A porous lightweight ceramic brick based on shell powder and preparation method thereof

Abstract

The present invention discloses a porous lightweight ceramic tile based on shell powder and a preparation method thereof. The raw material components of the porous lightweight ceramic tile include, by weight, 15-20 parts of calcined shell powder, 5-10 parts of shell raw powder, 15-21 parts of potassium stone powder, 15-20 parts of sodium feldspar, 4-8 parts of washed mud, 15-18 parts of kaolin, 8-12 parts of ceramic waste, 5-10 parts of low-temperature sand, and 1-3 parts of borax. The present invention uses calcined shell powder and shell raw powder as lightweight pore-forming agents, and simultaneously adds a certain amount of low-temperature flux raw materials and borax to form a liquid phase at a relatively low temperature to lock the CO2 gas formed by the calcium carbonate component in the shell raw powder during the firing process; in addition, the borax acts as a foam stabilizer during the high-temperature reaction process, thereby forming a uniform pore structure dominated by closed pores, and achieving a volume density of the product of 1.83-1.86 g / cm 3 , the flexural strength can reach 39.6-40.2MPa.

Description

Technical Field

[0001] The invention belongs to the technical field of building ceramics, and particularly relates to a porous lightweight ceramic brick based on shell powder and a preparation method thereof. Background Art

[0002] Porous ceramics have the advantages of light weight, fire resistance, thermal insulation, easy processing, direct pasting, short construction period and low cost. They have very broad application prospects in the fields of building energy conservation, industrial insulation and waterproofing engineering. Porous ceramics are currently an excellent green new energy-saving and environmentally friendly material.

[0003] At present, the preparation method of porous ceramics mostly adopts the foaming method, which adds a certain amount of foaming agents such as silicon carbide or calcium carbonate to the ceramic material, and generates CO2 gas during the high-temperature firing process, thereby forming a porous structure. However, the foaming temperature range of the silicon carbide foaming agent is relatively narrow, and the silicon carbide oxidation process is difficult to control. If it is not properly controlled during the high-temperature firing process, it is very easy to cause uneven pore structure, and pinholes are very likely to form when adding a glaze layer on the surface of the ceramic tile, thereby affecting the decorative effect of the tile surface. The firing temperature of calcium carbonate is relatively low, and it reacts to generate CO2 at around 900°C. The firing temperature of ceramic tiles is generally in the range of 1100-1200°C. Therefore, if calcium carbonate is used directly to prepare lightweight bricks, the pores formed at low temperature will be filled during the high-temperature firing process. Therefore, the porosity of the resulting product is low, and it is difficult to achieve the purpose of lightweight.

[0004] Therefore, there is an urgent need to find a new pore-forming material to prepare porous lightweight ceramic bricks with uniform pore structure, light weight and high strength. Summary of the Invention

[0005] The present invention aims to solve at least one of the technical problems existing in the above-mentioned prior art. To this end, the present invention provides a porous lightweight ceramic tile based on shell powder and a preparation method thereof. The pores of the ceramic tile are mainly closed-cell structures with uniform pore structure distribution, and are characterized by lightness and high strength.

[0006] In order to solve the above technical problems, the first aspect of the present invention provides a porous lightweight ceramic brick, whose raw material components include, by weight: 15-20 parts of calcined shell powder, 5-10 parts of shell raw powder, 15-21 parts of potassium stone powder, 15-20 parts of sodium feldspar, 4-8 parts of washed mud, 15-18 parts of kaolin, 8-12 parts of ceramic waste, 5-10 parts of low-temperature sand, and 1-3 parts of borax.

[0007] Specifically, shell is the mantle of mollusk, a calcified substance formed by the secretion of a special glandular cell of mollusk to protect the soft part of the body, and its components are mainly composed of calcium carbonate and silicates. The calcium carbonate content of shell raw powder is about 55-95%, which is often used as a pore-forming agent for ceramic materials. However, since calcium carbonate will react to generate CO2 at around 900°C, the pores formed at low temperatures will be filled during the high-temperature firing process of the ceramic material. Therefore, using shell raw powder as a pore-forming agent for ceramic materials does not have a good lightweight effect. The present invention uses calcined shell powder and shell raw powder as lightweight pore-forming agents, and introduces low-temperature flux raw materials (low-temperature sand, potassium stone powder, sodium feldspar) and borax. Each raw material works together to prepare a ceramic tile with a uniform pore structure distribution, light weight and high strength. Wherein: the shell raw powder forms CO2 gas after firing, forming a porous structure in the ceramic tile; the calcined shell powder forms a fibrous porous structure aggregate after calcination, providing a pore channel for the gas generated by the shell raw powder at high temperature; low-temperature flux raw materials and borax can effectively reduce the firing temperature, form a liquid phase at a lower temperature, and can effectively lock the CO2 gas formed by the calcium carbonate component in the shell raw powder during the firing process, thereby forming a pore structure mainly composed of closed holes; coupled with the stabilizing effect of borax in the high-temperature reaction process, a uniform porous structure is formed. Therefore, the present invention gives the ceramic tile a lightweight and high-strength by optimizing and reasonably compounding each raw material.

[0008] As a further improvement of the above scheme, the calcination temperature of the calcined shell powder is 1050-1150°C; the chemical composition of the calcined shell powder includes, by weight percentage: SiO2 33-36%, CaO 57-60%, Al2O3 0-1%, MgO0-0.5%, K2O 0-0.5%, Na2O 0-1%, Fe2O3 0-1%, and loss on ignition 4-6%.

[0009] Specifically, calcined shell powder is a porous fibrous shell powder formed after calcining shell raw powder. Adding a certain amount of calcined shell powder can be used as aggregate for porous ceramic tiles. Its unique pore structure can provide pore channels for the subsequent foaming process, thereby preparing lightweight ceramic tiles with high porosity; at the same time, the calcined shell powder of the present invention has a higher content of SiO2, which is beneficial to improving the mechanical properties of the product.

[0010] As a further improvement of the above scheme, the chemical composition of the shell raw powder includes, by weight percentage: SiO2 5-7%, CaO 48-50%, Al2O3 3-5%, MgO 0-0.5%, K2O 0-0.5%, Na2O 1-2%, Fe2O3 0-1%, and ignition loss 37-39%.

[0011] Preferably, the shell raw powder is high-calcium oyster shell powder, and the content of calcium carbonate in the shell raw powder is greater than 90%.

[0012] Specifically, the shell raw powder of the present invention has a high loss on ignition, and will form a large number of pores after firing, forming a porous structure in the product. In addition, the combined effect of calcined shell powder and low-temperature flux raw materials gives the product a lightweight structure.

[0013] As a further improvement of the above solution, the mass ratio of the calcined shell powder to the raw shell powder is (1.5-2.5): 1. The present invention improves the mechanical properties of the product while ensuring the lightweight of the product by controlling the usage relationship of the calcined shell powder and the raw shell powder.

[0014] As a further improvement of the above solution, the particle size of the calcined shell powder is 500-1200 mesh.

[0015] As a further improvement to the above solution, the particle size of the shell powder is 500-800 mesh. Shell powder with a particle size that is too large will form a larger pore structure, making it difficult to form a stable and uniform pore structure; shell powder with a particle size that is too small will have a high liquid phase viscosity during the firing process, making it difficult to form a good pore structure.

[0016] As a further improvement to the above solution, the chemical composition of the ceramic waste, by weight, includes: SiO2 58-62%, Al2O3 13-16%, Fe2O3 0-0.2%, CaO 6-8%, MgO 3-7%, K2O 1-3%, Na2O 2-3%, ZrO2 0-1%, ZnO 2-4%, and loss on ignition 1-2%. The ceramic waste of the present invention is excess powder generated during the ceramic production process, such as spray drying, sieving, aging, storage, and press molding. It is a recyclable ceramic raw material and does not negatively affect the performance of the product.

[0017] The second aspect of the present invention provides a method for preparing the above-mentioned porous lightweight ceramic brick, comprising the following steps:

[0018] (1) Mixing the raw materials for preparing porous lightweight ceramic tiles, wet grinding, and spray granulation to obtain powder;

[0019] (2) Pressing the powder into a shape, drying it, and firing it in a kiln to obtain the porous lightweight ceramic brick.

[0020] Preferably, in step (1), the temperature of the spray granulation is 450-550°C.

[0021] Preferably, in step (1), the moisture content of the powder is 7-9 wt%.

[0022] Preferably, in step (2), the calcination temperature is 1075-1150°C.

[0023] Preferably, in step (2), the firing cycle is 50-80 minutes.

[0024] Compared with the prior art, the above technical solution of the present invention has at least the following technical effects or advantages:

[0025] The present invention uses calcined shell powder and shell raw powder as lightweight pore-forming agents, utilizes shell raw powder to form CO2 gas after high-temperature firing, and forms a porous structure in the system; the calcined shell powder forms a fibrous porous structure aggregate after calcination, which provides a pore channel for the gas generated in the system; at the same time, a certain amount of low-temperature flux raw materials (low-temperature sand, potassium stone powder, sodium feldspar) and borax are added to reduce the firing temperature so that the system forms a liquid phase at a lower temperature to lock the CO2 gas formed by the calcium carbonate component in the shell raw powder during the firing process, forming a pore structure mainly with closed pores; in addition, borax acts as a foam stabilizer during the high-temperature reaction process, thereby forming a uniform porous pore structure. Therefore, the present invention gives ceramic tiles lightness and high strength by optimizing and reasonably compounding each raw material, and realizes a volume density of the product of 1.83-1.86g / cm 3 , the flexural strength can reach 39.6-40.2MPa. DETAILED DESCRIPTION

[0026] The present invention is described in detail below with reference to the examples to facilitate understanding of the present invention by those skilled in the art. It is necessary to point out that the examples are only used to further illustrate the present invention and are not to be construed as limiting the scope of protection of the present invention. Non-essential improvements and adjustments made to the present invention by those skilled in the art based on the above-mentioned invention should still fall within the scope of protection of the present invention. At the same time, the raw materials mentioned below that are not described in detail are all commercially available products; the process steps or preparation methods that are not mentioned in detail are all process steps or preparation methods known to those skilled in the art.

[0027] Example 1

[0028] A porous lightweight ceramic tile, whose raw material components include, by weight: 15 parts of calcined shell powder, 10 parts of raw shell powder, 21 parts of potassium stone powder, 20 parts of sodium feldspar, 5 parts of washed mud, 15 parts of kaolin, 8 parts of ceramic waste, 5 parts of low-temperature sand, and 1 part of borax.

[0029] The calcination temperature of the calcined shell powder is 1100°C, and the chemical composition of the calcined shell powder, by weight, includes: SiO2 33.10%, CaO 58.90%, Al2O3 0.90%, MgO 0.32%, K2O 0.28%, Na2O 0.80%, Fe2O3 0.90%, and loss on ignition 4.80%. The average particle size of the calcined shell powder is 500 mesh.

[0030] The chemical composition of the shell powder, by weight, includes: SiO2 5.10%, CaO 49.90%, Al2O3 4.00%, MgO 0.45%, K2O 0.35%, Na2O 1.7%, Fe2O3 0.50%, and loss on ignition 38.00%. The average particle size of the shell powder is 500 mesh.

[0031] The chemical composition of the ceramic waste, by weight percentage, includes: SiO2 59.80%, Al2O3 15.80%, Fe2O3 0.10%, CaO 7.91%, MgO 4.92%, K2O 2.07%, Na2O 2.80%, ZrO2 0.80%, ZnO 3.90%, and ignition loss 1.90%.

[0032] A method for preparing porous lightweight ceramic tiles comprises the following steps:

[0033] (1) Calcined shell powder, raw shell powder, potassium stone powder, sodium feldspar, washed mud, kaolin, ceramic waste, low-temperature sand and borax were weighed according to mass ratio, wet-grinded, and spray-granulated at 450° C. to obtain a powder with a moisture content of 9 wt %;

[0034] (2) The powder obtained in step (1) is evenly distributed in a mold, pressed into shape, dried, and then fired in a kiln, wherein: the firing temperature is 1075°C, and the firing cycle is 60 minutes, to obtain the porous lightweight ceramic brick of this embodiment.

[0035] Example 2

[0036] A porous lightweight ceramic tile, whose raw material components include, by weight: 20 parts of calcined shell powder, 8 parts of raw shell powder, 21 parts of potassium stone powder, 20 parts of sodium feldspar, 5 parts of washed mud, 15 parts of kaolin, 10 parts of ceramic waste, 5 parts of low-temperature sand, and 2 parts of borax.

[0037] The calcination temperature of the calcined shell powder is 1100°C, and the chemical composition of the calcined shell powder, by weight, includes: SiO2 34.00%, CaO 58.00%, Al2O3 0.90%, MgO 0.32%, K2O 0.28%, Na2O 0.70%, Fe2O3 0.90%, and loss on ignition 4.9%. The average particle size of the calcined shell powder is 800 mesh.

[0038] The chemical composition of the shell powder, by weight, includes: SiO2 6.20%, CaO 48.80%, Al2O3 4.00%, MgO 0.45%, K2O 0.35%, Na2O 1.70%, Fe2O3 0.50%, and loss on ignition 38.00%. The average particle size of the shell powder is 500 mesh.

[0039] The chemical composition of the ceramic waste, by weight percentage, includes: SiO2 60.30%, Al2O3 15.30%, Fe2O3 0.10%, CaO 7.91%, MgO 4.92%, K2O 2.12%, Na2O 2.80%, ZrO2 0.80%, ZnO 3.90%, and ignition loss 1.85%.

[0040] A method for preparing porous lightweight ceramic tiles comprises the following steps:

[0041] (1) Calcined shell powder, raw shell powder, potassium stone powder, sodium feldspar, washed mud, kaolin, ceramic waste, low-temperature sand and borax were weighed according to mass ratio, wet-grinded, and spray-granulated at 500° C. to obtain a powder with a moisture content of 8 wt%;

[0042] (2) The powder obtained in step (1) is evenly distributed in a mold, pressed into shape, dried, and then fired in a kiln, wherein: the firing temperature is 1100°C and the firing cycle is 65 minutes, thereby obtaining the porous lightweight ceramic brick of this embodiment.

[0043] Example 3

[0044] A porous lightweight ceramic tile, whose raw material components include, by weight: 20 parts of calcined shell powder, 10 parts of raw shell powder, 20 parts of potassium stone powder, 17 parts of sodium feldspar, 4 parts of washed mud, 15 parts of kaolin, 8 parts of ceramic waste, 5 parts of low-temperature sand, and 1 part of borax.

[0045] The calcination temperature of the calcined shell powder is 1100°C, and the chemical composition of the calcined shell powder, by weight, includes: SiO2 35.00%, CaO 57.00%, Al2O3 0.90%, MgO 0.37%, K2O 0.23%, Na2O 0.70%, Fe2O3 0.90%, and loss on ignition 4.90%. The average particle size of the calcined shell powder is 1500 mesh.

[0046] The chemical composition of the shell powder, by weight, includes: SiO2 6.20%, CaO 48.30%, Al2O3 4.50%, MgO 0.45%, K2O 0.35%, Na2O 1.20%, Fe2O3 0.50%, and loss on ignition 38.50%. The average particle size of the shell powder is 800 mesh.

[0047] The chemical composition of the ceramic waste, by weight percentage, includes: SiO2 61.50%, Al2O3 14.10%, Fe2O3 0.10%, CaO 7.91%, MgO 4.92%, K2O 2.12%, Na2O 2.80%, ZrO2 0.80%, ZnO 3.90%, and ignition loss 1.85%.

[0048] A method for preparing porous lightweight ceramic tiles comprises the following steps:

[0049] (1) Calcined shell powder, raw shell powder, potassium stone powder, sodium feldspar, washed mud, kaolin, ceramic waste, low-temperature sand and borax were weighed according to mass ratio, wet-grinded, and spray-granulated at 550° C. to obtain a powder with a moisture content of 7 wt %;

[0050] (2) The powder obtained in step (1) is evenly distributed in a mold, pressed into shape, dried, and then fired in a kiln, wherein: the firing temperature is 1120°C, and the firing cycle is 55 minutes, to obtain the porous lightweight ceramic brick of this embodiment.

[0051] Example 4

[0052] A porous lightweight ceramic tile, whose raw material components include, by weight: 20 parts of calcined shell powder, 10 parts of raw shell powder, 15 parts of potassium stone powder, 18 parts of sodium feldspar, 7 parts of washed mud, 15 parts of kaolin, 8 parts of ceramic waste, 6 parts of low-temperature sand, and 1 part of borax.

[0053] The content of SiO2 is 36.00%, CaO is 57.00%, Al2O3 is 0.90%, MgO is 0.37%, K2O is 0.23%, Na2O is 0.70%, Fe2O3 is 0.80%, and the loss on ignition is 4.00%. The average particle size of the calcined shell powder is 500 mesh.

[0054] The chemical composition of the shell powder, by weight, includes: SiO2 6.70%, CaO 47.80%, Al2O3 4.30%, MgO 0.45%, K2O 0.35%, Na2O 1.20%, Fe2O3 0.50%, and loss on ignition 38.70%. The average particle size of the shell powder is 500 mesh.

[0055] The chemical composition of the ceramic waste, by weight percentage, includes: SiO2 61.50%, Al2O3 14.10%, Fe2O3 0.10%, CaO 7.50%, MgO 5.33%, K2O 2.17%, Na2O 2.80%, ZrO2 0.80%, ZnO 3.90%, and ignition loss 1.80%.

[0056] A method for preparing porous lightweight ceramic tiles comprises the following steps:

[0057] (1) Calcined shell powder, raw shell powder, potassium stone powder, sodium feldspar, washed mud, kaolin, ceramic waste, low-temperature sand and borax were weighed according to mass ratio, wet-grinded, and spray-granulated at 550° C. to obtain a powder with a moisture content of 7 wt %;

[0058] (2) The powder obtained in step (1) is evenly distributed in a mold, pressed into shape, dried, and then fired in a kiln, wherein: the firing temperature is 1150°C and the firing cycle is 60 minutes, thereby obtaining the porous lightweight ceramic brick of this embodiment.

[0059] Comparative Example 1

[0060] A porous lightweight ceramic tile comprises the following raw material components in parts by weight: 25 parts of shell powder, 21 parts of potassium stone powder, 20 parts of sodium feldspar, 5 parts of washed mud, 15 parts of kaolin, 8 parts of ceramic waste, 5 parts of low-temperature sand, and 1 part of borax.

[0061] The chemical composition of the shell powder, by weight, includes: SiO2 5.10%, CaO 49.90%, Al2O3 4.00%, MgO 0.45%, K2O 0.35%, Na2O 1.7%, Fe2O3 0.50%, and loss on ignition 38.00%. The average particle size of the shell powder is 500 mesh.

[0062] The chemical composition of the ceramic waste, by weight percentage, includes: SiO2 59.80%, Al2O3 15.80%, Fe2O3 0.10%, CaO 7.91%, MgO 4.92%, K2O 2.07%, Na2O 2.80%, ZrO2 0.80%, ZnO 3.90%, and ignition loss 1.90%.

[0063] A method for preparing porous lightweight ceramic tiles comprises the following steps:

[0064] (1) shell powder, potassium stone powder, sodium feldspar, washed mud, kaolin, ceramic waste, low-temperature sand and borax were weighed according to the mass ratio, wet-grinded, and spray-granulated at 450° C. to obtain a powder with a moisture content of 9 wt %;

[0065] (2) The powder obtained in step (1) is evenly distributed in a mold, pressed into shape, dried, and then fired in a kiln, wherein: the firing temperature is 1075°C, and the firing cycle is 60 minutes, to obtain the porous lightweight ceramic brick of this comparative example.

[0066] Comparative Example 2

[0067] A porous lightweight ceramic tile comprises the following raw material components in parts by weight: 25 parts of calcined shell powder, 21 parts of potassium stone powder, 20 parts of sodium feldspar, 5 parts of washed mud, 15 parts of kaolin, 8 parts of ceramic waste, 5 parts of low-temperature sand, and 1 part of borax.

[0068] The calcination temperature of the calcined shell powder is 1100° C. The chemical composition of the calcined shell powder, by weight, comprises: SiO2 33.10%, CaO 58.90%, Al2O3 0.90%, MgO 0.32%, K2O 0.28%, Na2O 0.80%, Fe2O3 0.90%, and loss on ignition 4.80%. The average particle size of the calcined shell powder is 500 mesh.

[0069] The chemical composition of the ceramic waste, by weight percentage, includes: SiO2 59.80%, Al2O3 15.80%, Fe2O3 0.10%, CaO 7.91%, MgO 4.92%, K2O 2.07%, Na2O 2.80%, ZrO2 0.80%, ZnO 3.90%, and ignition loss 1.90%.

[0070] A method for preparing porous lightweight ceramic tiles comprises the following steps:

[0071] (1) Calcined shell powder, potassium stone powder, sodium feldspar, washed mud, kaolin, ceramic waste, low-temperature sand and borax were weighed according to mass ratio, wet-grinded, and spray-granulated at 450° C. to obtain a powder with a moisture content of 9 wt %;

[0072] (2) The powder obtained in step (1) is evenly distributed in a mold, pressed into shape, dried, and then fired in a kiln, wherein: the firing temperature is 1075°C, and the firing cycle is 60 minutes, to obtain the porous lightweight ceramic brick of this comparative example.

[0073] Comparative Example 3

[0074] A porous lightweight ceramic tile, whose raw material components include, by weight: 15 parts of calcined shell powder, 10 parts of raw shell powder, 21 parts of potassium stone powder, 20 parts of sodium feldspar, 8 parts of washed mud, 15 parts of kaolin, and 10 parts of ceramic waste.

[0075] The calcination temperature of the calcined shell powder is 1100° C. The chemical composition of the calcined shell powder, by weight, comprises: SiO2 33.10%, CaO 58.90%, Al2O3 0.90%, MgO 0.32%, K2O 0.28%, Na2O 0.80%, Fe2O3 0.90%, and loss on ignition 4.80%. The average particle size of the calcined shell powder is 500 mesh.

[0076] The chemical composition of the shell powder, by weight, includes: SiO2 5.10%, CaO 49.90%, Al2O3 4.00%, MgO 0.45%, K2O 0.35%, Na2O 1.7%, Fe2O3 0.50%, and loss on ignition 38.00%. The average particle size of the shell powder is 500 mesh.

[0077] The chemical composition of the ceramic waste, by weight percentage, includes: SiO2 59.80%, Al2O3 15.80%, Fe2O3 0.10%, CaO 7.91%, MgO 4.92%, K2O 2.07%, Na2O 2.80%, ZrO2 0.80%, ZnO 3.90%, and ignition loss 1.90%.

[0078] A method for preparing porous lightweight ceramic tiles comprises the following steps:

[0079] (1) Calcined shell powder, raw shell powder, potassium stone powder, sodium feldspar, washed mud, kaolin, and ceramic waste were weighed according to mass ratio, wet-grinded, and spray-granulated at 450° C. to obtain a powder with a moisture content of 9 wt %;

[0080] (2) The powder obtained in step (1) is evenly distributed in a mold, pressed into shape, dried, and then fired in a kiln, wherein: the firing temperature is 1075°C, and the firing cycle is 60 minutes, to obtain the porous lightweight ceramic brick of this comparative example.

[0081] Performance Testing

[0082] The porous lightweight ceramic tile samples prepared in Examples 1-4 and Comparative Examples 1-3 were subjected to performance tests, wherein the flexural strength was tested according to the GB / T3810.4-2016 ceramic tile test method, and the test results are shown in Table 1.

[0083] Table 1 Comparative table of performance tests of samples prepared in Examples 1-4 and Comparative Examples 1-3

[0084] sample <![CDATA[Apparent density (g / cm 3 )]]> Flexural strength (MPa) Example 1 1.83 39.6 Example 2 1.86 40.2 Example 3 1.85 39.8 Example 4 1.83 39.6 Comparative Example 1 2.13 32.5 Comparative Example 2 2.05 32.7 Comparative Example 3 2.16 29.3

[0085] As shown in Table 1, the ceramic brick samples prepared in Examples 1-4 of the present invention have a bulk density of 1.83-1.86 g / cm 3 The flexural strength reaches 39.6-40.2MPa, which exceeds the industry standard JG / T 567-2019 "Lightweight and high-strength ceramic panels for construction" (volume density is 1.75-1.95g / cm 3 , flexural strength is greater than or equal to 28 MPa). Compared with Example 1, Comparative Examples 1-3 do not add calcined shell powder, shell raw powder, low-temperature sand and borax, respectively. Not only does the bulk density of the products increase, failing to meet the standards of lightweight ceramic tiles, but the flexural strength also decreases.

[0086] For those skilled in the art to which the present invention belongs, a number of simple deductions or substitutions can be made without departing from the concept of the present invention, without having to resort to creative work. Therefore, based on the disclosure of the present invention, simple improvements made by those skilled in the art to the present invention should be within the scope of protection of the present invention. The above embodiments are preferred embodiments of the present invention, and all processes similar to the present invention and equivalent changes made should fall within the scope of protection of the present invention.

Claims

1. A porous lightweight ceramic tile, characterized in that: Its raw material components include, by weight: 15-20 parts of calcined shell powder, 5-10 parts of raw shell powder, 15-21 parts of potassium stone powder, 15-20 parts of sodium feldspar, 4-8 parts of washed mud, 15-18 parts of kaolin, 8-12 parts of ceramic waste, 5-10 parts of low-temperature sand, and 1-3 parts of borax; the calcination temperature of the calcined shell powder is 1050-1150°C; the chemical composition of the calcined shell powder includes, by weight percentage: SiO2 33-36%, CaO 57-60%, Al2O3 0-1%, MgO 0-0.5%, K2O 0-0.5%, Na2O 0-1%, Fe2O3 0-1%, and ignition loss 4-6%.

2. The porous lightweight ceramic tile according to claim 1, characterized in that: The chemical composition of the shell raw powder includes, by weight percentage, SiO2 5-7%, CaO 48-50%, Al2O3 3-5%, MgO0-0.5%, K2O 0-0.5%, Na2O1-2%, Fe2O3 0-1%, and ignition loss 37-39%.

3. The porous lightweight ceramic tile according to claim 1, characterized in that: The mass ratio of the calcined shell powder to the raw shell powder is (1.5-2.5):

1.

4. The porous lightweight ceramic tile according to claim 1, characterized in that: The particle size of the calcined shell powder is 500-1200 meshes.

5. The porous lightweight ceramic tile according to claim 1 or 2, characterized in that: The particle size of the shell raw powder is 500-800 meshes.

6. The porous lightweight ceramic tile according to claim 1, characterized in that: The chemical composition of the ceramic waste includes, by weight percentage, SiO2 58-62%, Al2O3 13-16%, Fe2O3 0-0.2%, CaO 6-8%, MgO 3-7%, K2O 1-3%, Na2O 2-3%, ZrO2 0-1%, ZnO 2-4%, and ignition loss 1-2%.

7. A method for preparing a porous lightweight ceramic tile according to any one of claims 1 to 6, characterized in that: The following steps are involved: (1) Mixing the raw materials for preparing porous lightweight ceramic tiles, wet grinding, and spray granulation to obtain powder; (2) Pressing the powder into a shape, drying it, and firing it in a kiln to obtain the porous lightweight ceramic brick.

8. The method for preparing porous lightweight ceramic tiles according to claim 7, characterized in that: In step (1), the spray granulation temperature is 450-550° C.; and / or the moisture content of the powder is 7-9 wt %.

9. The method for preparing porous lightweight ceramic tiles according to claim 7, characterized in that: In step (2), the calcination temperature is 1075-1150° C.; and / or the calcination period is 50-80 min.