Semi-wet granule preparation technology for tile production

Abstract

The present invention relates to the semi-wet granule preparation technology, which aims to reduce energy and resource consumption in the production of ceramic tiles used in the field of ceramic tile materials.

Description

[0001] SEMI-WET GRANULE PREPARATION TECHNOLOGY FOR TILE PRODUCTION

[0002] FIELD OF THE INVENTION

[0003] The present invention relates to the semi-wet granule preparation technology, which aims to reduce energy and resource consumption in the production of ceramic tiles used in the field of ceramic tile materials.

[0004] PRIOR ART

[0005] Ceramic tile materials are basic products widely used in the construction and decoration industry, and the production processes of these materials are characterized by high energy and resource consumption. In ceramic tile production, it is of great importance that the raw materials are prepared homogeneously with appropriate composition and grain size distribution. This process consists of a series of operations such as grinding, sieving, mixing-homogenizing, spray drying, drying and cooking.

[0006] In the state of the art, spray drying in particular requires high thermal energy consumption in the drying and final firing stages of the shaped tiles. The preparation of ceramic raw materials is generally carried out by spray drying the ceramic clay formed according to a specific recipe, known as the "wet method". This method allows the production of ceramic tiles in different formats due to the excellent quality of the granulate produced; however, the process is associated with high consumption of raw materials, water and energy. This situation stands out as a factor that negatively impacts the goal of low carbon emissions and a sustainable ceramic industry.

[0007] The following documents are found during the preliminary patent research done.

[0008] SIPO document with application number CN111775281A presents a dry process based green tile short flow preparation method that does not require drying. The method involves crushing the raw material into particles smaller than 40 mm, dry grinding in a Raymond mill, and obtaining powder by selecting particles smaller than 100 mesh. The resulting powder is fed to the pelletizer and turned into granular materials with a moisture content of 6-8%. These granules are transported to the automatic brick press and converted into semi-finished products and then baked in the oven at 1120-1160 °C for 45-70 minutes. At the end of the process, the product is sorted and packaged. This method can use clay or shale and provides high-quality granules with a moisture content of 4-9%, thus shortening the production process and reducing costs.

[0009] In the SIPO document with application number CN103056959A, the ceramic raw material preparation process is suitable for the preparation of ceramic tile molding powder lot by a short and dry method. The process begins with crushing soft and hard raw materials to a size of 20-50 mm with a crusher, then finely grinding and mixing them to a size of 0.063- 0.045 mm with a grinder. The resulting fine powder lot is pelletized to extreme wetness by adding water and 10-12% moisture is achieved. It is then dried to 6-8% moisture in a fluidized bed dryer, screened, and large particles are smoothed out with an optimized shaper. Finally, the screened qualified materials are transferred to the storage chamber to be left for aging before profiling.

[0010] SIPO document with application number CN115888953A comprises the continuous ball milling system and material grinding method used in the ceramic raw material preparation process. The system consists of multiple roughing ball mills, slurry bulk tanks that temporarily store the semi-finished slurry, a combined continuous ball mill for fine grinding (consisting of the first and second ball mills), and a tank that stores the finished product slurry. The raw materials are stored as semi-finished slurry after coarse grinding, mixed and subjected to fine grinding. This process increases grinding efficiency and reduces energy consumption by ensuring a homogeneous and finely structured finished product slurry.

[0011] As a result of the research on the state of the art, an R&D study should be carried out on the current technical studies and methods should be developed that will increase the pulpsludge density and the solid matter ratio in the solid-liquid mixture (pulp) and reduce the amount of water to be evaporated and reduce the amount of energy consumed and the amount of CO2. As a result, all abovementioned problems have made it necessary to make an improvement in the relevant technical field.

[0012] OBJECT OF THE INVENTION

[0013] The present invention aims to eliminate the abovementioned problems and to make a development in the relevant technical field.

[0014] The main object of the present invention is to reveal a semi-wet granule preparation structure that reduces energy and resource consumption in the production of ceramic tiles used in the field of ceramic coating materials.

[0015] Another object of the present invention is to reduce energy costs by reducing energy consumption in spray dryers.

[0016] Another object of the present invention is to provide an efficient production process by increasing the solid ratio and density of the ceramic solid-liquid mixture (pulp).

[0017] Another object of the present invention is to increase production efficiency by obtaining a homogeneous and high density (solid matter ratio) sludge.

[0018] Another object of the present invention is to save energy by reducing the amount of water to be evaporated.

[0019] Another object of the present invention is to reduce carbon emissions by reducing the energy consumption used for drying.

[0020] BRIEF DESCRIPTION OF THE INVENTION

[0021] In order to achieve all the objectives mentioned above and which will emerge from the detailed explanation below, the present invention is a method of preparing semi-wet granules in the production of ceramic tiles used in the field of ceramic tile materials. Accordingly, by increasing the sludge density, the amount of water to be evaporated will be reduced by 20-30%, thus reducing the amount of energy consumed by 20-25% and the amount of CO2 by 20-25%, comprising the process steps of; a) preparing the ceramic mixture and grinding the same in a dry grinding mill (4) to a particle size of 5-75p, b) mixing plastic clays (2) with water in the dissolving mixer (5) to form a homogeneous slip, c) grinding of medium and hard raw materials (3) in the wet grinding mill (6) with the addition of water, d) mixing the dry ground ceramic mixture in process step a, the clay that has been turned into homogeneous slip in process step b, and the wet ground medium and hard raw materials in process steps c, and passing the mixture through the screening unit (7) to separate unwanted particles larger than 100-175p, e) converting the raw materials passed through the screening unit (7) in process step d into a homogeneous slip using a high-speed solid-liquid mixer (8), f) feeding the sludge obtained in process step e to the spray dryer (9), g) converting the sludge fed to the spray dryer (9) in the process step f into granule form by spraying the same into the spray dryer (9) and drying the same.

[0022] A preferred embodiment of the invention is to use 5-10% by weight of calcite, 10-20% by weight of siliceous kaolin, 30-40% by weight of clay, 10-15% by weight of fired dry ground tile waste, and 10-15% by weight of melting raw material as the ceramic mixture mentioned in method step a.

[0023] Another preferred embodiment of the invention is that the high-speed solid-liquid mixer (8) used in process step d mixes the raw materials at a speed of 10-3000 rpm.

[0024] A preferred embodiment of the invention is that the granules obtained in process step f have the following size distribution ranges;

[0025] • 500 microns, at a rate of 5-20% by weight,

[0026] • 250 microns, at a rate of 45-55% by weight

[0027] • 150 microns, at a rate of 15-25% by weight,

[0028] • 75 microns, at a rate of 5% to 15% by weight,

[0029] • >75 microns, at a rate of 1 % to 10% by weight, Another preferred embodiment of the invention is to perform the grinding step in step a) in a dry grinding mill (4).

[0030] A preferred embodiment of the invention is that the process of turning the plastic clays into homogeneous slip in process step b is carried out in the dissolving mixer (5).

[0031] Another preferred embodiment of the invention is to grind the medium and hard raw materials in process step c by adding 30-40% water by weight in the wet grinding mill (6).

[0032] BRIEF DESCRIPTION OF DRAWINGS

[0033] Figure 1 shows the flow diagram of Semi-Wet Granule Preparation Technology for Tile Production used as coating material.

[0034] The figures are not required to be scaled and the details which are not necessary for understanding the present invention may be neglected. Moreover, the elements that are at least substantially identical or have at least substantially identical functions are shown by the same number.

[0035] DESCRIPTION OF THE REFERENCE NUMBERS IN FIGURES

[0036] 1. Standard, alternative and secondary raw materials

[0037] 2. Plastic clay

[0038] 3. Medium and hard raw materials

[0039] 4. Dry grinding mill

[0040] 5. Dissolving mixer

[0041] 6. Wet grinding mill

[0042] 7. Screening unit

[0043] 8. High speed solid-liquid mixer

[0044] 9. Spray dryer DETAILED DESCRIPTION OF THE INVENTION

[0045] In this detailed description, the Semi-Wet Granule Preparation Technology for Tile Production, which is the subject of the invention, is explained with examples that will not create any limiting effect, only for a better understanding of the subject.

[0046] The subject of the invention relates to a method that aims to increase environmental and economic efficiency by reducing energy, water and raw material consumption through semi-wet granule preparation technology used in ceramic tile production.

[0047] Ceramic coating materials are widely used in the construction and decoration sectors. Ceramic tile production is a very energy and resource intensive process. The production stages comprises the homogeneous preparation of raw materials with a specific composition and appropriate grain size distribution, drying of shaped tiles and finally firing of ceramic tiles. Spray dryers, in particular, are among the devices that consume high energy during the production phase. In addition, large amounts of water are used in the preparation of ceramic clay, which has undesirable consequences both economically and environmentally. In traditional ceramic production processes, grinding the raw materials using the wet grinding method and granulating this mixture in the spray dryer results in high energy and water consumption. This not only increases costs but also has negative effects on the environment with high carbon emissions. Ceramic tile production consists of a series of successive steps, and each stage requires different amounts of energy, raw materials and water consumption. To detail this process:

[0048] 1. Raw Material Preparation: In the first step, the raw materials used in ceramic tile production are prepared. These raw materials are clay, kaolin, feldspar and quartz group raw materials. Raw materials are mixed in certain proportions and then ground to become fine powder. This process is carried out to ensure the desired mineralogical and chemical structure of the tiles while ensuring the raw materials have a homogeneous structure. During the raw material preparation phase, 0.1 -0.3 kWh / m2of electrical energy is used. Depending on the carbon emission factor of the electricity source, an estimated 0.04-0.1 kg CO2e of carbon is released during this phase. This calculation is based on an average electricity emission factor of 0.4 kg CO2 / kWh. In total, raw material consumption is between 26-32 kg / m2and water usage is 1-2 liters / m2. This water allows the mixture to be easily ground and mixed.

[0049] 2. Grinding, Mixing and Granulation: The prepared raw materials are mixed with water in the second stage and turned into slip (pulp-mud). During the granulation process, water helps bind clay and other materials together, ensuring a homogeneous granules structure. The sludge is then granulated in a spray dryer. The granulated raw material becomes easier to process during the pressing stage and the tile is brought to the desired shape. Rheology modifier auxiliary chemicals deemed necessary for this process are also used. During the mixing and granulation process, 0.2-0.5 kWh / m2of electrical energy is consumed, while 0.5-1 liters / m2of water is used. At this stage, approximately 0.08-0.2 kg 0.08-0.2 kg CO2e carbon emission is emitted. The carbon footprint of electricity can vary depending on the fossil fuel ratio of the energy source.

[0050] 3. Pressing: Granulated raw materials are converted into tile form at this stage. By applying high pressure in special press machines, the granules are compressed and given the desired form. The pressing process is the stage where the final shape and thickness of the tiles are decided. During this phase, 0.1 -0.2 kWh / m2of electrical energy is used. At this stage, approximately 0.04-0.08 kg CO2e emissions are emitted. Although pressing is a low energy requirement stage, it emits carbon depending on the emission factor of the electricity source used.

[0051] 4. Drying: The tiles that gain their form through the pressing process are taken to the dryers at this stage. The drying process is done to remove the water contained in the granules and increases the durability of the tiles before final firing. During the drying phase, 0.5-1 kWh / m2of electricity and natural gas energy is consumed. The 0.5-1 litre / m2of water used in this process evaporates and moves away from the environment, thus reducing the moisture content of the tiles to a suitable level for firing. Since the emission factor of natural gas is 0.2 kg CO2 / kWh, an estimated 0.2-0.4 kg CO2e emissions occur at this stage. Choosing natural gas provides lower carbon emissions than electricity.

[0052] 5. Glazing: Dried tiles are prepared for surface coating during the glazing stage. An aesthetic and protective surface is provided to the tiles by applying glaze and various pigments. Glazing ensures that the tile is waterproof and also gives it a decorative appearance. During the glazing process, 0.1 -0.3 kWh / m2of electrical energy is used and 0.5-1 liter / m2of water is consumed. This water helps to apply the glaze coating evenly to the surface. During this process, 0.04-0.1 kg CO2e carbon emissions occur. The emission rate in this electrically powered process may vary depending on the electricity source.

[0053] 6. Firing: Firing is the stage where the most energy consumption occurs in ceramic tile production. The tiles are vitrified by firing them at high temperatures; this ensures that the surface of the tiles hardens and becomes non-porous. During the firing process, 4-6 kWh / m2of natural gas energy is consumed. Considering the emission factor of natural gas, 0.8-1.2 kg CO2e is released during the firing phase. This stage accounts for a significant portion of the carbon emissions in ceramic tile production. This process increases the durability of the tile and makes the surface impervious to liquids and dirt. The high temperature during the firing process plays a critical role in achieving the final structure of the tiles.

[0054] 7. Cooling: The tiles coming out of the kiln are taken to the cooling stage where their temperature is lowered in a controlled manner. This process prevents cracks and deformations that can be caused by sudden temperature changes. During cooling, 0.1- 0.2 kWh / m2of electrical energy is consumed and 0.04-0.08 kg CO2e emissions occur. In this electrically powered phase, carbon emissions depend on the energy source used. The controlled cooling process ensures that the internal and external structure of the tiles hardened by firing remains balanced.

[0055] 8. Cutting and Packaging: In the final stage of the production process, the tiles that come out of the firing and cooling processes are cut to the desired sizes and packaged. During the cutting and packaging processes, 0.1 -0.2 kWh / m2of electrical energy is used and 0.04-0.08 kg CO2is released. This low-energy phase makes a limited contribution to total carbon emissions. At this stage, the tiles are brought to standard sizes and made ready for use. The packaging process is important and done properly to prevent the tiles from being damaged during transportation. At the end of all stages of ceramic tile production, total energy consumption varies between 5-10 kWh / m2. Total estimated carbon emissions are in the range of 1.2-2.2 kg C02 / m2. Carbon emissions from electricity and natural gas may vary depending on the type of energy used and the production technology. The average emission factor of electrical energy is accepted as 0.4 kg CO2 / kWh, and the emission factor of natural gas is accepted as 0.2 kg CO2 / kWh. The firing process has the highest carbon emissions due to the intensive use of natural gas.

[0056] Considering the above-mentioned, the inefficiency of current methods in terms of energy and resources is understood.

[0057] The ceramic tile production process using semi-wet granule preparation technology is as follows;

[0058] Step A Raw Material Preparation:

[0059] Dry grinding: The first step is the processing of standard, alternative and secondary raw materials (1) used in the production of ceramic tiles in dry grinding mills. Secondary raw materials are recycled materials such as fired tile shards and intermediate and process wastes from other industries. This step is done to increase energy efficiency and reduce water consumption. Most of the water used in the traditional wet method is eliminated in this step.

[0060] Step B Preparation of Plastic Clays and Wet Grinding:

[0061] Use of dissolving mixer (5): Softer raw materials such as plastic clay (2) are made liquid by mixing with water with the help of a dissolving mixer (5).

[0062] Wet grinding mill (6): Medium and hard raw materials (3) are ground in the wet grinding mill (6) with water and the size is reduced until the appropriate grain size distribution and size are achieved under optimum grinding conditions. In this process, water prevents particles from sticking and a homogeneous mixture is achieved by controlling the viscosity with additional chemicals. Medium hard raw materials are materials such as quartz, sand, kaolin, alkali-containing fluxes, fired tile shards and carbonate group raw materials (e.g. calcite and dolomite). In this step, plastic clays (2) and medium hard raw materials (3) are prepared to form a homogeneous mixture with other raw materials in the following stages.

[0063] Step C: Screening and Dispersion:

[0064] Screening unit (7): The mixed raw materials are passed through the screening unit (7) in order to obtain fine particles and to remove the amount that is not of the desired size. This stage is performed to ensure the homogeneity of the mixture and the appropriate particle size.

[0065] Step D: Homogenization of the Mixture:

[0066] Use of high-speed solid-liquid mixer (8): Dry ground raw materials are combined with a mixture of plastic clay and hard raw material pulp in liquid form. With the help of a high speed mixer, these two different materials are turned into homogeneous slip. This mixture has high solids content and density. This stage is critical for ensuring a more efficient drying process in the spray dryer (9).

[0067] The ceramic mixture obtained in step C contains 5-10% by weight of calcite, 10-20% by weight of siliceous kaolin, 30-40% by weight of clay, 10-15% by weight of fired dry ground tile waste, and 10-15% by weight of flux raw material. The amount of kaolin in the clay is between 30-50% by weight.

[0068] Clay and kaolin are minerals commonly used in inorganic coating materials, and both materials offer properties that increase mechanical and chemical resistance. Clay group raw materials consist of smectite, illite, muscovite, bentonite, montmorillonite, kaolin, halloysite and mixed-structure hydrated alumina silicate minerals that do not fall into a specific class. The kaolin group contains layered structures, especially kaolinite. These different mineral structures show different effects in stabilizing the rheological (flow and deformation) properties of the coating materials. While the various minerals found in the clay structure provide flexibility and durability, the layered structure of kaolinite contributes to the formation of a more regular distribution and a homogeneous structure. Therefore, the use of clay and kaolin in coating materials is of great importance in terms of providing rheological balance, providing buoyancy, plasticity, firing resistance, water retention capacity and chemical composition. While clays often contain impurities such as Fe2O3and TiO2, kaolin is in a purer form. Kaolins, a group of high-purity hydrated aluminum silicates, attract attention with their whiteness, low plasticity, refractoriness, chemical inertness and layered tetrahedral-octahedral structures. Kaolins have a soft structure and can be easily ground into powder.

[0069] In conclusion, although clay and kaolin have similarities in terms of mineralogical aspects, they differ in terms of purity and areas of use. While clays are more suitable for opening with water (due to their plasticity), kaolin are more suitable for grinding due to their low plasticity.

[0070] Step E Granule Preparation:

[0071] Spray dryer (9): The prepared homogeneous and dense sludge is fed to the spray dryer (9). In this dryer, the water in the sludge is evaporated and granules are obtained. The semi-wet method ensures that the sludge has a higher solids content, allowing less water to be evaporated during the drying process and therefore saving energy.

[0072] Step F: Shaping the Granules:

[0073] Shaping the Granules: The granules obtained at the exit of the spray dryer (9) are used in tile shaping machines within a certain granule size distribution range. In this step, the granules are compressed according to the desired tile sizes and formats.

[0074] Step G Drying of Shaped Tiles:

[0075] Tile drying: The shaped tiles are dried in drying ovens to achieve low moisture content. This stage is necessary to increase the strength of the ceramic tiles and make them ready for the final firing stage.

[0076] Step H: Firing the Ceramic Tiles:

[0077] Final firing: The dried tiles are fired in high temperature kilns. This stage is the final step in the ceramic tile production process and ensures that the tiles gain their hardness and durability. The shapes, size distribution and dimensions of the granules prepared beforehand are important to ensure energy efficiency in the cooking process. Step I: Use of Waste and By-Products:

[0078] Integration of waste and by-products: This process allows waste materials and byproducts to be incorporated into the ceramic clay. This contributes to environmental sustainability and optimizes the use of raw materials.

[0079] Step J Final Control:

[0080] Control and quality audit: The produced ceramic tiles are passed through quality control stages. Parameters such as surface defects, color differences and durability are tested.

[0081] By increasing the sludge density because of the ceramic tile production process using semi-wet granule preparation technology, a 20-30% reduction in the amount of water to be evaporated is achieved. This reduction means that less water needs to be evaporated during the drying phase, resulting in a 20-25% saving in energy consumption. At the same time, thanks to less energy consumption, carbon emissions are significantly reduced, with CO2emissions falling by 20-25%. These results contribute to the development of a sustainable production process that aims to reduce environmental impacts while increasing energy efficiency.

[0082] The protection scope of the invention is specified in the claims and cannot be limited to the description made for illustrative purposes in this brief and detailed description. It is clear that a person skilled in art can present similar embodiments in the light of the above descriptions without departing from the main theme of the invention.

Claims

CLAIMS1. Semi-wet granule preparation method used in the field of ceramic tile production, characterized in that; reducing the amount of water to be vaporized by 20-30%, thereby reducing the amount of energy consumed by 20-25% and CO2 emissions by 20-25%by increasing the sludge density, comprising the process steps of; a) preparing the ceramic mixture and grinding the same in a dry grinding mill (4) to a particle size of 5-75p, b) mixing plastic clays (2) with water in the dissolving mixer (5) to form a homogeneous slip, c) grinding of medium and hard raw materials (3) in the wet grinding mill (6) with the addition of water, d) mixing the dry ground ceramic mixture in process step a, the clay that has been turned into homogeneous slip in process step b, and the wet ground medium and hard raw materials in process steps c, and passing the mixture through the screening unit (7) to separate unwanted particles larger than 100-175p, e) converting the raw materials passed through the screening unit (7) in process step d into a homogeneous slip using a high-speed solid-liquid mixer (8), f) feeding the sludge obtained in process step e to the spray dryer (9), g) converting the sludge fed to the spray dryer (9) in the process step f into granule form by spraying the same into the spray dryer (9) and drying the same2. Semi-wet granule preparation method for ceramic tile production according to claim 1 , characterized by using 5-10% by weight of calcite, 10-20% by weight of siliceous kaolin, 30-40% by weight of clay, 10-15% by weight of fired dry ground tile waste, and 10-15% by weight of melting raw material as the ceramic mixture mentioned in method step a.

3. Semi-wet granule preparation method for ceramic tile production according to claim 1 , characterized in that; the high-speed solid-liquid mixer (8) used in process step d mixes the raw materials at a speed of 10-3000 rpm.

4. Semi-wet granule preparation method for ceramic tile production according to claim 1 , characterized in that; the granules obtained in process step f have the following size distribution ranges;• 500 microns, at a rate of 5-20% by weight,• 250 microns, at a rate of 45-55% by weight• 150 microns, at a rate of 15-25% by weight,• 75 microns, at a rate of 5% to 15% by weight,• >75 microns, at a rate of 1% to 10% by weight.

5. Semi-wet granule preparation method for ceramic tile production according to claim 1 , characterized by performing the grinding step in step a) in a dry grinding mill (4).

6. Semi-wet granule preparation method for ceramic tile production according to claim 1 , characterized in that; the process of turning the plastic clay into homogeneous slip in process step b is carried out in the dissolving mixer (5).

7. Semi-wet granule preparation method for ceramic tile production according to claim 1 , characterized by grinding the medium and hard raw materials in process step c by adding 30-40% water by weight in the wet grinding mill (6).

Images