- Time:Nov 18, 2022
In 1970, Japan began to produce magnesia carbon bricks, and used them in the hot spots and slag lines of electric furnaces, and also used magnesia carbon bricks in 50t ultra-high power electric furnaces. In the early 1980s, aluminum-carbon intrusive nozzles and aluminum-carbon slides with sidewall slits were developed. In the late 1980s, Japan developed aluminum-zirconium carbon skateboards that did not contain SiO2.
Due to the development of modern technologies such as aerospace, atomic energy, and electronics, ordinary refractory materials are difficult to meet the needs, and functional materials with high temperature resistance and special properties are urgently needed. Since the beginning of the 20th century, special refractory materials of pure oxides have been gradually developed. In the 20th and 30th generations, there were products for sale, and the 90th generation has become a commodity with mature technology, including alumina, magnesia, zirconia, beryllium oxide, calcium oxide, thorium oxide, uranium oxide, cerium oxide and other products. After the 1970s, the production technology and application scope of various carbides, nitrides, borides, silicides and other non-oxide products with a melting point above 2000 ° C have made great breakthroughs.
During the Second World War, France first started to develop cermets. After decades of hard work, there were Al2O3-Ni series, Al2O3-Fe series, MgO-Mo series, TiC-Ni series, TiC-Ni-Mo series, Cr3C2 series The manufacturing process of -Ni-Cr series is relatively mature. At the same time, progress has been made in high-temperature inorganic coatings, and high-temperature anti-oxidation coatings, high-temperature lubricating coatings, heat treatment protective coatings, high-temperature insulating coatings, wear-resistant coatings, anti-atomic radiation coatings, and infrared radiation coatings have been developed successively. layers, spectrally selective absorbing coatings, etc. In addition, research on high-temperature ceramic fiber reinforced materials has also achieved great results.
In 1899, there was a patent for processing and manufacturing insulation bricks with diatomite. After 1920, thermal insulation refractory materials that can be used at higher temperatures gradually appeared. Before the Second World War, Germany already had siliceous heat insulating bricks and special magnesia bricks with high porosity for gas furnaces, which can be used at steelmaking temperatures. Japan has also trial-produced 2~3 kinds of insulation bricks. In 1935, the UK developed and used heat-insulating refractory materials that were in direct contact with furnace gas. Insulation refractory materials developed rapidly in the United States and were widely used during World War II.
In 1941, the Central Research Institute of Babcock and Wilcox Co. in the United States discovered that a stream of kaolinite melt was sprayed with compressed air to obtain a fiber similar in shape to asbestos. Originally used as thermal insulation for jet engines and rockets. In the 1950s, Jones Manville Company began to manufacture such products, mainly as fillers for kiln expansion joints at that time. In the early 1960s, refractory fiber secondary products such as felt, blanket, paper, rope, etc. were successively produced. In the middle period, refractory fiber products were used as industrial furnace lining to achieve remarkable energy-saving effects, and high-purity aluminum silicate fibers were successively developed. New varieties such as high aluminum fiber. In the 1970s, multi-product fibers were successfully developed. In 1974, a production line with an annual output of 500-700 tons was built in the UK, and polycrystalline alumina fibers with a temperature of 1600°C were first introduced. In the 1980s, the United States produced Al2O3 72% mullite fiber, and Japan developed Al2O3 80% alumina fiber. At the same time, zirconia fiber, boron oxide fiber, boron carbide fiber, silicon carbide fiber, carbon fiber, boron fiber fusion fiber, titanium boride fiber, boron nitride fiber, silicon nitride whisker, etc. have been successfully developed.
In the 20th century, the kiln began to be large-scale, and it was difficult to use only bricks. The furnace shell was reinforced with iron components, and the kiln built with refractory bricks inside was developed. At the same time, the shape of the kiln is also complicated due to the requirement of good thermal efficiency. It is no longer possible to build a kiln of the expected shape with only general-shaped products, and special-shaped bricks of various complex shapes have been used. However, the furnace-building technique for combining products of various shapes becomes complicated. In this case, W.A.LschaEFER of the United States believes that it is convenient and easy to embed the reinforcing material in the material before forming and combine the shape of the kiln on site. This idea was created by Lschaefer in 1914 as a monolithic refractory material. At that time, plastics were mainly manufactured, which were used to repair the brick walls of boilers. The application was simple, and it was gradually recognized by the industry, and the output has been increasing. In 1918, France began to sell aluminate cement. It is generally believed that European and American countries used aluminate cement as a binder for refractory castables in 1925.
During World War II, the United States used refractory castables and refractory plastics as linings for boilers and petroleum equipment. Some people also believe that cement fine powder castables were developed in 1932, and air-hardening refractory plastics were quickly developed, which is the basic prototype of today's unshaped refractory materials. Japan imported monolithic refractories sporadically before the Second World War. In 1951, it imported monolithic refractory materials from the United States to repair boilers. It was not until 1955 that monolithic refractory materials were officially produced. They are widely used in petrochemical, ironmaking, Cement, non-ferrous metallurgy, environmental protection and sanitation and other thermal equipment. By 1960, unshaped refractory materials in the United States, Japan, and Germany accounted for 37.1%, 31.7%, and 36.8% of the total refractory output, respectively.
After the 1980s, the total output of refractory materials in industrially developed countries declined, but the output of unshaped refractory materials did not change much, so the output of unshaped refractory materials increased relatively. For example, the output of refractory materials in Japan dropped from 2.7 million t to about 2 million t from 1976 to 1985, of which unshaped refractory materials remained at about 900,000 t, and its ratio increased from 34% to 44%. The output of materials was 1.775 million tons and 1.327 million tons respectively, a decrease of 25%, of which shaped refractory materials decreased by 42%, and unshaped refractory materials decreased by 7%, so the ratio of unshaped refractory materials increased from 47.5% to 59.2%. Refractories have reached 50%. Moreover, the variety of unshaped refractory materials is increasing, and the application field is expanding year by year, and it has entered the field of high-temperature melting furnaces.
ZHENJIN REFRACTORIES is committed to one-stop general contracting services such as R&D and manufacturing of refractory materials for cement, lime, non-ferrous, steel, glass and chemical industries, technical solution design, construction and supply of supporting products. It is a company integrating production, marketing, research and export A high-temperature kiln overall solution service provider.
