Yellow river mud-based environment-friendly functional ceramic mud containing high-sr microcrystalline calcite and preparation method thereof

Abstract

The present application relates to a kind of high strontium microcrystalline calcite containing Yellow River mud base environmental protection function ceramic mud, the high strontium microcrystalline calcite containing Yellow River mud base environmental protection function ceramic mud is made of the following weight parts of raw materials: Yellow River mud 40~70 parts, high strontium microcrystalline calcite powder 10~30 parts, porcelain stone 15~25 parts, feldspar 5~10 parts, quartz 5~10 parts, fiber material 3~8 parts, green body water reducing agent 0.5~2 parts.The high strontium microcrystalline calcite containing Yellow River mud base environmental protection function ceramic mud and its preparation method have the advantages of low raw material cost, high flexural strength, low scrap rate, can retain good far infrared emission function and the like.

Description

Technical Field

[0001] This invention relates to the field of environmentally friendly ceramics technology, and in particular to a Yellow River mud-based environmentally friendly functional ceramic clay containing high-strontium microcrystalline calcite and its preparation method. Background Technology

[0002] Currently, Yellow River silt is a special type of sediment formed by the Yellow River's erosion and deposition, rich in various minerals. Statistics show that the Yellow River carries a massive amount of sediment annually, and how to utilize this silt for resource recovery has always been a research hotspot in environmental protection and materials science. High-strontium microcrystalline calcite is a natural stone with special therapeutic effects, containing trace elements such as strontium, calcium, and iron. Although existing technologies have attempted to use Yellow River silt in the preparation of ceramsite, bricks, or ordinary ceramics, and to add high-strontium microcrystalline calcite powder to coatings or simple ceramic matrices to achieve health benefits, the following shortcomings remain in its application: Traditional Yellow River clay ceramics often require the addition of kaolin to improve plasticity or refractoriness. However, kaolin is a non-renewable mineral resource, and its extraction has a certain environmental impact. Furthermore, existing Yellow River clay processing techniques often result in insufficient aging time, leading to poor plasticity and significant shrinkage during drying and firing. Additionally, if high-strontium microcrystalline calcite powder contains carbonate minerals such as calcite, it is prone to decomposition and gas generation during high-temperature ceramic sintering (typically above 1200℃), causing blistering, cracking, or deformation of the ceramic body, severely impacting yield and mechanical properties.

[0003] Therefore, the development of a ceramic clay material and its preparation process that does not require kaolin, can utilize Yellow River mud as a base material, and can stably support the function of high strontium microcrystalline calcite powder is of great practical significance. Summary of the Invention

[0004] To overcome the shortcomings of the prior art, this invention provides a Yellow River mud-based environmentally friendly functional ceramic clay containing high-strontium microcrystalline calcite and its preparation method, which has advantages such as low raw material cost, high flexural strength, low scrap rate, and good retention of far-infrared emission function.

[0005] The technical solution adopted by the present invention to solve the above-mentioned technical problems is as follows: An environmentally friendly functional ceramic clay material based on Yellow River mud containing high-strontium microcrystalline calcite is made from the following raw materials in parts by weight: 40-70 parts Yellow River mud, 10-30 parts high-strontium microcrystalline calcite powder, 15-25 parts porcelain stone, 5-10 parts feldspar, 5-10 parts quartz, 3-8 parts fiber material, and 0.5-2 parts body water-reducing agent.

[0006] Yellow River mud serves as the base material, providing a silicon source and part of the aluminum source, reducing costs and being environmentally friendly. High-strontium microcrystalline calcite powder serves as the functional phase, providing far-infrared radiation and trace elements. Porcelain stone serves as the framework / aluminum source, replacing kaolin, supplementing Al2O3, and improving refractoriness. Feldspar serves as a flux, lowering the sintering temperature and promoting mullite crystal growth. Quartz serves as a lean material, reducing high-temperature shrinkage and regulating the porosity of the green body. Fiber materials are used for toughening, improving the strength of the green body, and reducing drying cracking. A green body water-reducing agent is used to reduce the moisture content of the mud and improve fluidity.

[0007] Preferably, the particle size of the selected high-strontium microcrystalline calcite powder is 38–74 μm.

[0008] Preferably, the fiber material is an interwoven fiber composed of lignin fiber, polyester fiber and basalt fiber in a mass ratio of 2:1:1.

[0009] Preferably, the water-reducing agent for the preform is a polycarboxylate-based water-reducing agent.

[0010] Preferably, the Yellow River mud is Yellow River clay, whose main chemical components include SiO2 (77.33%) and Al2O3 (9.2%).

[0011] In addition, this application also provides a method for preparing Yellow River mud-based environmentally friendly functional ceramic clay containing high strontium microcrystalline calcite, including the steps of raw material pretreatment, batching and ball milling, pressure filtration and dewatering and vacuum kneading, fiber reinforcement and aging, secondary kneading and molding, drying and sintering.

[0012] Furthermore, the specific steps are as follows: S1: Raw material pretreatment Yellow River mud: Air-dry naturally until the moisture content is below 10%, crush and pass through an 80-120 mesh sieve to remove coarse sand and impurities; High-strontium microcrystalline calcite powder: After coarsely crushing the high-strontium microcrystalline calcite, ball mill it for 2-6 hours, pass it through a 200-400 mesh sieve, and then calcine the high-strontium microcrystalline calcite powder at 600-800℃ for 2 hours to decompose the carbonates such as calcite and prevent the generation of bubbles during high-temperature sintering. Cool and set aside; Auxiliary raw materials: Porcelain stone, feldspar, and quartz are ball-milled to below 200 mesh and set aside. S2: Ingredient ball milling Weigh out the Yellow River mud obtained from S1, high-strontium microcrystalline calcite powder, porcelain stone, feldspar, quartz, and water-reducing agent according to the formula, add them to the ball mill jar, add water according to the ratio of material:ball:water = 1:(1.5-2):(0.6-0.8), and ball mill and mix for 4-8 hours until the fineness of the slurry reaches less than 5% residue on a 10,000-mesh sieve; S3: Filter press dewatering and vacuum plying The ball-milled slurry was dewatered by pressure filtration to a moisture content of 22%-28%, and then subjected to a first vacuum plucking process at a vacuum degree of -0.09 MPa to obtain preliminary clay strips. S4: Fiber Reinforcement and Aging First, the fiber material is moistened and dispersed with a green body water-reducing agent solution, then added to the preliminary clay strips and mixed evenly in a piling machine; then the mixed fiber clay material is placed in a sealed environment at a constant temperature of 20-25℃ for 30-60 days to age. S5: Secondary clay preparation and shaping The aged clay is taken out and subjected to a second vacuum kneading process. The final clay moisture content is controlled to be 20%-23%, which yields the finished clay. After molding, the clay body is obtained. S6: Drying and Sintering The shaped green body is dried at 80-100℃ until the moisture content is <1%, and then sintered in a kiln. The sintering conditions are as follows: the temperature is increased to 300℃ at a rate of 100-150℃ / h to remove free water; the temperature is increased to 600℃ at a rate of 200℃ / h to remove structural water; then the temperature is held at 600-800℃ for 1-2 hours; finally, the temperature is increased to 1250-1350℃ at a rate of 150℃ / h and held for 2-4 hours, and then naturally cooled to obtain the final product.

[0013] The present invention employs the above-described structure and has the following advantages: 1. This invention utilizes abundant Yellow River silt to replace some traditional minerals and completely abandons kaolin, using porcelain stone as the aluminum source. This not only reduces raw material costs but also provides a new way to utilize Yellow River silt resources.

[0014] 2. By adding feldspar as a flux, the sintering temperature is controlled within a reasonable range of 1250-1350℃. The finished product has a water absorption rate of less than 0.5% and a flexural strength of more than 40MPa, which meets the standards of modern high-end porcelain.

[0015] 3. By pre-firing the high-strontium microcrystalline calcite powder and setting a heat preservation section of 600-800℃ in the sintering process, the problem of the green body cracking caused by the high-temperature decomposition of carbonates in high-strontium microcrystalline calcite is effectively solved, ensuring the high-temperature stability of high-strontium microcrystalline calcite powder in the ceramic matrix and preserving its far-infrared emission function.

[0016] 4. The long-term aging process of 30-60 days greatly improves the plasticity and density of the clay, and the toughening effect of the fiber material significantly reduces the scrap rate. Attached Figure Description

[0017] Fig. 1 This is a comparison chart of far-infrared emissivity for Embodiments 1 and 2 of the present invention; Fig. 2 The effect of the amount of high-strontium microcrystalline calcite powder added on far-infrared emissivity. Detailed Implementation

[0018] To clearly illustrate the technical features of this solution, the invention will be described in detail below through specific implementation methods and in conjunction with the accompanying drawings.

[0019] (I) Example 1 (Ordinary Daily Use)

[0020] 1.1 Raw material ratio: 60 parts Yellow River mud, 15 parts high strontium microcrystalline calcite powder, 20 parts porcelain stone, 8 parts potassium feldspar, 5 parts quartz, 4 parts lignin fiber, and 1 part polycarboxylate water-reducing agent.

[0021] 1.2 Preparation method

[0022] S1: Raw material pretreatment

[0023] Yellow River mud: air-dry until the moisture content is below 10%, crush and pass through a 120-mesh sieve to remove coarse sand and impurities; High-strontium microcrystalline calcite powder: coarsely crush the high-strontium microcrystalline calcite and ball-mill for 3 hours, pass through a 200-mesh sieve, then calcine the high-strontium microcrystalline calcite powder at 700℃ for 2 hours to decompose the carbonates such as calcite and prevent the generation of bubbles during high-temperature sintering, cool and set aside; Auxiliary raw materials: porcelain stone, feldspar, and quartz are ball-milled to below 200 mesh and set aside. S2: Ingredient ball milling Weigh out the Yellow River mud obtained from S1, high-strontium microcrystalline calcite powder, porcelain stone, feldspar, quartz, and water-reducing agent according to the formula, add them to the ball mill jar, add water at the ratio of material:ball:water = 1:1.5:0.6, and ball mill and mix for 4 hours until the fineness of the slurry reaches less than 5% residue on a 10,000-mesh sieve; S3: Filter press dewatering and vacuum plying The ball-milled slurry was dehydrated by pressure filtration to a moisture content of 23%, and then subjected to a first vacuum plucking process at a vacuum degree of -0.09 MPa to obtain preliminary clay strips. S4: Fiber Reinforcement and Aging First, the fiber material is moistened and dispersed with a green body water-reducing agent solution, then added to the initial clay strips and mixed evenly in a piling machine; then the mixed fiber clay material is placed in a sealed environment at a constant temperature of 25°C for 45 days to age. S5: Secondary clay preparation and shaping The aged clay is taken out and subjected to a second vacuum kneading process. The final clay moisture content is controlled at 22%, which yields the finished clay. After molding, the clay body is obtained. S6: Drying and Sintering The shaped green body is dried at 100℃ to a moisture content of <1%, and then sintered in a kiln. The sintering conditions are as follows: the temperature is increased to 300℃ at a rate of 120℃ / h to remove free water; the temperature is increased to 600℃ at a rate of 200℃ / h to remove structural water; then the temperature is held at 600-800℃ for 2 hours; finally, the temperature is increased to 1300℃ at a rate of 150℃ / h and held for 3 hours. After natural cooling, the ordinary daily-use functional ceramic material of this application is obtained.

[0024] 1.3 Tests and Results

[0025] Finished product appearance: No cracks or deformation.

[0026] Test results: such as Figs. 1-2 As shown, the far-infrared emissivity (8-14μm) of the ceramic material obtained in this application is 0.88, which is higher than the 0.75 of traditional ceramics. Furthermore, mechanical property tests revealed that its flexural strength can reach 42.5MPa.

[0027] (II) Example 2: (High-performance ceramics)

[0028] 2.1 Raw material ratio: 45 parts Yellow River mud, 25 parts high strontium microcrystalline calcite powder, 18 parts porcelain stone, 10 parts albite, 8 parts quartz, 5 parts basalt fiber, and 1.5 parts water-reducing agent.

[0029] 2.2 Preparation method: Same as Example 1, aging time 60 days, sintering temperature 1280℃.

[0030] 2.3 Tests and Results: Finished product appearance: No cracks or deformation.

[0031] Test results: The test on the negative ion release of ceramic materials is to detect the ability of ceramic materials to release negative ions.

[0032] After testing the finished product obtained in Example 2, the results showed that the high-performance ceramic of this application retains the high trace element content of high-strontium microcrystalline calcite, and the negative ion release can reach more than 1000 ions / cm³.

[0033] Mechanical performance testing was conducted, and the tested mechanical properties met the usage requirements.

[0034] The specific embodiments described above should not be construed as limiting the scope of protection of this invention. Any alternative modifications or variations made to the embodiments of this invention by those skilled in the art will fall within the scope of protection of this invention. All aspects not detailed in this invention are well-known to those skilled in the art.

Claims

1. A Yellow River mud-based environmentally friendly functional ceramic clay containing high-strontium microcrystalline calcite, characterized in that, It is made from the following raw materials in parts by weight: 40-70 parts Yellow River mud, 10-30 parts high strontium microcrystalline calcite powder, 15-25 parts porcelain stone, 5-10 parts feldspar, 5-10 parts quartz, 3-8 parts fiber material, and 0.5-2 parts body water reducing agent.

2. The Yellow River mud-based environmentally friendly functional ceramic clay containing high-strontium microcrystalline calcite according to claim 1, characterized in that, The selected high-strontium microcrystalline calcite powder has a particle size of 38–74 μm.

3. The Yellow River mud-based environmentally friendly functional ceramic clay containing high-strontium microcrystalline calcite according to claim 1, characterized in that, The fiber material is an interwoven fiber composed of lignin fiber, polyester fiber and basalt fiber in a mass ratio of 2:1:

1.

4. The Yellow River mud-based environmentally friendly functional ceramic clay containing high-strontium microcrystalline calcite according to claim 1, characterized in that, The water-reducing agent for the preform is a polycarboxylate-based water-reducing agent.

5. A method for preparing Yellow River mud-based environmentally friendly functional ceramic clay containing high-strontium microcrystalline calcite as described in any one of claims 1-4, characterized in that, The process includes steps such as raw material pretreatment, batching and ball milling, pressure filtration and dewatering and vacuum plowing, fiber reinforcement and aging, secondary plowing and molding, drying and sintering.

6. The method for preparing Yellow River mud-based environmentally friendly functional ceramic clay containing high-strontium microcrystalline calcite according to claim 5, characterized in that, The specific steps are as follows: S1: Raw material pretreatment Yellow River mud: air-dry until the moisture content is below 10%, crush and pass through an 80-120 mesh sieve to remove coarse sand and impurities; High-strontium microcrystalline calcite powder: coarsely crush the high-strontium microcrystalline calcite and ball-mill for 2-6 hours, pass through a 200-400 mesh sieve, then calcine the high-strontium microcrystalline calcite powder at 600-800℃ for 2 hours, cool and set aside; Auxiliary raw materials: porcelain stone, feldspar, and quartz are ball-milled to below 200 mesh and set aside. S2: Ingredient ball milling Weigh out the Yellow River mud obtained from S1, high-strontium microcrystalline calcite powder, porcelain stone, feldspar, quartz, and water-reducing agent according to the formula, add them to the ball mill jar, add water according to the ratio of material:ball:water = 1:(1.5-2):(0.6-0.8), and ball mill and mix for 4-8 hours until the fineness of the slurry reaches less than 5% residue on a 10,000-mesh sieve; S3: Filter press dewatering and vacuum plying The ball-milled slurry was dewatered by pressure filtration to a moisture content of 22%-28%, and then subjected to a first vacuum plucking process at a vacuum degree of -0.09 MPa to obtain preliminary clay strips. S4: Fiber Reinforcement and Aging First, the fiber material is moistened and dispersed with a green body water-reducing agent solution, then added to the preliminary clay strips and mixed evenly in a piling machine; then the mixed fiber clay material is placed in a sealed environment at a constant temperature of 20-25℃ for 30-60 days to age. S5: Secondary clay preparation and shaping The aged clay is taken out and subjected to a second vacuum kneading process. The final clay moisture content is controlled to be 20%-23%, which yields the finished clay. After molding, the clay body is obtained. S6: Drying and Sintering The shaped green body is dried at 80-100℃ until the moisture content is <1%, and then sintered in a kiln. The sintering conditions are as follows: the temperature is increased to 300℃ at a rate of 100-150℃ / h to remove free water; the temperature is increased to 600℃ at a rate of 200℃ / h to remove structural water; then the temperature is held at 600-800℃ for 1-2 hours; finally, the temperature is increased to 1250-1350℃ at a rate of 150℃ / h and held for 2-4 hours, and then naturally cooled to obtain the final product.

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