium nitrate; 5.8-6.1 parts of magnesium nitrate; and 4-6 parts of nitric acid, wherein the coal gangue is activated coal gangue.

[0022] Furthermore, the weight proportions of the components in the ceramic binder are: 12 parts of coal gangue; 1 part of sodium hydroxide; 3.3 parts of silicon dioxide; 0.9 part of sodium oxide; 31.1 parts of deionized water; 21 parts of anhydrous ethanol; 12.5 parts of ethyl orthosilicate; 24 parts of aluminum nitrate nonahydrate; 0.45 parts of sodium nitrate; 1.68 parts of potassium nitrate; 4.5 parts of boric acid; 0.8 part of lithium nitrate; 6.1 parts of magnesium nitrate; and 5 parts of nitric acid.

[0023] Furthermore, in step 4, the mass ratio of diamond abrasive, vitrified bond, and temporary binder is 60:15:1, the diamond abrasive is diamond, CBN, or silicon carbide, and the particle size is w0.5~w20; the temporary binder is polyethylene glycol or dextrin.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] 1) In the present invention, the concentration of sodium hydroxide in the alkaline activator for preparing geopolymer is in the range of 8~10 mol / L. Within the range, the strength and hardness of the grinding wheel increase with the increase of the sodium hydroxide concentration. If the concentration is too low, the geopolymerization reaction cannot be fully carried out. If the concentration is too high, sodium hydroxide will react with carbon dioxide in the air to form carbonate, resulting in a decrease in strength. The molar mass ratio of silicon dioxide to sodium oxide in the alkaline activator is 2.8~3.2:1. If the ratio is too high, the speed of the geopolymerization reaction and the viscosity of the geopolymer will be reduced, and the time of the geopolymerization reaction will be increased. If the ratio is too low, sodium metasilicate crystals will be precipitated, reducing the strength of the grinding wheel. 2) The proportion of metal salt ions is 3~5 mol%. If the proportion is too large, the bending strength of the grinding wheel will be reduced. The strength of the grinding wheel is guaranteed within the range. The strength and wear resistance of the grinding wheel are guaranteed, and the frequency of grinding wheel dressing is reduced. The hardness grade reaches M grade or above, the bending strength reaches 75~95MPA, and the tensile strength is 170~198 , volume density 1.5~2.5 3) The present invention prepares a ceramic bond grinding wheel through geopolymerization, using coal gangue as the main raw material. The production and stock of coal gangue are huge. The present invention can effectively reduce the impact of coal gangue on the environment and save costs to a certain extent. The sintering temperature is reduced to 600-650℃, saving 20-30% of energy and resources. The grinding wheel has uniform pore distribution, long service life and excellent grinding performance. DETAILED DESCRIPTION

[0026] To facilitate understanding of the present invention, the present invention will be described more fully below. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive.

[0027] Example 1

[0028] A vitrified bond grinding wheel prepared by geopolymerization using coal gangue comprises an abrasive, a vitrified bond, and a temporary binder in a mass ratio of 60:15:1, wherein the abrasive is diamond with a particle size of w1; the temporary binder is dextrin, and the vitrified bond is prepared from the following raw materials in parts by weight: 10 parts of coal gangue, 0.7 parts of sodium hydroxide, 3 parts of silicon dioxide, 0.9 parts of sodium oxide, 30.2 parts of deionized water, 20.5 parts of anhydrous ethanol, 11 parts of ethyl orthosilicate, 22 parts of aluminum nitrate nonahydrate, 0.4 parts of sodium nitrate, 1.45 parts of potassium nitrate, 4.2 parts of boric acid, 0.75 parts of lithium nitrate, 5.8 parts of magnesium nitrate, and 5 parts of nitric acid.

[0029] A method for preparing a vitrified bond grinding wheel using coal gangue through geopolymerization in this embodiment includes the following steps:

[0030] Step 1: The composition of the gangue is measured to be 62% silicon dioxide, 30% aluminum oxide, 1% sodium oxide, 3% potassium oxide, 1% calcium oxide, 2% magnesium oxide, and 1% impurities.

[0031] Step 2: Mechanical-thermal composite activation of coal gangue: Place the coal gangue raw stone into a planetary ball mill for ball milling at a ball milling speed of 500r / min and a ball milling time of 30min; thermally activate the coal gangue powder after mechanical ball milling and place it into a box-type high-temperature furnace for calcination at a box-type high-temperature furnace heating rate of 5℃ / min, a thermal activation temperature of 750℃, and an activation time of 2h; sieve the calcined coal gangue with a sieve mesh size of 250 mesh, and take 10 parts of the sieved coal gangue;

[0032] Step 3: Preparation of geopolymer material: Take 0.7 parts of sodium hydroxide, 3 parts of silicon dioxide, 0.9 parts of sodium oxide, 2.1 parts of deionized water A, and 6.8 parts of deionized water B; add sodium hydroxide powder to deionized water A and stir and dissolve thoroughly to obtain 8 mol / L sodium hydroxide solution for standby use; add silicon dioxide powder and sodium oxide powder to deionized water B, stir and mix evenly to obtain a water glass suspension; add sodium hydroxide solution to the water glass suspension, stir and mix evenly to obtain an alkali activator for coal gangue; add the alkali activator to the sieved coal gangue, stir and mix evenly to obtain a geopolymer material; and cure the geopolymer material at a temperature of 25°C and a humidity of 70% for 24 hours;

[0033] Step 4: Preparation of ceramic binder system: take 11 parts of tetraethyl orthosilicate, 4.8 parts of deionized water, and 3.6 parts of anhydrous ethanol; in solution B, 22 parts of aluminum nitrate nonahydrate, 0.4 parts of sodium nitrate, 1.45 parts of potassium nitrate, 4.2 parts of boric acid, 0.75 parts of lithium nitrate, 5.8 parts of magnesium nitrate, 16.5 parts of deionized water, 16.9 parts of anhydrous ethanol, and 5 parts of nitric acid at a concentration of 6 mol / L; mix the deionized water and anhydrous ethanol evenly, add tetraethyl orthosilicate to the mixed solution, stir evenly with a magnetic stirrer at room temperature at a speed of 350 r / min, and use it as solution A for later use; add aluminum nitrate nonahydrate, sodium nitrate, and potassium nitrate; , boric acid, lithium nitrate, and magnesium nitrate are sequentially added to a mixed solution of deionized water and anhydrous ethanol, and ultrasonically stirred to be uniform, and the solution is set aside as solution B; solution A is mixed with solution B, stirred uniformly, and nitric acid is added to adjust the pH to 4, and the mixture is mixed uniformly to obtain a sol; the sol is stirred under constant temperature and drying conditions until it gels, and aged at room temperature, the drying temperature is 80°C, the drying time is 24h, the aging time is 24h, and after aging, it is put into a planetary ball mill for ball milling, the ball milling speed is 500r / min, the time is 25min, and the sieving is performed, and the sieving mesh size is 250 mesh; the sieved powder is mixed with activated coal gangue powder, and stirred uniformly to obtain a ceramic binder;

[0034] Step 5: Preparation of a vitrified bond grinding wheel: diamond abrasive with a particle size of w1 was taken, and diamond abrasive grains, a vitrified bond, and a temporary binder were uniformly mixed in a mass ratio of 60:15:1, pressed into shape, and pressed into shape at a pressure of 25 MPa. The mixture was placed in a high-temperature sintering furnace and sintered at a heating rate of 5°C / min, a sintering temperature of 600°C, and a holding time of 2 h. Finally, the mixture was cooled to room temperature to obtain a diamond vitrified bond grinding wheel.

[0035] The geopolymer material vitrified bond grinding wheel prepared in this embodiment has a hardness grade of N or above, a bending strength of 78 MPA, and a tensile strength of 172 The grinding wheel pores are evenly distributed, the grinding wheel density is uniform, and the volume density is 1.6 .

[0036] Example 2

[0037] A vitrified bond grinding wheel prepared by geopolymerization using coal gangue comprises an abrasive, a vitrified bond, and a temporary binder in a mass ratio of 60:15:1, wherein the abrasive is CBN with a particle size of w1; the temporary binder is polyethylene glycol, and the vitrified bond is prepared from the following raw materials in parts by weight: 10 parts of coal gangue, 0.9 parts of sodium hydroxide, 3 parts of silicon dioxide, 0.9 parts of sodium oxide, 30.2 parts of deionized water, 20.5 parts of anhydrous ethanol, 11.2 parts of tetraethyl orthosilicate, 24 parts of aluminum nitrate nonahydrate, 0.4 parts of sodium nitrate, 1.45 parts of potassium nitrate, 4.2 parts of boric acid, 0.7 parts of lithium nitrate, 5.8 parts of magnesium nitrate, and 4 parts of nitric acid.

[0038] A method for preparing a vitrified bond grinding wheel using coal gangue through geopolymerization in this embodiment includes the following steps:

[0039] Step 1: It is measured that the proportion of each component in the coal gangue is 62% silicon dioxide, 30% aluminum oxide, 1% sodium oxide, 3% potassium oxide, 1% calcium oxide, 2% magnesium oxide, and 1% impurities.

[0040] Step 2, mechanical-thermal composite activation of coal gangue: the coal gangue raw stone is placed in a planetary ball mill for ball milling at a ball milling speed of 500 r / min and a ball milling time of 30 min; the coal gangue powder after mechanical ball milling is thermally activated and placed in a box-type high-temperature furnace for calcination at a box-type high-temperature furnace heating rate of 5°C / min, a thermal activation temperature of 750°C, and an activation time of 2 h; the calcined coal gangue is sieved to a mesh size of 250 mesh, and 10 parts of the sieved coal gangue are taken;

[0041] Step 3, preparation of geopolymer material: take 0.9 parts of sodium hydroxide, 3 parts of silicon dioxide, 0.9 parts of sodium oxide, 2.1 parts of deionized water A, and 6.8 parts of deionized water B; add sodium hydroxide powder to deionized water A and stir and dissolve thoroughly to obtain a 10 mol / L sodium hydroxide solution for standby use; add silicon dioxide powder and sodium oxide powder to deionized water B, stir and mix uniformly to obtain a water glass suspension; add sodium hydroxide solution to the water glass suspension, stir and mix uniformly to obtain an alkali activator for coal gangue; add the alkali activator to the sieved coal gangue, stir and mix uniformly to obtain a geopolymer material; and cure the geopolymer material at a temperature of 25°C and a humidity of 70% for 24 hours;

[0042] Step 4, preparation of ceramic binder system: take 11.2 parts of tetraethyl orthosilicate, 4.8 parts of deionized water, and 3.6 parts of anhydrous ethanol; in solution B, 24 parts of aluminum nitrate nonahydrate, 0.4 parts of sodium nitrate, 1.45 parts of potassium nitrate, 4.2 parts of boric acid, 0.7 parts of lithium nitrate, 5.8 parts of magnesium nitrate, 16.5 parts of deionized water, 16.9 parts of anhydrous ethanol, and 4 parts of nitric acid at a concentration of 6 mol / L; mix the deionized water and anhydrous ethanol evenly, add tetraethyl orthosilicate to the mixed solution, stir evenly with a magnetic stirrer at room temperature at a speed of 350 r / min, and use it as solution A for later use; add aluminum nitrate nonahydrate, sodium nitrate, and potassium nitrate; , boric acid, lithium nitrate, and magnesium nitrate are sequentially added to a mixed solution of deionized water and anhydrous ethanol, and ultrasonically stirred to be uniform, and the solution is set aside as solution B; solution A is mixed with solution B, stirred uniformly, and nitric acid is added to adjust the pH to 5, and the mixture is mixed uniformly to obtain a sol; the sol is stirred under constant temperature drying conditions until it gels, and aged at room temperature, with a drying temperature of 70°C, a drying time of 24h, and an aging time of 18h. After aging, the sol is milled in a planetary ball mill at a ball milling speed of 500r / min for 25min, and sieved to a mesh size of 250; the sieved powder is mixed with activated coal gangue powder, and stirred uniformly to obtain a ceramic binder;

[0043] Step 5, preparation of a vitrified bond grinding wheel: taking CBN abrasive with a particle size of w0.5, mixing the CBN abrasive, vitrified bond, and temporary binder in a mass ratio of 60:15:1, pressing into a shape, pressing into a shape at a pressure of 25 MPa, placing the shape into a high-temperature sintering furnace, sintering at a heating rate of 5°C / min, a sintering temperature of 600°C, holding time of 2 h, and finally cooling to room temperature to obtain a diamond vitrified bond grinding wheel;

[0044] The geopolymer material vitrified bond grinding wheel prepared in this embodiment has a hardness grade of N or above, a bending strength of 83 MPa, and a tensile strength of 178.6 The grinding wheel pores are evenly distributed, the grinding wheel density is uniform, and the volume density is 1.73 .

[0045] Example 3

[0046] A vitrified bond grinding wheel prepared by geopolymerization using coal gangue comprises an abrasive, a vitrified bond, and a temporary binder in a mass ratio of 60:15:1, wherein the abrasive is silicon carbide with a particle size of w1; the temporary binder is dextrin, and the vitrified bond is prepared from the following raw materials in parts by weight: 10 parts of coal gangue, 1 part of sodium hydroxide, 3 parts of silicon dioxide, 0.9 part of sodium oxide, 30.1 parts of deionized water, 20.5 parts of anhydrous ethanol, 11.5 parts of ethyl orthosilicate, 22.5 parts of aluminum nitrate nonahydrate, 0.4 part of sodium nitrate, 1.45 parts of potassium nitrate, 4.3 parts of boric acid, 0.75 part of lithium nitrate, 5.85 parts of magnesium nitrate, and 6 parts of nitric acid.

[0047] Step 1: It is measured that the proportion of each component in the coal gangue is 62% silicon dioxide, 30% aluminum oxide, 1% sodium oxide, 3% potassium oxide, 1% calcium oxide, 2% magnesium oxide, and 1% impurities.

[0048] Step 2, mechanical-thermal composite activation of coal gangue: the coal gangue raw stone is placed in a planetary ball mill for ball milling at a ball milling speed of 500 r / min and a ball milling time of 25 min; the coal gangue powder after mechanical ball milling is thermally activated and placed in a box-type high-temperature furnace for calcination at a box-type high-temperature furnace heating rate of 5°C / min, a thermal activation temperature of 850°C, and an activation time of 2 h; the calcined coal gangue is sieved to a mesh size of 250 mesh, and 10 parts of the sieved coal gangue are taken;

[0049] Step 3, preparation of geopolymer material: take 1 part of sodium hydroxide, 3 parts of silicon dioxide, 0.9 parts of sodium oxide, 1.9 parts of deionized water A, and 6.8 parts of deionized water B; add sodium hydroxide powder to deionized water A and stir and dissolve thoroughly to obtain a 10 mol / L sodium hydroxide solution for standby use; add silicon dioxide powder and sodium oxide powder to deionized water B, stir and mix evenly to obtain a water glass suspension; add sodium hydroxide solution to the water glass suspension, stir and mix evenly to obtain an alkali activator for coal gangue; add the alkali activator to the sieved coal gangue, stir and mix evenly to obtain a geopolymer material; and cure the geopolymer material at a temperature of 25°C and a humidity of 65% for 24 hours;

[0050] Step 4, preparation of ceramic binder system: take 11.5 parts of tetraethyl orthosilicate, 4.9 parts of deionized water, and 3.7 parts of anhydrous ethanol; in solution B, 22.5 parts of aluminum nitrate nonahydrate, 0.4 parts of sodium nitrate, 1.45 parts of potassium nitrate, 4.3 parts of boric acid, 0.75 parts of lithium nitrate, 5.85 parts of magnesium nitrate, 16.5 parts of deionized water, 16.8 parts of anhydrous ethanol, and 6 parts of nitric acid at a concentration of 6 mol / L; mix the deionized water and anhydrous ethanol evenly, add tetraethyl orthosilicate to the mixed solution, stir evenly with a magnetic stirrer at room temperature at a speed of 350 r / min, and use it as solution A for later use; add aluminum nitrate nonahydrate, sodium nitrate, Potassium nitrate, boric acid, lithium nitrate, and magnesium nitrate are sequentially added to a mixed solution of deionized water and anhydrous ethanol, and ultrasonically stirred to be uniform, and the solution is set aside as solution B; solution A and solution B are mixed, stirred uniformly, and nitric acid is added to adjust the pH to 3, and mixed uniformly to obtain a sol; the sol is stirred under constant temperature drying conditions until it gels, and aged at room temperature, with a drying temperature of 80° C., a drying time of 24 h, and an aging time of 18 h. After aging, the sol is milled in a planetary ball mill at a ball milling speed of 500 r / min for 25 min, and sieved to a mesh size of 250; the sieved powder is mixed with activated coal gangue powder and uniformly stirred to obtain a ceramic binder;

[0051] Step 5, preparation of a vitrified bond grinding wheel: taking silicon carbide abrasive with a particle size of w1, mixing silicon carbide abrasive, vitrified bond, and temporary binder in a mass ratio of 60:15:1, pressing into shape, pressing into shape at a pressure of 25 MPa, placing the mixture in a high-temperature sintering furnace, heating at a rate of 5°C / min, sintering at a temperature of 650°C, holding for 2 h, holding at a temperature of 650°C, and finally cooling to room temperature to obtain a diamond vitrified bond grinding wheel;

[0052] The geopolymer material vitrified bond grinding wheel prepared in this embodiment has a hardness grade of N or above, a bending strength of 85.6 MPA, and a tensile strength of 182.3 The grinding wheel pores are evenly distributed, the grinding wheel density is uniform, and the volume density is 1.82 .

[0053] Example 4

[0054] A vitrified bond grinding wheel prepared by geopolymerization using coal gangue comprises an abrasive, a vitrified bond, and a temporary binder in a mass ratio of 60:15:1, wherein the abrasive is diamond with a particle size of w1; the temporary binder is dextrin, and the vitrified bond is prepared from the following raw materials in parts by weight: 12 parts of coal gangue, 0.9 parts of sodium hydroxide, 2.8 parts of silicon dioxide, 0.9 parts of sodium oxide, 30.8 parts of deionized water, 20.8 parts of anhydrous ethanol, 11 parts of ethyl orthosilicate, 22.9 parts of aluminum nitrate nonahydrate, 0.48 parts of sodium nitrate, 1.62 parts of potassium nitrate, 4.1 parts of boric acid, 0.75 parts of lithium nitrate, 5.95 parts of magnesium nitrate, and 4.2 parts of nitric acid.

[0055] Step 1: It is measured that the proportion of each component in the coal gangue is 62% silicon dioxide, 30% aluminum oxide, 1% sodium oxide, 3% potassium oxide, 1% calcium oxide, 2% magnesium oxide, and 1% impurities.

[0056] Step 2, mechanical-thermal composite activation of coal gangue: the coal gangue raw stone is placed in a planetary ball mill for ball milling at a ball milling speed of 500 r / min and a ball milling time of 30 min; the coal gangue powder after mechanical ball milling is thermally activated and placed in a box-type high-temperature furnace for calcination at a box-type high-temperature furnace heating rate of 5°C / min, a thermal activation temperature of 800°C, and an activation time of 2.5 h; the calcined coal gangue is sieved to a mesh size of 250 mesh, and 12 parts of the sieved coal gangue are taken;

[0057] Step 3, preparation of geopolymer material: take 0.9 parts of sodium hydroxide, 2.8 parts of silicon dioxide, 0.9 parts of sodium oxide, 2.1 parts of deionized water A, and 6.9 parts of deionized water B; add sodium hydroxide powder to deionized water A and stir and dissolve thoroughly to obtain a 10 mol / L sodium hydroxide solution for standby use; add silicon dioxide powder and sodium oxide powder to deionized water B, stir and mix uniformly to obtain a water glass suspension; add the sodium hydroxide solution to the water glass suspension, stir and mix uniformly to obtain an alkali activator for coal gangue; add the alkali activator to the sieved coal gangue, stir and mix uniformly to obtain a geopolymer material; and cure the geopolymer material at a temperature of 25°C and a humidity of 65% for 24 hours;

[0058] Step 4, preparation of ceramic binder system: take 11 parts of tetraethyl orthosilicate, 4.8 parts of deionized water, and 3.6 parts of anhydrous ethanol; in solution B, 22.9 parts of aluminum nitrate nonahydrate, 0.48 parts of sodium nitrate, 1.62 parts of potassium nitrate, 4.1 parts of boric acid, 0.75 parts of lithium nitrate, 5.95 parts of magnesium nitrate, 17 parts of deionized water, 17.2 parts of anhydrous ethanol, and 4.2 parts of nitric acid at a concentration of 6 mol / L; mix the deionized water and anhydrous ethanol evenly, add tetraethyl orthosilicate to the mixed solution, stir evenly with a magnetic stirrer at room temperature at a speed of 350 r / min, and use it as solution A for later use; add aluminum nitrate nonahydrate, sodium nitrate, and nitric acid; Potassium, boric acid, lithium nitrate, and magnesium nitrate are sequentially added to a mixed solution of deionized water and anhydrous ethanol, and ultrasonically stirred to obtain a solution B. Solution A and solution B are mixed and stirred to obtain a solution B. After the solution A and solution B are mixed and stirred to obtain a solution B, nitric acid is added to adjust the pH to 5, and the solution is mixed to obtain a sol. The sol is stirred under a constant temperature drying condition until it gels, and aged at room temperature. The drying temperature is 80°C, the drying time is 24 hours, and the aging time is 24 hours. After aging, the solution is milled in a planetary ball mill at a speed of 500 r / min for 25 minutes, and sieved to obtain a sieve size of 250 mesh. The sieved powder is mixed with activated coal gangue powder and stirred to obtain a ceramic binder.

[0059] Step 5, preparation of a vitrified bond grinding wheel: taking diamond abrasive grain size w1, mixing diamond abrasive grains, vitrified bond and temporary binder in a mass ratio of 60:15:1, pressing into shape, pressing into shape at a pressure of 25 MPa, placing the mixture in a high-temperature sintering furnace, sintering at a heating rate of 5°C / min, a sintering temperature of 650°C, a holding time of 2 h, a holding temperature of 650°C, and finally cooling to room temperature to obtain a diamond vitrified bond grinding wheel;

[0060] The geopolymer gelled vitrified bond grinding wheel prepared in this embodiment has a hardness grade of M or above, a bending strength of 87.2 MPA, and a tensile strength of 188.6 The grinding wheel pores are evenly distributed, the grinding wheel density is uniform, and the volume density is 2.12 .

[0061] Example 5

[0062] A vitrified bond grinding wheel prepared by geopolymerization using coal gangue comprises an abrasive, a vitrified bond and a temporary binder in a mass ratio of 60:15:1, wherein the abrasive is diamond with a particle size of w1; the temporary binder is dextrin, and the vitrified bond is prepared from the following raw materials in parts by weight: 12 parts of coal gangue, 0.9 parts of sodium hydroxide, 2.8 parts of silicon dioxide, 0.9 parts of sodium oxide, 31 parts of deionized water, 20.8 parts of anhydrous ethanol, 11.5 parts of ethyl orthosilicate, 23.2 parts of aluminum nitrate nonahydrate, 0.49 parts of sodium nitrate, 1.65 parts of potassium nitrate, 4.3 parts of boric acid, 0.78 parts of lithium nitrate, 5.9 parts of magnesium nitrate and 4 parts of nitric acid.

[0063] Step 1: It is measured that the proportion of each component in the coal gangue is 62% silicon dioxide, 30% aluminum oxide, 1% sodium oxide, 3% potassium oxide, 1% calcium oxide, 2% magnesium oxide, and 1% impurities.

[0064] Step 2, mechanical-thermal composite activation of coal gangue: the coal gangue raw stone is placed in a planetary ball mill for ball milling at a ball milling speed of 500 r / min and a ball milling time of 30 min; the coal gangue powder after mechanical ball milling is thermally activated and placed in a box-type high-temperature furnace for calcination at a box-type high-temperature furnace heating rate of 5°C / min, a thermal activation temperature of 800°C, and an activation time of 2.5 h; the calcined coal gangue is sieved to a mesh size of 250 mesh, and 12 parts of the sieved coal gangue are taken;

[0065] Step 3, preparation of geopolymer material: take 0.9 parts of sodium hydroxide, 2.8 parts of silicon dioxide, 0.9 parts of sodium oxide, 2.1 parts of deionized water A, and 6.9 parts of deionized water B; add sodium hydroxide powder to deionized water A and stir and dissolve thoroughly to obtain a 10 mol / L sodium hydroxide solution for standby use; add silicon dioxide powder and sodium oxide powder to deionized water B, stir and mix uniformly to obtain a water glass suspension; add the sodium hydroxide solution to the water glass suspension, stir and mix uniformly to obtain an alkali activator for coal gangue; add the alkali activator to the sieved coal gangue, stir and mix uniformly to obtain a geopolymer material; and cure the geopolymer material at a temperature of 25°C and a humidity of 65% for 24 hours;

[0066] Step 4, preparation of ceramic binder system: take 11.5 parts of tetraethyl orthosilicate, 5.0 parts of deionized water, and 4 parts of anhydrous ethanol; in solution B, 23.2 parts of aluminum nitrate nonahydrate, 0.49 parts of sodium nitrate, 1.65 parts of potassium nitrate, 4.3 parts of boric acid, 0.78 parts of lithium nitrate, 5.9 parts of magnesium nitrate, 17 parts of deionized water, 16.8 parts of anhydrous ethanol, and 4 parts of nitric acid at a concentration of 6 mol / L; mix the deionized water and anhydrous ethanol evenly, add tetraethyl orthosilicate to the mixed solution, stir evenly with a magnetic stirrer at room temperature at a speed of 350 r / min, and use it as solution A for standby; add aluminum nitrate nonahydrate, sodium nitrate, potassium nitrate, Boric acid, lithium nitrate, and magnesium nitrate are sequentially added to a mixed solution of deionized water and anhydrous ethanol, and ultrasonically stirred to obtain a solution B. Solution A and solution B are mixed and stirred to obtain a solution B. After the solution A and solution B are mixed and stirred to obtain a solution B, nitric acid is added to adjust the pH to 5, and the solution is mixed to obtain a sol. The sol is stirred under a constant temperature drying condition until it gels, and aged at room temperature. The drying temperature is 90° C., the drying time is 36 hours, and the aging time is 24 hours. After aging, the sol is milled in a planetary ball mill at a speed of 500 r / min for 25 minutes, and sieved to obtain a sieve size of 250 mesh. The sieved powder is mixed with activated coal gangue powder and stirred to obtain a ceramic binder.

[0067] Step 5, preparation of a vitrified bond grinding wheel: taking diamond abrasive grain size w1, mixing diamond abrasive grains, vitrified bond and temporary binder in a mass ratio of 60:15:1, pressing into shape, pressing into shape at a pressure of 25 MPa, placing the mixture in a high-temperature sintering furnace, heating at a rate of 5°C / min, sintering at a temperature of 625°C, holding for 2 h, holding at a temperature of 625°C, and finally cooling to room temperature to obtain a diamond vitrified bond grinding wheel;

[0068] The geopolymer material vitrified bond grinding wheel prepared in this embodiment has a hardness grade of M or above, a bending strength of 90 MPA, and a tensile strength of 193 The grinding wheel pores are evenly distributed, the grinding wheel density is uniform, and the volume density is 2.3 .

[0069] Example 6

[0070] A vitrified bond grinding wheel prepared by geopolymerization using coal gangue comprises an abrasive, a vitrified bond, and a temporary binder in a mass ratio of 60:15:1, wherein the abrasive is diamond with a particle size of w1; the temporary binder is dextrin; and the vitrified bond is prepared from the following raw materials in parts by weight: 12 parts of coal gangue; 1 part of sodium hydroxide; 3.3 parts of silicon dioxide; 0.9 part of sodium oxide; 31.1 parts of deionized water; 21 parts of anhydrous ethanol; 12.5 parts of ethyl orthosilicate; 24 parts of aluminum nitrate nonahydrate; 0.45 parts of sodium nitrate; 1.68 parts of potassium nitrate; 4.5 parts of boric acid; 0.8 part of lithium nitrate; 6.1 parts of magnesium nitrate; and 5 parts of nitric acid.

[0071] Step 1: It is measured that the proportion of each component in the coal gangue is 62% silicon dioxide, 30% aluminum oxide, 1% sodium oxide, 3% potassium oxide, 1% calcium oxide, 2% magnesium oxide, and 1% impurities.

[0072] Step 2, mechanical-thermal composite activation of coal gangue: the coal gangue raw stone is placed in a planetary ball mill for ball milling at a ball milling speed of 500 r / min and a ball milling time of 30 min; the coal gangue powder after mechanical ball milling is thermally activated and placed in a box-type high-temperature furnace for calcination at a box-type high-temperature furnace heating rate of 5°C / min, a thermal activation temperature of 800°C, and an activation time of 2.5 h; the calcined coal gangue is sieved to a mesh size of 250 mesh, and 12 parts of the sieved coal gangue are taken;

[0073] Step 3, preparation of geopolymer material: take 1 part of sodium hydroxide, 3.3 parts of silicon dioxide, 0.9 parts of sodium oxide, 2.1 parts of deionized water A, and 6.9 parts of deionized water B; add sodium hydroxide powder to deionized water A and stir and dissolve thoroughly to obtain a 10 mol / L sodium hydroxide solution for standby use; add silicon dioxide powder and sodium oxide powder to deionized water B, stir and mix uniformly to obtain a water glass suspension; add sodium hydroxide solution to the water glass suspension, stir and mix uniformly to obtain an alkali activator for coal gangue; add the alkali activator to the sieved coal gangue, stir and mix uniformly to obtain a geopolymer material; and cure the geopolymer material at a temperature of 25°C and a humidity of 65% for 24 hours;

[0074] Step 4, preparation of ceramic binder system: take 12.5 parts of tetraethyl orthosilicate, 5.0 parts of deionized water, and 4 parts of anhydrous ethanol; in solution B, 24 parts of aluminum nitrate nonahydrate, 0.45 parts of sodium nitrate, 1.68 parts of potassium nitrate, 4.5 parts of boric acid, 0.8 parts of lithium nitrate, 6.1 parts of magnesium nitrate, 17.1 parts of deionized water, 17 parts of anhydrous ethanol, and 5 parts of nitric acid at a concentration of 6 mol / L; mix the deionized water and anhydrous ethanol evenly, add tetraethyl orthosilicate to the mixed solution, stir evenly with a magnetic stirrer at room temperature at a speed of 350 r / min, and use it as solution A for later use; add aluminum nitrate nonahydrate, sodium nitrate, potassium nitrate, boric acid, and 17.1 parts of deionized water, and add 17 parts of anhydrous ethanol to the mixed solution; mix the deionized water and anhydrous ethanol evenly, add tetraethyl orthosilicate to the mixed solution, stir evenly with a magnetic stirrer at room temperature at a speed of 350 r / min, and use it as solution A for later use; mix aluminum nitrate nonahydrate, sodium nitrate, potassium nitrate, and boric acid; Acid, lithium nitrate, and magnesium nitrate are sequentially added to a mixed solution of deionized water and anhydrous ethanol, and ultrasonically stirred to be uniform, and the solution is set aside as solution B; solution A and solution B are mixed, stirred uniformly, and nitric acid is added to adjust the pH to 4, and mixed uniformly to obtain a sol; the sol is stirred under constant temperature drying conditions until it gels, and aged at room temperature, the drying temperature is 90°C, the drying time is 36 hours, and the aging time is 24 hours. After aging, the sol is placed in a planetary ball mill, the ball milling speed is 500 r / min, the time is 25 minutes, and the sieving is performed, and the sieving mesh size is 250 mesh; the sieved powder is mixed with activated coal gangue powder, and stirred uniformly to obtain a ceramic binder;

[0075] Step 5, preparation of a vitrified bond grinding wheel: taking diamond abrasive grain size w1, mixing diamond abrasive grains, vitrified bond and temporary binder in a mass ratio of 60:15:1, pressing into shape, pressing into shape at a pressure of 25 MPa, placing the mixture in a high-temperature sintering furnace, heating at a rate of 5°C / min, sintering at a temperature of 625°C, holding for 2 h, holding at a temperature of 625°C, and finally cooling to room temperature to obtain a diamond vitrified bond grinding wheel;

[0076] The geopolymer material vitrified bond grinding wheel prepared in this embodiment has a hardness grade of M or above, a bending strength of 95 MPA, and a tensile strength of 198 The grinding wheel pores are evenly distributed, the grinding wheel density is uniform, and the volume density is 2.5 .

[0077] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

Claims

1. A vitrified bond grinding wheel prepared by geopolymerization of coal gangue, characterized in that: The vitrified bond grinding wheel comprises abrasive, vitrified bond and temporary binder, wherein the mass ratio of the abrasive, vitrified bond and temporary binder is 60:15:1; The ceramic binder is prepared from the following raw materials in parts by weight: 10-12 parts of coal gangue; 0.7-1.1 parts of sodium hydroxide; 2.8-3.3 parts of silicon dioxide; 0.9-1.2 parts of sodium oxide; 30-31.1 parts of deionized water; 20.4-21 parts of anhydrous ethanol; 11-12.5 parts of ethyl orthosilicate; 22-24 parts of aluminum nitrate nonahydrate; 0.4-0.5 parts of sodium nitrate; 1.41-1.68 parts of potassium nitrate; 4.1-4.5 parts of boric acid; 0.7-0.8 parts of lithium nitrate; 5.8-6.1 parts of magnesium nitrate; and 4-6 parts of nitric acid. The abrasive is diamond, CBN or silicon carbide, and the temporary binder is polyethylene glycol or dextrin; The gangue is subjected to mechanical-thermal composite activation: the raw gangue is placed in a planetary ball mill for ball milling at a speed of 500 r / min and a milling time of 25 min; the gangue powder subjected to mechanical ball milling is thermally activated and placed in a box-type high-temperature furnace for calcination at a heating speed of 5°C / min, a thermal activation temperature of 850°C, and an activation time of 2 h; the calcined gangue is sieved with a sieve mesh size of 250 meshes.

2. The vitrified bond grinding wheel prepared by geopolymerization of coal gangue according to claim 1, characterized in that: The ceramic binder is prepared from the following raw materials in parts by weight: 12 parts of coal gangue; 1 part of sodium hydroxide; 3.3 parts of silicon dioxide; 0.9 part of sodium oxide; 31.1 parts of deionized water; 21 parts of anhydrous ethanol; 12.5 parts of ethyl orthosilicate; 24 parts of aluminum nitrate nonahydrate; 0.45 parts of sodium nitrate; 1.68 parts of potassium nitrate; 4.5 parts of boric acid; 0.8 part of lithium nitrate; 6.1 parts of magnesium nitrate; and 5 parts of nitric acid.

3. A method for preparing a vitrified bond grinding wheel by geopolymerization using coal gangue, characterized in that: The following steps are involved: Step 1: Mechanical-thermal composite activation of coal gangue; mechanically activating the coal gangue to obtain coal gangue powder, thermally activating the coal gangue powder to obtain active coal gangue powder, and then sieving to obtain coal gangue powder of the desired mesh size; The gangue is mechanically activated, specifically: the gangue is placed in a planetary ball mill for mechanical ball milling, the ball milling speed is 480-500 r / min, and the ball milling time is 25-30 min; The gangue powder is thermally activated, specifically: the gangue powder is calcined in a box-type high-temperature furnace at a heating rate of 5°C / min, a calcination temperature of 750-850°C, and a calcination time of 2-2.5h; Step 2: Preparation of geopolymer material: adding sodium hydroxide powder to deionized water and stirring thoroughly to dissolve to obtain a sodium hydroxide solution; adding silicon dioxide powder and sodium oxide powder to deionized water and stirring to mix uniformly to obtain a water glass suspension; adding the sodium hydroxide solution to the water glass suspension and stirring to obtain an alkali activator for coal gangue; adding the alkali activator to the sieved coal gangue powder and stirring to obtain a geopolymer gelling material; curing the geopolymer gelling material; The concentration of the obtained sodium hydroxide solution is 8~10mol / L; Curing the geopolymer cementitious material, specifically: curing at a temperature of 25-30°C and a humidity of 65-75% for 24-36 hours; Step 3: Preparation of a ceramic binder system; deionized water and anhydrous ethanol are uniformly mixed, and tetraethyl orthosilicate is added to the mixed solution, and magnetic stirring is performed to obtain solution A; aluminum nitrate nonahydrate, sodium nitrate, potassium nitrate, boric acid, lithium nitrate, and magnesium nitrate are sequentially added to the mixed solution of deionized water and anhydrous ethanol, and stirred to obtain solution B; solution A and solution B are mixed, stirred to obtain a pH value, and mixed to obtain a sol; the sol is stirred under constant temperature and drying conditions until it gels, aged at room temperature, ball-milled, and sieved; the sieved gel powder is mixed with the geopolymer gelling material cured in step 2, and stirred to obtain a ceramic binder; Nitric acid is added to adjust the pH range to 3-5, and the sol is dried at a constant temperature of 70-90°C for 24-36 hours; Step 4: Preparation of a vitrified bond grinding wheel; diamond abrasive, vitrified bond, and temporary binder are uniformly mixed, placed in a mold, and pressed into a grinding wheel shape; the pressed grinding wheel is sintered, and finally cooled to room temperature to obtain the vitrified bond grinding wheel; The pressure for pressing into a grinding wheel shape is 15~25MPa; the sintering temperature is 600-650℃, the heating rate is 5℃ / min, and the holding time is 2h; The weight proportions of the components in the ceramic binder are as follows: 10-12 parts of coal gangue; 0.7-1.1 parts of sodium hydroxide; 2.8-3.3 parts of silicon dioxide; 0.9-1.2 parts of sodium oxide; 30-31.1 parts of deionized water; 20.4-21 parts of anhydrous ethanol; 11-12.5 parts of ethyl orthosilicate; 22-24 parts of aluminum nitrate nonahydrate; 0.4-0.5 parts of sodium nitrate; 1.41-1.68 parts of potassium nitrate; 4.1-4.5 parts of boric acid; 0.7-0.8 parts of lithium nitrate; 5.8-6.1 parts of magnesium nitrate; and 4-6 parts of nitric acid, wherein the coal gangue is activated coal gangue.

4. The method for preparing a vitrified bond grinding wheel by geopolymerization using coal gangue according to claim 3, characterized in that: The components of the coal gangue in step 1 are 62% silicon dioxide, 30% aluminum oxide, 1% sodium oxide, 3% potassium oxide, 1% calcium oxide, 2% magnesium oxide, and 1% impurities, where % is the mass fraction; The mesh size of the screening is 250 mesh.

5. The method for preparing a vitrified bond grinding wheel by geopolymerization using coal gangue according to claim 3, characterized in that: In step 3, the speed of magnetic stirring is 300-350 r / min, the temperature is room temperature; the aging time is 18-24 h; the speed of sol ball milling is 450-500 r / min, the time is 20-25 min, and the mesh size of screening is 250 mesh.

6. The method for preparing a vitrified bond grinding wheel by geopolymerization using coal gangue according to claim 3, characterized in that: The weight proportions of the components in the ceramic binder are: 12 parts of coal gangue; 1 part of sodium hydroxide; 3.3 parts of silicon dioxide; 0.9 parts of sodium oxide; 31.1 parts of deionized water; 21 parts of anhydrous ethanol; 12.5 parts of ethyl orthosilicate; 24 parts of aluminum nitrate nonahydrate; 0.45 parts of sodium nitrate; 1.68 parts of potassium nitrate; 4.5 parts of boric acid; 0.8 parts of lithium nitrate; 6.1 parts of magnesium nitrate; 5 parts of nitric acid.

7. The method for preparing a vitrified bond grinding wheel by geopolymerization using coal gangue according to claim 6, characterized in that: In step 4, the mass ratio of diamond abrasive, vitrified bond, and temporary binder is 60:15:1, the diamond abrasive is diamond, CBN, or silicon carbide, and the particle size is w0.5-w20; the temporary binder is polyethylene glycol or dextrin.