Fly ash water-permeable brick processing technology
Through scientific proportioning and process optimization, multi-functional seepage bricks are prepared using fly ash and slag, which solves the problems of waste of resources and single functions, and realizes the high strength and versatility of seepage bricks, reducing environmental pressure and maintenance costs.
Patent Information
- Application Number
- CN202510429042.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-08
- Publication Date
- 2025-07-08
- Estimated Expiration
- Not applicable · inactive patent
AI Technical Summary
The traditional water seepage brick processing technology fails to make full use of fly ash and slag, resulting in waste of resources and environmental pollution. At the same time, the water seepage brick has a single function, and the strength and water seepage performance are difficult to balance, which affects product quality and municipal maintenance costs.
Fly ash, coal-based kaolin, slag and additives are used as the main raw materials, and water seepage bricks with filtration and water storage functions are prepared through scientific proportioning, multi-cavity mold design and step-drying technology, combined with calcination and drilling treatment.
It realizes waste reuse, improves the strength, hardness and durability of seepage bricks, optimizes multifunctional performance, and reduces municipal expenditure costs.
Smart Images
Figure CN120271325A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of building material processing, and particularly relates to a processing technology for fly ash permeable bricks. Background Art
[0002] With the acceleration of the urbanization process, the scale of municipal infrastructure construction has been continuously expanding, and the demand for building materials has also been increasing day by day. At the same time, with the acceleration of the urbanization process, the environmental problems faced by cities have become increasingly prominent. Among them, waste treatment and water resource management have become two major challenges. Against this background, it is particularly urgent to develop building materials with environmental protection performance and excellent functions. Therefore, fly ash permeable bricks have emerged as the times require.
[0003] In the traditional processing technology of permeable bricks, the utilization of fly ash and slag has not been fully realized. Instead, more expensive raw materials are selected, which not only causes waste of resources, increases the degree of environmental pollution, but also increases the dependence on natural raw materials. In addition, the permeable bricks prepared by the traditional permeable brick process only have basic permeable functions and lack practical functions such as filtration and water storage. These permeable bricks cannot provide water source supplementation for the surrounding environment and cannot effectively regulate water resources. Secondly, the unreasonable ratio and manufacturing process lead to the difficulty of achieving a good balance between the strength and permeable performance of the permeable bricks, thereby affecting the strength, hardness and durability of the permeable bricks, making the product quality uneven and increasing the later maintenance and replacement costs of the municipal department. Summary of the Invention
[0004] The purpose of the present invention is to provide a processing technology for fly ash permeable bricks to solve the technical problems existing in the prior art.
[0005] In order to achieve the above invention purpose, the technical solution adopted by the present invention is as follows:
[0006] A processing technology for fly ash permeable bricks includes the following steps: S1: Raw material preparation, taking fly ash, coal-series kaolin, slag, additives and deionized water for standby; proportioning according to the mass percentages of 30% - 70% of fly ash, 3% - 25% of coal-series kaolin, 15% - 45% of slag, 1% - 2% of additives and 15% - 30% of deionized water; S2: Mixing and stirring, putting fly ash, coal-series kaolin and slag into a double-screw mixer according to the proportions in S1, mixing at a low speed of 20 - 35 r / min for 15 - 30 min; spraying atomized deionized water into the double-screw mixer and continuing to stir for 15 - 20 min to form wet materials; adding additives to the wet materials and mixing at a high speed of 60 - 90 r / min for 5 - 10 min to form a mixture; S3: Pressing, filling the mixture into a multi-chamber mold, adding corresponding performance components according to the requirements of different chambers, and using a hydraulic brick machine to maintain for 10 - 20 s under a pressure of 5 - 30 MPa to form a precast blank; S4: Drying, placing the blank in S3 in a drying oven, drying for 1 - 2 h under the condition of controlling the temperature at 50 - 65 °C, drying for 1 - 2 h under the condition of 70 - 80 °C, and drying for 2 - 4 h under the condition of 90 - 110 °C to form the final blank; S5: Calcining, placing the blank in S4 in a kiln, calcining according to a preset sintering program, controlling the calcining temperature at 900 - 1200 °C, and controlling the calcining time at 2 - 4 h; S6: Cooling, placing the brick body calcined in S5 in a room-temperature environment for natural cooling to obtain fly ash permeable bricks; S7: Drilling, drilling drainage channels and connecting pipes on the side and bottom of the fly ash permeable bricks in S6 through a drilling device.
[0007] Furthermore, the moisture content of the fly ash is 1% - 3%, and it passes through a 200 - 300 mesh sieve; the coal-series kaolin is crushed by a jaw crusher to a particle size less than 3 - 6 mm and ground by a disc grinder to a diameter less than 35 μm; the slag is screened into three grades of particles for standby.
[0008] Furthermore, the additives in S1 are made of one or several of water reducing agents, binders or waterproof agents.
[0009] Furthermore, the multi-chamber mold in S3 includes: an anti-slip convex mold core, an array of water permeable holes and a layered partition board. The layered partition board is at least three layers, which are divided into a water permeable layer located in the upper layer, a filtering layer located in the middle layer and a water storage layer located in the bottom layer.
[0010] Furthermore, a glass fiber grid is laid on the filtering layer, and a 0.2% - 0.5% polypropylene fiber mixture is filled; multiple water absorption bags are placed in the water storage layer.
[0011] Further, the capacity of the water absorption sac is 20 - 40 ml, and the distribution density is 2 - 3 per square centimeter.
[0012] Further, the aperture of the water seepage holes is 2 - 4 mm, and the hole spacing is 2 - 5 mm.
[0013] Further, the thicknesses of the water permeable layer, the filtering layer and the water storage layer are 8 - 12 mm.
[0014] Further, the mass percentage of the fly ash is 40% - 60%, the mass percentage of the coal - series kaolin is 5% - 20%, and the mass percentage of the slag is 20% - 35%.
[0015] Compared with the prior art, the present invention has the following beneficial effects:
[0016] The present invention uses waste fly ash and slag as the main raw materials and applies them to manufacture permeable bricks, which solves the problem of waste treatment, reduces the environmental pressure, realizes the recycling of resources, and conforms to the concept of sustainable development; and through scientific proportioning and the multi - cavity mold used in the pressing process, the permeable bricks have multiple functions, optimizing the performance of the permeable bricks. The drying and calcination processes effectively avoid the cracking of the green body caused by the rapid evaporation of water, ensuring the integrity and quality stability of the brick body, thereby improving the strength, hardness and durability of the brick body, achieving a better balance between the strength and water permeability of the brick body, and fundamentally reducing the cost of municipal expenditure. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Figure 1 is the flow chart of the present invention;
[0018] Figure 2 is the schematic diagram of the relationship between the slag addition amount and the compressive strength and water permeability coefficient of the permeable brick;
[0019] Figure 3 is the schematic diagram of the relationship between the forming pressure and the compressive strength and water permeability performance of the permeable brick;
[0020] Figure 4 is the schematic diagram of the relationship between the sintering temperature and the compressive strength and water permeability coefficient;
[0021] Figure 5 is the schematic diagram of the relationship between the constant - temperature time and the compressive strength and water permeability coefficient; DETAILED DESCRIPTION OF THE INVENTION
[0022] In order to make the content of the present invention easier to be clearly understood, the following will, in conjunction with the accompanying drawings in the embodiments of the present invention, clearly and completely describe the technical solutions in the embodiments of the present invention. The same components are denoted by the same reference numerals. It should be noted that the terms "front", "rear", "left", "right", "upper" and "lower" used in the following description refer to the directions in the drawings, and the terms "inner" and "outer" respectively refer to the directions towards or away from the geometric center of a specific component.
[0023] Embodiment 1:
[0024] As Figure 1 shown, in this embodiment, a processing technology for fly ash permeable bricks is provided, including the following steps:
[0025] S1: Preparation of raw materials. Take fly ash, coal-series kaolin, slag, additives and deionized water for standby; mix them according to the mass percentages of 30% - 70% of fly ash, 3% - 25% of coal-series kaolin, 15% - 45% of slag, 1% - 2% of additives and 15% - 30% of deionized water; the moisture content of the fly ash is 1%, and it passes through a 200-mesh sieve. Its main chemical components are SiO2, Al2O3, Cao, Fe2O3, MgO, etc. Among them, the mass contents of SiO2 and Al2O3 are above 70%, with high activity, and its particle size is small, and the particle morphology is spherical; the coal-series kaolin is crushed by a jaw crusher to a particle size less than 3 mm and ground by a disc mill to a diameter less than 35 μm. It is mainly associated with large coal mines; the slag is screened into three grades of particles for standby, and the particle size of the slag is 0.45 - 0.6 mm.
[0026] S2: Mixing and stirring. Put fly ash, coal-series kaolin and slag into a double-screw mixer according to the ratio in S1, and mix them at a low speed of 20 r / min for 15 min; spray atomized deionized water into the double-screw mixer and continue stirring for 15 min to form wet materials; add additives to the wet materials and mix them at a high speed of 60 r / min for 5 min to form mixed materials; the temperature of the sprayed atomized deionized water is 20 - 60 °C, and the total amount of sprayed water is 10% of fly ash, coal-series kaolin and slag.
[0027] S3: Compression. Fill the mixture into a multi - cavity mold, add corresponding performance components according to the requirements of different cavities, and use a hydraulic brick press to maintain for 10 s under a pressure of 5 MPa to form a pre - formed body. The performance components are anti - slip convex mold cores, water - seepage hole arrays, layered partitions, etc. The multi - cavity mold in S3 includes: anti - slip convex mold cores, water - seepage hole arrays, and layered partitions. The layered partitions are at least three layers, which are divided into a permeable layer at the upper layer, a filtering layer at the middle layer, and a water storage layer at the bottom layer. A fiberglass grid is laid on the filtering layer, and a 0.2% polypropylene fiber mixture is filled. Multiple water - absorbing sacs are placed in the water storage layer. The water - absorbing sacs can quickly absorb the rainwater that enters the brick body through the water - seepage holes and store it. After absorbing rainwater, the water - absorbing sacs can slowly release the stored water under arid or high - temperature conditions. In summer, the water - absorbing sacs can effectively reduce the surface temperature and relieve the urban heat island effect. In winter, the water absorption can slow down the surface icing and improve road safety. The capacity of the water - absorbing sac is 20 ml, and the distribution density is 2 per square centimeter. The aperture of the water - seepage holes is 2 mm, and the hole spacing is 2 mm. The thicknesses of the permeable layer, filtering layer, and water storage layer are 8 mm. The anti - slip convex mold core is in a strip, cylindrical, or frustum - shaped structure, and its height is usually 1 - 2 mm, which can ensure the anti - slip effect without affecting walking comfort.
[0028] S4: Drying. Place the pre - formed body in S3 in a drying oven and dry it for 1 h under the condition of controlling the temperature at 50°C, dry it for 1 h under the condition of 70°C, and dry it for 2 h under the condition of 90°C to form the final pre - formed body. The drying process is a stepped drying mode. In each stage, different temperature, humidity, and time parameters are set according to the operator to gradually complete the drying process of the pre - formed body, which is more flexible and efficient. In the initial stage, a lower temperature and higher humidity are adopted to delay the evaporation of surface moisture, ensure the gradual transfer of internal moisture, reduce the internal and external shrinkage difference, gradually adjust the drying conditions, and improve the drying uniformity, thereby effectively preventing cracking.
[0029] S5: Calcination. Place the pre - formed body in S4 in a kiln and carry out calcination according to the preset sintering procedure. The calcination temperature is controlled at 900°C, and the calcination time is controlled at 2 h. The sintering procedure includes the kiln temperature and the calcination time.
[0030] S6: Cooling. Place the brick body after calcination in S5 in a room - temperature environment and let it cool naturally to obtain fly - ash permeable bricks.
[0031] S7: Drilling. Drill drainage channels and connecting pipes on the side and bottom of the fly - ash permeable bricks in S6 through a drilling device. The drilling device is a numerical - control drilling machine, which can accurately control the movement trajectory and drilling parameters of the drill bit through a preset digital control system, thereby realizing the automated drilling operation of the permeable bricks.
[0032] Example Two:
[0033] In this example, a processing technology for fly ash permeable bricks is provided, including the following steps:
[0034] S1: Raw material preparation. Prepare fly ash, coal-series kaolin, slag, water reducer and deionized water for use; mix them according to the mass percentage of 40% fly ash, 5% coal-series kaolin, 20% slag, 1% water reducer and 15% deionized water; the moisture content of the fly ash is 2%, and it is sieved through a 250-mesh sieve; its main chemical components are SiO2, Al2O3, Cao, Fe2O3, MgO, etc., among which the mass content of SiO2 and Al2O3 is above 70%, with high activity, and its particle size is small, and the particle morphology is spherical; the coal-series kaolin is crushed by a jaw crusher to a particle size less than 5 mm and ground by a disc grinder to a diameter less than 35 μm, and it is mainly associated with large coal mines; the slag is screened into three grades of particles for standby; the particle size of the slag is 0.6 - 1 mm; the temperature of the sprayed and atomized deionized water is 20 °C, and the total water spraying amount is 10% of the fly ash, coal-series kaolin and slag;
[0035] S2: Mixing and stirring. Put fly ash, coal-series kaolin and slag into a double-screw mixer according to the ratio in S1, and mix them at a low speed of 25 r / min for 20 min; spray and atomize deionized water into the double-screw mixer, and continue stirring for 17 min to form wet materials; add additives to the wet materials, and mix them at a high speed of 80 r / min for 7 min to form mixed materials;
[0036] S3: Compression. Fill the mixture into a multi - cavity mold, and add corresponding performance components according to the requirements of different cavities. The performance components are anti - slip convex mold cores, water seepage hole arrays, layered partitions, etc. Use a hydraulic brick press to maintain a pressure of 25 MPa for 15 s to form a pre - formed body. The multi - cavity mold in S3 includes: anti - slip convex mold cores, water seepage hole arrays, and layered partitions. The layered partitions are at least three layers, which are divided into a permeable layer located in the upper layer, a filtering layer located in the middle layer, and a water storage layer located in the bottom layer. A fiberglass grid is laid on the filtering layer, and a 0.3% polypropylene fiber mixture is filled in. Multiple water absorption sacs are placed in the water storage layer. The water absorption sacs can quickly absorb the rainwater that enters the brick body through the water seepage holes and store it. After absorbing rainwater, the water absorption sacs can slowly release the stored water under drought or high - temperature conditions. In summer, the water absorption sacs can effectively reduce the surface temperature and relieve the urban heat island effect. In winter, the water absorption can slow down the surface icing and improve road safety. The capacity of the water absorption sac is 30 ml, and the distribution density is 3 per square centimeter. The aperture of the water seepage holes is 3 mm, and the hole spacing is 4 mm. The thicknesses of the permeable layer, filtering layer, and water storage layer are 9 mm. The anti - slip convex mold core is in a strip, cylindrical, or frustum - shaped structure, and its height is usually 1 - 2 mm, which can ensure the anti - slip effect without affecting walking comfort.
[0037] S4: Drying. Place the pre - formed body in S3 in a drying oven and dry it for 1.5 h under the condition of controlling the temperature at 55°C, dry it for 1.5 h under the condition of 75°C, and dry it for 3 h under the condition of 105°C to form the final pre - formed body. The drying process is a stepped drying mode. In each stage, different temperature, humidity, and time parameters are set according to the operator to gradually complete the drying process of the pre - formed body, which is more flexible and efficient. In the initial stage, a lower temperature and higher humidity are adopted to slowly evaporate the surface moisture, ensure the gradual transfer of internal moisture, reduce the internal and external shrinkage differences, gradually adjust the drying conditions, and improve the drying uniformity, thereby effectively preventing cracking.
[0038] S5: Calcination. Place the pre - formed body in S4 in a kiln and carry out calcination according to the preset sintering program. The calcination temperature is controlled at 1000°C, and the calcination time is controlled at 3 h. The sintering program includes the kiln temperature and the calcination time.
[0039] S6: Cooling. Place the brick body after calcination in S5 in a room - temperature environment and let it cool naturally to obtain fly - ash permeable bricks.
[0040] S7: Drilling. Drill drainage channels and connecting pipes on the side and bottom of the fly - ash permeable bricks in S6 through a drilling device. The drilling device is a numerical - control drilling machine, which can accurately control the movement trajectory and drilling parameters of the drill bit through a preset digital control system, thereby realizing the automated drilling operation of the permeable bricks.
[0041] Example 3:
[0042] In this example, a processing technology for fly ash permeable bricks is provided, including the following steps:
[0043] S1: Preparation of raw materials. Prepare fly ash, coal-series kaolin, slag, binder, and deionized water; mix them according to the mass percentage of 60% fly ash, 20% coal-series kaolin, 35% slag, 1% binder, and 15% deionized water. The moisture content of the fly ash is 3%, and it passes through a 300-mesh sieve. Its main chemical components are SiO2, Al2O3, Cao, Fe2O3, MgO, etc. The mass content of SiO2 and Al2O3 is above 70%, with high activity. Moreover, its particle size is small, and the particle morphology is spherical. The coal-series kaolin is crushed by a jaw crusher to a particle size less than 6 mm and ground by a disc grinder to a diameter less than 35 μm. It is mainly associated with large coal mines. The slag is screened into three grades of particles for standby. The particle size of the slag is 1 mm - 2 mm.
[0044] S2: Mixing and stirring. Put fly ash, coal-series kaolin, and slag into a double-screw mixer according to the ratio in S1, and mix them at a low speed of 35 r / min for 30 min. Spray atomized deionized water into the double-screw mixer and continue stirring for 20 min to form wet materials. Add additives to the wet materials and mix them at a high speed of 90 r / min for 10 min to form mixed materials. The temperature of the sprayed atomized deionized water is 60 °C, and the total amount of sprayed water is 10% of fly ash, coal-series kaolin, and slag.
[0045] S3: Compression. Fill the mixture into a multi - cavity mold, add corresponding performance components according to the requirements of different cavities, and use a hydraulic brick press to maintain at a pressure of 30 MPa for 20 s to form a pre - formed body. The performance components are anti - slip convex die cores, water seepage hole arrays, and layered partitions, etc. The multi - cavity mold in S3 includes: anti - slip convex die cores, water seepage hole arrays, and layered partitions. The layered partition is at least three layers, which are divided into a permeable layer at the upper layer, a filtering layer at the middle layer, and a water storage layer at the bottom layer. A fiberglass grid is laid on the filtering layer, and a 0.5% polypropylene fiber mixture is filled in. Multiple water absorption bags are placed in the water storage layer. The water absorption bags can quickly absorb the rainwater that enters the brick body through the water seepage holes and store it. After absorbing rainwater, the water absorption bags can slowly release the stored water under arid or high - temperature conditions. In summer, the water absorption bags can effectively reduce the surface temperature and alleviate the urban heat island effect. In winter, the water absorption can slow down the surface icing and improve road safety. The capacity of the water absorption bag is 40 ml, and the distribution density is 3 per square centimeter. The aperture of the water seepage hole is 4 mm, and the hole spacing is 5 mm. The thicknesses of the permeable layer, filtering layer, and water storage layer are 12 mm. The anti - slip convex die core is in a strip, cylindrical, or frustum - shaped structure, and its height is usually 1 - 2 mm, which can ensure the anti - slip effect without affecting walking comfort.
[0046] S4: Drying. Place the pre - formed body in S3 in a drying oven and dry it for 2 h under the condition of controlling the temperature at 65℃, dry it for 2 h under the condition of 80℃, and dry it for 4 h under the condition of 110℃ to form the final pre - formed body. The drying process is a step - by - step drying mode. In each stage, different temperature, humidity, and time parameters are set according to the operator to gradually complete the drying process of the pre - formed body, which is more flexible and efficient. In the initial stage, a lower temperature and higher humidity are adopted to slowly evaporate the surface moisture, ensure the gradual transfer of internal moisture, reduce the internal and external shrinkage difference, gradually adjust the drying conditions, and improve the drying uniformity, thereby effectively preventing cracking.
[0047] S5: Calcination. Place the pre - formed body in S4 in a kiln and calcine it according to the preset sintering procedure. The calcination temperature is controlled at 1200℃, and the calcination time is controlled at 4 h. The sintering procedure includes the kiln temperature and the calcination time.
[0048] S6: Cooling. Place the brick body after calcination in S5 in a room - temperature environment and let it cool naturally to obtain fly - ash permeable bricks.
[0049] S7: Drilling. Drill drainage channels and connecting pipes on the side and bottom of the fly - ash permeable bricks in S6 through a drilling device. The drilling device is a numerical control drilling machine, which can accurately control the movement trajectory and drilling parameters of the drill bit through a preset digital control system, thus realizing the automatic drilling operation of the permeable bricks.
[0050] The water-permeable bricks made in Examples 1 to 3 were tested for the compressive strength and water permeability coefficient performance of the fly ash water-permeable brick products according to the standard of JC / T945-2005 "Water-permeable Bricks". The test results are as follows:
[0051] Table (1) Experiment on the mixing ratio of fly ash and coal-series kaolin
[0052] According to Table (1), the compressive strength of the water-permeable brick increases with the increase of the binder content. In Example 3, there are bulges and cracks in the brick billet after sintering because the binder content is high, the viscosity of the billet is large, it melts during high-temperature sintering, and the tensile stress changes greatly during the cooling process.
[0053] Table (2) Influence of slag particle size on the performance of fly ash water-permeable bricks
[0054]
[0055] According to Table (2), with the increase of the slag particle size, the compressive strength of the water-permeable brick decreases and the water permeability coefficient increases. Because as the coarse aggregate becomes coarser, the density of the green billet becomes smaller and the voids in the billet increase, which is not conducive to the sintering of the product, so the compressive strength decreases and the water permeability performance improves.
[0056] As Figure 2 shown, the slag particle size was controlled to be 1.00 - 2.00 mm, and the addition amounts of slag were changed to 20%, 25%, 30%, and 35% respectively, and the influence of the slag addition amount on its compressive strength and water permeability coefficient was obtained; as Figure 2 can be seen: with the increase of the coarse aggregate addition amount, the compressive strength of the product decreases and the water permeability performance improves. The reason is that with the increase of the coarse aggregate addition amount, the density of the billet decreases and the voids in the billet increase, resulting in a decrease in compressive strength and an improvement in water permeability performance.
[0057] As Figure 3 shown, the semi-dry pressing method was used for molding, and the mixture of fly ash: coal-series kaolin: slag = 60:15:25 was used as the raw material for the pressed billet, and tests were carried out in the pressure range of 5 - 30 MPa to investigate the influence of the molding pressure on the compressive strength and water permeability performance; as Figure 3It can be seen that with the increase of the forming pressure, the compressive strength of the permeable brick increases while the water permeability decreases. In the range where the pressure is less than 25 MPa, the compressive strength and water permeability change significantly with the forming pressure. After the pressure exceeds 25 MPa, the change of its properties with the pressure becomes gentle. The reason is that in the initial stage of pressing, the position movement and rearrangement of fly ash, peat and slag are obvious during the pressing process. And with the increase of the pressure, the packing density between the raw material particles becomes larger and the voids become smaller, resulting in a significant increase in the compressive strength and a decrease in the water permeability. After the pressure exceeds 25 MPa, the raw materials are already close to dense packing, and when the pressure continues to increase, the change of properties is not obvious, resulting in the compressive strength and water permeability tending to be stable.
[0058] As Figure 4 shown, on the basis of the above tests, calcination was carried out at 950 °C, 1000 °C, 1050 °C, 1100 °C, 1150 °C, 1200 °C and held for 30 min, then cooled naturally to test the influence of different sintering temperatures on the properties of the products. It can be Figure 4 seen that with the increase of the sintering temperature, the compressive strength of the product increases and the water permeability coefficient decreases. However, if the temperature is too high, the product will vitrify, affecting the brick body forming. A series of physical and chemical reactions will occur during the firing process of the green body. When the temperature reaches 950 °C, the particles start to bond with each other, forming certain pores, and the strength of the product increases and the water permeability is very good. But when the temperature reaches 1000 °C, many low-melting-point components in the system start to melt, causing the particles to move and rearrange, but the amount of the generated liquid phase is not much and the pore filling rate is low. Therefore, the compressive strength of the product increases significantly, but the change range of the water permeability is small. When the temperature continues to increase, the amount of the generated liquid phase becomes more and more, the pore filling rate increases, and the density further increases, resulting in a decrease in the water permeability and an increase in the compressive strength. When the temperature reaches 1200 °C, the permeable brick vitrifies.
[0059] As Figure 5 shown, on the basis of the above tests, it was kept at a constant temperature of 1100 °C for 0.3 h, 0.5 h, 1.0 h, 1.5 h respectively, and then cooled naturally. It can be Figure 5 seen that with the extension of the holding time, the water permeability coefficient decreases significantly, but the compressive strength of the permeable brick increases. The reason is that at the same sintering temperature of 1100 °C, with the extension of the holding time, the amount of the generated high-temperature liquid phase increases, and the liquid phase fills part of the voids, causing the porosity of the brick body to decrease, resulting in a decrease in the water permeability of the permeable brick and an increase in the compressive strength.
[0060] In summary, first, with the increase of the forming pressure, the compressive strength of the permeable brick increases while the water permeability decreases. A high sintering temperature is beneficial to improving the compressive strength of the permeable brick, but the water permeability decreases. With the extension of the constant temperature time, the water permeability decreases, but the compressive strength of the permeable brick can be improved. This is because the forming pressure, sintering temperature, and constant temperature time are related to the density and porosity of the green body, and the density and porosity of the green body directly determine the compressive strength and water permeability of the permeable brick. Second, the raw material ratio is fly ash: coal-series kaolin: coarse aggregate = 60%: 15%: 25%, the forming pressure is 25 MPa, the sintering temperature is 1100 °C, and the constant temperature is 40 min. Under these conditions, the permeable brick made of lignite fly ash and coal-series kaolin has a compressive strength of 325 MPa and a water permeability coefficient of 0.96×10 -2 cm / s.
[0061] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the protection scope of the present invention.
Claims
1. A processing technology for fly ash permeable bricks, characterized in that: It includes the following steps: S1: Raw material preparation. Prepare fly ash, coal-series kaolin, slag, additives and deionized water for use. Mix them according to the mass percentages of 30% - 70% of fly ash, 3% - 25% of coal-series kaolin, 15% - 45% of slag, 1% - 2% of additives and 15% - 30% of deionized water. S2: Mixing and stirring. Put fly ash, coal-series kaolin and slag into a double-screw mixer according to the ratio in S1, and mix them at a low speed of 20 - 35 r / min for 15 - 30 min. Spray atomized deionized water into the double-screw mixer and continue stirring for 15 - 20 min to form wet materials. Add additives to the wet materials and mix them at a high speed of 60 - 90 r / min for 5 - 10 min to form mixed materials. S3: Pressing. Fill the mixed materials into a multi-chamber mold, add corresponding performance components according to the requirements of different chambers, and use a hydraulic brick press to keep them under a pressure of 5 - 30 MPa for 10 - 20 s to form precast blanks. S4: Drying. Place the blanks in S3 in a drying oven, and dry them for 1 - 2 h under the condition of controlling the temperature at 50 - 65 °C, for 1 - 2 h under the condition of 70 - 80 °C, and for 2 - 4 h under the condition of 90 - 110 °C to form final blanks. S5: Calcining. Place the blanks in S4 in a kiln and calcine them according to the preset sintering procedure. Control the calcining temperature at 900 - 1200 °C and the calcining time at 2 - 4 h. S6: Cooling. Place the bricks after calcining in S5 in a room-temperature environment and let them cool naturally to obtain fly ash permeable bricks. S7: Drilling. Drill drainage channels and connecting pipes on the side and bottom of the fly ash permeable bricks in S6 through a drilling device.
2. The processing technology of fly ash permeable bricks according to claim 1, characterized in that: The moisture content of the fly ash is 1% - 3%, and it passes through a 200 - 300 mesh sieve; the coal-series kaolin is crushed by a jaw crusher to a particle size less than 3 - 6 mm and ground by a disc grinder to a diameter less than 35 μm; the slag is screened into three grades of particles for standby.
3. The processing technology of fly ash permeable bricks according to claim 1, characterized in that: The additives in S1 are made of one or several of water reducing agents, binders or waterproof agents.
4. The processing technology of fly ash permeable bricks according to claim 1, characterized in that: The multi-chamber mold in S3 includes: an anti-slip convex mold core, a water seepage hole array and a layered partition board. The layered partition board has at least three layers, which are divided into a permeable layer at the upper layer, a filtering layer at the middle layer and a water storage layer at the bottom layer.
5. The processing technology of fly ash permeable bricks according to claim 4, characterized in that: Lay a fiberglass grid on the filtering layer and fill it with 0.2% - 0.5% of polypropylene fiber mixture; put multiple water absorption bags in the water storage layer.
6. The processing technology of fly ash permeable bricks according to claim 5, characterized in that: The capacity of the water absorption bag is 20 - 40 ml, and the distribution density is 2 - 3 per square centimeter.
7. The processing technology of fly ash permeable bricks according to claim 4, characterized in that: The aperture of the water seepage hole is 2 - 4 mm, and the hole spacing is 2 - 5 mm.
8. The processing technology of fly ash permeable bricks according to claim 4, characterized in that: The thicknesses of the permeable layer, the filtering layer and the water storage layer are 8 - 12 mm.
9. The processing technology of fly ash permeable bricks according to claim 1, characterized in that: The mass percentage of the fly ash is 40% - 60%, the mass percentage of the coal-series kaolin is 5% - 20%, and the mass percentage of the slag is 20% - 35%.