CN-118206365-B - Low-loss high-flatness foamed ceramic and preparation process thereof

CN118206365BCN 118206365 BCN118206365 BCN 118206365BCN-118206365-B

Abstract

The invention discloses a low-loss high-flatness foamed ceramic, which is prepared by taking silicon carbide as a foaming agent and sintering at high temperature, wherein the raw materials for preparing the foamed ceramic are calculated by mass percent of oxides, and the ：SiO 2 64～70.5％、Al 2 O 3 16～19％、Fe 2 O 3 0～3.5％、TiO 2 0～1％、CaO 0.5～3％、MgO 1.5～3.5％、K 2 O 3～5％、Na 2 O 2～4％. high-temperature melt viscosity and surface tension of the foamed ceramic can be improved through the raw material formula, so that the foamed ceramic can be uniformly expanded in the foaming process, the flatness problem in the sintering process of the foamed ceramic can be solved, the use standard of the sintered product can be achieved only by cutting in a small amount or without cutting, the utilization rate of finished products of the foamed ceramic material is greatly improved, and the cost of the foamed ceramic is reduced.

Inventors

ZHANG GUOTAO
LIU WENLONG
Zha Huangsong
XUE JUNDONG
DUAN MOHUA

Assignees

景德镇金绿能新材料科技有限公司
广东金绿能科技有限公司
广东金意陶陶瓷集团有限公司
佛山市三水金意陶陶瓷有限公司
景德镇金意陶陶瓷有限公司

Dates

Publication Date: 20260508
Application Date: 20240327

Claims (7)

1. A low-loss high-flatness foamed ceramic is prepared by taking silicon carbide as a foaming agent and sintering at high temperature, and is characterized by comprising the following raw materials in percentage by mass of oxide ：SiO 2 64～70.5%、Al 2 O 3 16～19%、Fe 2 O 3 0～3.5%、TiO 2 0～1%、CaO 0.5～3%、MgO 1.5～3.5%、K 2 O 3～5%、Na 2 O 2～4%; The preparation process of the low-loss high-flatness foamed ceramic comprises the following steps of ball milling and granulating raw materials of the foamed ceramic according to mass percent to form powder, then scattering the powder into a fireproof kiln furniture to form a powder layer, scraping the powder, feeding the powder into a kiln for sintering at 1160-1170 ℃ for 8-13.5 hours, cooling and discharging the kiln furniture, and removing the fireproof kiln furniture to obtain the low-loss high-flatness foamed ceramic; The thickness of the powder layer is more than or equal to 80mm, and the linear thermal expansion coefficient alpha of the foamed ceramic raw material meets the following conditions ：30～200℃：5.7×10 -6 K -1 ≤α≤6.4×10 -6 K -1 ;30～600℃：6.7×10 -6 K -1 ≤α≤7.6×10 -6 K -1 .
2. The low-loss and high-flatness foamed ceramic according to claim 1, wherein the mass ratio of K element to Na element in the raw material for preparing the foamed ceramic is 0.95-1.5.
3. The foamed ceramic with low loss and high flatness according to claim 1, wherein a known ceramic coloring material is added to the raw material for preparing said foamed ceramic.
4. The preparation process of the low-loss high-flatness foamed ceramic is characterized by comprising the following steps of ball-milling and granulating raw materials of the foamed ceramic according to mass percent to form powder, then scattering the powder into a fireproof kiln to form a powder layer, scraping the powder, feeding the powder into a kiln to be sintered at 1160-1170 ℃ for 8-13.5 h, cooling the kiln, and removing the fireproof kiln to obtain the low-loss high-flatness foamed ceramic; The thickness of the powder layer is more than or equal to 80mm, and the linear thermal expansion coefficient alpha of the foamed ceramic raw material meets the following conditions ：30～200℃：5.7×10 -6 K -1 ≤α≤6.4×10 -6 K -1 ;30～600℃：6.7×10 -6 K -1 ≤α≤7.6×10 -6 K -1 .
5. The process for preparing a foamed ceramic having a low loss and high flatness of claim 4, wherein said powder layers comprise at least two materials, a first powder layer and a second powder layer, wherein said first powder layer and said second powder layer are respectively applied with ceramic coloring materials having different colors, and a predetermined pattern is formed by a known cloth method.
6. The process for preparing a foamed ceramic having a low loss and high flatness according to claim 4, further comprising the steps of edging and/or cutting the foamed ceramic having a low loss and high flatness, the cutting comprising the step of cutting the foamed ceramic blank laterally from the middle.
7. The process for preparing the low-loss and high-flatness foamed ceramic according to claim 4, wherein the process parameters of the powder are that the volume weight is more than or equal to 0.87g/ml, the water content of the powder is 5.5-6.0%, the powder is 1-2% above a 20-mesh sieve, 45-70% of 20-40 meshes, 80-97% of 20-60 meshes, the powder green strength of a 100-mesh sieve is less than or equal to 1.5%, and the powder green strength of a foamed ceramic layer is higher than 1.3Mpa.

Description

Low-loss high-flatness foamed ceramic and preparation process thereof Technical Field The invention relates to the field of building ceramics, in particular to a low-loss high-flatness foamed ceramic and a preparation process thereof. Background The foamed ceramic board is a wall material commonly used in the field of building decoration, and is a high-porosity ceramic material which is prepared by taking polished ceramic slag, waste stone tailings, stone saw mud and other solid waste materials as main raw materials and firing the solid waste materials by adopting a high-temperature foaming technology, has the performances of light weight, high strength, heat preservation, sound insulation, fire resistance and moisture resistance, but the wide application in the field of building is limited by the higher production cost. At present, the production of foamed ceramics is generally carried out by granulating the foamed ceramics into powder, spreading the powder in a mold frame made of refractory materials, foaming at high temperature and sintering. According to the existing manufacturing process, certain concave-convex deformation exists on the surface layer and the bottom layer after the plate is discharged from the kiln, the allowance of about 15-20 mm of the surface layer is required to be removed in the cutting processing process, the allowance of about 10-15 mm of the bottom layer is removed, more cut leftover materials exist, and the yield of the foamed ceramic is only about 70%. Therefore, the production cost of the foamed ceramics is always high. In order to solve the above technical problems, there is a need for a low-loss high-flatness foamed ceramic and a production process thereof. Disclosure of Invention The invention mainly aims to provide a low-loss high-flatness foamed ceramic and a preparation process thereof. In order to achieve the above object, in one aspect, the present invention provides a low-loss high-flatness foamed ceramic, which is prepared by sintering silicon carbide as a foaming agent at high temperature, wherein the raw materials for preparing the foamed ceramic comprise, in mass percentage of oxides ：SiO2 64～70.5％、Al2O3 16～19％、Fe2O3 0～3.5％、TiO20～1％、CaO 0.5～3％、MgO 1.5～3.5％、K2O 3～5％、Na2O 2～4％. According to the invention, the viscosity and the surface tension of the high-temperature melt of the foamed ceramic are improved by regulating and controlling the consumption of each component in the raw material components, so that the foamed ceramic uniformly expands in the foaming process, the flatness problem in the firing process of the foamed ceramic can be improved, the foamed powder can be stably foamed in the firing process, the upper surface, the lower surface and the four sides of the obtained product are relatively flat, the fired blank product can reach the use standard only by a small amount of cutting or without cutting, the utilization rate of the finished product of the foamed ceramic material can be greatly improved, and the cost of the foamed ceramic is reduced. Preferably, in the raw materials for preparing the foamed ceramic, the mass ratio of the K element to the Na element is 0.95-1.5. The high-temperature viscosity of the powder during the high-temperature foaming of the formula is further controlled, so that the pore diameter uniformity of the burnt product can be ensured, and the flatness of the product surface is further improved. Preferably, the raw materials for preparing the foamed ceramic are additionally added with a known ceramic pigment. Different colors at the uniform sintering temperature can be formed, and the color of the sintered product can be achieved through powder color mixing or slurry color mixing, so that a certain decorative effect is achieved. On the other hand, the invention also provides a preparation process of the low-loss high-flatness foamed ceramic, which comprises the following steps of ball-milling and granulating raw materials of the foamed ceramic according to mass percent to form powder, then scattering the powder into a fireproof kiln furniture to form a powder layer, scraping the powder layer, feeding the powder layer into a kiln for sintering at 1160-1170 ℃ for 8-13.5 h, cooling and discharging the kiln furniture, and removing the fireproof kiln furniture to obtain the low-loss high-flatness foamed ceramic. The particle size and water content of the powder can be controlled in a desired range by spray granulation. The ball milling slurry ageing process can improve the performance of the powder, the longer ageing time can fully decompose the organic matters in the slurry, reduce the influence of the organic matters on the green body in the sintering process, and is beneficial to improving the uniformity of the moisture of the powder and convenient for molding. According to the preparation method, the thickness of the powder layer is more than or equal to 80mm, and the larger the linear thermal expansion coefficient of the foamed