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CN-121990836-A - Andalusite high-temperature push plate and preparation method thereof

CN121990836ACN 121990836 ACN121990836 ACN 121990836ACN-121990836-A

Abstract

The invention discloses a andalusite high-temperature push plate and a preparation method thereof. The preparation method comprises the specific steps of mixing andalusite particles, fused quartz particles, andalusite fine powder, cordierite fine powder, activated alumina fine powder, aluminum-silicon alloy powder and rare earth composite yttrium-zirconium ceramic powder to obtain a premix, adding modified aluminum sol into the premix, stirring to obtain a mixture, pressing the mixture to form a raw blank, drying and roasting the green blank, and cooling to room temperature to obtain the andalusite high-temperature pushing plate. Wherein the modified aluminum sol is prepared by uniformly mixing boric acid and aluminum sol. The preparation method has the advantages of simple technical process, low sintering temperature and obvious energy-saving benefit, and the prepared andalusite high-temperature pushing plate has high density, low apparent porosity, high-temperature strength, good thermal shock stability and high softening temperature under load, and improves the service performance of the high-temperature pushing plate.

Inventors

  • ZHANG HAN
  • XU CHUNYU
  • XIAO ZIXIU

Assignees

  • 武汉科技大学

Dates

Publication Date
20260508
Application Date
20260313

Claims (10)

  1. 1. The preparation method of the andalusite high-temperature pushing plate is characterized by comprising the following specific steps of: s1, mixing andalusite particles and fused quartz particles according to the mass ratio of 100:10-15 to obtain mixed particles; S2, mixing andalusite fine powder, cordierite fine powder, active alumina fine powder, aluminum-silicon alloy powder and rare earth composite yttrium zirconium ceramic powder according to the mass ratio of 100:5-7:2.0-3.0:1.5-2.5:2.8-3.2 to obtain mixed fine powder; s3, mixing the mixed particles and the mixed fine powder according to the mass ratio of 100: (42-55) to obtain a premix; s4, adding modified aluminum sol accounting for 4.2-5.5wt% of the mass of the premix into the premix, and stirring to obtain a mixture; s5, placing the mixture into a die, and performing compression molding under 120-130 MPa for 40-60 seconds to obtain a green blank; S6, drying the raw blank for 12-15 hours at 80-110 ℃, placing the raw blank in a high-temperature furnace, heating to 1400-1480 ℃ at a temperature rising rate of 5-8 ℃ per minute, preserving heat for 3-5 hours, and cooling to room temperature at a cooling rate of 3-4 ℃ per minute to obtain the andalusite high-temperature push plate; Wherein the modified aluminum sol is prepared by uniformly mixing boric acid and the aluminum sol according to the mass ratio of (0.3-0.4) to 100, and the solid content of the aluminum sol is 12-15 wt%.
  2. 2. The method for preparing the andalusite high-temperature pushing plate according to claim 1, wherein in the step S1, the granularity of andalusite particles is 0.1-0.5 mm, and the main chemical components of the andalusite particles are that the content of Al 2 O 3 is more than or equal to 59wt%, the content of Fe 2 O 3 is less than or equal to 0.3wt% and the content of CaO is less than or equal to 0.1wt%.
  3. 3. The method for preparing a andalusite high-temperature push plate according to claim 1, wherein in the step S1, the granularity of the fused silica particles is 0.3-0.8 mm.
  4. 4. The method for preparing a andalusite high-temperature push plate according to claim 1, wherein in the step S2, the granularity of the andalusite fine powder is less than or equal to 70 μm, and the main chemical components of the andalusite fine powder are that the content of Al 2 O 3 is more than or equal to 59wt%, the content of Fe 2 O 3 is less than or equal to 0.3wt% and the content of CaO is less than or equal to 0.1wt%.
  5. 5. The method for producing a andalusite high-temperature push plate according to claim 1, wherein in step S2, the cordierite fine powder has a particle size of 80 μm or less.
  6. 6. The method for preparing a andalusite high-temperature push plate according to claim 1, wherein in the step S2, the granularity of the activated alumina fine powder is less than or equal to 15 μm.
  7. 7. The method for preparing a andalusite high-temperature push plate according to claim 1, wherein in the step S2, the granularity of the aluminum-silicon alloy powder is less than or equal to 85 μm.
  8. 8. The method for preparing a andalusite high-temperature push plate according to claim 1, wherein in the step S2, the mass ratio of aluminum to silicon of the aluminum-silicon alloy powder is (35-40) to 100.
  9. 9. The method for preparing a andalusite high-temperature push plate according to claim 1, wherein in the step S2, the rare earth composite yttrium zirconium ceramic powder is of the brand YZ-8.8QLD, see GB/T31968-2025.
  10. 10. A andalusite high-temperature push plate prepared by the preparation method according to any one of claims 1 to 9.

Description

Andalusite high-temperature push plate and preparation method thereof Technical Field The invention relates to the technical field of refractory materials, in particular to a andalusite high-temperature push plate and a preparation method thereof. Background Andalusite is an important natural mineral raw material of the aluminum-silicon series, and is widely used in the field of refractory materials because it can be converted to mullite in situ at high temperatures (Li Yuanyuan, xu Haijun. Phase transition and deformation of andalusite, kyanite and pennisetum [ J ], mineral rock geochemistry bulletin, 2023,42 (2): 402-419). Andalusite often contains small amounts of Fe 2O3、TiO2、MnO2 and alkali metal oxides (K 2 O and Na 2 O) other impurities in addition to the main components Al 2O3 and SiO 2. Andalusite can generate irreversible mullite conversion at high temperature, and mullite crystals and silicon-rich glass phases with three-dimensional interweaved network structures are generated in situ (Dan Gan, fan Muxu, liu Pengcheng, and the like). The transformation process gives a series of remarkable advantages to the material, namely, firstly, the mullite network can bring extremely high-temperature strength and excellent creep resistance, secondly, the transformation is accompanied by moderate volume expansion (about 5-8%) which can effectively offset partial shrinkage in the sintering process of the material, so that the product is endowed with excellent high-temperature volume stability, and furthermore, the material has good thermal shock resistance due to the microstructure of multi-microcracks generated by expansion (Wang Tuan, arlin, wu Yongsheng, and the like). However, the volume expansion associated with andalusite during mullite formation, particularly over-expansion caused by secondary mullite formation, becomes a difficult problem in the preparation process of andalusite materials, and affects the usability of the finished material. Therefore, how to regulate mullite behavior of andalusite and improve volume stability and mechanical properties of the material becomes a key problem of current research. Different from other bricks and other devices, the push plate bears the pressure in the vertical direction of the objects to be burned in the high-temperature service process, and continuously bears the extrusion in the horizontal direction of the push rod, and the push plate is required to be not deformed, the push plates cannot be stuck at high temperature (otherwise, the push plates are sintered into a whole and are difficult to separate, and the stable operation of a high-temperature kiln is influenced), so that severe requirements are provided for the performances of the push plate, such as high-temperature strength, low-melt phase, load softening and the like. The patent technology 'andalusite push plate and a preparation method (201310639428.6)' disclose that the andalusite push plate is prepared by taking andalusite, white corundum, mullite, alumina micropowder, kaolin and the like as main raw materials through the process steps of proportioning, trapping, forming, drying, high-temperature sintering and the like, and the defects of poor stability, low flexural strength and the like of the push plate are overcome. However, since kaolin is selected as a raw material, a low-melting-point phase is easily generated in the high-temperature sintering process, so that the high-temperature thermal strength of the andalusite pushing plate is reduced, and meanwhile, the sticking between the pushing plates is easily caused. In addition, the sintering temperature of the push plate is high, the heat preservation time is long, and the energy consumption and the development cost of the push plate are increased. From the above, the main problems faced in the development of andalusite push plates are the following: (1) The andalusite material has obvious advantages, and the phase transformation of the andalusite material can form good combination, thereby obviously improving the high-temperature thermal strength of the material. However, it is not desirable to introduce low-melting materials so as not to impair the high temperature performance of the andalusite pusher plate. (2) The phase transformation and sintering densification of andalusite are promoted, namely, the phase transformation of andalusite is accompanied by a certain volume expansion, which is favorable for the densification of high-temperature sintering of the material, but the excessive volume expansion is extremely easy to crack and destroy the material. Therefore, control of the conversion rate of andalusite is critical. (3) The firing temperature of the andalusite pushing plate is reduced to reduce energy consumption, namely, the firing temperature of the andalusite material is higher, and the difficulty of completely converting the andalusite into mullite is higher, and methods of increasing the firing temperature, prolonging the heat pr