CN-121990813-A - Low-temperature open-pore porous ceramic and preparation method thereof

Abstract

The invention discloses a preparation method of low-temperature open-pore porous ceramic, which comprises the steps of taking one of tailings, metallurgical slag or natural clay minerals as a framework material, taking water-soluble chloride salt powder as a pore-forming agent and waste glass powder as a structure stabilizer, mixing the three materials according to a set proportion, pressing and forming, sintering at a temperature lower than 1000 ℃ to obtain a compact ceramic body, immersing the compact ceramic body in water to dissolve chloride salt, and drying to obtain the open-pore porous ceramic. The solution of the dissolved chlorine salt in the preparation method can be subjected to evaporation and crystallization treatment to recycle the pore-forming agent, so that the recycling is realized. The invention realizes the preparation of the porous ceramic with stable structure at low temperature, has simple process, energy conservation and consumption reduction, and the pore-forming agent can be recycled, thereby having the advantages of environmental protection and cost.

Inventors

• JIANG FENG
• WANG HAO
• FU HANG
• LING XIANG

Assignees

• 南京工业大学

Dates

Publication Date

20260508

Application Date

20260308

Claims (8)

1. 1. The preparation method of the low-temperature open-pore porous ceramic is characterized by comprising the following steps of: step one, preparation of raw materials Preparing a framework material, a pore-forming agent and a structure stabilizer, wherein the framework material is one of tailings, metallurgical slag or natural clay minerals, the pore-forming agent is water-soluble chloride, and the structure stabilizer is waste glass powder; Step two, preparation of porous ceramics Uniformly mixing the framework material, the pore-forming agent and the structure stabilizer according to a set proportion, and performing compression molding to obtain a ceramic blank, then sintering the ceramic blank at a temperature lower than 1000 ℃, and cooling to obtain a dense ceramic body containing chlorine salt; wherein, the chlorine salt solution obtained by dissolution is evaporated and crystallized, and the chlorine salt pore-forming agent with the purity meeting the requirement can be recovered.
2. 2. The method of claim 1, wherein the mass ratio of the framework material, the pore-forming agent and the structural stabilizer is 75-65:25-30:5.
3. 3. The method according to claim 1, wherein the sintering temperature in the second step is 850 ℃ to 980 ℃ and the sintering time is 1.5 to 2 hours.
4. 4. The method according to claim 1, wherein the tailings are selected from iron tailings or copper tailings, the metallurgical slag is selected from steel slag, blast furnace slag or red mud, and the natural clay mineral is selected from bentonite, kaolin or diatomaceous earth.
5. 5. The method of claim 1, wherein the chloride salt is NaCl or KCl.
6. 6. The method of claim 5, wherein the chloride salt is NaCl.
7. 7. The method of claim 1, wherein the framework material and the pore-forming agent are both 200 mesh and the structural stabilizer is 300 mesh.
8. 8. A low temperature open pore porous ceramic produced by the production method of any one of claims 1 to 7, characterized in that the porous ceramic has a apparent porosity of 45% to 70% and a compressive strength of 10MPa to 60MPa.

Description

Low-temperature open-pore porous ceramic and preparation method thereof Technical Field The invention relates to the technical field of ceramic material preparation, in particular to a low-temperature open-pore porous ceramic and a preparation method thereof. Background The porous ceramic is widely applied to the fields of filtration and separation, catalyst carriers, heat insulation materials, biomedical materials, sound absorption and damping materials, sensitive elements, energy and the like by virtue of the adjustable pore structure (comprising porosity, pore size distribution and pore morphology) and excellent physicochemical properties. The properties of porous ceramics are highly dependent on their microstructure, which is determined by the manufacturing technique. Among the preparation methods, the pore-forming agent method is regarded as one of the most widely used and basic porous ceramic preparation methods. Among the preparation methods of porous ceramics, the method of adding pore-forming agent is widely used because of its simple process and good controllability of pore structure. However, the existing pore-forming agent technology has the following outstanding defects that (1) the sintering temperature is high, the sintering temperature of the traditional porous ceramic is generally higher than 1200 ℃ in order to achieve the densification sintering of ceramic particles, the energy consumption is high, the cost is high, (2) the pore-forming agent cannot be recycled, no matter the organic pore-forming agent removed through combustion or the inorganic pore-forming agent removed through thermal decomposition disappears after the organic pore-forming agent is combusted, the organic pore-forming agent is consumed in the process and cannot be recycled, and the resource waste is caused, and (3) the decomposition of the pore-forming agent in the sintering process can cause the cracking of a blank or the collapse of a pore wall, so that the mechanical property and the pore uniformity of a final product are influenced. In addition, research using inorganic salts (such as NaCl) as pore formers has been partially performed, and there is still a process of removing the pore formers first and then sintering at high temperature (> 1000 ℃), resulting in the preformed pores being closed or deformed during the subsequent high temperature process, and thus it is difficult to obtain an ideal open pore structure. Therefore, the development of the preparation method of the porous ceramic with low-temperature sintering, recoverable pore-forming agent and reasonable process sequence has important industrial application value and environmental protection significance. Disclosure of Invention The embodiment of the application provides a low-temperature open-pore porous ceramic and a preparation method thereof, and the method adopts waste glass powder as a low-temperature structure stabilizer, creatively implements a process of 'low-temperature sintering densification first and then leaching out a pore-forming agent by water', successfully realizes low-temperature sintering below 1000 ℃, realizes the whole-course recovery and recycling of a chloride salt pore-forming agent, and solves the problems of high energy consumption, high cost and difficult control of a pore structure in the traditional method at one time. The embodiment of the application provides a preparation method of low-temperature open-pore porous ceramic, which is characterized by comprising the following steps: step one, preparation of raw materials Preparing a framework material, a pore-forming agent and a structure stabilizer, wherein the framework material is one of tailings, metallurgical slag or natural clay minerals, the pore-forming agent is water-soluble chloride, and the structure stabilizer is waste glass powder; Step two, preparation of porous ceramics Uniformly mixing the framework material, the pore-forming agent and the structure stabilizer according to a set proportion, and performing compression molding to obtain a ceramic blank, then sintering the ceramic blank at a temperature lower than 1000 ℃, and cooling to obtain a dense ceramic body containing chlorine salt; wherein, the chlorine salt solution obtained by dissolution is evaporated and crystallized, and the chlorine salt pore-forming agent with the purity meeting the requirement can be recovered. Preferably, the mass ratio of the framework material, the pore-forming agent and the structural stabilizer is 75-65:25-30:5. Preferably, the sintering temperature in the second step is 850-980 ℃ and the sintering time is 1.5-2 h. Preferably, the tailings are selected from iron tailings or copper tailings, the metallurgical slag is selected from steel slag, blast furnace slag or red mud, and the natural clay mineral is selected from bentonite, kaolin or diatomite. Preferably, the chloride salt is NaCl or KCl. Preferably, the chloride salt is NaCl. Preferably, the framework material and the