In modern industrial production, refractory is an indispensable supporting material in high-temperature process, and its performance and quality are directly related to production efficiency, product quality and safe operation of equipment. As a high-performance refractory raw material, sintered mullite plays an important role in the refractory industry with its unique physical and chemical properties and wide application fields.

I. Characteristics of sintered mullite

Sintered Mullite is a kind of refractory material with Mullite as the main component, and its main component is aluminosilicate, which has the characteristics of high mullite phase content, low porosity and high refractoriness. The following are its main features:

(1) high mullite phase content

Mullite phase is the core component of sintered mullite, and its content directly affects the properties of materials. According to different product grades, the content of mullite phase ranges from 55% to 78%. High mullite phase content endows sintered mullite with excellent high-temperature properties, which enables it to maintain stable structure and properties in extreme high-temperature environment.

(2) Low porosity

The porosity of sintered mullite is extremely low, the highest is only 2.8%. Low porosity means high compactness inside the material, which can effectively prevent gas from permeating and diffusing at high temperature, thus improving the corrosion resistance and thermal shock resistance of the material. In high temperature environment, sintered mullite with low porosity can better resist chemical corrosion and physical wear and prolong its service life.

(3) High fire resistance

The fire resistance of sintered mullite is extremely high, and the fire resistance of different grades of products is between 1750℃ and 1850℃. This feature enables it to withstand extreme high temperature environment and is suitable for various high temperature industrial furnaces and equipment. High refractoriness not only ensures the stability of materials at high temperature, but also effectively prevents materials from softening and deformation at high temperature, and ensures the safe operation of equipment.

(4) Good thermal shock stability

Sintered mullite has good thermal shock stability and can maintain structural integrity in the environment of rapid temperature change. This characteristic makes it perform well in the process of frequent thermal cycles, and it is not easy to crack and peel off. In practical applications, such as continuous casting tundish, glass furnace and other equipment in iron and steel industry, sintered mullite can withstand rapid temperature changes and ensure the continuous operation of the equipment.

(5) high hardness and high bulk density

Sintered mullite has high bulk density and hardness, which makes it excellent in wear resistance and compressive strength. High bulk density means that the particles in the material are closely arranged, which can effectively resist the impact and wear of external forces. In high temperature environment, the high hardness and high bulk density of sintered mullite enable it to bear a large mechanical load and is suitable for various high-temperature wear-resistant parts.

II. Application of sintered mullite

The excellent properties of sintered mullite make it widely used in many fields. The following are some main application fields:

(1) Iron and steel industry

In iron and steel industry, sintered mullite is often used to manufacture key components such as high temperature furnace lining, continuous casting tundish and ladle lining. Its high refractoriness and good thermal shock stability can effectively resist the erosion and thermal shock of high-temperature molten steel, prolong the service life of furnace lining and improve production efficiency. For example, in the continuous casting tundish, the sintered mullite lining can withstand the erosion and temperature change of high-temperature molten steel, ensuring the quality of molten steel and the smooth continuous casting process.

(2) Glass industry

Glass melting furnace is the key equipment in glass production, and sintered mullite is one of the important materials for manufacturing glass melting furnace. Its low porosity and high refractoriness can effectively prevent the penetration and erosion of glass liquid and ensure the stability of the furnace at high temperature. The furnace lining made of sintered mullite can withstand the high temperature melting and chemical erosion of glass liquid, prolong the service life of the furnace and reduce the production cost.

(3) Ceramic industry

In the ceramic industry, sintered mullite can be used to make high-temperature ceramic products, such as ceramic kiln furniture, ceramic sintered plates and so on. Its high mullite phase content and high hardness can improve the mechanical strength and wear resistance of ceramic products, and at the same time ensure the stability of products during high temperature sintering. Ceramic kiln furniture made of sintered mullite can withstand the firing temperature of high-temperature ceramic products and ensure the quality and performance of ceramic products.

(4) Petrochemical industry

There are a large number of high-temperature equipment in petrochemical industry, such as cracking furnace and catalytic cracking unit. Sintered mullite can be used to manufacture the lining materials of these equipments. Its high fire resistance and good chemical corrosion resistance can effectively resist the corrosion and chemical reaction of high-temperature oil and gas, and ensure the safe operation of the equipment. In addition, sintered mullite can also be used to manufacture high-temperature wear-resistant components in petrochemical industry, such as high-temperature valves and pipelines.

III. Production and Quality Control of Sintered Mullite

The production process of sintered mullite needs strict quality control to ensure the performance and quality of products. The following are the main links of its production and quality control:

(1) Selection of raw materials

The production of sintered mullite needs to select high-quality raw materials, such as high-purity bauxite and silica. The quality of raw materials directly affects the properties of sintered mullite, so it is necessary to carry out strict chemical analysis and physical detection on raw materials to ensure that their components meet the production requirements.

(2) Production technology

The production process of sintered mullite includes raw material mixing, molding and sintering. In the production process, it is necessary to strictly control the process parameters of each link, such as mixing time, molding pressure, sintering temperature, etc., to ensure the uniformity and compactness of products. For example, the sintering temperature directly affects the formation of mullite phase and the densification degree of materials, so it is necessary to accurately control the sintering temperature and time.

(3) Quality inspection

The quality inspection of sintered mullite is an important link in the production process, which mainly includes chemical analysis, physical property inspection and mineral composition analysis. Chemical analysis is used to detect the content of each chemical component in the product to ensure that it meets the standard requirements; Physical properties testing includes the determination of density, porosity, fire resistance and other indicators to evaluate the physical properties of products; Mineral composition analysis is used to determine the content and distribution of mullite phase and ensure the high temperature performance of products. Through strict quality inspection, quality problems in the production process can be found in time to ensure the stability of product quality.

Iv. Market and development trend of sintered mullite

With the continuous development of modern industry, the market demand of sintered mullite is also increasing. Its wide application in steel, glass, ceramics, petrochemical and other fields makes it an important product in the refractory market. In the future, the development of sintered mullite will show the following trends:

(1) High performance

With the continuous improvement of industrial production requirements for refractories, sintered mullite will develop towards high performance. By optimizing the production process and adding high-performance additives, the fire resistance, thermal shock resistance and chemical corrosion resistance of sintered mullite are further improved to meet the application requirements under higher temperature and more complicated working conditions.

(2) Environmental protection

Under the background of increasingly strict environmental protection policy, the production of sintered mullite will pay more attention to environmental protection. Production enterprises will adopt more energy-saving and environmentally-friendly production processes to reduce energy consumption and pollutant emissions in the production process. At the same time, develop recyclable sintered mullite products, reduce resource waste and realize sustainable development.

(3) customization

Different industrial fields have different requirements on the properties and specifications of sintered mullite, so sintered mullite will develop in the direction of customization. The manufacturer will provide customized sintered mullite products according to the specific needs of customers to meet the requirements of different application scenarios.

As a high-performance refractory, sintered mullite plays an important role in modern industry with its excellent physical and chemical properties and wide application fields. With the continuous progress of industrial technology and the increasing market demand, the properties of sintered mullite will be continuously improved, and its application fields will be further expanded, providing more reliable high-temperature material guarantee for industrial production.