China's glass industry has developed rapidly, has long been the world's first glass production power. The rapid development of the glass industry, naturally promote the development of China's glass kiln refractory materials and technological progress. Modern glass production technology compared with the traditional process has been a qualitative leap, towards a higher efficiency, lower energy consumption, better product quality in the direction of continuous development. Kiln as the core of glass production equipment, its technical level is also progressing, widely used to improve the combustion strength, strengthen the heat transfer effect, reduce heat loss, reduce the product and environmental pollution and other new technologies. The technological progress of the kiln requires a variety of quality refractory materials as a guarantee condition, requiring refractories to withstand higher temperatures, more abrupt temperature changes, more intense chemical erosion, more severe stress damage, and only supporting the use of multiple varieties High-quality refractory materials, kiln new technology, energy efficient, low pollution and other advantages can be achieved. High-quality refractory materials for modern high-temperature technology is not only consumable materials, but also to achieve high-temperature new technology necessary functional materials.
Foreign refractory materials for glass kilns
1.AZS and high zirconia brick
On the melting of AZS brick is to improve its anti-erosion and wear resistance of the production process, in addition to the oxidation method of melting, so that the product carbon content down to 0.005%, glass phase precipitation temperature increased to 1450 ℃ outside. The casting and annealing processes have also been improved to produce fused AZS with little or no shrinkage. ZrO2 content of more than 90% of the high zirconia brick, the thermal shock performance is very good, such as ZrO2> 95%, SiO2 <1.4%. Stabilizer <3.7% of high zirconia brick, the bulk density of 4.7g / cm3, porosity <18.4%, thermal shock resistance from room temperature to 1400 ℃ (15 minutes interval) up to 15 to 20 times. Japan produces a cast zirconia brick with a zirconia content of> 90%, called ZFC brick, and its corrosion resistance is better than ZrO2 content of 40% of the AZS brick, at 1500 ~ 1600 ℃, 16 hours after the glass phase Precipitation, little pollution on the glass, after 800 ~ 1250 ℃ thermal shock resistance test 40 times without cracks.
2. Chrome brick and chrome brick
To the static pressure molding of dense chromium oxide brick for E glass and C glass cell kiln wall, card or other parts of the erosion of serious, life expectancy of up to 6 to 7 years. In recent years, chromium products have made new progress, such as the addition of Cr2O3 in AZS brick to form Al2O3-ZrO2-SiO2-Cr2O3 refractory, at high temperatures, Cr2O3 on the one hand and Al2O3 to form a solid melt, on the other hand because Cr2O3 is The high melting point material, which enters the glass phase of the brick, increases the viscosity of the glass phase, thereby increasing the exudation temperature of the glass phase and greatly increasing the glass resistance to glass. A US company produces a re-bonding AZS / Cr2O3 refractory, its chemical composition and physical properties is excellent, compared with the original Al2O3 / Cr2O3 material, the annual furnace to reduce power consumption 4%, yield increased by 15% The cost is reduced by 3.75%, the glass quality is not affected, the kind of brick can be press molding, hand pound molding or isostatic pressing, and then high temperature sintering.
3. Basic bricks
The high purity directly combusted alkaline brick at 1800 ℃ is widely used in regenerative walls and arch. Germany has introduced a new material named RUBINAI · EZ with its chemical composition of MgO 75%, ZrO213.5%, SiO29 .5%, it is zirconite with the combination of magnesite bricks, in the early sintering, brick structure of zirconium silicate and magnesium oxide, along the granite around the formation of a layer of forsterite and zirconia protective layer, This structure greatly improves the brick anti-alkali and anti-sulfate erosion performance, do the middle of the thermal storage room lattice brick effect is good.
4. Olivine magnets
The olivine-binding phase has a particularly strong resistance to erosion, and the corrosion resistance of the magnesium brick can be improved by increasing the forsterite content in the magnesium briquette phase. To this end, 20% of the perovaleite fines were added to the ingredients of the magnesium bricks to form a mortar-binding matrix that protects the magnesite particles and reduces the erosion. The brick price is relatively cheap, foreign has been used for a large number of glass kiln regenerator lattice in the middle.
5. Barium fossil olivine brick
In view of the good erosion resistance of olivine and the lack of thermal shock resistance, the introduction of barium feldspar in its combined phase can obviously improve the thermal shock resistance of the brick. The barium feldspar is formed during the firing process and is present only in the bound matrix phase. When the content of barium feldspar is 15%, the best performance of silicon is about 1250 ℃. Studies have shown that barium feldspar can resist alkali and sulphate erosion.
6. Unshaped refractories
Unstable refractory in the application of glass kiln is also a development trend. British use of refractory concrete prefabricated block masonry thermal storage room, lattice brick bottom arch, flue, small furnace pallets, burners, etc., greatly reducing the kiln structure of the joints, improve the furnace speed and shorten the cold repair time , France Xipu ERSOL ER1681 is based on ER1681 fused particles as the main component of the amorphous refractory series, and the use of electric frit with the bottom of the pool, its excellent anti-glass erosion, and the tendency to precipitate bubbles and the formation of stones Weak. Some of Japan's glass kiln bottom has all used ER2SOL series of unshaped materials. The theoretical research on refractory materials for foreign glass kilns revolves around how to further improve the anti-glass erosion and improve the mechanical properties in order to further extend the life of the kiln.
7. Insulation material for glass kiln
Foreign glass kiln insulation widely used high alumina brick, lightweight silicon brick and fiber, mainly based on aluminosilicate fiber-based materials. In Germany, in addition to the use of diatomaceous earth, aluminosilicate and silicate fiber materials, widely used calcium silicate-based light products, in addition to Didier and the glass industry in close cooperation with the development of a composite board, It is made up of two materials, called "SSH" (Shood Supral H). The first layer in the composite panel has a thickness of 50 to 75 mm and is made of a relatively dense clay refractory. The thickness of the second layer is 100 to 125 mm. It is made of ultra-lightweight refractory (refractory clay or calcium silicate Material) made. The total thickness of the composite board is 150 to 200 mm, and the size of the composite board is the same as the size of the brick surface to be insulated.
The CIS uses light phosphate concrete, fiber products and fillers. The binding agent for the light refractory granule filler is an aluminophosphate binder, the acid ratio of the binder is 2.3, the density is between 1.55 and 1.6 g / cm3, the particles are industrial Al2O3, artificial Al2O3, and the working temperature is 1800 ℃. Lightweight phosphate concrete is a kind of new type of lightweight heat-resistant concrete made of phosphate as binder and porous clay. The main performance parameters of light phosphate concrete are: density 800 ~ 1100kg / m3 , The compressive strength range is 7 ~ 12MPa, the thermal conductivity is 0.3 ~ 0.35W / cm · k, the long-term use temperature is 1270 ℃.
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