Building brick and method for producing the same

Abstract

The present disclosure provides a building brick and a preparation method thereof. The building brick comprises 0.5 wt% to 3 wt% of iron (Fe), 1 wt% to 5 wt% of aluminum (Al), 10 wt% to 20 wt% of silicon (Si), 1 wt% to 10 wt% of sodium (Na), 50 wt% to 65 wt% of calcium (Ca), and 10 wt% to 25 wt% of magnesium (Mg), based on the total weight of the iron, aluminum, silicon, sodium, calcium, and magnesium in the building brick.

Description

Technical Field

[0001] This disclosure relates to a building brick and its preparation method. Background Technology

[0002] In the steelmaking process, steel plants generally use refractory materials as furnace linings. Therefore, when the furnace reaches its service life, it will be dismantled to maintain the reliability of the high-temperature environment, resulting in waste refractory materials.

[0003] The traditional method of disposing of waste refractory materials through landfill not only imposes a heavy burden on the environment but is also not economically efficient. Therefore, recycling and reusing waste refractory materials can not only reduce resource waste but also reduce corporate carbon emissions. Summary of the Invention

[0004] According to an embodiment of this disclosure, a building brick is provided. The building brick comprises: 0.5 wt% to 3 wt% iron (Fe), 1 wt% to 5 wt% aluminum (Al), 10 wt% to 20 wt% silicon (Si), 1 wt% to 10 wt% sodium (Na), 50 wt% to 65 wt% calcium (Ca), and 10 wt% to 25 wt% magnesium (Mg), based on the total weight of iron, aluminum, silicon, sodium, calcium, and magnesium in the building brick.

[0005] According to embodiments of this disclosure, a method for preparing building bricks is also provided. The method comprises mixing a refractory material, glass powder, and an alkaline aqueous solution to obtain a mixture; performing a casting process on the mixture to obtain a green body; and performing a calcination process on the green body to obtain the building bricks as described in this disclosure. According to embodiments of this disclosure, the alkaline aqueous solution contains sodium carbonate, sodium bicarbonate, sodium percarbonate, sodium hydroxide, or a combination thereof. Attached Figure Description

[0006] Figure 1 This is a flowchart of the steps in the method 10 for preparing building bricks as disclosed in this embodiment;

[0007] Figure 2 This is a scanning electron microscope image of the building brick (2) as described in Embodiment 2 of this disclosure;

[0008] Figure 3 This is a scanning electron microscope image of the building brick (3) described in Comparative Example 3.

[0009] [Symbol Explanation]

[0010] 10. Methods for preparing building bricks; and

[0011] Steps 12, 14, and 16. Detailed Implementation

[0012] The following provides a detailed description of the building bricks and their preparation method as disclosed herein. It should be understood that the following description provides many different embodiments or examples for implementing different aspects of this disclosure. The specific elements and arrangements described below are merely for illustrative purposes and are not intended to limit the scope of this disclosure. In this disclosure, the term "about" means that the specified amount can be increased or decreased by an amount that is generally and reasonably understood by those skilled in the art.

[0013] The use of ordinal numbers such as "first," "second," "third," etc., in the specification and claims to modify elements of the claims does not in itself imply or represent any prior ordinal number of the claimed element, nor does it represent the order of one claimed element with another, or the order of manufacturing process. The use of these ordinal numbers is only to enable a claim element with a certain name to be clearly distinguished from another claim element with the same name.

[0014] Traditional brick-making requires expensive clay as a raw material, at 1100 o C to 1,300 o Sintering carbon at high temperatures results in problems such as high carbon emissions and high energy consumption. In addition, building bricks made from inorganic polymers are prone to expansion and disintegration when stored at room temperature.

[0015] This disclosure provides a building brick. According to an embodiment of this disclosure, the building brick is formed using waste refractory material. The waste refractory material selected in this disclosure may contain silicon, aluminum, magnesium, and calcium. By mixing specific waste refractory material with a specific alkaline activator (e.g., containing glass powder and an alkaline aqueous solution) and carrying out a bonding reaction, it can be calcined at a relatively low temperature (e.g., 600°C). o C to 1,000 o The building bricks disclosed herein (C below) not only reduce energy consumption but also provide new applications for industrial waste, thereby reducing the amount of waste.

[0016] According to the embodiments disclosed herein, the method for preparing building bricks can reduce the calcination temperature and shorten the calcination time, resulting in building bricks with good crystallinity (calcium magnesium aluminum silicate with a needle-like crystalline structure). According to the embodiments disclosed herein, due to the specificity of its structure, the building bricks disclosed herein possess excellent physical properties (fire resistance, heat resistance, acid resistance, compressive strength, and low moisture absorption), meet brick specifications, and can replace traditional high-temperature (1,300°C) kiln clay bricks.

[0017] According to embodiments of this disclosure, the building bricks disclosed herein may contain approximately 0.5 wt% to 3 wt% (e.g., 1 wt%, or 2 wt%) of iron (Fe), 1 wt% to 5 wt% (e.g., 2 wt%, 3 wt%, or 4 wt%) of aluminum (Al), 10 wt% to 20 wt% (e.g., 11 wt%, 12 wt%, 13 wt%, 14 wt%, 15 wt%, 16 wt%, 17 wt%, 18 wt%, or 19 wt%) of silicon (Si), 1 wt% to 10 wt% (e.g., 2 wt%, 3 wt%, 4 wt%, 5 wt%, 6 wt%, 7 wt%, 8 wt%, or 9 wt%) of sodium (Na), and 50 wt% to 6 wt% of... The building brick contains 5 wt% (e.g., 51 wt%, 52 wt%, 53 wt%, 54 wt%, 55 wt%, 56 wt%, 57 wt%, 58 wt%, 59 wt%, 60 wt%, 61 wt%, 62 wt%, 63 wt%, 64 wt%) of calcium (Ca) and 10 wt% to 25 wt% (e.g., 11 wt%, 12 wt%, 13 wt%, 14 wt%, 15 wt%, 16 wt%, 17 wt%, 18 wt%, 19 wt%, 20 wt%, 21 wt%, 22 wt%, 23 wt%, or 24 wt%) of magnesium (Mg), based on the total weight of iron, aluminum, silicon, sodium, calcium, and magnesium in the brick. According to embodiments of this disclosure, the iron, aluminum, silicon, sodium, calcium, and magnesium content of the building brick can be determined using an X-ray fluorescence spectrometer (XRF).

[0018] According to embodiments of this disclosure, in the building bricks described herein, the atomic ratio of silicon to sodium can be approximately 0.5 to 10 (e.g., approximately 1, 2, 3, 4, 5, 6, 7, 8, or 9). According to embodiments of this disclosure, when the atomic ratio of silicon to sodium in the building bricks described herein is within the above range, the building bricks described herein may have a needle-like crystalline structure, which makes the overall structure more dense and improves the physical properties of the building bricks (fire resistance, heat resistance, acid resistance, compressive strength, and low moisture absorption).

[0019] According to the embodiments disclosed herein, the iron, aluminum, silicon, sodium, calcium, and / or magnesium contained in the building bricks disclosed herein may exist in the form of oxides (e.g., iron oxide, aluminum oxide, silicon oxide, sodium oxide, calcium oxide, and / or magnesium oxide), and therefore the building bricks disclosed herein are a composite oxide.

[0020] According to an embodiment of this disclosure, the building brick comprises calcium magnesium aluminum silicate having a needle-like crystalline structure. According to an embodiment of this disclosure, the characteristic peak value (2θ) of the calcium magnesium aluminum silicate in the X-ray diffraction spectrum of the building brick is 23 to 24 degrees, 29 to 31 degrees, and 36 to 38 degrees. According to an embodiment of this disclosure, the length of the needle-like crystalline structure of the calcium magnesium aluminum silicate can be about 4 μm to 10 μm (e.g., 5 μm, 6 μm, 7 μm, 8 μm, 9 μm), and the width can be about 0.5 μm to 3 μm (e.g., 1 μm, 1.5 μm, 2 μm, or 2.5 μm).

[0021] According to the embodiments disclosed herein, the X-ray diffraction pattern of the building brick has a first integrated intensity (S1) at the characteristic peak value (2θ) between 36 and 38 degrees, and the X-ray diffraction pattern of the building brick has a second integrated intensity (S2) at the characteristic peak value (2θ) between 42 and 43 degrees, wherein the ratio of the first integrated intensity to the second integrated intensity (S1 / S2) can be about 0.1 to 0.2 (e.g., 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, or 0.19).

[0022] According to the embodiments disclosed herein, when the building bricks disclosed herein contain the aforementioned specific amounts of elements and have a needle-like crystalline structure of calcium magnesium aluminum silicate, the compressive strength of the building bricks can be approximately 150 kgf / cm². 2 Up to 800 kgf / cm 2 (e.g., 200 kgf / cm) 2 300kgf / cm 2 400kgf / cm 2 500kgf / cm 2 600kgf / cm 2 or 700 kgf / cm 2 The water absorption rate of the building bricks can be approximately 5% to 20% (e.g., 6%, 8%, 10%, 12%, 14%, 16%, or 18%).

[0023] According to the embodiments disclosed herein, the compressive strength is assessed using a compressive strength measuring instrument (model Zwick Roell Z020, Zwick / Roell GmbH). According to the embodiments disclosed herein, the water absorption rate is assessed according to standard procedures.

[0024] According to embodiments of this disclosure, this disclosure also provides a method for preparing building bricks, used to prepare the building bricks described herein. Please refer to... Figure 1 According to the embodiments disclosed herein, the method 10 for preparing building bricks includes mixing a refractory material, a glass powder, and an alkaline aqueous solution to obtain a mixture (step 12). The mixture is then subjected to a casting process to obtain a green body (step 14). Finally, the green body is subjected to a calcination process to obtain the building brick (step 16).

[0025] According to the embodiments disclosed herein, the refractory material used to make building bricks may be waste refractory material, the source of which may be furnace slag, converter slag, oxide slag, reduction slag, coal fly ash, coal bottom ash, aluminum slag, waste catalyst, waste glass, waste building materials, waste gypsum, sludge, bottom mud, or a combination thereof.

[0026] According to embodiments of this disclosure, the waste refractory materials selected for this disclosure may contain silicon, aluminum, magnesium, and calcium, especially waste refractory materials with high contents of magnesium and calcium. According to embodiments of this disclosure, the refractory material contains approximately 0.5 wt% to 5 wt% (e.g., 1 wt%, 2 wt%, 3 wt%, or 4 wt%) of iron (Fe), 1.5 wt% to 6 wt% (e.g., 2 wt%, 3 wt%, 4 wt%, or 5 wt%) of aluminum (Al), 1 wt% to 10 wt% (e.g., 2 wt%, 3 wt%, 4 wt%, 5 wt%, 6 wt%, 7 wt%, 8 wt%, or 9 wt%) of silicon (Si), and 35 wt% to 55 wt% (e.g., 36 wt%, 37 wt%, 38 wt%, 39 wt%, 40 wt%, 41 wt%, 42 wt%, 43 wt%, or 44 wt%). The refractory material contains 45 wt%, 46 wt%, 47 wt%, 48 wt%, 49 wt%, 50 wt%, 51 wt%, 52 wt%, 53 wt%, and 54 wt% of calcium (Ca) and 30 wt% to 50 wt% (e.g., 31 wt%, 32 wt%, 33 wt%, 34 wt%, 35 wt%, 36 wt%, 37 wt%, 38 wt%, 39 wt%, 40 wt%, 41 wt%, 42 wt%, 43 wt%, 44 wt%, 45 wt%, 46 wt%, 47 wt%, 48 wt%, or 49 wt%) of magnesium (Mg), based on the total weight of iron, aluminum, silicon, calcium, and magnesium in the refractory material. According to embodiments of this disclosure, when the refractory material contains the above-mentioned specific amounts of elements, it can be used in combination with a specific alkali activator (e.g., glass powder and an alkaline aqueous solution) and calcined at a relatively low temperature to prepare the building bricks of this disclosure.

[0027] According to embodiments of this disclosure, the refractory material described herein may not contain sodium. According to embodiments of this disclosure, the refractory material described herein contains 0.01 wt% to 1 wt% (e.g., 0.02 wt%, 0.05 wt%, 0.1 wt%, 0.2 wt%, 0.3 wt%, 0.4 wt%, 0.5 wt%, 0.6 wt%, 0.7 wt%, 0.8 wt%, or 0.9 wt%) of sodium (Na), based on the total weight of iron, aluminum, silicon, sodium, calcium, and magnesium.

[0028] According to the embodiments disclosed herein, the iron, aluminum, silicon, sodium, calcium, and / or magnesium contained in the building bricks disclosed herein may exist in the form of oxides (e.g., iron oxide, aluminum oxide, silicon oxide, sodium oxide, calcium oxide, and / or magnesium oxide), and therefore the building bricks disclosed herein are a composite oxide.

[0029] According to embodiments of this disclosure, the glass powder may contain silicon oxide. According to embodiments of this disclosure, the glass powder may also contain potassium oxide, calcium oxide, magnesium oxide, boron oxide, aluminum oxide, sodium oxide, lead oxide, barium oxide, tin oxide, zinc oxide, phosphorus oxide, bismuth oxide, or combinations thereof. According to the embodiments disclosed herein, the silica content of the glass powder can be from 30 wt% to 99 wt% (e.g., 35 wt%, 40 wt%, 45 wt%, 50 wt%, 55 wt%, 60 wt%, 65 wt%, 70 wt%, 75 wt%, 80 wt%, 85 wt%, 90 wt%, 95 wt%, or 97 wt%), while the content of other components besides the glass powder can be from 1 wt% to 50 wt% (e.g., 2 wt%, 5 wt%, 10 wt%, 15 wt%, 20 wt%, 25 wt%, 30 wt%, 35 wt%, 40 wt%, or 45 wt%).

[0030] According to embodiments of this disclosure, the weight ratio of the refractory material to the glass powder can be approximately 0.5 to 2 (e.g., 0.6, 0.7, 0.8, 1, 1.2, 1.4, 1.6, or 1.8). According to embodiments of this disclosure, the building bricks described herein can be prepared at lower calcination temperatures using the glass powder and the specific weight ratio of the refractory material to the glass powder. According to embodiments of this disclosure, the particle size of the glass powder is not particularly limited and can be approximately 10 μm to 1,000 μm (e.g., 20 μm, 50 μm, 80 μm, 100 μm, 300 μm, 500 μm, or 800 μm). According to embodiments of this disclosure, the source of the glass powder is not limited and can be recycled glass powder.

[0031] According to embodiments of this disclosure, the alkaline aqueous solution comprises sodium carbonate, sodium bicarbonate, sodium percarbonate, sodium hydroxide, or a combination thereof. According to embodiments of this disclosure, the alkaline aqueous solution may be an aqueous solution of sodium carbonate, sodium bicarbonate, sodium percarbonate, or sodium hydroxide. According to embodiments of this disclosure, the weight ratio of the refractory material to the alkaline aqueous solution may be about 0.5 to 3 (e.g., 0.6, 0.7, 0.8, 1, 1.5, 2, or 2.5). According to embodiments of this disclosure, by using a specific alkaline aqueous solution, a specific concentration of the alkaline aqueous solution, and a specific weight ratio of the refractory material to the alkaline aqueous solution, the building bricks described herein can be prepared at a lower calcination temperature.

[0032] According to the embodiments disclosed herein, the concentration of the alkaline aqueous solution can be approximately 4M to 12M (e.g., 5M, 6M, 7M, 8M, 9M, 10M, or 11M). According to the embodiments disclosed herein, when the concentration of the alkaline aqueous solution is too low or too high, the mixture of the refractory material and the alkali activator is less able to effectively dehydrate and condense, resulting in calcium magnesium aluminum silicate without a needle-like crystalline structure (or with a lower amount of calcium magnesium aluminum silicate with a needle-like crystalline structure). According to the embodiments disclosed herein, when the concentration of the alkaline aqueous solution is 5M to 7M, it can further promote the reaction of silicon, aluminum, magnesium, and calcium within the green body to form calcium magnesium aluminum silicate.

[0033] According to the embodiments disclosed herein, the calcination process involved in the preparation method of building bricks disclosed herein involves a calcination temperature of approximately 600°C. o C to 1,000 o C (e.g., approximately 700) o C, 750 o C, 800 o C, 850 o C, 900 o C, or 950 o C), and its calcination time can be approximately 30 minutes to 6 hours (e.g., 1 hour, 2 hours, 3 hours, 4 hours, or 5 hours). When the calcination temperature is too low, the mixture of the refractory material and the alkali activator cannot effectively dehydrate and condense, and cannot produce calcium magnesium aluminum silicate with a needle-like crystalline structure. Therefore, the product obtained after the calcination process is prone to breakage. When the calcination temperature is too high, in addition to energy consumption, the excessively high calcination temperature will destroy the cemented structure, resulting in a product with larger pores, which in turn leads to a decrease in compressive strength and water absorption. According to the embodiments disclosed herein, when the calcination temperature of the calcination process described herein is 650... o C to 900 oAt C, the reaction of silicon, aluminum, magnesium, and calcium in the green body can be further promoted to convert them into calcium magnesium aluminum silicate.

[0034] According to the embodiments disclosed herein, before the refractory material is mixed with glass powder or alkaline aqueous solution, the refractory material can be subjected to a pulverization process to reduce the particle size of the refractory material, which is beneficial to subsequent processes.

[0035] According to the embodiments disclosed herein, after mixing refractory material, glass powder and alkaline aqueous solution, a dispersion process can be used to uniformly disperse the refractory material and glass powder in the alkaline aqueous solution to obtain the mixture.

[0036] According to the embodiments disclosed herein, after obtaining the mixture, a drying process can be performed on the mixture, and the temperature of the drying process can be 25°C. o C to 150 o C (e.g., 50) o C, 70 o C, 80 o C, 100 o C, 120 o C, or 140 o C), and the drying process can last from 6 hours to 48 hours (e.g., 8 hours, 12 hours, 16 hours, 20 hours, 24 hours, 28 hours, 32 hours, 36 hours, 40 hours, 44 hours).

[0037] According to an embodiment of this disclosure, the mixture may be ground and sieved before being subjected to the molding process. According to an embodiment of this disclosure, after the mixture is subjected to the molding process, the resulting material may be subjected to a compression molding process to form the preform. According to an embodiment of this disclosure, the pressure of the compression molding process may be from approximately 1,000 psi to 5,000 psi (e.g., 1,500 psi, 2,000 psi, 2,500 psi, 3,000 psi, 3,500 psi, 4,000 psi, or 4,500 psi).

[0038] To make the above-described contents and other objects, features and advantages of this disclosure more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings.

[0039] Preparation of building bricks

[0040] Example 1

[0041] 120 parts by weight of waste refractory material (elemental analysis of iron, aluminum, silicon, sodium, calcium, and magnesium is shown in Table 1), 120 parts by weight of glass powder (trade code 90740F, sold by Ferro) (elemental analysis of iron, aluminum, silicon, sodium, calcium, and magnesium is shown in Table 1), and 50 parts by weight of an aqueous solution of sodium hydroxide (concentration of sodium hydroxide is 4M) were uniformly mixed to obtain a mixture. The mixture was then dried at room temperature (25°C) for 1 day and at 100°C for 1 hour. Next, the mixture was ground using a powder mill, and the resulting material was sieved (sieve size 50 mesh). The resulting material was then pressed into shape (pressure 3,500 psi) and heated to 700°C. o Calcination at C for 4 hours yields building bricks (1).

[0042] Elemental analysis of the building brick (1) was performed using X-ray fluorescence spectrometer (XRF), and the results are shown in Table 1. Next, the compressive strength and water absorption of the building brick (1) were measured, and the results are shown in Table 2. Then, the building brick (1) was analyzed using X-ray diffractometer (XRD), revealing characteristic peaks of calcium magnesium aluminum silicate at diffraction angles (2θ) of 23-24 degrees, 29-31 degrees, and 36-38 degrees.

[0043] Comparative Example 1

[0044] Comparative Example 1 was prepared according to the method for preparing building bricks described in Example 1, except that the calcination temperature was changed from 700°C to 100°C. o C decreased to 500 o C. After calcination, the resulting material was observed to crumble, making it impossible to obtain building bricks.

[0045] Example 2

[0046] Example 2 was carried out according to the method for preparing building bricks described in Example 1, except that the concentration of sodium hydroxide aqueous solution was increased from 4M to 6M to obtain building bricks (2).

[0047] Elemental analysis of the building brick (2) was performed using an X-ray fluorescence spectrometer (XRF), and the results are shown in Table 1. Next, the compressive strength and water absorption of the building brick (2) were measured, and the results are shown in Table 2. Then, the building brick (2) was analyzed using an X-ray diffractometer (XRD), revealing characteristic peaks of calcium magnesium aluminum silicate at diffraction angles (2θ) of 23-24°, 29-31°, and 36-38°. The integrated intensity (S1) of the characteristic peak at diffraction angles (2θ) of 36-38° and the integrated intensity (S2) of the characteristic peak at diffraction angles (2θ) of 42-43° were calculated, and the ratio of integrated intensity (S1 / S2) was found to be 0.145.

[0048] Comparative Example 2

[0049] Comparative Example 2 was prepared according to the method for preparing building bricks described in Example 2, except that the calcination temperature was changed from 700°C to 100°C. o C decreased to 500 o C. After calcination, the resulting material was observed to crumble, making it impossible to obtain building bricks.

[0050] As can be seen from Examples 1 and 2, and Comparative Examples 1 and 2, when the calcination temperature is increased from 700... o C decreased by 500 o C. Because the mixture of refractory material and alkali activator is less able to effectively dehydrate and condense to form calcium magnesium aluminum silicate with needle-like crystalline structure, the resulting product after calcination is prone to breakage.

[0051] Comparative Example 3

[0052] Comparative Example 3 was prepared according to the method for preparing building bricks described in Example 1, except that the sodium hydroxide aqueous solution was replaced with water to obtain building bricks (3).

[0053] Elemental analysis of the building bricks (3) was performed using X-ray fluorescence spectrometer (XRF), and the results are shown in Table 1. Next, the compressive strength and water absorption of the building bricks (3) were measured, and the results are shown in Table 2. Then, the building bricks (3) were analyzed using X-ray diffractometer (XRD), and no characteristic peaks of calcium magnesium aluminum silicate were observed.

[0054] The building bricks (2) obtained in Example 2 and the building bricks (3) obtained in Comparative Example 3 were observed using a scanning electron microscope (SEM). The results are as follows: Figure 2 and Figure 3 As shown. By Figure 2 It can be seen that the building bricks (2) disclosed herein do indeed contain a large amount of calcium magnesium aluminum silicate with a needle-like crystalline structure, and the structure is relatively dense. In contrast... Figure 3 Building bricks (3) do not have a needle-like crystalline structure of calcium magnesium aluminum silicate and have large pores.

[0055] Comparative Example 4

[0056] Comparative Example 4 was prepared according to the method for preparing building bricks described in Comparative Example 3, except that the calcination temperature was changed from 700°C to 300°C. o C decreased to 500 o C. After calcination, the resulting material was observed to crumble, making it impossible to obtain building bricks.

[0057] Table 1

[0058]

[0059] Example 3

[0060] Example 3 was carried out according to the method for preparing building bricks described in Example 2, except that the calcination temperature was changed from 700°C to 100°C. o C increased to 850 o C, to obtain building bricks (4).

[0061] The compressive strength and water absorption rate of the building bricks (4) were measured, and the results are shown in Table 2.

[0062] Example 4

[0063] Example 4 was carried out according to the method for preparing building bricks described in Example 2, except that the calcination temperature was changed from 700°C to 100°C. o C increased to 1,000 o C, to obtain building bricks (5).

[0064] The compressive strength and water absorption rate of the building bricks (5) were measured, and the results are shown in Table 2.

[0065] Example 5

[0066] Example 5 was carried out according to the method for preparing building bricks described in Example 1, except that the concentration of the sodium hydroxide aqueous solution was increased from 4M to 8M to obtain building bricks (6).

[0067] The compressive strength and water absorption rate of the building bricks (6) were measured, and the results are shown in Table 2.

[0068] Example 6

[0069] Example 6 was carried out according to the method for preparing building bricks described in Example 1, except that the concentration of the sodium hydroxide aqueous solution was increased from 4M to 12M to obtain building bricks (7).

[0070] The compressive strength and water absorption rate of the building bricks (7) were measured, and the results are shown in Table 2.

[0071] Table 2

[0072]

[0073] As shown in Tables 1 and 2, because Comparative Example 3 did not use an aqueous sodium hydroxide solution, the sodium content in the green body was too low during calcination (the atomic ratio of silicon to sodium in Comparative Example 3 was approximately 32). This prevented the formation of needle-like crystalline calcium magnesium aluminum silicates by breaking down the bonds of silicon oxide during calcination. Consequently, the resulting green brick had a relatively loose structure with large pores, leading to poor compressive strength (below 100 kgf / cm²). 2 The bricks have a high water absorption rate (above 25%), which does not meet the specifications for bricks.

[0074] Furthermore, Examples 2 and 3 utilize specific amounts of glass powder and sodium hydroxide aqueous solution as alkali activators (sodium hydroxide aqueous solution concentration of 6M, refractory material to glass powder weight ratio of 1:1, and refractory material to sodium hydroxide aqueous solution weight ratio of 2.4:1), and at 700 o C to 850 o Calcination was carried out at C. As shown in Table 2, the building bricks obtained in Examples 2 and 3 have better compressive strength (above 600 kgf / cm²). 2 It has a higher water absorption rate (above 25%), which meets the specifications for second-grade bricks.

[0075] In summary, the waste refractory materials selected in this disclosure contain silicon, aluminum, magnesium, and calcium elements, and by combining them with specific alkaline activators (such as those containing glass powder and alkaline aqueous solutions), they can be calcined at relatively low temperatures (e.g., 600°C). o C to 1,000 o (C) The building bricks (calcium magnesium aluminum silicate with a needle-like crystalline structure) disclosed herein are obtained. In this way, in addition to obtaining building bricks with excellent physical properties, new applications for industrial waste are also provided, thereby achieving the goal of reducing waste volume.

[0076] Although this disclosure has been presented above with reference to several embodiments, it is not intended to limit this disclosure. Anyone skilled in the art can make any modifications and alterations without departing from the spirit and scope of this disclosure. Therefore, the scope of protection of this disclosure shall be determined by the appended claims.

Claims

1. A type of building brick, characterized in that, The building brick is a composite oxide, and it comprises: 0.5 wt% to 3 wt% iron, 1 wt% to 5 wt% aluminum, 10 wt% to 20 wt% silicon, 1 wt% to 10 wt% sodium, 50 wt% to 65 wt% calcium, and 10 wt% to 25 wt% magnesium, based on the total weight of iron, aluminum, silicon, sodium, calcium and magnesium in the building brick. The X-ray diffraction pattern of the building brick has a first integrated intensity S1 at the characteristic peak value 2θ between 36 and 38 degrees, and a second integrated intensity S2 at the characteristic peak value 2θ between 42 and 43 degrees, wherein the ratio of the first integrated intensity to the second integrated intensity S1 / S2 is 0.1 to 0.

2. The building bricks contain calcium magnesium aluminum silicate with a needle-like crystalline structure; The characteristic peak values ​​2θ of the X-ray diffraction patterns of this calcium magnesium aluminum silicate in building bricks are 23 to 24 degrees, 29 to 31 degrees, and 36 to 38 degrees. The method for preparing building bricks includes: A refractory material, a glass powder, and an alkaline aqueous solution are mixed to obtain a mixture, wherein the alkaline aqueous solution contains sodium carbonate, sodium bicarbonate, sodium percarbonate, sodium hydroxide, or a combination thereof. The mixture is subjected to a molding process to obtain a blank; as well as The green body is subjected to a calcination process to obtain the building brick; The calcination process involves temperatures ranging from 600°C to 1,000°C.

2. The building brick as described in claim 1, characterized in that, The calcium magnesium aluminum silicate has needle-like crystal structures with a length of 4 μm to 10 μm and a width of 0.5 μm to 3 μm.

3. The building brick as described in claim 1, characterized in that, The atomic ratio of silicon to sodium is between 0.5 and 10.

4. The building brick as described in claim 1, characterized in that, The compressive strength of the bricks used in this building is 150 kgf / cm². 2 Up to 800 kgf / cm 2 .

5. The building brick as described in claim 1, characterized in that, The water absorption rate of the bricks used in this building is 5% to 20%.

6. A method for preparing building bricks, characterized in that, The method for preparing the building brick as described in claim 1 comprises: A refractory material, a glass powder, and an alkaline aqueous solution are mixed to obtain a mixture, wherein the alkaline aqueous solution contains sodium carbonate, sodium bicarbonate, sodium percarbonate, sodium hydroxide, or a combination thereof. The mixture is subjected to a molding process to obtain a preform; and The blank is subjected to a calcination process to obtain the building brick as described in claim 1.

7. The method for preparing building bricks as described in claim 6, characterized in that, The refractory material contains 0.5 wt% to 5 wt% iron, 1.5 wt% to 6 wt% aluminum, 1 wt% to 10 wt% silicon, 35 wt% to 55 wt% calcium, and 30 wt% to 50 wt% magnesium, based on the total weight of iron, aluminum, silicon, calcium and magnesium in the refractory material.

8. The method for preparing building bricks as described in claim 6, characterized in that, The glass powder contains silicon dioxide.

9. The method for preparing building bricks as described in claim 8, characterized in that, The glass powder also contains potassium oxide, calcium oxide, magnesium oxide, boron oxide, aluminum oxide, sodium oxide, lead oxide, barium oxide, tin oxide, zinc oxide, phosphorus oxide, bismuth oxide, or a combination thereof.

10. The method for preparing building bricks as described in claim 8, characterized in that, The silica content of the glass powder is 30 wt% to 99 wt%, based on the total weight of the glass powder.

11. The method for preparing building bricks as described in claim 6, characterized in that, The concentration of this alkaline aqueous solution ranges from 4M to 12M.

12. The method for preparing building bricks as described in claim 6, characterized in that, The calcination process takes between 30 minutes and 6 hours.

13. The method for preparing building bricks as described in claim 6, characterized in that, The weight ratio of the refractory material to the glass powder is 0.5 to 2.

14. The method for preparing building bricks as described in claim 6, characterized in that, The weight ratio of the refractory material to the alkaline aqueous solution is 0.5 to 3.

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