Refractory materials are a class of inorganic non-metallic materials with a refractoriness not less than 1580°C. Refractoriness refers to the Celsius temperature at which the refractory cone sample resists the action of high temperature without softening and melting under no load. However, only the definition of refractoriness cannot fully describe refractory materials, and 1580°C is not certain. It is now defined as all materials whose physical and chemical properties allow it to be used in a high temperature environment are called refractory materials. Refractory materials, as a necessity of industrial basic materials, are widely used in industrial fields such as steel, metallurgy, chemical industry, petroleum, machinery manufacturing, electric power, and power.
With the rapid development of China's industry in recent years and the implementation of the national 13th Five-Year Plan, the refractory industry will inevitably meet the needs of industrial development and continue to innovate. With the rapid development of smelting technology and the iron and steel industry, refractories have also achieved a series of major technological changes. The transformation of precision and high-end products series based on the principle of design, etc., can be summed up in a few points. Next, let the technicians of Henan Lite Refractories to share with you!
Six development characteristics of refractory materials:
1. High purity
Among the refractory raw materials in various countries, those natural raw materials with low purity, such as silica, clay, etc., are decreasing due to the adverse effects of large amounts of impurities and insufficient performance. Correspondingly, those high-purity natural raw materials with few impurities and excellent performance or purified natural raw materials, such as zircon, graphite, etc., are used in increasing amounts. At the same time, the development and application of artificially synthesized raw materials such as magnesia, silicon carbide, spinel, etc. have also received increasing attention from industry professionals.
2. Densification
Due to the increasing requirements for the strength and high-temperature performance of refractory products during use, refractory products, especially refractory bricks, are developing in the direction of densification, long size, and large size. Correspondingly, high-pressure forming and high-temperature firing technologies are also constantly developing.
3. Precision
With the development of smelting technology and steel and other industries, the shape of refractory products has become increasingly complex, and the performance requirements have become increasingly refined. Therefore, the design of refractory materials, performance and production technology, and even construction technology in various countries are becoming more and more sophisticated. Among them, refractory materials for continuous casting are a more concentrated and prominent representative of the trend of precision; at the same time, they are also developing in the direction of functionalization.
4. The continuous popularity of carbon-containing refractories
Because carbon materials can absorb the stress caused by high strength, thermal expansion or rapid temperature changes at high temperatures, and can prevent molten metal or slag from infiltrating, carbon-containing refractories have gained considerable popularity and application in various countries, and they are constantly being used. Development, its typical representatives are magnesia-carbon bricks and magnesia-calcium-carbon bricks.
5. Development of oxide and non-oxide composite materials
Oxide and non-oxide composite materials have different industrial approaches such as direct bonding, reactive bonding and carbon bonding. The results of development research in recent years have shown that, compared with carbon-bonded materials, composite materials have much higher room temperature and high temperature strength and much better oxidation resistance; compared with oxide products, composite materials have significantly higher heat resistance Shock performance.
6. Unshaped ratio
Unshaped refractories have the advantages of easy mechanization and automatic construction, easy to extend life through later repair, and saving man-hours and materials. The proportion of unshaped refractories in the overall refractories is increasing year by year. Abroad, the amorphous rate in industrialized countries such as the United States, Japan, and Western Europe has exceeded 50% in recent years. In recent years, my country has made a series of achievements in the development and application of monolithic refractories.
