Carbon-containing refractories will give way to non-oxide composite materials

Based on the high temperature refractory materials industry, is the guarantee of high technology. Since more than 70% of the refractory services to the metallurgical industry, so most people from metallurgical science and technology development to see its role in promoting the formation of modern refractories.Large-scale blast furnace and high-pressure, high-temperature technology, requires refractory should have high temperature resistance, corrosion resistance, erosion and good thermal shock resistance, requiring the service life of 15 years, or even more than 20 years, so we had a silicon nitride bonded silicon carbide, sialon bonded SiC and Sialon bonded corundum refractories and other non-oxide composite oxide, until the emergence of metals, non-oxide and oxide composite refractories. Modern steel-making industry, especially the birth of clean steel smelting technology, requiring carbon content must be reduced to very low levels, forcing the leading independent steelmaking refractories coquettish decades of carbon refractories give other new non-oxide oxide composite refractories. Because these materials can not be compared with an oxide system performance. Their continuity is high temperature resistance, slag and iron corrosion, abrasion resistance, thermal shock, etc., which, precisely as the quality required of high-temperature refractory thermal shock properties. High technological level of our industry and the level of technology in recent years, the rapid development of both iron and steel, nonferrous metals, cement, glass, ceramics progress to world attention, steel production has exceeded the United States and Japan's and, refractories production also ranked first in the world, refractories research center is to transfer to China, we should assume this responsibility, in accordance with the high-quality, non-polluting, low consumption, low cost to establish the principle of non-oxide with Chinese characteristics (metal) and oxide composite refractory material as the center of modern architecture.Refractory nitride materials in accordance with the progress of high-quality, non-polluting, low consumption, low-cost principle, China has in natural minerals (carbonaceous clay, bauxite, etc.) transition and bulk industrial waste (gangue, nitrogen, etc.) regeneration the use of a lot of work done. For example the use of carbonaceous clay and coal gangue as precursor material, wherein the carbonaceous play (C) role, using the carbothermal reduction and nitridation method to prepare a cheap b-Sialon; exploit bauxite and magnesite synthetic magnesium Aron (Mg AlON); even a simple way will be made gangue mullite (3Al2O3 · 2SiO2) and so on. It is particularly worth mentioning is that the use of discarded oxygen, nitrogen, using flash combustion pressure rapid synthesis of silicon nitride prepared cheap (Si3N4), it costs only a common process (including self-propagating process) of a few tenths one, making valuable materials previously considered to be in the refractory industry applications, manufactures have been exported to America, Japan, Korea and other countries. These results not only greatly improve the resource-priced and environmentally friendly creative process, but also that with Chinese characteristics in non-oxide material system has been gradually established, we have for non-oxide and oxide composite refractory systems provide adequate and inexpensive of raw materials, modern refractories laid the basis for development in our country.Non-oxide composite materials, the development of new non-oxide refractory composites representative nothing more than the Si-based and Al-based nitride or carbide, as the two largest element in the earth's crust, and easy to nitride, carbide. When they are used as refractory applications, people were surprised to find that they have advanced refractory should have excellent quality, so quickly from Si3N4-SiC, SiC-SiC, b-Sialon-SiC grown to b-Sia lon-Al2O3 and b -Sialon-Al2O3-SiC and AlN, AlON, MgAlON other systems.1 corundum - SiC composite material progress. Sialon is a silicon (Si) aluminum (Al) oxygen (O) nitrogen (N) compounds referred to, the first high-tech ceramics have been developed, and its excellent performance refractories industry attention quickly, France Sovie company first its made of Sialon bonded corundum (b-Sialon-Al2O3) refractories for blast furnaces, to obtain good results, is considered the life of blast furnace refractory material of choice for more than 15-20 years. China has carried out several units for this study has now reached the level of industrial production. Our focus is to simplify processes, reduce costs and improve quality. Study found that in b-Sialon-Al2O3 system by adding SiC can significantly improve their resistance to slag, iron corrosion and mechanical properties; in b-Sialon-SiC system by adding alkali erosion Al2O3 can greatly improve performance, which developed b-Sialon - Al2O3-SiC ternary composites.2. Magnesium composites Aron progress. The English expression magnesium Aron MgAlON, magnesium (M g) of aluminum (Al) oxygen (O) nitrogen (N) compounds short. Al and AlON (Aron) are excellent high-tech ceramic materials, but the former is easy to absorb water, which is heat stable, and therefore added as a stabilizer Mg become MgAlON material. MgAlON than the b-Sialon-Al2O3 better resistance to slag, iron erosion and mechanical properties, thus causing the refractories industry attention. Some new refractories, MgAlON-corundum and MgAlON-spinel composite materials have been developed, they have good chemical and mechanical properties, is an excellent class of refractories used in reducing atmosphere. When a solution of its antioxidant ability, will become clean steel smelting of fine materials.Composite material properties of the first two system b-Sialon-MgAlON composite materials have been developed. Needless to say, this is a class worthy of further development of the material, now extends Fe, Mn and other types of materials, have gained good results.Such material has a very excellent resistance to slag, iron corrosion resistance and mechanical properties, but also exhibit antioxidant properties of self-healing, showing as a senior refractories are essential factors. Such tiles have been dozens of blast furnaces in the domestic use of ceramic cups are more than 12 years as a life of material design.3 amorphous composites(A) corundum - silicon nitride ceramic cup unfired brick furnace. Because high-quality, low-cost silicon nitride can be a lot of supply, so it is a direct application of refractories possible. Our company has developed and the Central Plains refractory corundum - silicon nitride ceramic cup unfired brick blast furnace has a very superior physical and chemical properties, the production process is simple, and no pollution generated when the brick has been applied in a blast furnace, and get a good results.(2) Magnesium oxide - nitride - Fe metal ladle slag line carbon materials. In the clean steel production, magnesium carbon materials have been used as a ladle lining is no longer used, and generally slag oxide material and difficult to withstand erosion, we made magnesia - nitride - metallic silicon material with good The slag resistance. Since silicon nitride has a strong resistance to slag erosion and oxidation does not leave space, do not reduce the material density and strength, its life and magnesium carbon material can already be comparable, is a very promising ladle using carbon slag line material.(3) Corundum - silicon nitride - Metal gas components. Supply components made of refractory oxides, usually because of hot metal or slag blowing holes penetrate and damage. Silicon nitride with molten iron and slag interfacial tension is large, has a strong ability to resist penetration of slag and iron. After further adding a metal material, not only to promote sintering material, and the oxidation of the silicon nitride protective effect. Its performance has exceeded corundum mullite materials, even more than the chromium corundum material.(4) Other. When using non-oxide high-temperature furnace refractory oxide composite, the non-oxide composite gunning inevitably develop. Accordingly, in order to blast furnace iron trough castable material represented by the same or gravity casting material to the development of non-oxide composite material containing silicon nitride, sialon or magnesium Aron are doing the test, and have achieved good results. Also containing silicon nitride, silicon carbide and iron blast furnace is also actively promoting in stemming.