Method for preparing ceramsite by using belt type roasting machine

Abstract

The invention provides a preparation method of ceramsite by a belt type roasting machine, and belongs to the technical field of building material preparation, and the preparation method comprises the following steps: arranging a material distribution baffle plate above a conveyor belt of the belt type roasting machine, and controlling the thickness of a ceramsite material layer to be sintered in the process of conveying the ceramsite by the belt type roasting machine to realize thin material layer roasting, while the heat transfer efficiency during material layer roasting is improved, the sintering period is shortened and the ceramsite preparation efficiency is improved, the conditions of oversintering of ceramsite on the surface layer of the material layer and undersintering of ceramsite in the material layer are avoided, the uniformity of the strength of the sintered ceramsite is improved, and the qualified rate of ceramsite products is improved; volatile components in the coal gangue are extracted from the material layer by roasting the material layer in sections, heat is provided by combustion of the volatile components, external energy dependence is reduced, fuel supply is reduced, and fuel cost is reduced; through the process design of combining a thin material layer with segmented roasting, the hardening rate of ceramsite is reduced, the cylinder compressive strength fluctuation of a finished product is reduced, and the porosity uniformity is improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of building material preparation, and particularly relates to a preparation method of a belt-type calcining machine for ceramsite. BACKGROUND

[0002] Ceramsite is a kind of light and porous building material, which is widely used in the fields of concrete aggregate, thermal insulation material and the like. The traditional production process takes clay or shale as raw material, and has the problems of large resource consumption and high cost. Coal gangue, as a solid waste of coal industry, has a huge annual emission amount, and has the resource utilization potential because of its similar chemical composition to the raw material of ceramsite, and has been used to prepare ceramsite. Due to the limitation of the existing washing process, the coal in the coal gangue cannot be washed clean, so that the coal gangue contains a high heat; however, a large amount of external heat needs to be provided in the calcining process to successfully calcine the coal gangue, and once the high-calorific-value coal gangue ceramsite is ignited, the ceramsite is burned into a lump, resulting in poor quality of the ceramsite product and low product yield, and the preparation process needs to be improved. SUMMARY

[0003] The present application aims to at least solve one of the problems in the prior art or related art.

[0004] Therefore, according to the embodiments of the present application, a preparation method of a belt-type calcining machine for ceramsite is provided, which comprises the following steps:

[0005] Adjusting the mixing ratio of the coal gangue and the auxiliary material to prepare the ceramsite;

[0006] A material distribution baffle is arranged above the conveying belt of the belt-type calcining machine, and the feeding speed of the feeder and the conveying speed of the belt-type calcining machine are controlled to adjust the thickness of the material layer;

[0007] Drying treatment is performed on the ceramsite to reduce the water content of the ceramsite;

[0008] The ceramsite is calcined in stages, and natural gas is introduced during the calcination to extract the volatile matter from the material layer.

[0009] In a feasible embodiment, the mixing ratio of the coal gangue and the auxiliary material is adjusted to prepare the ceramsite, which comprises the following steps:

[0010] The coal gangue is sieved according to the particle size;

[0011] The coal gangue with a particle size greater than 10 mm is sent to a crusher and crushed to a particle size of less than or equal to 10 mm;

[0012] The coal gangue with a particle size of less than or equal to 10 mm is mixed with the auxiliary material, so that the water content of the mixed material is 8% to 12%, and the mass ratio of SiO2 to Al2O3 in the mixed material is adjusted to 2.5 to 4.0;

[0013] The mixture is fed into a vertical mill device to be ground into fine powder with a size of 100-200 mesh;

[0014] Water is added to the fine powder, and after stirring, the ceramic granules with a diameter of 8-12 mm are formed.

[0015] In a feasible implementation, a material baffle is arranged above the conveying belt of the belt roaster, and the feeding speed of the feeder and the conveying speed of the belt roaster are controlled to adjust the thickness of the material layer, including the steps of:

[0016] The position of the baffle is arranged and adjusted so that the vertical distance between the lower edge of the baffle and the surface of the conveying belt is 100-300 mm;

[0017] The feeding speed of the feeder and the conveying speed of the belt roaster are controlled to control the thickness of the material layer to be 100-300 mm.

[0018] In a feasible implementation, the ceramic granules are subjected to drying treatment to reduce the water content of the ceramic granules, including the steps of:

[0019] When the drying temperature reaches 80°C, the ceramic granules are fed into a drying device;

[0020] The drying temperature is raised to 200°C in 2-3 stages, and the total drying time is controlled to be 60-120 minutes, so that more than 90% of the external water in the ceramic granules is removed, and the water content of the ceramic granules is ≤0.5%.

[0021] In a feasible implementation, the ceramic granules are subjected to stage roasting, natural gas is introduced during roasting, and volatile components are extracted from the material layer, including the steps of:

[0022] The roasting process is divided into a pyrolysis section, a decarburization section, and a roasting section;

[0023] In the pyrolysis section, the ceramic granules are roasted at a temperature of 300-500°C for 15-30 minutes to remove 80% of the volatile components in the ceramic granules;

[0024] In the decarburization section, the ceramic granules are roasted at a temperature of 700-900°C for 20-30 minutes to remove 20% of the volatile components and 80% of the fixed carbon in the ceramic granules;

[0025] In the roasting section, the ceramic granules are roasted at a temperature of 1100-1200°C for 10-20 minutes;

[0026] Among them, after entering the latter half of the decarburization section, a multi-point injection burner is used to introduce natural gas to form high-temperature flue gas through natural gas combustion.

[0027] In a feasible implementation, the belt roaster is divided into three independent air zones, i.e., a pyrolysis zone, a decarburization zone, and a roasting zone, along the length direction of the belt roaster;

[0028] thermocouples are arranged in each air zone;

[0029] the air pressure and air volume of the gas in each air zone are controlled to make the mixture uniformly heated;

[0030] the thermocouples feed back the temperature of the air zone to the PLC system to dynamically adjust the gas flow and air volume in each air zone through the PLC system.

[0031] In a feasible embodiment, in the pyrolysis zone, the air pressure is controlled to be 1.5-2.5 kPa and the air speed is controlled to be 1.2-1.8 m / s to extract the volatile matter from the material layer;

[0032] In the decarburization zone, the air pressure is controlled to be 0.5-1.2 kPa and the air speed is controlled to be 0.8-1.2 m / s to remove the fixed carbon from the material layer;

[0033] In the roasting zone, the air pressure is controlled to be 1.5-2.5 kPa and the air speed is controlled to be 0.8-1.2 m / s to enhance the heat penetration to the material layer.

[0034] In a feasible embodiment, the preparation method of the ceramic particle belt roaster further comprises:

[0035] The ceramic particles are gradient air-cooled to below 80℃.

[0036] In a feasible embodiment, the ceramic particles are gradient air-cooled to below 80℃, which comprises the steps of:

[0037] When the temperature reaches 1200℃, the ceramic particles are discharged from the kiln and transferred to the air-cooling bin;

[0038] The high-speed air-cooling is started to cool the ceramic particles at a cooling rate of 120-150℃ / h for about 4-5 hours to cool the ceramic particles to 600℃;

[0039] The medium-speed air-cooling is switched to cool the ceramic particles at a cooling rate of 60-100℃ / h for about 3-5 hours to cool the ceramic particles to 300℃;

[0040] The low-speed air-cooling or the intermittent air-blower is switched to cool the ceramic particles at a cooling rate of 40-60℃ / h for about 3.6-5.5 hours to cool the ceramic particles to 80℃.

[0041] In a feasible embodiment, the preparation method of the ceramic particle belt roaster further comprises:

[0042] After the ceramic particles are cooled, the ceramic particles are screened;

[0043] The ceramic particles with a particle size of 8-12 mm and a cylinder pressure strength of ≥5 MPa are screened out as the finished product;

[0044] The rest of the ceramsite is sent back to the vertical mill device to continue participating in the granulation process.

[0045] Compared with the prior art, the method for preparing ceramsite by using a belt calciner has the beneficial effects that:

[0046] The method for preparing ceramsite by using a belt calciner provided in the embodiments of the present application controls the thickness of the ceramsite layer to be calcined during the conveying of the ceramsite by the belt calciner by arranging the material baffle above the conveying belt of the belt calciner, realizes thin-layer calcination, improves the heat transfer efficiency during the calcination of the layer, shortens the calcination period, improves the ceramsite preparation efficiency, avoids the overcalcination of the surface ceramsite and the undercalcination of the internal ceramsite in the layer, improves the uniformity of the strength of the calcined ceramsite, and improves the qualified rate of the ceramsite product; the volatile matter in the coal gangue is extracted from the layer by the segmented calcination of the layer, heat is provided by the combustion of the volatile matter, the dependence on external energy is reduced, the supply of fuel is reduced, and the fuel cost is reduced; natural gas is used as the fuel during the calcination, the generation of pollutants such as sulfur oxides and dust during the combustion is reduced, energy is saved, and the environment is protected; the process design of the thin-layer combined with the segmented calcination reduces the ceramsite hardening rate, reduces the strength fluctuation of the finished product cylinder, and improves the uniformity of the porosity. BRIEF DESCRIPTION OF DRAWINGS

[0047] Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The drawings are for purposes of illustration only and are not to be construed as limiting the application. Moreover, in the drawings, like reference numerals designate similar parts throughout the several views, and in which:

[0048] Figure 1 A schematic step flow chart of the method for preparing ceramsite by using a belt calciner according to an embodiment of the present application is shown in FIG. 1.

[0049] Figure 2 A schematic process flow chart of the method for preparing ceramsite by using a belt calciner according to an embodiment of the present application is shown in FIG. 2. DETAILED DESCRIPTION

[0050] In the description of the present application, it should be understood that the terms “center”, “longitudinal”, “transverse”, “length”, “width”, “thickness”, “upper”, “lower”, “front”, “rear”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inner”, “outer”, “clockwise”, “counterclockwise”, and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0051] In addition, the terms "first", "second", etc. are used only for the purpose of description, and should not be understood as indicating or implying relative importance or implying the number of the technical features indicated. Therefore, the features defined as "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "a plurality of" is two or more, unless otherwise explicitly specified and limited.

[0052] In the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting", "fixing" and the like should be understood in a broad sense, for example, can be fixedly connected, can be detachably connected, or integrally connected; can be mechanically connected, or electrically connected; can be directly connected, or indirectly connected through an intermediate medium, or the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0053] The preferred embodiments of the present application are described below in conjunction with the accompanying drawings, and it should be understood that the preferred embodiments described herein are only used to illustrate and explain the present application, and are not used to limit the present application.

[0054] As shown in Figure 1 According to the embodiments of the present application, a method for preparing a ceramic particle by a belt roaster is provided, comprising:

[0055] Step 100: adjusting the mixing ratio of coal gangue and auxiliary materials to prepare ceramic particles;

[0056] Step 200: setting a material baffle above the conveying belt of the belt roaster, and controlling the feeding speed of the feeder and the conveying speed of the belt roaster to adjust the thickness of the material layer;

[0057] Step 300: drying the ceramic particles to reduce the moisture content of the ceramic particles;

[0058] Step 400: roasting the ceramic particles in stages, and introducing natural gas during the roasting to extract volatile components from the material layer.

[0059] The belt calciner preparation method for ceramsite provided in this application embodiment controls the thickness of the ceramsite layer to be calcined during the conveyor belt calciner process by setting a material distribution baffle above the belt calciner. This achieves thin-layer calcination, improves heat transfer efficiency during calcination, shortens the calcination cycle, and increases the ceramsite preparation efficiency. Simultaneously, it avoids over-calcination of the surface ceramsite and under-calcination of the interior ceramsite, improving the uniformity of ceramsite strength after calcination and increasing the product qualification rate. By calcining the material layer in stages, volatile matter in the coal gangue is extracted from the material layer, and the combustion of volatile matter provides heat, reducing dependence on external energy sources, thus reducing fuel supply and lowering fuel costs. Natural gas is used as fuel during calcination, reducing the generation of sulfur oxides, dust, and other pollutants, resulting in energy conservation and environmental protection. The thin-layer combined with staged calcination process design reduces the ceramsite caking rate, minimizes fluctuations in the finished product cylinder compressive strength, and improves porosity uniformity.

[0060] Furthermore, high-calorific-value coal gangue with a calorific value of 500kcal / kg to 800kcal / kg is selected as the main raw material, supplemented with clay, shale or pore-forming agents to produce ceramsite.

[0061] It should be noted that while using high-calorific-value coal gangue as raw material to produce ceramsite relies on the gangue's own heat for firing, which reduces energy consumption and lowers the production cost, ceramsite made from high-calorific-value coal gangue tends to clump together during firing, resulting in a rough, dark brown surface and incomplete internal decarburization, giving it a black color. This application improves the sintering quality and efficiency of ceramsite by precisely controlling the material layer thickness and performing thin-layer firing. Furthermore, segmented firing of the thin layer extracts volatiles from the coal gangue, further reducing reliance on external energy sources, decreasing fuel supply, and lowering the overall production cost.

[0062] like Figure 2 As shown, in one feasible implementation, adjusting the mixing ratio of coal gangue and auxiliary materials to produce ceramsite includes the following steps:

[0063] The coal gangue is screened according to its particle size;

[0064] Coal gangue with a particle size greater than 10mm that has been screened out is fed into a crusher and crushed to a particle size ≤10mm;

[0065] Coal gangue with a particle size ≤10mm is mixed with auxiliary materials to make the moisture content of the mixture 8% to 12%, and the mass ratio of SiO2 to Al2O3 in the mixture is adjusted to 2.5 to 4.0.

[0066] The mixture is fed into a vertical mill and ground into fine powder of 100-200 mesh.

[0067] Water is added to the fine powder, and after stirring, the ceramic granules with a diameter of 8mm-12mm are formed.

[0068] In the technical scheme, the large particle size of the coal gangue is crushed to not more than 10mm, and then the coal gangue with a particle size of less than or equal to 10mm is mixed with auxiliary materials for granulation, and the mass ratio of SiO2 to Al2O3 is controlled in the range of 2.5-4.0 to reduce the glass phase melting temperature, improve the calcination efficiency and the performance of the ceramic granules after firing; the water content of the ceramic granules is accurately controlled to ensure the green strength, reduce the drying cracking rate of the subsequent ceramic granules, and improve the yield; the mixed material is ground into fine powder with a particle size of 100-200, and water is added for granulation and particle size control to enhance the compressive strength of the ceramic granules.

[0069] As a preferred scheme, the mass ratio of SiO2 to Al2O3 is 3, and the performance of the ceramic granules is further improved by accurately controlling the silicon-aluminum ratio and high-temperature firing of the thin material layer, so that the bulk density of the finished ceramic granules reaches 600kg / m 3 ~1000kg / m 3 , the cylinder pressure strength is ≥5MPa, and the 1h water absorption rate is ≤10%.

[0070] Further, when mixing, 3%-5% of CaCO3 or Na2CO3 is added as a mineralizer to reduce the glass phase melting temperature of the coal gangue, which is beneficial to improve the sintering efficiency.

[0071] It should be noted that the traditional process is difficult to stably control the ceramic firing process, and the porosity distribution of the finished product is uneven. The stability requirement of the thin material layer on the coal gangue is lower than that of the thick material layer, i.e. the requirement on the raw material is low. In this application, the coal gangue is mixed according to the mass ratio of silicon to aluminum of 3:1 (silicon dioxide about 60%, aluminum oxide about 20%), and the coal gangue is homogenized, which can ensure the stability of the coal gangue for a period of time, reduce the fluctuation of the composition of the coal gangue, and improve the adaptability of the raw material.

[0072] In a feasible implementation, a material baffle is arranged above the conveying belt of the belt calciner, and the feeding speed of the feeder and the conveying speed of the belt calciner are controlled to adjust the thickness of the material layer, including the steps of:

[0073] The position of the baffle is arranged and adjusted so that the vertical distance between the lower edge of the baffle and the surface of the conveying belt is 100mm-300mm;

[0074] The feeding speed of the feeder and the conveying speed of the belt calciner are controlled to control the thickness of the material layer to be 100mm-300mm.

[0075] In this technical solution, based on controlling the feeding speed of the feeder and the conveying speed of the belt calciner, the lower edge of the baffle limits the ceramsite conveyed by the belt calciner, automatically controlling the thickness of the material layer to 100mm-300mm. By reducing the material layer thickness and calcining with a thin material layer, the material layer temperature is kept below the auto-ignition temperature, avoiding the situation where the heat transfer efficiency is low during calcination due to excessive material layer thickness, resulting in over-burning of the surface layer and under-burning of the interior, leading to uneven strength of the finished product. By using the baffle in conjunction with the belt calciner to convey the ceramsite, thin material layer calcination is automatically achieved without the need for manual adjustment of the material layer thickness. Through thin material layer calcination of the ceramsite, the quality stability of the fired product is improved.

[0076] As a preferred option, the thickness of the material layer is 150mm to 250mm, resulting in better quality of the finished product after firing.

[0077] In one feasible implementation, the ceramsite is dried to reduce its moisture content, including the following steps:

[0078] When the drying temperature reaches 80℃, the ceramsite is fed into the drying equipment;

[0079] The drying temperature is increased to 200℃ in 2-3 stages, and the total drying time is controlled to be 60-120 minutes to remove more than 90% of the external water from the ceramsite, so that the moisture content of the ceramsite is ≤0.5%.

[0080] In this technical solution, segmented heating combined with wind speed control ensures a smooth transition in drying temperature, reduces the crack rate of ceramsite during drying, and improves the yield of the finished product after drying. At the same time, segmented heating and dehydration can also shorten the total drying time and reduce the energy consumption of the system during the drying stage.

[0081] like Figure 2 As shown, in one feasible embodiment, the ceramsite is calcined in stages, with natural gas introduced during calcination to extract volatiles from the material layer, including the following steps:

[0082] The roasting process is divided into a pyrolysis section, a decarburization section, and a roasting section.

[0083] During the pyrolysis stage, the ceramic particles are calcined at 300–500°C for 15–30 minutes to remove 80% of the volatile matter.

[0084] In the decarburization stage, the ceramic particles are calcined at 700–900°C for 20–30 minutes to remove 20% of the volatile matter and 80% of the fixed carbon.

[0085] During the roasting section, roast at 1100–1200℃ for 10–20 minutes;

[0086] Wherein, after entering the latter half of the decarburization section, natural gas is introduced by using a multi-point injection burner to form high-temperature flue gas by natural gas combustion.

[0087] In this technical solution, the volatile matter in the coal gangue is released in the pyrolysis section to reduce the self-burning and hardening of the ceramsite and reduce the phenomenon of ceramsite sintering into a group to improve the surface quality of the ceramsite. At the same time, by removing the volatile matter in the pyrolysis section and relying on the heat of the ceramsite itself, the supply of fuel for self-burning is reduced, so that the ceramsite can be calcined with a small amount of natural gas, saving energy and protecting the environment. The decarburization section removes 20% of the volatile matter and 80% of the fixed carbon in the ceramsite, making the decarburization of the ceramsite more sufficient, reducing the bulk density of the ceramsite, improving the uniformity of the porosity of the finished product, realizing the lightweight of the ceramsite, and improving the strength of the ceramsite. The calcination section completely converts the mineral phase, improves the cylinder pressure strength, ensures the ceramsite to be qualified, and further improves the strength of the ceramsite. By introducing natural gas into the latter half of the decarburization section and the calcination section, the oxidation / reduction atmosphere in the latter half of the decarburization section and the calcination section is precisely controlled, the mineral phase conversion of Fe2O3 in the coal gangue is promoted, and at the same time, the high-temperature flue gas generated by natural gas combustion is precisely supplemented by the multi-point injection burner to ensure that the calcination temperature and atmosphere meet the calcination requirements. In addition, the use of natural gas instead of traditional high-pollution fuels reduces the emission of sulfur oxides and realizes clean combustion.

[0088] Further, 3-5 rows of natural gas injectors are transversely arranged along the calcination zone (high-temperature zone) of the latter half of the decarburization section and the calcination section at an interval of 300-500 mm; each row of injectors uses a cyclone nozzle and independently controls the air supply to enhance the mixing of fuel gas and air, ensure uniformity of heat distribution during firing, and further improve the firing quality of the ceramsite.

[0089] In some examples, the flue gas generated after calcination enters a supporting flue gas purification system for desulfurization and dust removal treatment, greatly reducing the sulfur oxides in the flue gas and reducing dust emissions to meet environmental protection requirements.

[0090] In a feasible implementation, a pyrolysis zone, a decarburization zone, and a calcination zone are divided into three independent air zones along the length direction of the belt calciner;

[0091] A thermocouple is arranged in each air zone;

[0092] The air pressure and air volume of the fuel gas in each air zone are controlled to uniformly heat the mixed material;

[0093] The thermocouples feed back the temperature of the air zone to the PLC system to dynamically adjust the fuel gas flow and air volume of each subzone through the PLC system.

[0094] In the technical scheme, three independent air zone partitions of a pyrolysis zone, a decarburization zone and a roasting zone are divided on the belt roaster along the length direction of the belt roaster to form an air distribution structure, the temperature gradient of each air zone is controlled, the flow and air volume of each zone are dynamically adjusted, the temperature of each air zone is ensured to meet the dynamic roasting design requirements of the thin material layer of each section, the thin material layer can be quickly and uniformly heated, and then the thin material layer is dynamically roasted to avoid the agglomeration of the haydite, so that the strength and porosity of the haydite product are more uniform, and the demand of the high-end building material market is met.

[0095] Further, the interval of the thermocouple in each air zone is 300mm-500mm.

[0096] In a feasible implementation, in the pyrolysis zone, the wind pressure is controlled to be 1.5kPa-2.5kPa, and the wind speed is controlled to be 1.2m / s-1.8m / s, so that the volatile matter is extracted from the material layer;

[0097] In the decarburization zone, the wind pressure is controlled to be 0.5kPa-1.2kPa, and the wind speed is controlled to be 0.8m / s-1.2m / s, so that the fixed carbon is removed from the material layer;

[0098] In the roasting zone, the wind pressure is controlled to be 1.5kPa-2.5kPa, and the wind speed is controlled to be 0.8m / s-1.2m / s, so that the heat penetration to the material layer is enhanced.

[0099] In the technical scheme, the pyrolysis zone adopts a high-wind-pressure high-wind-volume gas mode to efficiently extract the volatile matter from the material layer and prevent secondary combustion; the decarburization zone adopts a low-wind-pressure low-wind-volume gas mode to prolong the residence time and effectively remove the fixed carbon; and the roasting zone adopts a high-wind-pressure low-wind-volume gas mode to enhance the heat penetration, reduce the strength difference between the surface and the core of the haydite, and improve the quality of the haydite.

[0100] Further, the natural gas flow valve and the combustion air fan speed are dynamically adjusted by a PID algorithm to control the mixing of the natural gas and the air, and then the oxidation / reduction atmosphere is controlled.

[0101] Further, a raw material pre-homogenization system is suggested, which dynamically adjusts the process parameters by combining online component detection and intelligent control technology, improves the stability of the raw material, is suitable for various coal gangues, and improves the comprehensive utilization rate of the coal gangues. An online gas analyzer is installed in the roasting zone to monitor the O2 and CO contents and the CO2 / CO ratio, and reflect the reduction strength.

[0102] In some examples, the gas analyzer is a ZrO2 oxygen sensor and an NDIR infrared CO / CO2 analyzer, and the sampling frequency is ≥1Hz.

[0103] In a feasible implementation, the haydite belt roaster preparation method further includes: gradient air cooling the haydite to below 80℃.

[0104] In the technical solution, the calcined ceramsite is gradient air-cooled to below 80℃, the crystal phase of the ceramsite is slowly transformed, the micro-cracks on the surface and inside of the ceramsite are reduced, the ceramsite cooling burst rate is reduced, the total cooling time is shortened, and the energy consumption in the cooling stage is reduced.

[0105] In an available embodiment, the ceramsite is gradient air-cooled to below 80℃, comprising the steps of:

[0106] When the temperature reaches 1200℃, the ceramsite is discharged from the kiln and transferred to the air-cooling bin;

[0107] The high-speed air-cooling is started, the ceramsite is cooled at a cooling rate of 120℃ / h-150℃ / h, and the ceramsite is cooled to 600℃ for about 4-5 hours;

[0108] The medium-speed air-cooling is switched to, the ceramsite is cooled at a cooling rate of 60℃ / h-100℃ / h, and the ceramsite is cooled to 300℃ for about 3-5 hours;

[0109] The low-speed air-cooling or intermittent air-blower starting and stopping is switched to, the ceramsite is cooled at a cooling rate of 40℃ / h-60℃ / h, and the ceramsite is cooled to 80℃ for about 3.6-5.5 hours.

[0110] In the technical solution, the specific process parameters of the three-stage gradient air-cooling are given, the cooling time is shortened in the high-speed stage, and the total air-cooling energy consumption is reduced; the cooling rate in the three stages of air-cooling matches the ceramsite thermal stress curve, the crystal phase is slowly transformed, the micro-cracks of the ceramsite are reduced, the structural integrity of the ceramsite is ensured, and the burst rate is reduced.

[0111] As shown in Figure 2 In an available embodiment, the ceramsite preparation method by the belt calciner further comprises:

[0112] After the ceramsite is cooled, the ceramsite is screened;

[0113] The ceramsite with a particle size of 8mm-12mm and a cylinder pressure strength of ≥5MPa is screened out as a finished product;

[0114] The rest of the ceramsite is sent back to the vertical mill equipment to continue participating in the granulation process.

[0115] In the technical solution, the cooled ceramsite is screened to ensure the uniformity of the size and cylinder pressure strength of the ceramsite finished product; the ceramsite that does not meet the standard is re-milled and re-made to improve the raw material utilization rate and reduce the production cost; through the waste recycling, no solid waste is discharged, and it is more environmentally friendly.

[0116] Those skilled in the art can easily understand that the above-mentioned embodiments can be freely combined and superimposed without conflict.

[0117] The above merely provides preferred embodiments of the present application, and is not used to limit the present application. Any modification, equivalent replacement, and improvement made within the principle and technical scope of the present application should be included in the protection scope of the present application. The above merely provides preferred embodiments of the present application, and it should be pointed out that, for those skilled in the art, without departing from the technical principle of the present application, a number of improvements and modifications can be made, and these improvements and modifications should be considered as the protection scope of the present application.

Claims

1. A method for the production of ceramsite by a belt roaster, characterized by, The belt calcining machine preparation method of the ceramsite comprises the steps of: adjusting the mixing ratio of coal gangue and auxiliary materials to prepare ceramsite; adjusting the mixing ratio of coal gangue and auxiliary materials to prepare ceramsite; adjusting the mixing ratio of coal gangue and auxiliary materials to prepare ceramsite; adjusting the mixing ratio of coal gangue and auxiliary materials to prepare ceramsite; adjusting the mixing ratio of coal gangue and auxiliary materials to prepare ceramsite.

2. The belt calcining machine preparation method of the ceramsite according to claim 1, wherein the step of adjusting the mixing ratio of coal gangue and auxiliary materials to prepare ceramsite comprises the steps of: screening the coal gangue according to the particle size; sending the coal gangue with a particle size greater than 10 mm into a crusher to be crushed to a particle size of less than or equal to 10 mm; mixing the coal gangue with a particle size of less than or equal to 10 mm with auxiliary materials to make the water content of the mixture 8% to 12%, and adjust the mass ratio of SiO2 to Al2O3 in the mixture to 2.5 to 4.0; sending the mixture into a vertical mill device to be ground into fine powder with a mesh size of 100 to 200; adding water to the fine powder, and stirring to form ceramsite with a diameter of 8 mm to 12 mm.

3. The belt calcining machine preparation method of the ceramsite according to claim 1, wherein the step of adjusting the mixing ratio of coal gangue and auxiliary materials to prepare ceramsite comprises the steps of: adjusting the position of the baffle to make the vertical distance between the lower edge of the baffle and the surface of the conveying belt 100 mm to 300 mm; controlling the feeding speed of the feeder and the conveying speed of the belt calcining machine to control the thickness of the material layer to be 100 mm to 300 mm.

4. The belt calcining machine preparation method of the ceramsite according to claim 1, wherein the step of adjusting the mixing ratio of coal gangue and auxiliary materials to prepare ceramsite comprises the steps of: sending the ceramsite into a drying device when the drying temperature reaches 80℃; raising the drying temperature to 200℃ in 2 to 3 stages, controlling the total drying time to be 60 minutes to 120 minutes, removing more than 90% of the external water in the ceramsite, and making the water content of the ceramsite less than or equal to 0.5%.

5. The belt calcining machine preparation method of the ceramsite according to claim 1, wherein the step of adjusting the mixing ratio of coal gangue and auxiliary materials to prepare ceramsite comprises the steps of: dividing the calcining process into a pyrolysis stage, a decarburization stage, and a calcining stage; in the pyrolysis stage, calcining at a temperature of 300 to 500℃ for 15 to 30 minutes to remove 80% of the volatile matter in the ceramsite; in the decarburization stage, calcining at a temperature of 700 to 900℃ for 20 to 30 minutes to remove 20% of the volatile matter and 80% of the fixed carbon in the ceramsite; in the calcining stage, calcining at a temperature of 1100 to 1200℃ for 10 to 20 minutes; wherein, after entering the second half of the decarburization stage, a multi-point jet burner is used to introduce natural gas to form high-temperature flue gas through natural gas combustion. ​ ​ ​ 6. The method according to claim 5, wherein, three independent air zones, namely pyrolysis zone, decarburization zone and calcination zone, are divided along the length direction of the belt calciner; a thermocouple is arranged in each air zone; the air pressure and air volume of the fuel gas in each air zone are controlled to uniformly heat the mixture; the thermocouples feed back the temperature of the air zones to the PLC system to dynamically adjust the fuel gas flow and air volume of each air zone.

7. The method according to claim 6, wherein, in the pyrolysis zone, the air pressure is controlled to be 1.5-2.5 kPa and the air speed is controlled to be 1.2-1.8 m / s to extract the volatile matter from the material layer; in the decarburization zone, the air pressure is controlled to be 0.5-1.2 kPa and the air speed is controlled to be 0.8-1.2 m / s to remove the fixed carbon from the material layer; in the calcination zone, the air pressure is controlled to be 1.5-2.5 kPa and the air speed is controlled to be 0.8-1.2 m / s to enhance the heat penetration to the material layer. The method further comprises: gradient air cooling the ceramic aggregate to below 80℃.

9. The method according to claim 8, wherein, the step of gradient air cooling the ceramic aggregate to below 80℃ comprises: when the temperature reaches 1200℃, the ceramic aggregate is discharged from the kiln and transferred to the air cooling bin; high-speed air cooling is started to cool the ceramic aggregate at a rate of 120-150℃ / h for about 4-5 hours to cool the ceramic aggregate to 600℃; medium-speed air cooling is started to cool the ceramic aggregate at a rate of 60-100℃ / h for about 3-5 hours to cool the ceramic aggregate to 300℃; low-speed air cooling or intermittent air blowing is started to cool the ceramic aggregate at a rate of 40-60℃ / h for about 3.6-5.5 hours to cool the ceramic aggregate to 80℃. The method further comprises: after the ceramic aggregate is cooled, the ceramic aggregate is sieved; ceramic aggregate with a particle size of 8-12 mm and a cylinder compressive strength of ≥5 MPa is sieved out as finished product; the rest of the ceramic aggregate is sent back to the vertical mill device to continue to participate in the granulation process. ​ ​ ​ ​ 8. The method of claim 1, wherein the method further comprises the step of: ​ ​ ​ ​ ​ ​ ​ ​ ​ 10. The method of claim 2, wherein the method is characterized by: ​ ​ ​ ​

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