High-performance microcrystalline glass and preparation method thereof

Abstract

The invention provides a preparation method of high-performance microcrystalline glass, which comprises the following steps: 1) blast furnace slag and low-alkalinity solid waste are mixed and subjected to ball milling to obtain a mixed material, and the particle size of the mixed material is less than or equal to 10 [mu] m; and 2) pressing the mixed material in the step 1) to obtain a raw material green body, and sintering at 800-1000 DEG C to obtain the glass ceramic. The bending strength of the glass ceramic prepared by the preparation method is 145 MPa or above, the acid corrosion resistance is 95% or above, and the alkali corrosion resistance is 98.9% or above.

Description

Technical Field

[0001] The present invention belongs to the field of glass-ceramics, and particularly relates to a high-performance glass-ceramics and a preparation method thereof. Background Art

[0002] Blast furnace slag is a by-product generated during the blast furnace ironmaking process. Although its utilization rate is relatively high, it is mainly used in the preparation of products such as cement and concrete, and high-value-added utilization is relatively rare. Since its composition is similar to that of CaO-MgO-Al2O3-SiO2 system glass-ceramics and it mainly exists in a vitreous state after water quenching, it is suitable for the preparation of high-value-added glass-ceramics.

[0003] Due to the high CaO content of blast furnace slag and the general alkalinity being between 1.0 and 1.2, during the sintering process, due to rapid crystallization, poor densification will occur, which is not conducive to the preparation of glass-ceramics with high density, high strength, and excellent acid and alkali corrosion resistance. Therefore, its composition should be adjusted before being used in the preparation of glass-ceramics. Currently, the main method is to add other high-aluminum-silicon solid wastes and then remelt to adjust its composition, but this also means huge heat consumption; thermally modifying blast furnace slag can reduce heat consumption, but it also faces the problem of heat supplementation, and industrial equipment needs to be updated. Otherwise, problems such as uneven composition and many shrinkage holes will occur, which is not conducive to the preparation of glass-ceramics with high density, high strength, and excellent acid and alkali corrosion resistance.

[0004] Aiming at the huge energy consumption of thermal modification, the present invention proposes the concept of "cold modification", that is, through high-energy ball milling, the mixture of blast furnace slag and low-alkalinity solid wastes (such as fly ash, waste glass, etc.) is mixed evenly and the particle size of the raw materials is reduced. During the sintering process, through the mutual diffusion of atoms between high-aluminum-silicon substances such as fly ash and waste glass and blast furnace slag, reaction sintering is carried out to obtain almost fully dense glass-ceramics. The "cold modification" method proposed by the present invention directly uses industrially obtained blast furnace slag and low-alkalinity solid wastes (such as fly ash, waste glass, etc.) as raw materials, which is easy to implement and operate, does not require additional heat consumption, and the prepared glass-ceramics are almost fully dense, with excellent mechanical properties and acid and alkali resistance, which helps to promote the high-value-added utilization of blast furnace slag and low-alkalinity solid wastes (such as fly ash, waste glass, etc.). Summary of the Invention

[0005] To solve the problems existing in the prior art, the present invention provides a high-performance glass-ceramics and a preparation method thereof, aiming to obtain glass-ceramics with high flexural strength and high erosion resistance by means of low-temperature sintering.

[0006] As an aspect of the present invention, a preparation method of a high-performance glass-ceramics is provided, including the following steps:

[0007] 1) Mix and ball mill blast furnace slag and low-alkalinity solid waste to obtain a mixed material, and the particle size of the mixed material ≤ 10 μm;

[0008] 2) Press the mixed material in step 1) to obtain a raw green body, and then sinter it at 800 - 1000 °C to obtain the glass-ceramics.

[0009] As a preferred embodiment of the preparation method of a high-performance glass-ceramics of the present invention, by mass, the composition of the blast furnace slag includes CaO: 30 - 45%, MgO: 5 - 15%, Al2O3: 5 - 20%, SiO2: 30 - 40%, Fe2O3: 0 - 2%, TiO2: 0 - 2%, and the balance is impurities; the low-alkalinity solid waste includes at least one of fly ash or waste glass. By mass, the composition of the fly ash includes CaO: 1 - 10%, MgO: 0 - 5%, Al2O3: 20 - 35%, SiO2: 40 - 60%, TiO2: 0.5 - 2%, Fe2O3: 5 - 15%, and the balance is impurities; by mass, the composition of the waste glass includes CaO: 5 - 15%, MgO: 0 - 5%, Al2O3: 1 - 20%, SiO2: 50 - 75%, Na2O: 10 - 20%, and the balance is impurities.

[0010] As a preferred embodiment of the preparation method of a high-performance glass-ceramics of the present invention, the addition amount of the low-alkalinity solid waste is 30 - 70% of the total mass.

[0011] As a preferred embodiment of the preparation method of a high-performance glass-ceramics of the present invention, in step 1), the ball-to-material ratio of the ball milling is ≥ 5:1.

[0012] As a preferred embodiment of the preparation method of a high-performance glass-ceramics of the present invention, in step 1), the rotation speed of the ball milling is ≥ 300 r / min, and the ball milling time is ≥ 24 h.

[0013] As a preferred embodiment of the preparation method of a high-performance glass-ceramics of the present invention, in step 2), the pressure of the press molding is 20 - 100 MPa, and the pressure holding time is 30 - 120 s.

[0014] As a preferred embodiment of the preparation method of a high-performance glass-ceramics of the present invention, in step 2), the sintering time is 1 - 4 h.

[0015] As another aspect of the present invention, there is provided a high-performance glass-ceramics prepared by the aforementioned method. The bending strength of the glass-ceramics is above 145 MPa, the acid erosion resistance is above 95%, and the alkali erosion resistance is above 98.9%.

[0016] According to the technical solution of the present invention, it is creatively proposed that the particle size of the mixed material after ball milling has a significant impact on the performance of the glass-ceramics after sintering. This is because as the particle size decreases, the sintering activity increases, which is beneficial to improving the density of the glass-ceramics at low temperatures. In addition, during the sintering process, since the Al element in the low-alkalinity solid waste diffuses into the blast furnace slag, and the diffusion depth exceeds the particle size of the blast furnace slag, it effectively "neutralizes" the problem of fast crystallization and hindrance to sintering densification caused by the high alkalinity of the blast furnace slag. At the same time, due to the low sintering temperature, the grain size of the glass-ceramics is small, so the mechanical properties are high.

[0017] According to the technical solution of the present invention, it is creatively proposed that the addition ratio of the low-alkalinity solid waste has a significant impact on the performance of the glass-ceramics after sintering. This is because when the addition amount is small, there is not enough low-alkalinity substance to "neutralize" the problems of easy crystallization and poor densification caused by the high alkalinity of the blast furnace slag.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] 1. The present invention uses blast furnace slag and low-alkalinity solid waste as raw materials, and with "cold conditioning", it can prepare almost fully dense glass-ceramics without the need for heat conditioning, effectively improving the performance of the glass-ceramics while reducing the production cost;

[0020] 2. The flexural strength of the glass-ceramics obtained by the present invention is above 145 MPa, the acid resistance is above 95%, and the alkali resistance is above 98.9%. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only the embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained according to the provided drawings.

[0022] Figure 1 XRD patterns of the blast furnace slag used in the examples and comparative examples;

[0023] Figure 2 XRD patterns of the fly ash used in the examples and comparative examples;

[0024] Figure 3 XRD pattern of the waste glass used in the examples;

[0025] Figure 4 Optical microscope image of the glass-ceramics prepared in Example 1;

[0026] Figure 5 Optical microscope image of the glass-ceramics prepared in Example 2;

[0027] Figure 6 Optical micrograph of the glass-ceramics prepared in Example 3;

[0028] Figure 7 Optical micrograph of the glass-ceramics prepared in Example 4. Detailed implementation manners

[0029] The technical solutions in the embodiments will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0030] In the specific implementation manners of the present invention, the particle size values of the mixed materials mentioned all refer to the values corresponding to the median particle size D50. For the component contents of each substance, unless otherwise specified, they are all in mass. The XRD patterns of blast furnace slag, fly ash and waste glass used are as Figure 1-3 shown.

[0031] Example 1

[0032] A preparation method of a high-performance glass-ceramics, comprising the following steps:

[0033] 1) Mix blast furnace slag and fly ash according to a mass ratio of 1:1 and ball-mill for 24 h at a rotation speed of 300 r / min to obtain a mixed material with a particle size of 2 μm. The blast furnace slag is selected from water-quenched slag, with a vitrification degree of 90% and an initial particle size of 200 mesh, and the components include CaO: 40.8%, MgO: 5.5%, Al2O3: 15.2%, SiO2: 32.9%, TiO2: 0.6%, Fe2O3: 0.4%, and the balance impurities; the fly ash is selected from fly ash generated by power plants, with an initial particle size of 300 mesh, and the components include CaO: 6.2%, Al2O3: 33.2%, SiO2: 48.8%, TiO2: 1.3%, Fe2O3: 6.3%, and the balance impurities. The ball-to-material ratio of the ball-milling is 10:1.

[0034] 2) Press the mixed material in step 1) under a pressure condition of 30 MPa for 60 s to obtain a raw green body, and then sinter at 950 °C for 1 h and cool to room temperature in the furnace to obtain the glass-ceramics.

[0035] The glass-ceramics obtained in this example are polished. The microstructure diagram is as Figure 4As shown, it can be seen that the glass-ceramics obtained in this embodiment have a dense structure and no obvious pores are found. The properties of the above glass-ceramics are measured as follows: the flexural strength is 169.0 MPa, the acid resistance is 95.86%, and the alkali resistance is 98.99%.

[0036] Example 2

[0037] A preparation method of high-performance glass-ceramics includes the following steps:

[0038] 1) Mix blast furnace slag and fly ash in a mass ratio of 1:1 and ball mill for 24 h at a rotation speed of 300 r / min to obtain a mixed material with a particle size of 2 μm. The blast furnace slag is selected from water-quenched slag with a vitrification degree of 90% and an initial particle size of 200 mesh, and its composition includes CaO: 40.8%, MgO: 5.5%, Al2O3: 15.2%, SiO2: 32.9%, TiO2: 0.6%, Fe2O3: 0.4%, and the balance is impurities; the fly ash is selected from fly ash from power plant power generation with an initial particle size of 300 mesh, and its composition includes CaO: 6.2%, Al2O3: 33.2%, SiO2: 48.8%, TiO2: 1.3%, Fe2O3: 6.3%, and the balance is impurities. The ball-to-material ratio of the ball milling is 10:1.

[0039] 2) Press the mixed material in step 1) under a pressure condition of 30 MPa for 60 s to obtain a raw green body, and then sinter at 850 °C for 1 h and cool to room temperature in the furnace to obtain the glass-ceramics.

[0040] The glass-ceramics obtained in this embodiment are polished. The microstructure diagram is as Figure 5 As shown, it can be seen that the glass-ceramics obtained in this embodiment have a dense structure and no obvious pores are found. The properties of the above glass-ceramics are measured as follows: the flexural strength is 165.8 MPa, the acid resistance is 96.28%, and the alkali resistance is 99.95%.

[0041] Example 3

[0042] A preparation method of high-performance glass-ceramics includes the following steps:

[0043] 1) Mix blast furnace slag and fly ash in a mass ratio of 7:3 and ball mill for 24 h at a rotation speed of 300 r / min to obtain a mixed material with a particle size of 2.5 μm. The blast furnace slag is selected from water-quenched slag with a degree of vitrification of 90%, an initial particle size of 200 mesh, and its composition includes CaO: 40.8%, MgO: 5.5%, Al2O3: 15.2%, SiO2: 32.9%, TiO2: 0.6%, Fe2O3: 0.4%, and the balance being impurities; the fly ash is selected from fly ash from power plant power generation with an initial particle size of 300 mesh, and its composition includes CaO: 6.2%, Al2O3: 33.2%, SiO2: 48.8%, TiO2: 1.3%, Fe2O3: 6.3%, and the balance being impurities. The ball-to-material ratio of the ball milling is 10:1.

[0044] 2) Press the mixed material in step 1) under a pressure condition of 30 MPa and hold the pressure for 60 s to obtain a green body of the raw material, and then sinter it at 950 °C for 1 h and cool it to room temperature with the furnace to obtain the glass-ceramics.

[0045] Grind and polish the glass-ceramics obtained in this example. The microstructure diagram is as Figure 6 shown. It can be seen that the glass-ceramics obtained in this example have a dense structure and no obvious pores are found. Measure the properties of the above glass-ceramics as follows: the linear shrinkage rate is 20.4%, the flexural strength is 147.4 MPa, the acid erosion resistance is 97.02%, and the alkali erosion resistance is 99.94%.

[0046] Example 4

[0047] A preparation method of high-performance glass-ceramics includes the following steps:

[0048] 1) Mix blast furnace slag and fly ash in a mass ratio of 1:1 and ball mill for 12 h at a rotation speed of 300 r / min to obtain a mixed material with a particle size of 4.0 μm. The blast furnace slag is selected from water-quenched slag with a degree of vitrification of 90%, an initial particle size of 200 mesh, and its composition includes CaO: 40.8%, MgO: 5.5%, Al2O3: 15.2%, SiO2: 32.9%, TiO2: 0.6%, Fe2O3: 0.4%, and the balance being impurities; the fly ash is selected from fly ash from power plant power generation with an initial particle size of 300 mesh, and its composition includes CaO: 6.2%, Al2O3: 33.2%, SiO2: 48.8%, TiO2: 1.3%, Fe2O3: 6.3%, and the balance being impurities. The ball-to-material ratio of the ball milling is 10:1.

[0049] 2) Press the mixed material in step 1) under a pressure condition of 30 MPa and hold the pressure for 60 s to obtain a green body of the raw material, and then sinter it at 950 °C for 1 h and cool it to room temperature with the furnace to obtain the glass-ceramics.

[0050] The microcrystalline glass obtained in this example was polished, and the microstructure diagram is as follows Figure 7 shown. It can be seen that the microcrystalline glass obtained in this example has a dense structure, and no obvious pores are found. The properties of the above microcrystalline glass were measured as follows: the flexural strength is 152.2 MPa, the acid resistance is 97.82%, and the alkali resistance is 99.92%.

[0051] Example 5

[0052] A preparation method of a high-performance microcrystalline glass includes the following steps:

[0053] 1) Mix blast furnace slag and waste glass in a mass ratio of 1:1 and ball mill for 24 h at a rotation speed of 300 r / min to obtain a mixed material with a particle size of 2 μm. The blast furnace slag is selected from water-quenched slag, with a vitrification degree of 90%, an initial particle size of 200 mesh, and the composition includes CaO: 40.8%, MgO: 5.5%, Al2O3: 15.2%, SiO2: 32.9%, TiO2: 0.6%, Fe2O3: 0.4%, and the balance is impurities; the initial particle size of the waste glass is 300 mesh, and the composition includes CaO: 5%, MgO: 2%, Al2O3: 15%, SiO2: 63%, Na2O: 12%, and the balance is impurities. The ball-to-material ratio of the ball milling is 10:1.

[0054] 2) Press the mixed material in step 1) under a pressure of 30 MPa for 60 s to obtain a raw green body, and then sinter it at 850 °C for 1 h and cool it to room temperature with the furnace to obtain the microcrystalline glass.

[0055] The microcrystalline glass obtained in this example was polished, and its properties were measured as follows: the flexural strength is 149.2 MPa, the acid resistance is 96.23%, and the alkali resistance is 99.87%.

[0056] Comparative Example 1

[0057] A preparation method of a high-performance microcrystalline glass includes the following steps:

[0058] 1) Mix blast furnace slag and fly ash in a mass ratio of 1:1 to obtain a mixed material. The blast furnace slag is selected from water-quenched slag, with a vitrification degree of 90%, an initial particle size of 200 mesh, and the composition includes CaO: 40.8%, MgO: 5.5%, Al2O3: 15.2%, SiO2: 32.9%, TiO2: 0.6%, Fe2O3: 0.4%, and the balance is impurities; the fly ash is selected from fly ash generated by power plants, with an initial particle size of 200 mesh, and the composition includes CaO: 6.2%, Al2O3: 33.2%, SiO2: 48.8%, TiO2: 1.3%, Fe2O3: 6.3%, and the balance is impurities.

[0059] 2) Press the mixed material in step 1) under a pressure condition of 30 MPa, hold the pressure for 60 s to obtain a green blank of the raw material, and then sinter it at 950 °C for 1 h, and cool it to room temperature in the furnace to obtain the glass-ceramics.

[0060] The glass-ceramics obtained in this comparative example were polished, and their properties were measured as follows: the flexural strength was only 30.2 MPa. It can be seen that compared with Example 1, in this comparative example, due to the too large particle size of the mixed material, the fly ash did not play an effective "neutralizing" role in the rapid crystallization problem of blast furnace slag, resulting in a significant decrease in flexural strength.

[0061] Comparative Example 2

[0062] A method for preparing a high-performance glass-ceramics, comprising the following steps:

[0063] 1) Mix blast furnace slag and fly ash according to a mass ratio of 7:3 and ball mill for 2 h at a rotation speed of 200 r / min to obtain a mixed material with a particle size of 100 mesh (about 38 μm). The blast furnace slag is selected from water-quenched slag, with a degree of vitrification of 90%, an initial particle size of 200 mesh, and its composition includes CaO: 40.8%, MgO: 5.5%, Al2O3: 15.2%, SiO2: 32.9%, TiO2: 0.6%, Fe2O3: 0.4%, and the balance is impurities; the fly ash is selected from fly ash from power plant power generation, with an initial particle size of 300 mesh, and its composition includes CaO: 6.2%, Al2O3: 33.2%, SiO2: 48.8%, TiO2: 1.3%, Fe2O3: 6.3%, and the balance is impurities. The ball-to-material ratio of the ball milling is 10:1.

[0064] 2) Press the mixed material in step 1) under a pressure condition of 30 MPa, hold the pressure for 60 s to obtain a green blank of the raw material, and then sinter it at 950 °C for 1 h, and cool it to room temperature in the furnace to obtain the glass-ceramics.

[0065] The glass-ceramics obtained in this example were polished, and their properties were measured as follows: the flexural strength was 50.7 MPa. It can be seen that compared with Example 3, in this comparative example, due to the too large particle size of the mixed material, the fly ash did not play an effective "neutralizing" role in the rapid crystallization problem of blast furnace slag, resulting in a significant decrease in flexural strength.

[0066] Comparative Example 3

[0067] A method for preparing a high-performance glass-ceramics, comprising the following steps:

[0068] 1) Mix blast furnace slag and fly ash in a mass ratio of 9:1 and ball mill for 24 h at a rotational speed of 300 r / min to obtain a mixed material with a particle size of 3 μm. The blast furnace slag is selected from water-quenched slag with a vitrification degree of 90% and an initial particle size of 200 mesh, and its composition includes CaO: 40.8%, MgO: 5.5%, Al2O3: 15.2%, SiO2: 32.9%, TiO2: 0.6%, Fe2O3: 0.4%, and the balance is impurities; the fly ash is selected from fly ash generated by power plants, with an initial particle size of 200 mesh, and its composition includes CaO: 6.2%, Al2O3: 33.2%, SiO2: 48.8%, TiO2: 1.3%, Fe2O3: 6.3%, and the balance is impurities.

[0069] 2) Press the mixed material in step 1) under a pressure condition of 30 MPa for 60 s to obtain a green body of the raw material, and then sinter it at 950 °C for 1 h and cool it to room temperature in the furnace to obtain the glass-ceramics.

[0070] Grind and polish the glass-ceramics obtained in this comparative example, and measure its properties as follows: the flexural strength is 76.2 MPa, and the acid erosion resistance is 89.13%. It can be seen that compared with Example 1, due to the small addition ratio of fly ash, fly ash does not play an effective "neutralizing" role in the rapid crystallization problem of blast furnace slag, resulting in a significant decrease in flexural strength; due to the large addition ratio of blast furnace slag and high alkalinity, its acid erosion resistance decreases significantly.

[0071] It should be noted that according to the above embodiments of the present invention, those skilled in the art can fully implement the entire scope of the independent claims and dependent claims of the present invention, and the implementation process and method are the same as those of the above embodiments; and the parts not elaborated in detail in the present invention belong to the well-known technology in the art. However, the protection scope of the present invention is not limited thereto, and any changes or substitutions that can be easily thought of by those familiar with the art within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A method for preparing high-performance microcrystalline glass, characterized in that: The steps include: 1) mixing blast furnace slag and low-basicity solid waste and ball milling to obtain a mixed material, wherein the particle size of the mixed material is ≤10 μm; 2) The mixed material in step 1) is pressed into a sample to obtain a raw material green body, and then sintered at 800-1000° C. to obtain microcrystalline glass.

2. The preparation method according to claim 1, characterized in that The blast furnace slag comprises, by mass, CaO: 30-45%, MgO: 5-15%, Al2O3: 5-20%, SiO2: 30-40%, Fe2O3: 0-2%, TiO2: 0-2%, and the remainder impurities; the low-basicity solid waste comprises at least one of fly ash or waste glass, and the fly ash comprises, by mass, CaO: 1-10%, MgO: 0-5%, Al2O3: 20-35%, SiO2: 40-60%, TiO2: 0.5-2%, Fe2O3: 5-15%, and the remainder impurities; the waste glass comprises, by mass, CaO: 5-15%, MgO: 0-5%, Al2O3: 1-20%, SiO2: 50-75%, Na2O: 10-20%, and the remainder impurities.

3. The preparation method according to claim 1 or 2, characterized in that: The blast furnace slag is water-quenched slag, and the degree of vitrification is ≥80%.

4. The preparation method according to claim 1 or 2, characterized in that: The amount of low-alkalinity solid waste added is 30-70% of the total mass.

5. The preparation method according to claim 1 or 2, characterized in that: In step 1), the ball-to-material ratio of the ball mill is ≥5:

1.

6. The preparation method according to claim 1 or 2, characterized in that: In step 1), the ball milling speed is ≥300 r / min, and the ball milling time is ≥20 h.

7. The preparation method according to claim 1 or 2, characterized in that: In step 2), the sample pressing pressure is 20-100 MPa, and the pressure is maintained for 30-120 seconds.

8. The preparation method according to claim 1 or 2, characterized in that: In step 2), the sintering time is 1 to 4 hours.

9. A high-performance glass-ceramic, characterized in that: The high-performance glass slag is prepared by the preparation method described in any one of claims 1 to 8, and the bending strength of the microcrystalline glass is above 145 MPa, the acid corrosion resistance is above 95%, and the alkali corrosion resistance is above 98.9%.

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