Formula and preparation method of Roman tile

Abstract

The invention relates to the field of building ceramic materials, in particular to a formula and a manufacturing method of a Roman tile, in the formula, the proportion of waste residues is 50%-60%, the proportion of waste sand is 10%-15%, the proportion of waste soil is 10%-25%, functional additives with the addition being smaller than or equal to 5% are added, and the resource utilization rate of tailings is larger than or equal to 85%. The preparation process comprises the following steps: crushing and grinding the raw materials, carrying out dry ball-milling mixing (the moisture content is 18-22%), carrying out 25 MPa high-pressure forming (the blank density is greater than or equal to 2.2 g / cm < 3 >), carrying out gradient drying (the room temperature reaches 120 DEG C) and carrying out low-temperature glaze firing (1150-1210 DEG C). According to the formula and the preparation method of the Roman tile, the albite tailing waste is utilized and the process is optimized, so that the unification of environmental friendliness, high performance and economical efficiency is realized; the manufacturing process comprises the steps of raw material pretreatment, ingredient mixing, high-pressure forming, drying and biscuit firing, glazing and glaze firing and the like, and the quality and performance of the product are ensured. The Roman tile is suitable for multiple fields such as building, garden and cultural heritage restoration, and has a wide application prospect.

Description

Technical Field

[0001] The present invention relates to the field of building ceramic materials, and particularly to an environment-friendly Roman tile formula and preparation process mainly made of tailings waste of albite, aiming to realize the resource utilization of industrial waste residues and improve the performance of ceramic tiles. Background Art

[0002] With the improvement of environmental protection requirements and the aggravation of resource shortage problems, the following key problems have gradually emerged in the existing Roman tile production technology:

[0003] Dependence on natural resources for raw materials: Traditional formulas are mainly based on natural minerals such as clay, quartz sand, and feldspar. Large-scale mining is required, resulting in ecological damage and large price fluctuations of natural raw materials (for example, the cost of high-quality clay is about 200 - 300 yuan per ton), and the resources are gradually exhausted.

[0004] Characteristics of the production process: High firing temperature: The firing temperature of traditional ceramic tiles is usually 1250 - 1300 °C, with high energy consumption (the energy consumption per ton of products is about 800 - 1000 kWh). In addition, the process is extensive, the mixing uniformity of raw materials is poor, and the density of the green body is low (density ≤ 2.0 g / cm 3 ), which easily leads to insufficient strength of the finished product.

[0005] In addition, the existing environmental problems are becoming more and more serious. For example, there is tailing accumulation. After the mining of minerals such as albite, a large amount of tailing waste (waste residue, waste sand, waste soil) is generated, which is not effectively utilized by traditional technologies, occupying land and polluting the environment.

[0006] Due to problems such as dependence on natural resources, extensive process, and poor environmental protection of the existing Roman tile production technology, it is difficult to meet the requirements of green buildings and sustainable development.

[0007] Therefore, it is urgent to develop a technology that can systematically solve the defects of traditional Roman tile production technology through the high-value utilization of tailings, optimization of process parameters, and environmental protection design, providing an efficient, low-consumption, and environmentally friendly innovation solution for the building ceramic industry. Summary of the Invention

[0008] The present invention aims to solve at least one of the technical problems existing in the prior art. The present invention provides a formula and manufacturing method of Roman tiles.

[0009] A formula of Roman tiles includes the following components by proportion: 50% - 60% of waste residue, 10% - 15% of waste sand, 10% - 25% of waste soil, and additives, with the additives controlled within 5%.

[0010] The waste residue, waste sand, and waste soil are derived from the tailing waste soil, waste sand, and waste residue after albite mining.

[0011] Furthermore, the additives include reinforcing agents, binders, and fluxes.

[0012] A manufacturing method of Roman tiles, comprising the following steps:

[0013] S1. Raw material pretreatment: Screen and remove impurities from the tailings, waste soil, waste sand, and waste residue after feldspar mining, removing large particle impurities and harmful elements. The waste residue and waste sand need to be crushed to below 80 mesh, and the waste soil needs to be ground to 200 mesh. Remove iron impurities through magnetic separation;

[0014] S2. Batching and mixing: Accurately weigh various raw materials according to the formula, put them into a mixer and stir evenly. Adopt dry ball milling to make the uniformity better. The mixing time is ≥2 hours, and the moisture content is controlled at 18%-22%;

[0015] S3. Forming: Use existing press equipment for high-pressure forming to make the green body have good density and initial strength. During the pressing process, the pressure is 25 MPa, and the density of the obtained green body is ≥2.2 g / cm 3 ;

[0016] S4. Drying and bisque firing: Send the formed green body into a drying kiln for drying treatment to remove moisture and improve the strength of the green body. The drying temperature and time are reasonably adjusted according to the size and moisture content of the green body. The gradient drying is adopted during the drying process, and the gradient drying temperature is room temperature → 80°C → 120°C;

[0017] S5. Glazing and glaze firing: Use low-lead frit glaze for glazing and fire in a high-temperature shuttle kiln or roller hearth kiln. The firing process is divided into three stages: preheating, high-temperature firing, and cooling. The maximum firing temperature is controlled at 1150-1210°C, and the firing time is determined according to the product thickness and the type of ceramic tile to ensure that the ceramic tile reaches the best physical properties.

[0018] The beneficial effects of the present invention compared with the prior art: The Roman tile formula and its manufacturing method of the present invention achieve the unity of environmental protection, high performance, and economy by utilizing feldspar tailings waste and optimizing the process; its manufacturing process includes steps such as raw material pretreatment, batching and mixing, high-pressure forming, drying and bisque firing, glazing and glaze firing, etc., ensuring the quality and performance of the product. This Roman tile is applicable to multiple fields such as construction, gardening, and cultural heritage restoration, and has a broad application prospect. Specific embodiments

[0019] In the description of the present invention, it should be understood that the orientation or positional relationships indicated by the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc. are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation on the present invention.

[0020] In addition, the terms "first" and "second" are only used for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, the meaning of "a plurality" is two or more, unless otherwise specifically defined.

[0021] In the description of the embodiments of the present invention, if a certain feature is referred to as "arranged", "fixed", "connected", "installed" on another feature, it can be directly arranged, fixed, connected on another feature, or indirectly arranged, fixed, connected, installed on another feature.

[0022] In the description of the embodiments of the present invention, if it involves "several", its meaning is more than one; if it involves "a plurality", its meaning is more than two; if it involves "greater than", "less than", "exceeding", it should be understood as not including the present number; if it involves "above", "below", "within", it should be understood as including the present number. If it involves "first" and "second", it should be understood as used to distinguish technical features and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features or implicitly specifying the sequence relationship of the indicated technical features.

[0023] A formula for a Roman tile of the present invention includes the following components by proportion: 50%-60% of waste residue, 10%-15% of waste sand, 10%-25% of waste soil, and additives, with the additives controlled within 5%. The waste residue, waste sand, and waste soil are from the tailings waste soil, waste sand, and waste residue after the extraction of albite. The additives include a reinforcing agent, a binder, and a flux.

[0024] Waste residue (50%-60%): Albite tailings waste residue, rich in silicate, serving as the matrix framework.

[0025] Waste sand (10%-15%): Tailings waste sand, with a particle size below 80 mesh, adjusting the porosity of the green body.

[0026] Waste soil (10%-25%): Tailings waste soil, ground to 200 mesh to enhance plasticity;

[0027] Additives (≤5%): Composite functional components, including:

[0028] Reinforcing agent (such as silica powder or silicon carbide fiber, accounting for 2%-3%): Improve the flexural strength;

[0029] Binder (such as sodium carboxymethyl cellulose, accounting for 1%-1.5%): Improve the forming performance;

[0030] Flux (such as potassium feldspar powder or borax, accounting for 1%-2%): Lower the firing temperature.

[0031] Utilize the advantages of tailings waste: The composition of albite tailings is stable, containing SiO2 (60%-70%), Al2O3 (15%-20%) and a small amount of K2O, Na2O. It is easy to form a glass phase at high temperature, reducing energy consumption, improving environmental benefits, with a waste utilization rate of 80%-90%, and solving the problem of tailings accumulation pollution.

[0032] A method for making Roman tiles, characterized by comprising the following steps:

[0033] S1. Raw material pretreatment: Screen and remove impurities from the tailings waste soil, waste sand, and waste residue after albite mining, remove large particle impurities and harmful elements. The waste residue and waste sand need to be crushed to below 80 mesh, and the waste soil needs to be ground to 200 mesh. Remove iron impurities through magnetic separation, such as removing Fe2O3 with a magnetic separator (the content of magnetic impurities needs to be <0.3%) to avoid firing black spots.

[0034] S2. Batching and mixing: Accurately weigh various raw materials according to the formula, put them into a mixer and stir evenly. Use dry ball milling to make the uniformity better. The mixing time is ≥2 hours, and the moisture content is controlled at 18%-22%;

[0035] The ball-to-material ratio is 1:2, the rotation speed is 25-30 r / min, and the mixing time is ≥2 hours to ensure uniformity;

[0036] Adjust the moisture content to 18%-22% through spray humidification or a dryer to ensure the plasticity of the green body.

[0037] S3. Forming: Use existing press equipment for high-pressure forming to make the green body have good density and initial strength. During the pressing process, the pressure is 25 MPa, and the density of the obtained green body is ≥2.2 g / cm 3 ;

[0038] Adopt a hydraulic forming machine (pressure 25 MPa), and spray a hard alloy coating on the surface of the mold to extend its service life;

[0039] Obtain a green body density ≥2.2 g / cm3 , the initial value of the compressive strength ≥ 5 MPa.

[0040] S4, Drying and biscuit firing: Feed the formed green body into a drying kiln for drying treatment to remove moisture and improve the strength of the green body. The drying temperature and time are reasonably adjusted according to the size and moisture content of the green body. Gradient drying is adopted during the drying process, and the gradient drying temperature is room temperature → 80 °C → 120 °C;

[0041] The drying process includes two stages. The first stage (room temperature → 80 °C, 4 hours): Avoid cracking caused by rapid water loss; The second stage (80 °C → 120 °C, 3 hours): Dynamically adjust the wind speed in combination with a humidity sensor;

[0042] Function of biscuit firing: Initially form mullite crystal phase, and the water absorption rate of the green body drops below 8%.

[0043] S5, Glazing and glaze firing: Low-lead frit glaze is used for glazing, and firing is carried out in a high-temperature shuttle kiln or roller hearth kiln. The firing process is divided into three stages: preheating, high-temperature firing, and cooling. The highest firing temperature is controlled at 1150 - 1210 °C, and the firing time is determined according to the product thickness and type of ceramic tile to ensure that the ceramic tile reaches the best physical properties;

[0044] Glaze formula: Low-lead frit glaze (lead dissolution amount < 0.5 ppm), containing 50% - 55% SiO2, 10% - 15% CaO, 5% ZnO.

[0045] Firing process:

[0046] Preheating section (300 - 800 °C, 2 hours): Decomposition of organic matter and volatilization of moisture;

[0047] High-temperature section (1150 - 1210 °C, 1.5 hours): Liquid-phase sintering densification;

[0048] Cooling section (800 °C → room temperature, slow cooling for 4 hours): Inhibit glaze cracking.

[0049] Effect of the additive in the formula of the present invention:

[0050] (1) Reinforcing agent (2% - 3%)

[0051] Core materials: There are silica fume (nano-SiO2), silicon carbide fiber (SiC).

[0052] Mechanism of action

[0053] Physical enhancement: Silica fume fills the micropores of the green body (pore diameter is reduced to 1 - 5 μm), improving the density;

[0054] Chemical strengthening: React with Al2O3 at high temperature to form mullite (3Al2O3·2SiO2), and the flexural strength is increased by 40%-50% (reaching 15-20 MPa);

[0055] Fiber toughening: SiC fibers form a three-dimensional network structure, and the fracture toughness is increased to 2.5-3.0 MPa·m 1 / 2 (For traditional tiles, it is 1.2-1.8).

[0056] (2) Binder (1%-1.5%)

[0057] Core materials: Sodium carboxymethyl cellulose (CMC), Polyvinyl alcohol (PVA).

[0058] Mechanism of action

[0059] Plasticity improvement: CMC forms a colloidal film with water, and the plasticity index of the green body is increased from 0.3 to 0.6, reducing the forming cracking rate (<0.5%);

[0060] Drying strength: The molecular chains of PVA are cross-linked, and the compressive strength of the green body after drying is ≥5 MPa (only 2-3 MPa without addition).

[0061] (3) Flux (1%-2%)

[0062] Core materials: Potassium feldspar powder (KAlSi3O8), Borax (Na2B4O7·10H2O).

[0063] Mechanism of action

[0064] Low-temperature sintering: Borax reduces the melting temperature to 1150 °C (traditional process requires 1300 °C), saving 25%-30% of energy consumption;

[0065] Liquid phase regulation: Potassium feldspar promotes the formation of the glass phase (the proportion reaches 35%-40%), and the water absorption rate is reduced from 15% to ≤5%.

[0066] Advantages of the production method of the present invention

[0067] (1) Dry ball milling efficiency: The ultrafine particles (D50≤5 μm) of the additive act as a "grinding aid", shortening the ball milling time to 2 hours (traditionally 4-6 hours).

[0068] (2) High-pressure forming stability: The binder reduces the adhesion to the mold, and the pressing qualification rate is ≥98% (≤90% without addition).

[0069] (3) Glost firing defect control: The flux cooperates with the low-lead glaze, reducing the pinhole rate of the glaze surface from 8% to below 0.5%, and the glossiness is ≥85 GU (national standard ≥70 GU).

[0070] The environmental friendliness of the present invention has a dual emission reduction effect

[0071] (1) Raw material substitution: The additive enables the utilization rate of tailings to reach 85%-90%. For each ton of tiles, 1.2 tons of clay mining is reduced, and CO2 emissions are reduced by 0.8 tons.

[0072] (2) Low-temperature firing: The flux reduces the firing temperature by 150°C, and the NOx emissions from the kiln are reduced by 30% (measured ≤ 50mg / m 3 ).

[0073] The economy of the present invention balances cost and added value

[0074] (1) Direct cost: The cost of the additive accounts for about 8%-10%, but after considering the comprehensive energy consumption and waste treatment costs, the total cost is reduced by 15%-20%.

[0075] (2) Product premium: The selling price of high-performance tiles is increased by 30%-50%, which is suitable for the high-end green building market.

[0076] The embodiments of the present invention will be described below.

[0077] Example 1: Basic formula (high proportion of waste residue)

[0078] Composition of the formula: 60% waste residue, 15% waste sand, 20% waste soil, 5% additive. The additive includes 2.5% silica powder + 1.5% CMC + 1% borax;

[0079] Process parameters: Pressing pressure 25MPa, firing temperature 1150°C;

[0080] Index Test Results of Example 1 Traditional Clay Tiles Flexural Strength (MPa) 18.5 10-12 Water Absorption Rate (%) 4.8 12-15 <![CDATA[Density (g / cm 3 )]]> 2.35 1.9-2.1 Firing Energy Consumption (kWh / ton) 320 480

[0081] This example demonstrates the high utilization of waste residue. The strength of the Roman tiles of the present invention is significantly improved, but the glaze glossiness is slightly lower (80GU).

[0082] Example 2: High plasticity formula (optimization of waste soil)

[0083] Composition of the formula: 55% waste residue, 10% waste sand, 30% waste soil, 5% additive. The additive uses 2% silicon carbide fiber + 1.5% PVA + 1.5% potassium feldspar powder;

[0084] Process parameters: Pressing pressure 22MPa (reducing the pressure to adapt to high plasticity), firing temperature 1180°C;

[0085] Index Test Results of Example 2 Test Results of Example 1 <![CDATA[Fracture toughness (MPa·m 1 / 2 )]]> 2.8 2.0 Drying Cracking Rate (%) 0.2 0.5 Glossiness of Glaze Surface (GU) 88 80 Raw Material Cost (yuan / ton) 680 650

[0086] This example is suitable for tiles with complex shapes, and the glaze quality is better, but the density is slightly lower (2.2g / cm 3 ).

[0087] Example 3: Low-temperature energy-saving formula (flux strengthening)

[0088] Formulation composition: 50% waste residue, 15% waste sand, 25% waste soil, 10% additive. The additive is composed of 3% borax + 4% silica fume + 3% nano-zinc oxide;

[0089] Process parameters: Firing temperature 1100°C (breakthrough low temperature), firing duration 4 hours (30% shorter than traditional ones);

[0090] Index Test Results of Example 3 Industry Standard Thermal Shock Resistance (times) ≥10 times (20 - 25°C → cold water) ≥5 times (national standard) Lead Leaching Amount (ppm) 0.3 ≤0.5 (EU standard) <![CDATA[CO2 emissions (kg / ton)]]> 220 350 (traditional process)

[0091] This example has ultra-low temperature firing with outstanding environmental protection, but the dispersion uniformity of nanomaterials needs to be controlled.

[0092] Example 4: Composite reinforcement formula (functional expansion)

[0093] Formulation composition: 58% waste residue, 12% waste sand, 20% waste soil, 10% additive. The additive is composed of silicon carbide fiber (3%) + TiO2 photocatalytic glaze (5%) + silane coupling agent (2%);

[0094] Process indicators: Glaze firing temperature 1210°C (to activate photocatalytic activity), self-cleaning efficiency 90% under ultraviolet irradiation (pollutant degradation rate in 48 hours);

[0095] Highlights of the performance of this example:

[0096] (1) Self-cleaning function: Surface contact angle < 10° (super-hydrophilic), suitable for high-pollution areas;

[0097] (2) Weather resistance: No color change after 5000 hours of artificial aging test (traditional tiles turn yellow after 2000 hours).

[0098] Through the above examples, the core factors for performance improvement can be obtained, as follows:

[0099] (1) Synergistic effect of additives

[0100] The composite flux system of borax + potassium feldspar powder reduces the firing temperature by 150°C;

[0101] The "nano-micro" multi-scale reinforcement of silica fume + silicon carbide fiber increases the flexural strength by 80%.

[0102] (2) Regulation of waste particle size

[0103] Waste sand below 80 mesh, waste soil 200 mesh, optimizing the particle size distribution (D10 = 1μm, D50 = 15μm, D90 = 80μm), reducing the stress concentration in the green body.

[0104] (3) Balance between environmental protection and cost:

[0105] The utilization rate of tailings is ≥ 85%, and the solid waste treatment cost per ton of product is reduced by 200 - 300 yuan; with the low-temperature firing + short-cycle process, the comprehensive energy consumption is reduced by 40%.

[0106] Suggestions for adapting the product application scenarios made in the foregoing embodiments are shown in the following table:

[0107] Formula Type Applicable Scenario Recommended Reason Basic Formula Conventional Residential Roof High cost performance and qualified strength High Plasticity Formula Curved Tiles for Antique Buildings Good forming adaptability and strong glaze decoration Low - temperature Energy - saving Formula Demonstration Area Buildings Advantages of low - carbon certification and traceable emission reduction data Composite Reinforcement Formula Industrial Zone / Coastal High - Corrosion Environment Weather resistance + self - cleaning, low life - cycle cost

[0108] In summary, through fine-tuning of the formulation components and optimization of the process parameters, the Roman tiles can be accurately adapted to different application requirements, achieving triple breakthroughs in "performance - environmental protection - economy", and providing a replicable high-value solution for solid waste in the building ceramics industry.

[0109] The above describes the present invention and its implementation manners. This description is not restrictive. Generally speaking, if those of ordinary skill in the art are inspired by it and, without departing from the purpose of the present invention, design similar structural manners and embodiments of the technical solution without creative efforts, they shall fall within the protection scope of the present invention.

Claims

1. A formula for Roman tiles, characterized in that, It includes the following components by proportion: 50%-60% of waste residue, 10%-15% of waste sand, 10%-25% of waste soil and additives, and the additives are controlled within 5%. The waste residue, waste sand and waste soil are from the tailing waste soil, waste sand and waste residue after albite mining.

2. A formula for a Roman tile according to claim 1, characterized in that, The additives include reinforcing agents, binders and fluxes.

3. A manufacturing method of Roman tiles, characterized in that, It includes the following steps: S1. Raw material pretreatment: Screen and remove impurities from the tailing waste soil, waste sand and waste residue after albite mining, remove large particle impurities and harmful elements. The waste residue and waste sand need to be crushed to below 80 mesh, and the waste soil needs to be ground to 200 mesh. Remove iron impurities through magnetic separation. S2. Batching and mixing: Accurately weigh various raw materials according to the formula, put them into a mixer and stir evenly. Use dry ball milling to make the uniformity better. The mixing time is ≥2 hours, and the water content is controlled at 18%-22%. S3. Shaping: Use existing press equipment for high-pressure forming to make the green body have good density and initial strength. During the pressing process, the pressure is 25 MPa, and the density of the obtained green body is ≥ 2.2 g / cm 3 ; S4. Drying and biscuit firing: Send the formed green body into a drying kiln for drying treatment to remove moisture and improve the strength of the green body. The drying temperature and time are reasonably adjusted according to the size and water content of the green body. The gradient drying is adopted during the drying process, and the gradient drying temperature is room temperature → 80°C → 120°C. S5. Glazing and glaze firing: Low-lead frit glaze is used for glazing, and firing is carried out in a high-temperature shuttle kiln or roller hearth kiln. The firing process is divided into three stages: preheating, high-temperature firing and cooling. The highest firing temperature is controlled at 1150-1210°C, and the firing time is determined according to the product thickness and the type of ceramic tile to ensure that the ceramic tile reaches the best physical properties.