Rapidly fired domestic ceramic and method for making same

Abstract

This invention proposes a rapid-firing method for daily-use ceramics and its preparation, belonging to the field of daily-use ceramics manufacturing technology. The method involves obtaining raw materials through ball milling, sieving, and aging; shaping the raw materials into the desired form and drying them to control the moisture content of the dried raw materials to below 1%; and firing the dried raw materials in a roller kiln. This shortens the firing cycle of daily-use ceramics from the traditional 8-25 hours to 2-4 hours, increases kiln turnover by 2-10 times, and significantly improves production efficiency. The firing temperature is 50-100℃ lower than conventional formulas, and combined with the shortened firing cycle, the overall energy consumption per unit product is reduced.

Description

Technical Field

[0001] This invention belongs to the field of daily-use ceramics manufacturing technology, specifically relating to a rapid-firing daily-use ceramic and its preparation method. Background Technology

[0002] Everyday ceramics are closely related to people's daily lives; bowls, plates, cups, pots, and other daily ceramic products are necessities for households and the catering industry. However, traditional daily ceramics production faces many pressing technical problems that need to be solved: First, the firing cycle is long and energy consumption is high. The firing cycle for traditional tunnel kilns for daily-use ceramics typically ranges from 8 to 25 hours, with firing temperatures reaching 1250-1350℃. This results in persistently high energy consumption per unit product, which does not comply with current energy conservation and emission reduction policies. Existing rapid-firing technologies are mostly designed for architectural ceramics. Daily-use ceramics, due to their complex shapes, uneven wall thickness, and high requirements for whiteness and translucency, are far more sensitive to firing regimes than architectural ceramics, leading to slow progress in rapid-firing technology in the daily-use ceramics sector. Simply pursuing a shorter firing cycle can easily lead to defects such as deformation and cracking, significantly reducing the yield.

[0003] Secondly, the flux system has technical shortcomings. Flux is a key component for lowering the firing temperature of ceramics, and traditional daily-use ceramic blanks mainly rely on potassium feldspar flux. Potassium feldspar has an initial melting temperature of approximately 1150℃, a wide melting temperature range, and high viscosity at high temperatures, making it suitable only for traditional long-cycle firing. It is difficult to fully melt under low-temperature, rapid firing conditions, failing to meet the liquid phase formation requirements of rapid firing. While sodium feldspar has an even lower initial melting temperature (approximately 1000℃), which can lower the firing temperature to some extent, it forms an excessive amount of glassy phase during the cooling stage, leading to a significant decrease in the mechanical strength of the ceramic body. Products using sodium feldspar flux typically have a flexural strength of only 60-80 MPa, which is insufficient to meet the requirements for daily-use ceramics.

[0004] Therefore, developing a method for producing daily-use ceramics that can achieve rapid firing in roller kilns in 2-4 hours, simultaneously reduce the firing temperature by 50-100℃, and ensure that the product performance is no less than that of traditional processes is an urgent technical problem to be solved in the field of rapid firing of daily-use ceramics. Summary of the Invention

[0005] This invention addresses the problems of existing technologies by providing a method for rapidly firing daily-use ceramics and its preparation.

[0006] To achieve the above objectives, the technical solution adopted in this application is as follows: A method for preparing rapidly fired daily-use ceramics, comprising the following raw materials by weight: 15-25 parts feldspar, 10-15 parts quartz, 15-25 parts raw Longyan clay ore, 20-25 parts Datong clay, 5-10 parts bentonite, 10-15 parts washed mud, and 5-8 parts flux; wherein the flux is selected from one or more of borocalcite, spodumene, wollastonite, and diopside.

[0007] Preferably, the mass ratio of borocalcite to spodumene is 0.5 to 2:1.

[0008] As a preferred embodiment, its chemical composition by mass percentage is: Li2O 3%–8%, B2O3 10%–20%, Na2O+K2O 2%–8%, CaO+MgO 3%–15%, Al2O3 10%–20%, SiO2 40%–60%.

[0009] A method for preparing rapidly fired daily-use ceramics includes the following steps: Step 1: Weigh each raw material according to the above weight proportions, and obtain the billet after ball milling, sieving, and aging; Step 2: Shape the blank into the desired shape and dry it so that the moisture content of the dried blank is controlled below 1%; Step 3: The dried green body is fired in a roller kiln, with the firing cycle controlled at 2-4 hours; the firing temperature is 50-100℃ lower than that of conventional formula ceramics.

[0010] Preferably, in step three, the firing temperature is controlled at 1180-1220℃.

[0011] Preferably, in step three, the firing process is as follows: the temperature is increased to the firing temperature at 12-18℃ / min, held for 5-25 minutes, and then rapidly cooled to 750-850℃ at 20-35℃ / min in a rapid cooling device, followed by natural cooling with the furnace.

[0012] As a preferred option, the performance of the fired product should meet the following requirements: flexural strength ≥80MPa, water absorption rate 0.2%-2%, whiteness ≥70%, and thermal stability without cracking after three cycles of rapid cooling and heating from 180℃ to 20℃.

[0013] Compared with the prior art, the advantages and positive effects of the present invention are as follows: This application discloses a rapid-firing daily-use ceramic and its preparation method. The method involves obtaining a raw material through ball milling, sieving, and aging; shaping the raw material into the desired form and drying it to control the moisture content of the dried material to below 1%; and firing the dried material in a roller kiln. This reduces the firing cycle of daily-use ceramic from the traditional 8-25 hours to 2-4 hours, increases kiln turnover by 2-10 times, and significantly improves production efficiency. The firing temperature is 50-100℃ lower than conventional formulas, and combined with the shortened firing cycle, the overall energy consumption per unit product is reduced. Furthermore, the daily-use ceramic products prepared using the method of this application have a flexural strength ≥80MPa, a water absorption rate of 0.2%-2%, a whiteness ≥70%, and thermal stability that can withstand five cycles of rapid cooling and heating from 180℃ to 20℃ without cracking. All performance indicators are superior to or reach the level of products produced by traditional processes. This invention can be directly applied to existing roller kiln production lines without major equipment modifications. Only the raw material formula and firing regime need to be adjusted to achieve industrial production, and its application prospects are broad. Attached Figure Description

[0014] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0015] Figure 1 One of the physical images of the ceramic product of the present invention; Figure 2 The second is a physical image of the ceramic product of the present invention; Detailed Implementation

[0016] To better understand the above-mentioned objectives, features, and advantages of the present invention, the present invention will be further described below in conjunction with the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0017] Numerous specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways than those described herein, and therefore the invention is not limited to the specific embodiments disclosed in the following specification.

[0018] Example 1, such as Figures 1-2 As shown, a type of fast-fired daily ceramic is made by weighing the following raw materials in the following weight proportions: 20 parts feldspar, 12 parts quartz, 18 parts Longyan clay ore, 22 parts Datong clay, 8 parts bentonite, 12 parts washed mud, and 6 parts flux, wherein the flux is borosilicate. The rapid firing method for preparing daily-use ceramics in Example 1 is as follows: Add the above raw materials to a ball mill and ball mill until the residue on a 250-mesh sieve is ≤0.5%. After passing through a 250-mesh sieve, age for 48 hours to obtain a uniform billet. The blanks were rolled into disc-shaped products with a diameter of 18cm, and then dried in a drying kiln until the moisture content of the blanks was 0.8%. The dried green body is sent to a roller kiln for firing. The firing process is as follows: the temperature is raised to 1200℃ at a rate of 15℃ / min, held for 20 minutes, and then cooled to 800℃ at a rate of 25℃ / min in a rapid cooling device. After that, it is naturally cooled to room temperature with the furnace. The total firing cycle is 3.5 hours.

[0019] The fired product was tested and found to have the following properties: flexural strength of 88 MPa, water absorption of 0.85%, whiteness of 73%, and thermal stability (180℃→20℃) without cracking after 5 cycles.

[0020] Example 2 is a type of rapid-fired daily ceramic. The raw materials are weighed according to the following parts by weight: 18 parts feldspar, 10 parts quartz, 16 parts Longyan clay ore, 24 parts Datong clay, 6 parts bentonite, 14 parts washed mud, and 6 parts flux. The flux is a combination of borocalcite and spodumene in a mass ratio of 1:1. The rapid firing method for preparing daily-use ceramics in Example 2 is as follows: Add the above raw materials to a ball mill and ball mill until the residue on a 250-mesh sieve is ≤0.5%. After passing through a 250-mesh sieve, age for 48 hours to obtain a uniform billet. The blanks were rolled into disc-shaped products with a diameter of 18cm, and then dried in a drying kiln until the moisture content of the blanks was 0.8%. The dried billet is sent into a roller kiln for firing. The firing process is as follows: the temperature is raised to 1190°C at a rate of 16°C / min, held for 15 minutes, and then cooled to 800°C at a rate of 30°C / min in a rapid cooling device. After that, it is naturally cooled to room temperature with the furnace. The total firing cycle is 3 hours. The fired product was tested and found to have the following properties: flexural strength 98MPa, water absorption 0.93%, whiteness 72%, and thermal stability (180℃→20℃) without cracking after 5 cycles.

[0021] Example 3 is a type of rapid-fired daily ceramic. The raw materials are weighed according to the following parts by weight: 22 parts feldspar, 13 parts quartz, 17 parts Longyan clay ore, 21 parts Datong clay, 7 parts bentonite, 11 parts washed mud, and 5 parts flux, wherein the flux is wollastonite. The rapid firing method for preparing daily-use ceramics in Example 3 is as follows: Add the above raw materials to a ball mill and ball mill until the residue on a 250-mesh sieve is ≤0.5%. After passing through a 250-mesh sieve, age for 48 hours to obtain a uniform billet. The blanks were rolled into disc-shaped products with a diameter of 18cm, and then dried in a drying kiln until the moisture content of the blanks was 0.8%. The dried green body is sent to a roller kiln for firing. The firing process is as follows: the temperature is raised to 1200℃ at a rate of 18℃ / min, held for 15 minutes, and then cooled to 800℃ at a rate of 30℃ / min in a rapid cooling device. After that, it is naturally cooled to room temperature with the furnace. The total firing cycle is 2.5 hours.

[0022] The fired product was tested and found to have the following properties: flexural strength of 85 MPa, water absorption of 1.35%, whiteness of 73%, and thermal stability (180℃→20℃) without cracking after 5 cycles.

[0023] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments that can be applied to other fields. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A type of rapidly fired daily-use ceramic, characterized in that, It is composed of the following raw materials by weight: 15-25 parts feldspar, 10-15 parts quartz, 15-25 parts raw Longyan clay ore, 20-25 parts Datong clay, 5-10 parts bentonite, 10-15 parts washed mud, and 5-8 parts flux; the flux is selected from one or more of borocalcite, spodumene, wollastonite, and diopside.

2. The rapid-firing daily-use ceramic according to claim 1, characterized in that, The flux is a combination of borate and spodumene, with a mass ratio of borate to spodumene of 0.5 to 2:

1.

3. A rapid-firing daily-use ceramic according to claim 1, characterized in that, The flux is a composite flux, and its chemical composition by mass percentage is: Li2O 3%-8%, B2O3 10%-20%, Na2O+K2O 2%-8%, CaO+MgO 3%-15%, Al2O3 10%-20%, SiO2 40%-60%.

4. A method for preparing rapidly fired daily-use ceramics according to any one of claims 1-3, characterized in that, Includes the following steps: Step 1: Weigh each raw material according to the above weight proportions, and obtain the billet after ball milling, sieving, and aging; Step 2: Shape the blank into the desired shape and dry it so that the moisture content of the dried blank is controlled below 1%; Step 3: The dried billet is then fired in a roller kiln, with the firing cycle controlled at 2-4 hours.

5. The method for preparing rapidly fired daily-use ceramics according to claim 4, characterized in that, In step three, the firing temperature is controlled at 1180-1220℃.

6. The method for preparing rapidly fired daily-use ceramics according to claim 1, characterized in that, In step three, the firing process is as follows: the temperature is increased to the firing temperature at 12-18℃ / min, held for 5-25 minutes, and then rapidly cooled to 750-850℃ at 20-35℃ / min in a rapid cooling device, followed by natural cooling with the furnace.

7. A method for preparing rapidly fired daily-use ceramics according to any one of claims 4-6, characterized in that, The performance of the fired product meets the following requirements: flexural strength ≥80MPa, water absorption rate 0.2%-2%, whiteness ≥70%, and thermal stability without cracking after three cycles of rapid cooling and heating from 180℃ to 20℃.

Images