Ecological microporous sintered brick and preparation method thereof

Abstract

The present application relates to a kind of ecological microporous sintered brick and its preparation method, the ecological microporous sintered brick is made of the raw material of the component including the following: inorganic industrial residue, shale, organic industrial residue and optional river sand, the inorganic industrial residue includes lead-zinc smelting slag and / or lead-zinc tailings;Wherein, the weight ratio of each component is as follows: the inorganic industrial residue is 10-60, the shale is 25-70, the organic industrial residue is 5, and the river sand is 0-25;The compressive strength of the ecological microporous sintered brick is greater than or equal to 25MPa, and the apparent porosity is 11.54%-15.63%.The present application has the advantages that: inorganic industrial residue (fire method zinc smelting slag, lead-zinc tailings sand) and organic industrial residue (sugar filter mud, sludge, coffee residue) are simultaneously absorbed, and further mixed with tailings, construction waste, coal gangue and other various wastes, realizing the "harmless, reduction, resource" processing of various wastes, and the environmental benefits are remarkable.

Description

Technical Field

[0001] This invention relates to an eco-friendly microporous sintered brick and its preparation method, belonging to the field of building materials. Background Technology

[0002] Traditional building bricks are mostly made from clay. The large-scale mining and use of clay leads to the destruction of scarce arable land resources and has a negative impact on the ecological environment. Therefore, developing new brick-making raw materials and technologies that can replace clay has become an important research direction in the field of building materials.

[0003] On the other hand, with the acceleration of industrialization and urbanization, industries such as metallurgy and mining have generated a large amount of industrial waste (such as smelting slag and tailings), while urban life also generates a large amount of organic waste (such as sludge and coffee grounds). Traditional methods of treating these wastes (such as landfill and stockpiling) not only occupy land resources but also easily cause environmental pollution problems. How to achieve the resource-based and harmless treatment of these wastes is a pressing problem that needs to be solved in the environmental field.

[0004] Currently, there are two main methods for preparing industrial waste bricks, primarily divided into non-sintered bricks and sintered bricks. Non-sintered bricks are usually made by pressing cementitious materials, which limits their waste disposal capacity; sintered bricks, on the other hand, are sintered at high temperatures, enabling more thorough waste disposal, and the products have advantages in strength and durability. However, existing waste sintered brick technologies still suffer from problems such as a single source of slag, a narrow range of composition control, and a tendency to develop defects like "black core" and "cracking," limiting their large-scale application. Therefore, developing an eco-friendly sintered brick that can synergistically utilize various industrial and domestic wastes and has excellent product performance has significant practical significance and application value. Summary of the Invention

[0005] To overcome the shortcomings of existing technologies, this invention provides an ecological microporous sintered brick. The technical solution of this invention is as follows: An ecological microporous sintered brick is made from raw materials comprising the following components: inorganic industrial residues, shale, organic industrial residues, and optional river sand, wherein the inorganic industrial residues include lead-zinc smelting slag and / or lead-zinc tailings. The raw materials further include one or more of tailings, construction waste, slag, and coal gangue; wherein the weight proportions of each component are as follows: 10-60 parts of inorganic industrial residue, 25-70 parts of shale, 0-5 parts of organic industrial residue, and 0-25 parts of river sand; when the raw materials include tailings, construction waste, slag, and coal gangue, the weight proportions are: 10-60 parts of tailings, 5-20 parts of construction waste, 20-50 parts of shale, 5-20 parts of slag, and 5-20 parts of coal gangue; the compressive strength of the ecological microporous sintered brick is ≥25MPa, and the apparent porosity is 11.54%-15.63%.

[0006] The inorganic industrial residue comprises 10-30 parts of pyrometallurgical zinc slag and 0-30 parts of lead-zinc tailings sand.

[0007] In the pyrometallurgical zinc slag, the sum of the weight contents of Fe2O3 and SiO2 is greater than 62%; the lead-zinc tailings sand is in a slurry state and is mainly composed of Al2O3 and SiO2.

[0008] The shale is a type of shale, which contains the following oxides by mass percentage: 44%-62% SiO2, 9%-13% Al2O3, 0.6%-16% CaO, and 8%-16% Fe2O3.

[0009] The organic industrial residue includes one or more of sugar filter mud, silt and coffee grounds, mixed in any proportion.

[0010] The tailings are iron ore tailings and / or molybdenum ore tailings; the total content of oxides of silicon, calcium, aluminum, iron and magnesium in the tailings is greater than 93.5% of the total weight of the tailings; the total content of potassium, sodium, manganese and sulfur in the tailings is less than 0.01% of the total weight of the tailings.

[0011] The ecological microporous sintered brick has a bulk density of 2.13 kg / m³ - 2.28 kg / m³, a water absorption rate of 5.11%-7.87%, and a hardness value greater than 330 HV.

[0012] A method for preparing the aforementioned ecological microporous sintered brick includes the following steps: Step S1: Crush, grind and mix the raw materials to obtain mixture A; Step S2: Add water to the mixture A until the water content is 10 wt%, and stir to obtain mixture B; Step S3: Aging the mixture B to obtain mixture C; Step S4: After pressing and drying the mixture C, sinter it to obtain the ecological microporous sintered brick. In step S4, the moisture content of the brick blank after drying is reduced to below 5%. The sintering process is as follows: first, the temperature is raised to 800°C at a rate of 10°C / min, and then raised to 1000-1100°C at a rate of 5°C / min, and sintered at the temperature for 30 minutes to 8 hours.

[0013] In step S1, the raw material is crushed to a particle size of less than 2 mm and then ball-milled to a particle size of less than 100 μm; in step S3, the aging time is 48-96 hours; in step S4, the molding pressure is 8-10 MPa.

[0014] The advantages of this invention are: 1. It simultaneously absorbs inorganic industrial residues (pyrometallurgical zinc slag, lead-zinc tailings sand) and organic industrial residues (sugar filter mud, silt, coffee grounds), and can be further mixed with various wastes such as tailings, construction waste, and coal gangue, achieving the "harmless, reduced, and resource-based" treatment of various wastes, with significant environmental benefits.

[0015] By utilizing the high SiO2 and Al2O3 content in inorganic slag, some shale and clay raw materials are replaced, significantly reducing the consumption of arable land resources, which is in line with the development direction of green building materials.

[0016] 2. Through the in-situ mineralization of inorganic residues (such as zinc smelting slag) at high temperatures, combined with optimized raw material gradation and sintering process, the product has a compressive strength of up to 25-134MPa, making it suitable for various applications such as load-bearing structures.

[0017] By utilizing the combustion of organic residues (such as coffee grounds) during high-temperature sintering to form micropores, and combining this with precise control of sintering temperature and time, an apparent porosity of 11.54%-15.63% was achieved. This microporous structure endows the brick with excellent thermal insulation properties and a low bulk density (2.13-2.28 kg / m³).

[0018] The product exhibits excellent water absorption (5.11%-7.87%) and hardness (>330 HV), ensuring the durability and performance of the brick.

[0019] 3. It only requires conventional ceramic / building material production processes such as crushing, mixing, aging, molding, drying, and sintering, without the need for complex equipment, and is easy to carry out technical transformation and promotion on existing brick and tile production lines.

[0020] By utilizing the inherent fibrous structure and plasticity of organic residues (such as coffee grounds), the bonding performance of the mixture during the pressing process is effectively improved, reducing the cracking problem of brick blanks caused by high inorganic residue content and increasing the yield.

[0021] By adjusting the raw material ratio and sintering temperature, the final color of the brick can be controlled to meet the decorative needs of different architectural styles. Attached Figure Description

[0022] Figure 1 These are micrographs of samples with 15% doping and a sintering temperature of 1050℃, taken from a sample with a hardness test.

[0023] Figure 2 These are photographs of sintered ceramic bricks with different doping and sintering temperatures according to the present invention.

[0024] Figure 3 This is a graph showing the relationship between the amount of lead-zinc smelting slag added and the compressive strength of the present invention.

[0025] Figure 4 This is a graph showing the relationship between sintering temperature, open porosity, and compressive strength of the present invention. Detailed Implementation

[0026] The present invention will be further described below with reference to specific embodiments, and the advantages and features of the present invention will become clearer as a result. However, these embodiments are merely exemplary and do not constitute any limitation on the scope of the present invention. Those skilled in the art should understand that modifications or substitutions can be made to the details and form of the technical solutions of the present invention without departing from the spirit and scope of the present invention, but all such modifications and substitutions fall within the protection scope of the present invention.

[0027] Example 1: This invention relates to eco-friendly microporous sintered bricks, the raw material components (parts by weight) are as follows: Pyrometallurgical zinc smelting slag: 28.5 parts; Lead-zinc tailings sand: 0 parts; Shale: 66.5 parts; Coffee grounds: 5 parts; River sand: 0 parts Preparation method: Step S1: Crush the above raw materials to a particle size of less than 2 mm using a crusher, and then ball mill them to a particle size of less than 100 μm using a star ball mill. Mix them evenly to obtain mixture A. Step S2: Add water to mixture A until the water content is 10 wt%, and stir to obtain mixture B; Step S3: Aging the mixture B for 48 hours to obtain mixture C; Step S4: Press the mixture C under 10 MPa pressure to form a brick, dry it until the moisture content of the brick blank drops to below 5%, and then place it in a muffle furnace for sintering: heat it to 800°C at 10°C / min, then heat it to 1000°C at 5°C / min, hold it for sintering for 2 hours, and cool it with the furnace to obtain ecological microporous sintered brick.

[0028] Example 2: This invention relates to eco-friendly microporous sintered bricks, the raw material components (parts by weight) are as follows: Pyrometallurgical zinc smelting slag: 28.5 parts; Lead-zinc tailings sand: 0 parts; Shale: 66.5 parts; Coffee grounds: 5 parts; River sand: 0 parts; Preparation method: Step S1: Crush the above raw materials to a particle size of less than 2 mm using a crusher, and then ball mill them to a particle size of less than 100 μm using a star ball mill. Mix them evenly to obtain mixture A. Step S2: Add water to mixture A until the water content is 10 wt%, and stir to obtain mixture B; Step S3: Aging the mixture B for 48 hours to obtain mixture C; Step S4: Press the mixture C under 10 MPa pressure to form a brick, dry it until the moisture content of the brick blank drops to below 5%, and then place it in a muffle furnace for sintering: heat it to 800°C at 10°C / min, then heat it to 1100°C at 5°C / min, hold it for sintering for 2 hours, and cool it with the furnace to obtain ecological microporous sintered bricks.

[0029] Example 3: This invention relates to eco-friendly microporous sintered bricks, the raw material components (parts by weight) are as follows: Pyrometallurgical zinc smelting slag: 15 parts; Lead-zinc tailings sand: 30 parts; Shale: 25 parts; Coffee grounds: 5 parts; River sand: 25 parts; Preparation method: Step S1: Crush the above raw materials to a particle size of less than 2 mm using a crusher, and then ball mill them to a particle size of less than 100 μm using a star ball mill. Mix them evenly to obtain mixture A. Step S2: Add water to mixture A until the water content is 10 wt%, and stir to obtain mixture B; Step S3: Aging the mixture B for 48 hours to obtain mixture C; Step S4: Press the mixture C under 10 MPa pressure to form a brick, dry it until the moisture content of the brick blank drops to below 5%, and then place it in a muffle furnace for sintering: heat it to 800°C at 10°C / min, then heat it to 1000°C at 5°C / min, hold it for sintering for 2 hours, and cool it with the furnace to obtain ecological microporous sintered brick.

[0030] Example 4: This invention relates to eco-friendly microporous sintered bricks, the raw material components (parts by weight) are as follows: Pyrometallurgical zinc slag: 15 parts; Lead-zinc tailings sand: 30 parts; Shale: 25 parts; Coffee grounds: 5 parts; River sand: 25 parts Preparation method: Step S1: Crush the above raw materials to a particle size of less than 2 mm using a crusher, and then ball mill them to a particle size of less than 100 μm using a star ball mill. Mix them evenly to obtain mixture A. Step S2: Add water to mixture A until the water content is 10 wt%, and stir to obtain mixture B; Step S3: Aging the mixture B for 48 hours to obtain mixture C; Step S4: Press the mixture C under 10 MPa pressure to form a brick, dry it until the moisture content of the brick blank drops to below 5%, and then place it in a muffle furnace for sintering: heat it to 800°C at 10°C / min, then heat it to 1100°C at 5°C / min, hold it for sintering for 2 hours, and cool it with the furnace to obtain ecological microporous sintered bricks.

[0031] Example 5: This invention relates to eco-friendly microporous sintered bricks, the raw material components (parts by weight) are as follows: Iron ore tailings: 40 parts; Construction waste: 10 parts; Shale: 28 parts; Slag: 12 parts; coal gangue: 10 parts; coffee grounds: 5 parts.

[0032] Preparation method: Step S1: Crush the above raw materials to a particle size of less than 2 mm using a crusher, and then ball mill them to a particle size of less than 100 μm using a star ball mill. Mix them evenly to obtain mixture A. Step S2: Add water to mixture A until the water content is 10 wt%, and stir to obtain mixture B; Step S3: Aging the mixture B for 48 hours to obtain mixture C; Step S4: Press the mixture C under 10 MPa pressure to form a brick, dry it until the moisture content of the brick blank drops to below 5%, and then place it in a muffle furnace for sintering: heat it to 800°C at 10°C / min, then heat it to 1050°C at 5°C / min, hold it for sintering for 2 hours, and cool it with the furnace to obtain ecological microporous sintered bricks.

[0033] Example 6: This invention relates to eco-friendly microporous sintered bricks, the raw material components (parts by weight) are as follows: Pyrometallurgical zinc slag: 15 parts; lead-zinc tailings sand: 30 parts; shale: 25 parts; coffee grounds: 10 parts; river sand: 25 parts.

[0034] Preparation method: Step S1: Crush the above raw materials to a particle size of less than 2 mm using a crusher, and then ball mill them to a particle size of less than 100 μm using a star ball mill. Mix them evenly to obtain mixture A. Step S2: Add water to mixture A until the water content is 10 wt%, and stir to obtain mixture B; Step S3: Aging the mixture B for 48 hours to obtain mixture C; Step S4: Press the mixture C under 10 MPa pressure to form a brick, dry it until the moisture content of the brick blank drops to below 5%, and then place it in a muffle furnace for sintering: heat it to 800°C at 10°C / min, then heat it to 1050°C at 5°C / min, hold it for sintering for 2 hours, and cool it with the furnace to obtain ecological microporous sintered bricks.

[0035] Figure 1 Micrographs of hardness tests on samples sintered at 1050℃ with 15% doping. The following can be clearly observed from the images: 1. This indicates that the sample has a uniform texture and dense structure, with no obvious loose areas or microcracks, proving that the process of this invention can fully fuse the raw materials and achieve complete sintering.

[0036] 2. According to the hardness test data in Table 5, the diagonal length of the indentation of this sample is approximately 80-90 μm, and the calculated hardness value is as high as 697-853 HV (average 628.72 HV). The smaller the indentation size, the stronger the material's resistance to plastic deformation, i.e., the higher the hardness.

[0037] 3. No obvious pore aggregation or unmelted particles were observed in the micrograph, indicating that the present invention has achieved good microstructure uniformity through raw material gradation optimization and sintering process control, which is the basis for excellent macroscopic mechanical properties.

[0038] Figure 1 This provides direct evidence that the brick material of this invention has a dense microstructure and excellent hardness, ensuring the wear resistance and durability of the product during use.

[0039] Figure 2 The images show the appearance of bricks obtained under different doping amounts and sintering temperatures, from which we can conclude that: 1. All samples exhibited regular geometric shapes and smooth, crack-free surfaces, demonstrating that the present invention's technology of using organic residue (coffee grounds) to improve the plasticity of the green body is remarkably effective and effectively solves the "cracking" problem caused by high inorganic residue content in the prior art.

[0040] 2. As the amount of lead-zinc smelting slag added increases from 10% to 30%, the color of the brick gradually deepens from light gray to dark gray / brownish-gray; as the sintering temperature increases from 1000℃ to 1050℃, the color of the brick slightly deepens, presenting a richer color gradation.

[0041] This color change pattern indicates that by adjusting the raw material ratio and sintering process, the decorative needs of different architectural styles can be met without the need for additional colorants, thus reducing production costs.

[0042] All samples showed uniform cross-sectional color and no black core was observed due to incomplete combustion of organic matter or a reducing atmosphere, proving that the heating regime and holding time used in this invention can ensure that the organic residue is fully burned off while avoiding internal reduction reactions.

[0043] Figure 2 This demonstrates that the product of this invention has excellent appearance quality and controllable color, and solves the common technical problems of cracking and black core in existing waste sintered bricks.

[0044] Figure 3 The curve showing the relationship between lead-zinc smelting slag content and compressive strength reveals that, with the same doping amount, a lower sintering temperature (1000℃) actually yields higher compressive strength. This invention achieves significant energy saving and consumption reduction while ensuring excellent mechanical properties, thus possessing important industrial application value and economic benefits.

[0045] The product performance test results for each embodiment are shown in Table 1:

[0046] The effect of different lead-zinc smelting slag admixtures on bulk density (unit: kg / m³) is shown in Table 2:

[0047] The effect of different lead-zinc smelting slag admixtures on apparent porosity (unit: %) is shown in Table 3:

[0048] The effect of different lead-zinc smelting slag admixtures on water absorption rate (unit: %) is shown in Table 4:

[0049] The Vickers hardness test results for typical samples are shown in Table 5:

[0050] Hardness test results showed that the hardness values ​​of all samples were greater than 330 HV, indicating that the brick material of this invention is hard and has good wear resistance. The sample with 15% doping had an average hardness of 628.72 HV, exhibiting excellent mechanical properties.

[0051] Table 6 shows a performance comparison between the product of this invention and national standards:

[0052] The above embodiments demonstrate that by scientifically combining inorganic industrial residues, organic industrial residues, and shale as raw materials, and optimizing the sintering process, the present invention successfully prepares ecological microporous sintered bricks with high strength, good thermal insulation performance, and excellent durability, realizing the efficient resource utilization of various wastes and achieving significant economic and environmental benefits.

[0053] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. An ecological microporous sintered brick, characterized in that, The ecological microporous sintered brick is made from raw materials comprising the following components: inorganic industrial residue, shale, organic industrial residue, and optional river sand. The inorganic industrial residue includes lead-zinc smelting slag and / or lead-zinc tailings. The raw materials further include one or more of tailings, construction waste, slag, and coal gangue. The weight proportions of each component are as follows: 10-60 parts of inorganic industrial residue, 25-70 parts of shale, 0-5 parts of organic industrial residue, and 0-25 parts of river sand. When the raw materials include tailings, construction waste, slag, and coal gangue, the weight proportions are: 10-60 parts of tailings, 5-20 parts of construction waste, 20-50 parts of shale, 5-20 parts of slag, and 5-20 parts of coal gangue. The ecological microporous sintered brick has a compressive strength ≥25MPa and an apparent porosity of 11.54%-15.63%.

2. The ecological microporous sintered brick according to claim 1, characterized in that, The inorganic industrial residue comprises 10-30 parts of pyrometallurgical zinc slag and 0-30 parts of lead-zinc tailings sand.

3. The ecological microporous sintered brick according to claim 2, characterized in that, In the pyrometallurgical zinc slag, the sum of the weight contents of Fe2O3 and SiO2 is greater than 62%; the lead-zinc tailings sand is in a slurry state, mainly composed of Al2O3 and SiO2, and the sum of the weight contents of Al2O3 and SiO2 is 49-70 wt%.

4. The ecological microporous sintered brick according to claim 1, characterized in that, The shale is a type of shale, which contains the following oxides by mass percentage: 44%-62% SiO2, 9%-13% Al2O3, 0.6%-16% CaO, and 8%-16% Fe2O3.

5. The ecological microporous sintered brick according to claim 1, characterized in that, The organic industrial residue includes one or more of sugar filter mud, silt and coffee grounds, mixed in any proportion.

6. The ecological microporous sintered brick according to claim 1, characterized in that, The tailings are iron ore tailings and / or molybdenum ore tailings; the total content of oxides of silicon, calcium, aluminum, iron and magnesium in the tailings is greater than 93.5% of the total weight of the tailings; the total content of potassium, sodium, manganese and sulfur in the tailings is less than 0.01% of the total weight of the tailings.

7. The ecological microporous sintered brick according to any one of claims 1 to 6, characterized in that, The ecological microporous sintered brick has a bulk density of 2.13 kg / m³ - 2.28 kg / m³, a water absorption rate of 5.11%-7.87%, and a hardness value greater than 330 HV.

8. A method for preparing the ecological microporous sintered brick as described in any one of claims 1 to 7, characterized in that, Includes the following steps: Step S1: Crush, grind and mix the raw materials to obtain mixture A; Step S2: Add water to the mixture A until the water content is 10 wt%, and stir to obtain mixture B; Step S3: Aging the mixture B to obtain mixture C; Step S4: After pressing and drying the mixture C, sinter it to obtain the ecological microporous sintered brick. In step S4, the moisture content of the brick blank after drying is reduced to below 5%. The sintering process is as follows: first, the temperature is raised to 800°C at a rate of 10°C / min, and then raised to 1000-1100°C at a rate of 5°C / min, and sintered at the temperature for 30 minutes to 8 hours.

9. The method according to claim 8, characterized in that, In step S1, the raw material is crushed to a particle size of less than 2 mm and then ball-milled to a particle size of less than 100 μm; in step S3, the aging time is 48-96 hours; in step S4, the molding pressure is 8-10 MPa, the holding time is 1 min, and the sample is a disc.

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