A fly ash-containing glazed tile and a method for manufacturing the same

Abstract

The application discloses a fly ash-containing glazed tile and a preparation method thereof, wherein the glazed tile comprises a blank body and a glaze body covering the surface of the blank body; the blank body comprises 60-65% of shale, 15-20% of goose lake sand, 5-10% of red mud, 10-15% of fly ash and 0.5-0.8% of a binder according to mass percentage; and the glaze body comprises 20-30% of tailings, 5-10% of frit, 25-30% of feldspar and 30-35% of fly ash. The application can not only consume the dangerous waste of fly ash, but also reduce the production cost of the glazed tile, and has the advantage of resource treatment of fly ash.

Description

Technical Field

[0001] The present invention relates to the technical field of building materials, in particular to a glazed tile containing fly ash and a preparation method thereof. Background Art

[0002] Fly ash refers to the product collected and left over from the incineration of domestic waste through flue gas purification systems or heat recovery systems. It is listed as hazardous waste in the "National List of Hazardous Wastes" and mainly contains dioxins, heavy metals and other harmful substances.

[0003] Generally, the main method of handling fly ash is landfill. However, as the available landfill sites continue to decrease, and the use of landfill to handle fly ash will cause serious secondary pollution to the ecological environment, how to properly handle and effectively utilize fly ash resources has become an important issue facing the industry. Summary of the Invention

[0004] The object of the present invention is to provide a glazed tile containing fly ash and a preparation method thereof in order to solve the above problems.

[0005] The present invention achieves the above-mentioned object through the following technical solution: a glazed tile containing fly ash, comprising a body and a glaze covering the surface of the body, wherein the body comprises, by mass percentage, 60%-65% shale, 15%-20% Ehu sand, 5%-10% red mud, 10%-15% fly ash, and 0.5%-0.8% binder;

[0006] The glaze body comprises 20%-30% tailings, 5%-10% frit, 25%-30% feldspar, and 30%-35% fly ash.

[0007] Furthermore, the mass ratio of the shale, Ehu sand and red mud is 7:2:1.

[0008] Furthermore, the binder is polyvinyl alcohol.

[0009] Furthermore, the glaze body also includes 0.5%-1% colorant.

[0010] A method for preparing glazed tiles containing fly ash comprises the following steps:

[0011] Blank making: The raw materials for the blank are weighed according to the proportions, and shale, Ehu sand, red mud and fly ash are mixed and wet-milled to a 100-mesh sieve. The sieved slurry is dehydrated and dried, then crushed and a binder is added. The granules are then sieved through a 20-mesh sieve and aged for 6-8 hours. Finally, the blank is pressed into shape under a predetermined pressure and dried to control the moisture content of the blank to 3%-5%.

[0012] Glazing: Weigh the glaze raw materials according to the proportion, crush them to a 60-mesh sieve, add water to make a glaze slurry; then spray the glaze on the body to control the glaze thickness to 2-2.5mm, and finally dry the glaze;

[0013] Firing: In the firing kiln, after the temperature is raised to 1150-1180℃, it is kept warm for 20 minutes, then taken out of the kiln and cooled down. The firing cycle is controlled at 3 hours, and glazed tiles containing fly ash can be obtained.

[0014] Furthermore, the water-to-material mass ratio of the glaze slurry is 1.3:1.

[0015] The beneficial effects of the present invention are as follows: First, a certain amount of fly ash is added to the formula of the green body and the glaze body, and the glazed tiles prepared in this way can meet the requirements, and their compressive strength, frost resistance and water absorption rate all reach JC / T 765-2006 "Standard for Architectural Glazed Tiles", and compared with standards such as "Integrated Sewage Discharge Standard" (GB8978-1996), the contents of heavy metals Cu, Zn, Cr, and Pb have all met the standards, and the leaching results of the glazed tiles have reached the various limits specified in GB5085.3-2007 "Hazardous Waste Identification Standard - Leaching Toxicity Identification"; secondly, there is no need to pretreat the fly ash, which effectively saves energy consumption; thirdly, the prepared glazed tiles have high strength and good appearance, and their smooth and dense glaze can effectively form a dense protective layer on the outer layer of the glazed tiles, so that the heavy metals in the fly ash are effectively solidified, greatly reducing the leaching of heavy metals; generally speaking, the present invention can not only consume fly ash, a hazardous waste, but also reduce the production cost of glazed tiles, and treat the fly ash as a resource, effectively solving the technical problems in the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is the XRD pattern of the glazed tile prepared in Example 8;

[0017] Figure 2 This is an electron microscope image of the glazed tile prepared in Example 8. DETAILED DESCRIPTION

[0018] For ease of understanding of the present invention, the present invention will be described in more detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that when an element is described as being "fixed to" another element, it can be directly on the other element, or there can be one or more centered elements therebetween. When an element is described as being "connected to" another element, it can be directly connected to the other element, or there can be one or more centered elements therebetween. The terms "upper", "lower", "left", "right", "inside", "outside" and similar expressions used in this specification are for illustrative purposes only.

[0019] Unless otherwise defined, all technical and scientific terms used in this specification have the same meanings as those commonly understood by those skilled in the art to which this invention belongs. The terms used in this specification and in the description of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" as used in this specification includes any and all combinations of one or more of the relevant listed items.

[0020] The method for preparing the glazed tile containing fly ash according to the embodiment of the present invention comprises the following steps:

[0021] Blank making: The raw materials for the blank are weighed according to the proportion, and shale, Ehu sand, red mud and fly ash are mixed and wet-milled to a 100-mesh sieve. During the ball milling process, the raw material: ball: water is controlled to be 1:1.5:1.2; the sieved slurry is dehydrated with gypsum to control the moisture content to be equal to or less than 10%, and then dried in an oven. Subsequently, it is crushed and a binder is added, and then sieved and granulated with a 20-mesh sieve and aged for 6-8 hours; finally, it is pressed into shape by a mold at a predetermined pressure and placed in an oven to dry, so that the moisture content of the blank is controlled to be 3%-5%;

[0022] Glazing: Weigh the glaze raw materials according to the proportions. Grind the fly ash, tailings, and feldspar in a mortar to a 150-mesh sieve, then use a ball mill to grind the glaze to a 60-mesh sieve. Meanwhile, grind the frit in a ball mill to a 60-mesh sieve, add water to prepare a glaze slurry with a water-to-material ratio of 1.3:1. Then, spray the glaze onto the body to a thickness of 2-2.5mm, and finally dry the glaze.

[0023] Firing: In the firing kiln, after the temperature is raised to 1150-1180℃, it is kept warm for 20 minutes, then taken out of the kiln and cooled down. The firing cycle is controlled at 3 hours, and glazed tiles containing fly ash can be obtained.

[0024] It should be noted that the fly ash of the present invention comes from Jiangxi Jingsheng Environmental Protection Co., Ltd.

[0025] Example 1

[0026] A glazed tile containing fly ash, comprising a body and a glaze covering the surface of the body, wherein the body comprises, by mass percentage, 64% shale, 15.4% Ehu sand, 10% red mud, 10% fly ash, and 0.6% binder, wherein the binder is polyvinyl alcohol;

[0027] The glaze includes 30% tailings, 9.5% frit, 30% feldspar, 30% fly ash and 0.5% colorant.

[0028] Example 2

[0029] A glazed tile containing fly ash, comprising a body and a glaze covering the surface of the body, wherein the body comprises, by mass percentage, 65% shale, 19% Ehu sand, 5% red mud, 10.2% fly ash, and 0.8% binder, wherein the binder is polyvinyl alcohol;

[0030] The glaze includes 25% tailings, 10% frit, 30% feldspar, 34.1% fly ash and 0.9% colorant.

[0031] Example 3

[0032] A glazed tile containing fly ash, comprising a body and a glaze covering the surface of the body, wherein the body comprises, by mass percentage, 61% shale, 20% Ehu sand, 7.5% red mud, 11% fly ash, and 0.5% binder, wherein the binder is polyvinyl alcohol;

[0033] The glaze consists of 30% tailings, 10% frit, 25% feldspar, 34% fly ash and 1% colorant.

[0034] Example 4

[0035] A glazed tile containing fly ash, comprising a body and a glaze covering the surface of the body, wherein the body comprises, by mass percentage, 61% shale, 16.3% Ehu sand, 10% red mud, 12% fly ash, and 0.7% binder;

[0036] The glaze consists of 27% tailings, 9% frit, 28.3% feldspar, 35% fly ash and 0.7% colorant.

[0037] Example 5

[0038] A glazed tile containing fly ash, comprising a body and a glaze covering the surface of the body, wherein the body comprises, by mass percentage, 62% shale, 16.2% Ehu sand, 8% red mud, 13% fly ash, and 0.8% binder, wherein the binder is polytetrafluoroethylene;

[0039] The glaze body includes 30% tailings, 10% frit, 29% feldspar and 31% fly ash.

[0040] Example 6

[0041] A glazed tile containing fly ash comprises a body and a glaze covering the surface of the body. Calculated by mass percentage, the body comprises 60.2% shale, 17.2% Ehu sand, 8.6% red mud, 13.4% fly ash, and 0.6% binder, wherein the binder is polyvinyl alcohol, and the mass ratio of shale, Ehu sand, and red mud is 7:2:1.

[0042] The glaze consists of 27% tailings, 10% frit, 29.2% feldspar, 33% fly ash and 0.8% colorant.

[0043] Example 7

[0044] A glazed tile containing fly ash, comprising a body and a glaze covering the surface of the body, wherein the body comprises, by mass percentage, 61.3% shale, 18% Ehu sand, 6% red mud, 14% fly ash, and 0.7% binder, wherein the binder is polyurethane;

[0045] The glaze consists of 28% tailings, 9.4% frit, 30% feldspar, 32% fly ash and 0.6% colorant.

[0046] Example 8

[0047] A glazed tile containing fly ash, comprising a body and a glaze covering the surface of the body, wherein the body comprises, by mass percentage, 60% shale, 15% Ehu sand, 9.5% red mud, 15% fly ash, and 0.5% binder, wherein the binder is polyvinyl alcohol;

[0048] The glaze body includes 30% tailings, 5% frit, 30% feldspar and 5% fly ash.

[0049] The above embodiment was tested for performance related items, and the relevant test results are shown in the following table:

[0050] Table 1 Performance of glazed tiles

[0051]

[0052] Table 2 Heavy metal leaching concentrations and standard concentration limits in glazed tiles (unit: mg / L)

[0053]

[0054] Table 3 Appearance quality test results

[0055]

[0056] As can be seen from Table 1, as the proportion of fly ash content in the green body raw materials continues to increase, the water absorption rate, shrinkage rate and flexural strength of the glazed tiles all show a trend of first increasing and then decreasing. The various values ​​of the glazed tiles are in line with the current domestic industry standard JC709-1998 "Sintered Tiles", and it shows that the various performances of Example 6 are relatively outstanding, with a water absorption rate of 0.11%, a shrinkage rate of 6.13%, and a flexural strength of 18.99 MPa, indicating that when the mass ratio of shale, Ehu sand and red mud is 7:2:1, its green body formula is the best formula.

[0057] Table 2 shows that only Cd and Pb levels in the raw fly ash exceeded the limits set by the "Standard for Pollution Control of Municipal Waste Landfills" (GB16889-2008). Other heavy metals remained within the limits or were not detected due to low concentrations. The heavy metal Cu leached from the raw fly ash (10.4 mg / L) was reduced to 0.0463 mg / L in the glazed tiles; the Cd leached from the raw fly ash (2.37 mg / L) was reduced to 0.001 mg / L in the glazed tiles; the Zn leached from the raw fly ash (70.7 mg / L) was reduced to 0.1999 mg / L in the glazed tiles; and the Pb leached from the raw fly ash (0.94 mg / L) was reduced to 0.008 mg / L in the glazed tiles. Comparing the heavy metal contents of Cu, Zn, Cr, and Pb with those of the Integrated Wastewater Discharge Standard (GB8978-1996), the Pollution Control Standard for Municipal Waste Landfills (GB16889-2008), and the Hazardous Waste Identification Standard - Leaching Toxicity Identification (GB5085.3-2007) all meet the standards. Leaching toxicity data indicates that glazed tiles significantly solidify heavy metals in fly ash. It should be noted that the fly ash content in both the blank formulation and the glaze formula of Example 8 reached the maximum, but the leaching toxicity results showed that it met the various standard limits. The fly ash content of the remaining examples was lower than that of Example 8, and their leaching toxicity results therefore met the various standard limits.

[0058] As shown in Table 3, under the formula of the present invention, when different amounts of fly ash were added, the glazed tiles did not bend, the surface was relatively flat, there was no cracking, the samples were relatively intact, and the appearance quality of the prepared glazed tiles was good.

[0059] Figure 1 This is the XRD pattern of the glazed tile. Analysis results show that the primary crystalline phases of the sample are quartz and anorthite. The formation of quartz and anorthite increases the density of the glazed tile, indirectly enhancing its strength. Furthermore, the formation of quartz and anorthite reduces the shrinkage of the green body and the deformation of the glazed tile, thereby improving its quality.

[0060] Figure 2 The upper image (a) is an electron micrograph of the cross-section of the body and glaze, while the lower image (b) is an electron micrograph of the glaze surface layer. As can be seen from Figure a, the particles of the glazed tile body are densely packed together. A small amount of air bubbles and voids are caused by water vapor generated during the sintering process. However, the high overall density of the glazed tile will not affect its performance and use. The body and glaze are well combined, forming a good transition layer. Figure b shows that the surface glaze layer of the glazed tile is smooth and flat, with a high density, forming a good protective layer for the tile, improving its quality. It also effectively seals the heavy metals in the fly ash raw materials, effectively solidifying the heavy metals and reducing leaching toxicity.

[0061] The above shows and describes the basic principles, main features, and advantages of the invention. Those skilled in the art should understand that the invention is not limited to the above embodiments. The above embodiments and descriptions are merely illustrative of the principles of the invention. Various changes and improvements are possible without departing from the spirit and scope of the invention. Such changes and improvements are intended to fall within the scope of the invention. The scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A glazed tile containing fly ash, characterized in that: The green body includes a green body and a glaze covering the green body. Calculated by mass percentage, the green body comprises 60.2% shale, 17.2% Ehu sand, 8.6% red mud, 13.4% fly ash, and 0.6% binder, wherein the mass ratio of shale, Ehu sand, and red mud is 7:2:

1. The glaze consists of 27% tailings, 10% frit, 29.2% feldspar, 33% fly ash and 0.8% pigment.

2. The glazed tile according to claim 1, characterized in that: The binder is polyvinyl alcohol.

3. The glazed tile according to claim 1, characterized in that: The glaze body also includes 0.5%-1% colorant.

4. A method for preparing a glazed tile containing fly ash according to any one of claims 1 to 3, characterized in that: The following steps are involved: Blank making: The raw materials for the blank are weighed according to the proportion, and the shale, Ehu sand, red mud and fly ash are mixed and wet-milled to a 100-mesh sieve. The sieved slurry is dehydrated and dried, then crushed and a binder is added. The blank is then sieved through a 20-mesh sieve to form granules and aged for 6-8 hours. Finally, the blank is pressed into shape under a predetermined pressure through a mold and dried to control the moisture content of the blank to 3%-5%. Glazing: Weigh the glaze raw materials according to the proportion, crush them to a 60-mesh sieve, add water to make a glaze slurry; then spray the glaze on the body to control the glaze thickness to 2-2.5mm, and finally dry the glaze; Firing: In the firing kiln, after the temperature is raised to 1150-1180℃, it is kept warm for 20 minutes, then taken out of the kiln and cooled down. The firing cycle is controlled at 3 hours, and glazed tiles containing fly ash can be obtained.

5. The preparation method according to claim 4, characterized in that: The water-to-material mass ratio of the glaze slurry is 1.3:1.

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