Method for preparing ceramic water-permeable brick through extrusion molding by taking waste porcelain as raw material and product prepared by method

Abstract

The invention discloses a method for preparing a ceramic water permeable brick through extrusion molding by taking waste porcelain as a raw material and a product prepared by the method. Waste porcelain particles, Longyan kaolin, ulexite and straw powder are taken as raw materials, and a peptizing lubricating solution is prepared from a sodium tripolyphosphate aqueous solution and a sodium silicate aqueous solution; through grain composition and kaolin peptization, plasticity and slippage effects are provided for the pug, and through extrusion molding, drying and calcination, the high-permeability ceramic water permeable brick is obtained. According to the invention, the ceramic water-permeable brick with excellent performance can be obtained through extrusion molding by taking the waste ceramic as the raw material without adding an organic plasticizer and a lubricant, the production efficiency of the ceramic water-permeable brick is improved, and the preparation cost of the water-permeable brick product is reduced, so that high-added-value recycling of the ceramic solid waste is realized.

Description

Technical Field

[0001] The invention relates to the technical field of building ceramic materials, and in particular to a method for preparing ceramic permeable bricks by extrusion molding using waste ceramics as raw materials and the products obtained. Background Art

[0002] Porous permeable bricks are a green and environmentally friendly building material. When laid in courtyards, squares, and walkways, they can reduce the heat island effect of the surrounding environment and regulate the ambient temperature and humidity. Cement concrete-based unfired permeable bricks do not require sintering, are simple to make, and are relatively cheap, but their water permeability, water retention, and frost resistance are poor, making it difficult to achieve the temperature and humidity regulation required for sponge city construction. Ceramic-based sintered permeable bricks have excellent permeability, high water retention, and high mechanical strength and stable performance after high-temperature firing, but their preparation cost is relatively high.

[0003] Using industrial solid waste as raw materials, simplifying production processes, improving production efficiency, reducing sintering temperatures, and increasing sintering rates are all technical means to reduce the cost of preparing ceramic permeable bricks. How to reduce the preparation cost without affecting water permeability and mechanical strength is the key to the green and economic preparation of ceramic permeable bricks. At present, the existing technology mainly prepares ceramic permeable bricks through multi-layer cloth and dry pressing. Dry pressing is a commonly used molding method in the preparation process of ceramic permeable bricks. It has low requirements on the particle size and gradation of raw materials, and has low requirements on the plasticity, adhesion, slippage and other properties of the semi-dry materials. However, compared with extrusion molding, it has low production efficiency, high molding pressure and high equipment cost. To this end, a method for preparing sintered permeable bricks by extrusion molding of aeolian sand is proposed, but the raw material particles are relatively fine, resulting in a water permeability coefficient of the permeable brick of only 1.0 to 1.5×10 -2 cm / s. A method for preparing sintered permeable bricks by extrusion molding with shale and gangue as the main raw materials is to set a core of 1.0 to 2.5 mm in the extruder mouth so that the core head forms micropores of corresponding sizes on the brick body, thereby achieving high water permeability of the permeable bricks. However, the millimeter-level micropore size can easily cause the permeable bricks to be blocked and polluted by soil, gravel, grass, etc., and lose their permeability.

[0004] The preparation of sintered permeable bricks by dry pressing with waste porcelain as raw materials is a common waste porcelain recycling technology in the industry. However, there has been no report on the preparation of permeable bricks with waste porcelain as the main raw material by extrusion molding. The technical difficulty lies in the need to first crush the waste porcelain particles and ball mill them to a size below 0.2 mm, and then add binders such as PVA and HPMC and lubricants such as tung oil and glycerin to provide them with plasticity and lubricity before obtaining the mud for extrusion molding. However, finer particles lead to a decrease in the permeability of permeable bricks, and the crushing cost of waste porcelain is relatively high; larger particles of waste porcelain have large pores, excellent permeability and low preparation cost, but the molecular weight and molecular chain of organic matter make it difficult to provide viscosity and plasticity for larger particles of waste porcelain. Summary of the invention

[0005] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a method for preparing ceramic permeable bricks by extrusion molding using waste porcelain as raw materials, using waste porcelain particles, Longyan kaolin, ulexite, and straw powder as raw materials, preparing a degumming lubricating solution with sodium tripolyphosphate aqueous solution and sodium silicate aqueous solution, providing plasticity and slippage for the mud material through particle grading and kaolin degumming, and obtaining ceramic permeable bricks through extrusion molding, drying and calcining, so as to reduce the preparation cost of ceramic permeable bricks, improve the permeability of permeable bricks, and realize high added value reuse of ceramic solid waste. Another purpose of the present invention is to use the products prepared by the above preparation method.

[0006] The purpose of the present invention is achieved through the following technical solutions:

[0007] The present invention provides a method for preparing ceramic permeable bricks by extrusion molding using waste porcelain as raw materials, comprising the following steps:

[0008] (1) dry-mixing 40-50 parts of large-particle waste porcelain, 15-20 parts of fine-particle waste porcelain, 30-35 parts of Longyan kaolin, 5-15 parts of ulexite, and 5-10 parts of straw powder for 1-2 hours according to weight proportions to obtain a mixed dry material;

[0009] (2) stirring and mixing 18 to 23 parts of water, 1 to 2 parts of a 10 wt % sodium tripolyphosphate aqueous solution, and 2 to 4 parts of a 5 wt % sodium silicate aqueous solution according to weight proportions to obtain a disintegrating lubricating solution;

[0010] (3) adding the debonding lubricating solution to the mixed dry materials by spraying, wherein the amount thereof is 21 to 29 wt % of the mixed dry materials, and the obtained clay material after mixing is subjected to vacuum clay kneading and aging to obtain clay material for extrusion molding;

[0011] (4) The extrusion molding clay material is vacuum extruded at an extrusion pressure of 0.5-2 MPa and an extrusion rate of 5-10 mm / s. The obtained permeable brick green body is dried, heated to 1200-1250°C at a rate of 10-20°C / min, kept warm for 1-2 hours, and then naturally cooled to room temperature to obtain a high-permeability ceramic permeable brick.

[0012] Furthermore, the waste porcelain described in the present invention is obtained by crushing building ceramics and sanitary ceramics waste with a sintering temperature in the range of 1160-1220°C; the particle size of the large-particle waste porcelain is 0.5-1mm, and the particle size of the fine-particle waste porcelain is 0.2-0.5mm; the particle size of the Longyan kaolin and ulexite is 0.01-0.05mm, and the particle size of the straw powder is 0.2-0.5mm.

[0013] Furthermore, in the step (1) of the present invention, the dry mixing time is 1 to 2 hours; the stirring mixing time in the step (2) is 10 to 20 minutes; the mixing time in the step (3) is 0.5 to 1 hour; in the step (4), the green permeable brick is dried at 60° C. for 8 to 12 hours and at 120° C. for 1 to 2 hours. The thickness of the green permeable brick in the step (4) is 20 to 30 mm.

[0014] The product prepared by the method for preparing ceramic permeable bricks by extrusion molding using waste porcelain as raw materials has a flexural strength of more than 10 MPa and a water permeability coefficient of more than 7.0×10 -2 cm / s, the pore size of the permeable brick is less than 0.1mm, and the length of the wear-resistant grinding pit on the surface is less than 25mm.

[0015] The present invention has the following beneficial effects:

[0016] (1) The present invention uses waste porcelain as the main raw material for permeable bricks, supplemented by kaolin, ulexite, and straw powder, and can prepare ceramic permeable bricks by extrusion molding without the need for adding organic plasticizers and lubricants. This solves the technical problems of large particles of waste porcelain being difficult to extrude and mold to prepare permeable bricks, and small particles of waste porcelain having low permeability coefficients to prepare permeable bricks, thereby improving the production efficiency of ceramic permeable bricks, reducing the preparation cost of permeable brick products, and realizing high added value recycling of ceramic solid waste.

[0017] (2) The present invention utilizes the depolymerization and dispersion effect of sodium silicate and sodium tripolyphosphate on Longyan kaolin with excellent plasticity and viscosity to achieve the slippage of waste porcelain particles and other raw material particles, that is, to give large particles of waste porcelain plasticity and slippage. Large particles of waste porcelain serve as the skeleton of the mud material, and small particles of waste porcelain, sodium borate calcium stone, and straw powder are filled in it, while the depolymerized and dispersed Longyan kaolin is dispersed and wrapped on the surface of all particles, providing lubrication and extrusion effect for the mud material when external force acts. The depolymerized kaolin does not affect its viscosity after drying, thereby giving the permeable brick body a certain dry strength.

[0018] (3) The present invention utilizes the properties of straw powder such as pore formation, fiber reinforcement, and carbonization non-expansion to improve the green strength, yield rate, and water permeability of the extruded permeable bricks. The dispersed straw fiber powder and small particles of waste porcelain can avoid the shrinkage, deformation, cracking, and other defects of kaolin during the drying process. The pore size of the permeable brick is regulated by the amount of waste porcelain added, the amount of straw powder added, and the calcination temperature. The calcination temperature of the permeable brick is regulated by the amount of Longyan kaolin and ulexite added. Finally, through extrusion molding, ceramic sintered permeable bricks with high strength, appropriate pore size, large water permeability coefficient, and high wear resistance are mass-produced. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The present invention will be further described in detail below with reference to the embodiments and accompanying drawings:

[0020] Figure 1 Process flow chart of the preparation method of the embodiment of the present invention;

[0021] Figure 2 Appearance of the ceramic permeable brick prepared according to the embodiment of the present invention. DETAILED DESCRIPTION

[0022] Embodiment 1:

[0023] This embodiment provides a method for preparing ceramic permeable bricks by extruding waste porcelain as raw materials, such as Figure 1 As shown, the steps are as follows:

[0024] (1) Add 50 parts of large-particle waste porcelain, 15 parts of fine-particle waste porcelain, 30 parts of Longyan kaolin, 5 parts of ulexite, and 5 parts of straw powder into a kneader and dry mix for 2 hours to obtain a mixed dry material;

[0025] (2) 19 parts of water, 1 part of a 10 wt % sodium tripolyphosphate aqueous solution, and 2 parts of a 5 wt % sodium silicate aqueous solution were mixed by stirring for 10 minutes to obtain a disintegrating lubricating solution;

[0026] (3) adding the debonding lubricating solution to the mixed dry materials by spraying, the amount of which is 22 wt % of the mixed dry materials, and continuing to knead and mix for 1 hour, and then subjecting the obtained clay material to vacuum kneading and aging to obtain clay material for extrusion molding;

[0027] (4) The above-mentioned extrusion clay material is vacuum extruded at an extrusion pressure of 0.8 MPa and an extrusion rate of 10 mm / s to obtain a permeable brick blank with a thickness of 20 mm; the permeable brick blank is dried at 60°C for 8 hours and at 120°C for 1 hour, and then heated to 1230°C at a rate of 20°C / min, kept warm for 2 hours, and then naturally cooled to room temperature to obtain a high-permeability ceramic permeable brick.

[0028] Embodiment 2:

[0029] This embodiment provides a method for preparing ceramic permeable bricks by extruding waste porcelain as raw materials, such as Figure 1 As shown, the steps are as follows:

[0030] (1) adding 40 parts of large-particle waste porcelain, 15 parts of fine-particle waste porcelain, 30 parts of Longyan kaolin, 15 parts of ulexite, and 8 parts of straw powder into a kneader according to weight proportions and dry mixing for 1.5 hours to obtain a mixed dry material;

[0031] (2) 20 parts of water, 1.5 parts of a 10 wt % sodium tripolyphosphate aqueous solution, and 2.5 parts of a 5 wt % sodium silicate aqueous solution were mixed by stirring for 15 minutes to obtain a disintegrating lubricating solution;

[0032] (3) adding the debonding lubricating solution to the mixed dry materials by spraying, the amount of which is 24 wt % of the mixed dry materials, and continuing to knead and mix for 1 hour, and then subjecting the obtained clay material to vacuum kneading and aging to obtain the clay material for extrusion molding;

[0033] (4) The above-mentioned extrusion clay material is vacuum extruded at an extrusion pressure of 1.0 MPa and an extrusion rate of 8 mm / s to obtain a permeable brick blank with a thickness of 20 mm; the permeable brick blank is dried at 60°C for 10 h and at 120°C for 1 h, then heated to 1200°C at a rate of 15°C / min, kept warm for 1 h, and then naturally cooled to room temperature to obtain a high-permeability ceramic permeable brick.

[0034] Embodiment three:

[0035] This embodiment provides a method for preparing ceramic permeable bricks by extruding waste porcelain as raw materials, such as Figure 1 As shown, the steps are as follows:

[0036] (1) adding 45 parts of large-particle waste porcelain, 15 parts of fine-particle waste porcelain, 35 parts of Longyan kaolin, 5 parts of ulexite, and 10 parts of straw powder according to weight proportions into a kneader and dry mixing for 1.5 hours to obtain a mixed dry material;

[0037] (2) 22 parts of water, 2 parts of a 10 wt % sodium tripolyphosphate aqueous solution, and 3 parts of a 5 wt % sodium silicate aqueous solution were mixed and stirred for 20 minutes to obtain a disintegrating lubricating solution;

[0038] (3) adding the debonding lubricating solution to the mixed dry materials by spraying, the amount of which is 27 wt % of the mixed dry materials, and continuing to knead and mix for 0.5 h. The obtained clay is subjected to vacuum kneading and aging to obtain clay for extrusion molding;

[0039] (4) The above-mentioned extrusion clay material is vacuum extruded at an extrusion pressure of 2 MPa and an extrusion rate of 5 mm / s to obtain a permeable brick blank with a thickness of 30 mm; the permeable brick blank is dried at 60°C for 12 h and at 120°C for 2 h, then heated to 1240°C at a rate of 10°C / min, kept warm for 1 h, and then naturally cooled to room temperature to obtain a high-permeability ceramic permeable brick.

[0040] In the embodiment of the present invention, the waste porcelain is obtained by crushing building ceramics and sanitary ceramics waste with a sintering temperature in the range of 1160 to 1220°C; the particle size of large-particle waste porcelain is 0.5 to 1 mm, and the particle size of fine-particle waste porcelain is 0.2 to 0.5 mm; the particle size of Longyan kaolin (produced in Longyan, Fujian Province) and ulexite is 0.01 to 0.05 mm, and the particle size of straw powder is 0.2 to 0.5 mm.

[0041] The ceramic water-permeable bricks prepared in the embodiment of the present invention are as follows Figure 2 Its performance indicators are shown in Table 1.

[0042] Table 1 Performance indicators of ceramic permeable bricks prepared in the embodiments of the present invention

[0043]

Claims

1. A method for preparing ceramic permeable bricks by extrusion molding using waste porcelain as raw materials, Features The following steps are involved: (1) dry-mixing 40-50 parts of large-particle waste porcelain, 15-20 parts of fine-particle waste porcelain, 30-35 parts of Longyan kaolin, 5-15 parts of ulexite, and 5-10 parts of straw powder for 1-2 hours according to weight proportions to obtain a mixed dry material; (2) stirring and mixing 18 to 23 parts of water, 1 to 2 parts of a 10 wt % sodium tripolyphosphate aqueous solution, and 2 to 4 parts of a 5 wt % sodium silicate aqueous solution according to weight proportions to obtain a disintegrating lubricating solution; (3) adding the debonding lubricating solution to the mixed dry materials by spraying, wherein the amount thereof is 21 to 29 wt % of the mixed dry materials, and the obtained clay material after mixing is subjected to vacuum clay kneading and aging to obtain clay material for extrusion molding; (4) The extrusion molding clay material is vacuum extruded at an extrusion pressure of 0.5-2 MPa and an extrusion rate of 5-10 mm / s. The obtained permeable brick green body is dried, heated to 1200-1250°C at a rate of 10-20°C / min, kept warm for 1-2 hours, and then naturally cooled to room temperature to obtain a high-permeability ceramic permeable brick.

2. The method for preparing ceramic permeable bricks by extrusion molding using waste porcelain as raw materials according to claim 1, Features: The waste porcelain is obtained by crushing building ceramics and sanitary ceramics waste with a sintering temperature within the range of 1160-1220°C; the particle size of the large-particle waste porcelain is 0.5-1mm, and the particle size of the fine-particle waste porcelain is 0.2-0.5mm; the particle size of the Longyan kaolin and ulexite is 0.01-0.05mm, and the particle size of the straw powder is 0.2-0.5mm.

3. The method for preparing ceramic permeable bricks by extrusion molding using waste porcelain as raw materials according to claim 1, Features: The dry mixing time in step (1) is 1 to 2 hours; the stirring mixing time in step (2) is 10 to 20 minutes; the mixing time in step (3) is 0.5 to 1 hour; and the permeable brick green body in step (4) is dried at 60° C. for 8 to 12 hours and at 120° C. for 1 to 2 hours.

4. The method for preparing ceramic permeable bricks by extrusion molding using waste porcelain as raw materials according to claim 1, Features: The thickness of the green permeable brick in step (4) is 20 to 30 mm.

5. A product obtained by the preparation method according to any one of claims 1 to 4.

6. The product according to claim 5, Features: The flexural strength of the ceramic permeable brick is greater than 10MPa, and the water permeability coefficient is greater than 7.0×10 -2 cm / s, the pore size of the permeable brick is less than 0.1mm, and the length of the wear-resistant grinding pit on the surface is less than 25mm.

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