Method for synergistically preparing ceramsite from biomass combustion bottom slag and retired fan blade

Abstract

The invention discloses a method for synergistically preparing ceramsite from biomass combustion bottom slag and retired fan blades. The method comprises the following steps: respectively treating the biomass combustion bottom slag and the retired fan blades to obtain respective powder; 50-90 parts of biomass combustion bottom slag powder and 10-50 parts of retired fan blade powder are mixed to obtain a mixed raw material, and then the mixed raw material is granulated into wet raw material balls; performing aging and drying treatment on the wet raw material nodules obtained in the step 2 to obtain dry raw material nodules; 3, calcining the dry raw material balls obtained in the step 3 to obtain calcined ceramsite; according to the invention, the complementarity of the two raw material components is utilized, a foaming agent or a fluxing agent does not need to be additionally added, the produced ceramsite has remarkable performance, and the heavy metal leaching concentration is far lower than the limit value specified by the standard. The purpose of resource utilization of the biomass combustion bottom slag and the retired fan blade is achieved, and the preparation method has the advantages of being high in efficiency and low in energy consumption and has economic benefits and environmental benefits.

Description

Technical Field

[0001] The invention relates to the technical field of industrial solid waste resource utilization and artificial light aggregate preparation, and in particular to a method for preparing ceramsite in coordination with biomass combustion bottom ash and retired fan blades. Background Art

[0002] The statements herein merely provide background art related to the present invention and do not necessarily constitute prior art.

[0003] With the increasing depletion of fossil fuel resources and the increasingly severe global climate change, the use of renewable energy has become a global focus. Biomass energy has become an ideal renewable energy source due to its "zero carbon emission" characteristics. However, the widespread use of biomass energy has also led to the generation of a large amount of biomass combustion ash. According to statistics, global biomass power plants produce up to 476 million tons of biomass combustion ash each year, but the overall utilization rate is low. At present, the treatment of biomass combustion ash is mainly landfilled or piled up, which not only occupies a large amount of land resources, but also under the action of rainwater or wind, the harmful components in the ash may seep into the groundwater or be released into the atmosphere, bringing ecological risks. Therefore, how to effectively dispose of and utilize these ash is imminent.

[0004] Biomass combustion ash is mainly composed of inorganic mineral ash and incompletely burned carbon, including SiO2, Al2O3, CaO and Fe2O3, etc., and has the potential to be used as a raw material for ceramsite. As an artificial aggregate, ceramsite is widely used in building materials, water treatment, sound insulation materials and energy storage due to its porosity, light weight, high compressive strength, excellent thermal insulation and corrosion resistance. However, ceramsite prepared from a single raw material often leads to unstable preparation process due to the fluctuation of inherent characteristics.

[0005] In recent years, the widespread use of wind energy has triggered the problem of how to deal with retired wind turbines. According to a report by the Global Wind Energy Council, by 2023, the total installed capacity of wind power generation in the world has reached 1,021GW. However, the service life of wind turbines is usually only 20-25 years, which means that a large number of retired wind turbine components need to be dealt with urgently. According to statistics, by 2050, the world will generate about 290 million tons of retired wind turbine equipment each year.

[0006] The components of a wind turbine generator set include a base, a tower and rotor blades. The base and tower are usually made of concrete and metal materials, which are relatively easy to recycle. The rotor blades are made of materials such as glass fiber reinforced polymer, resin, balsa wood and PVC. Balsa wood and PVC can be manually sorted and recycled, but resin is usually adhered to the surface of glass fiber reinforced polymer in the form of a coating. The existing landfill and thermal decomposition treatment methods not only waste land resources, but also face problems such as high processing costs and high energy consumption, which brings huge challenges to the wind power industry and the ecological environment. Therefore, how to effectively utilize retired wind turbine blades as resources is also an important issue that needs to be solved urgently. Summary of the invention

[0007] In view of the problems existing in the prior art, the present invention provides a method for synergistically preparing expanded clay from biomass combustion bottom ash and retired fan blades. The method uses biomass combustion bottom ash and retired fan blades as raw materials, optimizes key factors such as raw material ratio and calcination parameters, and realizes resource utilization of these two solid wastes, thereby preparing high-performance expanded clay.

[0008] The technical solution of the present invention is as follows:

[0009] In a first aspect of the present invention, a method for preparing ceramsite by synergistically using biomass combustion bottom ash and retired fan blades is provided, comprising the following steps:

[0010] Step 1: respectively process the biomass combustion bottom ash and the rotor blades of the retired fan to obtain respective powders;

[0011] Step 2: Mix 50-90 parts of biomass combustion bottom ash powder and 10-50 parts of retired fan blade powder to obtain a mixed raw material, and then granulate the mixed raw material into wet raw material balls;

[0012] Step 3, aging and drying the wet raw material balls obtained in step 2 to obtain dry raw material balls;

[0013] Step 4: calcining the dry raw material balls obtained in step 3, wherein the calcination process comprises: firstly preheating from room temperature to 380-400°C at a heating rate of 8-10°C / min for 20-25min; then heating to 1150-1160°C at a heating rate of 8-10°C / min for sintering for 5-20min to obtain sintered ceramsite; and finally cooling the sintered ceramsite to obtain calcined ceramsite.

[0014] In some embodiments of the present invention, in the step one, when the biomass combustion bottom ashes are processed, they are first ground by a grinder and then sieved through a mesh sieve to obtain biomass combustion bottom ashes powder, wherein the rotation speed of the grinder is 1800-2000rpm and the mesh sieve is 100 mesh.

[0015] In some embodiments of the present invention, in step one, when processing the rotor blades of the retired fan, the rotor blades of the retired fan are first cut by a cutting machine, then the cut blades are coarsely crushed by a coarse crusher, and finally ground by a grinder and sieved through a mesh sieve to obtain retired fan blade powder.

[0016] In some embodiments of the present invention, the rotation speed of the cutter is 700-800 rpm, the rotation speed of the coarse crusher is 900-1000 rpm, the number of screens of the coarse crusher is 50 meshes, the rotation speed of the grinder is 1800-2000 rpm, and the mesh sieve is 100 meshes.

[0017] In some embodiments of the present invention, in the step 2, when mixing the biomass combustion bottom ash powder and the retired fan blade powder, the biomass combustion bottom ash powder and the retired fan blade powder are added to a stirring container in proportion and mixed and stirred for 15-20 minutes to obtain a uniformly mixed raw material.

[0018] In some embodiments of the present invention, the mixed raw material is transferred to a granulator, and 15-25% water of the total mass of the mixed raw material is added to the granulator; then the prepared balls are screened to select wet raw balls with a diameter of 10±1 mm.

[0019] In some embodiments of the present invention, in step three, the prepared wet raw material balls are placed at room temperature for aging for 20-24 hours, and then the aged wet raw material balls are transferred to a vacuum drying oven for drying.

[0020] In some embodiments of the present invention, the raw material is dried at a drying temperature of 100-110° C. for 20-24 hours to obtain dry raw balls.

[0021] In some embodiments of the present invention, in step 4, the sintered ceramsite is cooled by natural air cooling.

[0022] In a second aspect of the present invention, there is provided ceramsite, which is prepared by using the biomass combustion bottom ash and retired fan blades as described in the first aspect.

[0023] One or more technical solutions of the present invention have the following beneficial effects:

[0024] 1. The method for synergistically preparing ceramsite from biomass combustion bottom ash and retired fan blades provided by the present invention gives full play to the chemical properties of SiO2 and Al2O3 rich in biomass combustion bottom ash and retired fan blades, and combines the high content of CaO and MgO in retired fan blades to achieve the synergistic effect of the components. During the sintering process, this synergistic effect can generate crystalline phases such as mullite, calcium feldspar, and diopside, thereby significantly improving the mechanical properties of ceramsite. In addition, K2O and Na2O in biomass combustion bottom ash can effectively reduce the sintering temperature through the fluxing effect. This method not only improves the comprehensive utilization value of industrial solid waste, provides an innovative path for the resource treatment of biomass combustion bottom ash and retired fan blades, but also meets the requirements of green environmental protection and sustainable development.

[0025] 2. The present invention makes full use of the residual carbon, calcite, hematite in the bottom ash of biomass combustion and the resin coating of retired fan blades. Under high temperature conditions, calcite decomposes to generate CaO and CO2, hematite is reduced to FeO, Fe, Fe3O4 and CO2 by the residual carbon, and the resin undergoes an oxidation reaction to release gas. The CO2 generated by calcite and hematite, and the CO, CO2 and other gases produced by the oxidation reaction of the resin work together to significantly improve the pore structure inside the ceramsite through the expansion effect and reduce the bulk density of the ceramsite. At the same time, the heat released by the oxidation reaction of the residual carbon and the resin helps to reduce the sintering temperature. Overall, this method is efficient and low in energy consumption, and can produce high-performance ceramsite with excellent mechanical properties and low water absorption.

[0026] 3. The method for preparing ceramsite by mixing biomass combustion bottom ash with retired fan blades provided by the present invention, through high-temperature calcination, the raw materials undergo crystalline phase reorganization, so that heavy metal elements such as Cr, Cd, Cu and Pb are firmly wrapped in the crystalline phase of ceramsite, significantly reducing the possibility of toxic leaching. The prepared ceramsite product meets the relevant requirements of GB5085.3-2007 "Hazardous Waste Identification Standard Leaching Toxicity Identification", and realizes the harmless treatment and resource utilization of biomass combustion bottom ash and retired fan blades. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 The present invention is a process flow chart of the method for collaboratively preparing ceramsite from biomass combustion bottom ash and retired fan blades. DETAILED DESCRIPTION

[0028] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0029] In view of the problems existing in the prior art, the inventors have found through research that by using a variety of industrial solid wastes in the process of preparing ceramsite, not only can the comprehensive utilization of waste resources be achieved, but also the performance of ceramsite can be significantly improved, thereby enhancing its effect and reliability in practical applications. In addition, for the rotor blades of retired fans, the inventors found that in addition to SiO2 and Al2O3, retired fan blades also contain a high proportion of CaO and MgO, which can effectively make up for the defect of insufficient alkaline earth metal oxide content in biomass combustion bottom ash. For this reason, the inventors proposed to use biomass combustion bottom ash mixed with retired fan blades to prepare ceramsite in a coordinated manner.

[0030] In a typical embodiment of the present invention, a method for preparing ceramsite by cooperating with biomass combustion bottom ash and retired fan blades is proposed, such as Figure 1 As shown, the following steps are included:

[0031] Step 1: Process the biomass combustion bottom ash and the rotor blades of the retired fan separately to obtain their respective powders.

[0032] Specifically, when the biomass combustion bottom ash is processed, it is first ground by a grinder, and then sieved through a mesh sieve to obtain the biomass combustion bottom ash powder, wherein the rotation speed of the grinder is 1800-2000rpm, and the mesh sieve is 100 mesh.

[0033] When processing the rotor blades of the retired fan, the rotor blades of the retired fan are first cut by a cutting machine, then the cut blades are coarsely crushed by a coarse crusher, and finally ground by a grinder and sieved through a mesh sieve to obtain the retired fan blade powder.

[0034] Furthermore, the rotation speed of the cutter is 700-800rpm, the rotation speed of the coarse crusher is 900-1000rpm, the number of screens of the coarse crusher is 50 meshes, the rotation speed of the grinder is 1800-2000rpm, and the mesh sieve is 100 meshes.

[0035] By setting the mesh number of the sieve to 100 meshes, the particle size of the raw material is ensured to be less than 0.15 mm. The surface of the raw material with larger particles is relatively rough, and it is difficult to combine with other fine particles, resulting in that the raw material balls are not easy to form during the ball making process, and even uneven and loose raw material balls are formed. The finer particles have a larger surface area and strong water absorption, which leads to the agglomeration of the raw materials, resulting in cracks in the raw material balls during the forming process.

[0036] Step 2: Mix 50-90 parts of biomass combustion bottom ash powder and 10-50 parts of retired fan blade powder to obtain a mixed raw material, and then granulate the mixed raw material into wet raw material balls.

[0037] By setting the ratio of the two within this range, the two raw materials can be used to the maximum extent. Experimental studies have shown that if the content of retired fan blades is too high, the loss on ignition of ceramsite increases, making its internal structure denser, resulting in an increase in bulk density. This increase in density is not conducive to the lightweight properties of ceramsite. Therefore, by setting the ratio of the two, the performance of ceramsite prepared by the synergistic effect of biomass combustion bottom ash and retired fan blades can be ensured.

[0038] When mixing the biomass combustion bottom ash powder and the retired fan blade powder, the biomass combustion bottom ash powder and the retired fan blade powder are added to a stirring container in proportion and mixed and stirred for 15-20 minutes to obtain a uniformly mixed raw material.

[0039] Furthermore, the mixed raw material is transferred to a granulator, and water of 15-25% of the total mass of the mixed raw material is added to the granulator to ensure that the raw material particles can be fully bonded and smoothly formed during the spheroidization process. If too much water is added, the viscosity of the mixture will be too large, resulting in poor fluidity of the powder when the granulator is running, and too much water will cause the surface of the ball to be too slippery, affecting the mechanical properties of the sintered ceramsite. If insufficient water is added, the bonding property of the mixture is poor, and the bonding force between the powders is insufficient, resulting in an unsatisfactory granulation effect.

[0040] Furthermore, after granulation is completed, the prepared balls are screened and wet raw balls with a diameter of 10±1 mm are selected. Raw balls of this size can avoid premature sintering of the surface during the sintering process, thereby affecting the performance of the ceramsite, and also avoid incomplete sintering or long sintering time due to over-large raw balls, thereby increasing energy consumption and reducing production efficiency.

[0041] Step three, aging and drying the wet raw material balls obtained in step two to obtain dry raw material balls.

[0042] The prepared wet raw material balls are placed at room temperature for aging for 20-24 hours, and then the aged wet raw material balls are transferred to a vacuum drying oven for drying at a drying temperature of 100-110° C. for 20-24 hours to obtain dry raw material balls.

[0043] By setting the aging time of 20-24h, it is ensured that the wet raw material balls undergo certain physical or chemical changes at room temperature. By drying at a temperature of 100-110°C, the adsorbed water in the wet raw material balls can be effectively removed, while avoiding overdrying or premature sintering of the surface due to excessive temperature. The drying time is set to 20-24h to ensure that the water evaporates fully and prevent incomplete drying.

[0044] Step 4: calcining the dry raw material balls obtained in step 3, wherein the calcination process comprises: firstly preheating from room temperature to 380-400°C at a heating rate of 8-10°C / min for 20-25min; then heating to 1150-1160°C at a heating rate of 8-10°C / min for sintering for 5-20min to obtain sintered ceramsite; and finally cooling the sintered ceramsite to obtain calcined ceramsite.

[0045] Specifically, the sintered ceramsite can be cooled by natural air cooling.

[0046] During the preheating process, the crystal water molecules in the dry raw material balls are gradually released by preheating to avoid cracks or bursts caused by rapid evaporation of water during the subsequent high-temperature sintering process. The heating rate is set to 8-10°C / min, which can ensure a steady temperature rise and prevent stress concentration inside the dry raw material balls due to excessively fast temperature rise. The preheating temperature and time are set to 380-400°C and 20-25min, which helps to fully decompose the organic matter in the dry raw material balls, avoid excessively high temperatures causing premature sintering, or too short a preheating time to effectively remove the crystal water molecules.

[0047] During the sintering process, the residual carbon, calcite, hematite in the biomass combustion bottom ash and the resin coating of the retired fan blades are fully utilized. Under high temperature conditions, calcite decomposes to generate CaO and CO2, hematite is reduced to FeO, Fe, Fe3O4 and CO2 by the residual carbon, and the resin undergoes an oxidation reaction to release gas. The CO2 generated by calcite and hematite, as well as the CO, CO2 and other gases generated by the oxidation reaction of the resin, work together to significantly improve the pore structure inside the ceramsite and reduce the bulk density of the ceramsite through the expansion effect. At the same time, the heat released by the oxidation reaction of the residual carbon and the resin helps to reduce the sintering temperature. This synergistic effect can generate crystalline phases such as mullite, calcium feldspar, and diopside, thereby significantly improving the mechanical properties of the ceramsite. In addition, the K2O and Na2O in the biomass combustion bottom ash can effectively reduce the sintering temperature through the fluxing effect.

[0048] During the sintering process, maintaining a heating rate of 8-10℃ / min can effectively avoid excessive thermal stress inside the ceramsite due to too fast a temperature rise, thereby reducing the risk of deformation and ensuring smooth chemical reactions and crystal phase transitions. The sintering temperature range of 1150-1160℃ can promote full sintering of the raw materials in the ceramsite to form a dense structure and excellent mechanical properties. Too low a temperature will lead to incomplete sintering, while too high a temperature will cause excessive melting problems. The sintering time is set to 5-20min, which can balance the performance of the ceramsite with production efficiency, ensuring full reaction while avoiding unnecessary energy consumption and time waste.

[0049] In the cooling process, the natural air cooling method can not only effectively save energy and protect the environment and reduce equipment costs, but also provide a stable cooling rate, thereby reducing the risk of cracking of the expanded clay, and conforming to the concept of sustainable production.

[0050] In another typical embodiment of the present invention, a ceramsite is provided, which is prepared by synergistically using the above-mentioned biomass combustion bottom ash and retired fan blades.

[0051] Example 1

[0052] S1. Material preparation: the rotor blades of the retired fan are put into a cutting machine with a rotation speed of 800 rpm for cutting; then, the cut rotor blades of the retired fan are put into a coarse crusher with a screen number of 50 meshes and a rotation speed of 1000 rpm for coarse crushing; the biomass combustion bottom ash and the retired fan coarse material obtained by coarse crushing are transferred to a grinder with a rotation speed of 2000 rpm for fine grinding, and sieved through a 100-mesh sieve to obtain respective powders.

[0053] S2, granulation: 90 parts of biomass combustion bottom ash powder and 10 parts of retired fan blade powder are added to a stirring container and mixed for 20 minutes to obtain a uniform mixed raw material; then the mixed raw material is transferred to a granulator, and 25% of the total mass of water of the mixed raw material is added to the granulator; then the prepared balls are screened and wet raw balls with a diameter of 10±1 mm are selected.

[0054] S3, drying and aging: placing the prepared wet raw ball at room temperature for aging for 24 hours, and then transferring the aged wet raw ball to a vacuum drying oven for drying at a drying temperature of 100-110° C. for 24 hours to obtain dry raw ball.

[0055] S4, calcination: the dry raw material ball is transferred to a roasting furnace, and the temperature of the roasting furnace is controlled to be heated from room temperature to a preheating temperature of 400°C at a heating rate of 10°C / min, and the preheating time is set to 25min; after the preheating, the temperature of the roasting furnace is heated to a sintering temperature of 1160°C at a heating rate of 10°C / min, and the sintering time is set to 15min to obtain calcined ceramsite; the ceramsite after sintering is naturally cooled by air to obtain sintered ceramsite.

[0056] Example 2

[0057] The difference from Example 1 is that in step S2, 70 parts of biomass combustion bottom ash powder and 30 parts of retired fan blade powder are mixed.

[0058] Example 3

[0059] The difference from Example 1 is that in step S2, 50 parts of biomass combustion bottom ash powder and 50 parts of retired fan blade powder are mixed.

[0060] Example 4

[0061] The difference from Example 1 is that in step S2, 70 parts of biomass combustion bottom ash powder and 30 parts of retired fan blade powder are mixed; in step S4, the sintering temperature during the sintering process is 1150°C.

[0062] Example 5

[0063] The difference from Example 1 is that in step S2, 70 parts of biomass combustion bottom ash powder and 30 parts of retired fan blade powder are mixed; in step S4, the sintering time during the sintering process is 5 minutes.

[0064] Example 6

[0065] The difference from Example 1 is that in step S2, 70 parts of biomass combustion bottom ash powder and 30 parts of retired fan blade powder are mixed; in step S4, the sintering time during the sintering process is 20 minutes.

[0066] Comparative Example 1

[0067] The difference from Example 1 is that in step S2, 40 parts of biomass combustion bottom ash powder and 60 parts of retired fan blade powder are mixed.

[0068] Comparative Example 2

[0069] The difference from Example 1 is that in step S2, 70 parts of biomass combustion bottom ash powder and 30 parts of retired fan blade powder are mixed; in step S4, the sintering temperature during the sintering process is 1170°C.

[0070] Comparative Example 3

[0071] The difference from Example 1 is that in step S2, 70 parts of biomass combustion bottom ash powder and 30 parts of retired fan blade powder are mixed; in step S4, the sintering temperature during the sintering process is 1180°C.

[0072] Comparative Example 4

[0073] The difference from Example 1 is that in step S2, 70 parts of biomass combustion bottom ash powder and 30 parts of retired fan blade powder are mixed; in step S4, the sintering time during the sintering process is 25 minutes.

[0074] The main components of the biomass combustion bottom ash and retired fan blades used in Examples 1 to 6 of the present invention and Comparative Examples 1 to 4 are shown in Table 1.

[0075] Table 1 Composition of raw materials of biomass combustion bottom ash and retired fan blades (wt.%)

[0076] sample <![CDATA[SiO2]]> <![CDATA[Al2O3]]> CaO MgO <![CDATA[Fe2O3]]> <![CDATA[K2O]]> <![CDATA[Na2O]]> <![CDATA[SO3]]> Biomass combustion ash 48.49 11.47 12.23 2.99 6.93 3.90 0.34 1.41 Retired wind turbine blades 41.64 11.77 14.04 5.65 0.52 0.23 0 2.07

[0077] Performance parameters of ceramsite

[0078] 1. With reference to GB / T 17431.2-2010 "Lightweight aggregate and its test method Part 2: Lightweight aggregate test method", the bulk density, compressive strength, 1h water absorption rate and particle shape coefficient of the ceramsite of Examples 1 to 6 and Comparative Examples 1 to 4 were tested. The test results are shown in Table 2.

[0079] Table 2 Ceramic aggregate performance test results

[0080]

[0081]

[0082] From Table 2, it can be seen that in Examples 1 to 6, the bulk density of the ceramsite prepared by the method of the present invention is 0.872 to 1.030 g / cm 3 The compressive strength is as high as 25.27-39.45MPa, and the water absorption rate in 1h is only 0.072-0.128%, which shows good mechanical properties and extremely low water absorption characteristics. The particle shape coefficient of ceramsite is 1.035-1.323, indicating that it has good particle morphology. The prepared ceramsite products can meet the performance requirements of GB / T17431.1-2010 "Light Aggregate and Its Test Methods Part 1: Light Aggregate".

[0083] By comparing Examples 1 to 3 with Comparative Example 1, it can be found that as the amount of retired fan blades increases, the compressive strength of ceramsite increases significantly, and the 1h water absorption rate and particle shape coefficient gradually decrease. However, when the amount of retired fan blades is too high, the internal structure of the ceramsite becomes more dense due to the excessive loss on ignition, resulting in an increase in bulk density, which is not conducive to the lightweight characteristics of ceramsite.

[0084] By comparing Example 2, Examples 4 to 6 and Comparative Examples 2 to 4, it can be found that the compressive strength of ceramsite decreases significantly with the increase of sintering temperature and the extension of sintering time. This is mainly because under high temperature or long-term sintering conditions, too much liquid phase is generated inside the ceramsite, causing the original small pores to gradually merge into large pores, the pore walls become thinner, and may even cause structural collapse, thereby significantly weakening the mechanical properties of the ceramsite.

[0085] 2. Test of heavy metal content of dry raw balls and ceramsite in Example 2

[0086] The dry raw material balls and sintered ceramsite in Example 2 were crushed and ground into powders respectively, ensuring that the powder particle size was less than 3 mm. Subsequently, the powder sample was placed in an extraction bottle with a solid-liquid ratio of 1:10, and the extractant was an acetic acid solution with a pH of 3.0. The extraction bottle was fixed on a horizontal oscillator, oscillated at a speed of 110 rpm for 8 hours, and then allowed to stand for 16 hours. Finally, the concentration of heavy metals in the supernatant was quantitatively determined using an inductively coupled plasma mass spectrometer. Each group of experiments was repeated three times, and the test results are shown in Table 3.

[0087] Table 3 Test results of heavy metal content in dry raw balls and ceramsite of Example 2 (mg / L)

[0088]

[0089] It can be seen from Table 3 above that the heavy metal leaching concentrations of raw balls and ceramsite meet the limit values ​​specified in GB5085.3-2007 "Identification of leaching toxicity of hazardous waste identification standards". It is worth noting that due to the low boiling point of Zn, part of the Zn may volatilize into gas during the sintering process, and be covered by the liquid phase during the cooling process, adhering to the pore walls of the ceramsite. This process causes the leaching concentration of Zn in the ceramsite to increase after sintering, but it is still far below the limit value requirements of GB5085.3-2007. The above results show that after the biomass combustion bottom ash mixed with retired fan blades is prepared into ceramsite under appropriate sintering conditions, the heavy metals can be effectively encapsulated in the crystal phase structure of the ceramsite, thereby improving its environmental safety.

[0090] Although the above describes the specific implementation mode of the present invention in conjunction with the accompanying drawings, it is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art on the basis of the technical solution of the present invention without creative work are still within the scope of protection of the present invention.

Claims

1. A method for preparing ceramsite by using biomass combustion bottom ash and retired fan blades, characterized in that: The following steps are involved: Step 1: Process the biomass combustion bottom ash and the rotor blades of the retired fan separately to obtain their respective powders; Step 2: Mix 50-90 parts of biomass combustion bottom ash powder and 10-50 parts of retired fan blade powder to obtain a mixed raw material, and then granulate the mixed raw material into wet raw material balls; Step 3, aging and drying the wet raw material balls obtained in step 2 to obtain dry raw material balls; Step 4: calcining the dry raw material balls obtained in step 3, wherein the calcination process comprises: firstly preheating from room temperature to 380-400°C at a heating rate of 8-10°C / min for 20-25min; then heating to 1150-1160°C at a heating rate of 8-10°C / min for sintering for 5-20min to obtain sintered ceramsite; and finally cooling the sintered ceramsite to obtain calcined ceramsite.

2. The method for preparing ceramsite by using biomass combustion bottom ash and retired fan blades as claimed in claim 1, characterized in that: In the step 1, when the biomass combustion bottom ash is processed, it is first ground by a grinder, and then sieved through a mesh sieve to obtain biomass combustion bottom ash powder, wherein the rotation speed of the grinder is 1800-2000rpm, and the mesh sieve is 100 mesh.

3. The method for preparing ceramsite by using biomass combustion bottom ash and retired fan blades as claimed in claim 1, characterized in that: In the step 1, when processing the rotor blades of the retired fan, the rotor blades of the retired fan are first cut by a cutting machine, then the cut rotor blades are coarsely crushed by a coarse crusher, and finally ground by a grinder and sieved through a mesh sieve to obtain the retired fan blade powder.

4. The method for preparing ceramsite by using biomass combustion bottom ash and retired fan blades as claimed in claim 3, characterized in that: The rotation speed of the cutter is 700-800 rpm, the rotation speed of the coarse crusher is 900-1000 rpm, the number of screens of the coarse crusher is 50 meshes, the rotation speed of the grinder is 1800-2000 rpm, and the mesh sieve is 100 meshes.

5. The method for preparing ceramsite by using biomass combustion bottom ash and retired fan blades as claimed in claim 1, characterized in that: In the step 2, when mixing the biomass combustion bottom ash powder and the retired fan blade powder, the biomass combustion bottom ash powder and the retired fan blade powder are added to a stirring container in proportion and mixed and stirred for 15-20 minutes to obtain a uniformly mixed raw material.

6. The method for preparing ceramsite by using biomass combustion bottom ash and retired fan blades as claimed in claim 5, characterized in that: The mixed raw material is transferred to a granulator, and water accounting for 15-25% of the total mass of the mixed raw material is added to the granulator; then the prepared balls are screened to select wet raw balls with a diameter of 10±1 mm.

7. The method for preparing ceramsite by using biomass combustion bottom ash and retired fan blades as claimed in claim 1, characterized in that: In the step three, the prepared wet raw material balls are placed at room temperature for aging for 20-24 hours, and then the aged wet raw material balls are transferred to a vacuum drying oven for drying.

8. The method for preparing ceramsite by using biomass combustion bottom ash and retired fan blades as claimed in claim 7, characterized in that: Dry at a drying temperature of 100-110°C for 20-24 hours to obtain dry raw balls.

9. The method for preparing ceramsite by using biomass combustion bottom ash and retired fan blades as claimed in claim 1, characterized in that: In the step 4, the sintered ceramsite is cooled by natural air cooling.

10. A ceramsite, characterized in that: The biomass combustion bottom ash and retired fan blades are collaboratively prepared according to any one of claims 1 to 9.

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