Introduction to the most popular types of refracto

2022-09-22
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Introduction to the types of refractories used in foreign glass kilns

compared with traditional processes, modern glass production technology has made a qualitative leap, and continues to develop in the direction of higher efficiency, lower energy consumption and better product quality. As the core equipment of glass production, the technical level of kiln is also improving. New technologies such as improving combustion intensity, strengthening heat transfer effect, reducing heat loss and reducing pollution to products and the environment are widely used

China's glass industry has developed rapidly and has already become a leading glass production country in the world. The rapid development of the glass industry naturally promotes the development and technological progress of refractories for glass kilns in China. Compared with traditional processes, modern glass production technology has made a qualitative leap, and continues to develop in the direction of higher efficiency, lower energy consumption and better product quality. As the core equipment of glass production, the technical level of kiln is also improving. New technologies such as improving combustion intensity, strengthening heat transfer effect, reducing heat loss and reducing pollution to products and the environment are widely used. The technological progress of kilns requires multiple varieties of high-quality refractories as guarantee conditions, and requires that refractories can withstand higher temperatures, more rapid temperature changes, stronger chemical erosion, and more severe stress damage. Only by applying multiple varieties of high-quality refractories, can the advantages of new kiln technology such as high efficiency, energy saving, and low pollution be realized. High quality refractory is not only a consumable material for modern high-temperature technology, but also a functional material necessary to realize high-temperature new technology

foreign refractory materials for glass kilns

1. AZS and high zirconia bricks

the production process of electric melting AZS bricks is mainly to improve their corrosion resistance and wear resistance. In addition to adopting oxidation melting, the carbon content of products is reduced to 0. 005, the precipitation temperature of glass phase increased to more than 1450 ℃. The casting and annealing processes have also been improved, and fused AZS with small or no shrinkage cavity has been produced. High zirconia bricks with ZrO2 content above 90 have very good thermal shock performance, such as zro295 and sio21. 4。 Stabilizer 3. 7 high zirconia brick, bulk density 4. 7g/cm3, porosity 18. 4. The thermal shock resistance can reach 15 ~ 20 times from room temperature to 1400 ℃ (15 minute interval). Japan produces a kind of fused zirconia brick, whose zirconia content is 90, which is called ZFC brick. Its corrosion resistance is better than that of AZS brick with ZrO2 content of 40. At 1500~1600 ℃, there is no glass phase precipitation after 16 hours, and there is little pollution to glass. After 40 times of thermal shock resistance test at 800 ~ 1250 ℃, there is no crack

2。 Chrome bricks and chrome containing bricks

dense chrome oxide bricks formed by isostatic pressing are used for the side walls, necks or other severely eroded parts of E glass and C glass tank kilns, and their service life can reach 6 ~ 7 years. In recent years, chrome containing products have made new progress, such as adding Cr2O3 to AZS bricks to form al2o3-zro2-sio2-cr2o3 series refractories. At high temperature, Cr2O3 on the one hand forms a solid melt with Al2O3, on the other hand, because Cr2O3 is a high melting point material, entering the glass phase of bricks increases the viscosity of the glass phase, thereby improving the exudation temperature of the glass phase, and greatly improving the glass corrosion resistance of glass products. An American company has produced a kind of reconstituted fused cast azs/cr2o3 refractory with excellent chemical composition and physical properties. Compared with the original al2o3/cr2o3 material, the annual furnace period reduces power consumption by 4, the output increases by 15, and the cost decreases by 3. 75. The quality of glass is not affected. This kind of brick can be formed by machine pressing, manual tamping or isostatic pressing, and then sintered at high temperature

3。 Alkaline bricks

high purity direct bonded alkaline bricks fired at 1800 ℃ are widely used in regenerator walls and arches. Germany has introduced a new material, the trade name is rubinaiez, and its chemical composition is mgo75, zro213. 5,SiO29。 5. It is a periclase brick combined with zircon. At the initial stage of sintering, zirconium silicate in the brick structure reacts with magnesium oxide to form a protective layer of forsterite and zirconia along the periclase particles. This structure greatly improves the alkali and sulfate resistance of the brick, and has a good effect as a lattice brick in the middle of the regenerator

4。 Olivine magnesia brick

olivine binding phase has particularly strong corrosion resistance. The corrosion resistance of magnesia brick can be improved by increasing the content of olivine in the binding phase of magnesia brick. For this reason, 20% forsterite fine powder is added to the ingredients of magnesia brick to form a forsterite binding matrix that can protect magnesia particles and reduce erosion. The brick is relatively cheap, and has been widely used in the middle of the regenerator lattice of glass kiln abroad

5。 Barium feldspar olive brand popularity is further increased stone brick

in view of the good corrosion resistance and insufficient thermal shock resistance of olivine, the introduction of barium into its bonding phase will find that the measured output signal of the amplifier unit changes linearly, and stone can significantly improve the thermal shock resistance of the brick. Barium feldspar is formed in the burning process and only exists in the binding matrix phase. When the content of barium feldspar is 15, the performance of silicon is the best, and the service temperature is about 1250 ℃. Research shows that barium feldspar can resist alkali and sulfate erosion

6。 Unshaped refractories

the application of unshaped refractories in glass kilns is also a development trend. In Britain, refractory concrete precast blocks are used to build regenerators, lattice brick bottom arches, flues, small furnace supporting plates, burners, etc., which greatly reduce but cannot be directly used in design and calculation, reduce the joints of kiln structure, improve the furnace building speed and shorten the cold repair time. Ersol of sipe in France is an amorphous refractory series made of er1681 (changing the phase of power supply) fused particles, which is used in the pool bottom together with fused bricks, It has excellent glass erosion resistance, and has a weak tendency to precipitate bubbles and form stones. Some glass kilns in Japan have all used er2sol series amorphous materials. The theoretical research of refractories used in glass kilns abroad focuses on how to further improve the glass erosion resistance and improve the mechanical properties, in order to further extend the service life of kilns

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