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Method for preparing zirconium oxide nozzle brick with high temperature thermal shock resistance

A technology of thermal shock resistance and zirconia, which is applied in the field of refractory materials, can solve the problems of poor control of segregation content of additives, difficulty in removing impurity components, difficulty in crushing, etc., and achieve excellent high temperature thermal shock resistance and corrosion resistance. The effect of small sample shrinkage and high bulk density

Active Publication Date: 2016-07-06
SANXIANG ADVANCED MATERIALS
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The problems in the above methods are mainly that the produced zirconia product has high hardness and is difficult to break, the additives in the product are easy to segregate, the content is not easy to control, and the impurity components are difficult to remove, etc.
The nozzle bricks produced with the above zirconia as raw materials have a porosity of 11% to 15%, and a bulk density of 5.1 to 5.4g / cm 3 Among them, the shrinkage rate is about 12%, and the number of thermal shock resistance is generally 1 to 2 times. In downstream applications, the anti-erosion and thermal shock resistance are poor.

Method used

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Examples

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preparation example Construction

[0017] Specifically, the preparation method of the high-temperature thermal shock-resistant zirconia nozzle brick provided by the present invention includes:

[0018] 1. Grind the fused zirconia powder until the particle size is above 14500 mesh, the proportion of powder is 28wt% ~ 33wt%, the proportion of 8500 mesh ~ 14500 mesh powder is 23wt% ~ 29wt%, the proportion of 4500 mesh ~ 8500 mesh powder is 39wt% %-45wt%, powder below 4500 mesh accounts for ≤3wt%;

[0019] 2. Mix the ground zirconia powder and carbonamide in a weight ratio of 1:0.85~1.35 (preferably until uniform), and then calcine at 135~180°C without air or in an inert atmosphere for 8~ After 12 hours, add the calcined zirconia powder into a dilute acid solution with a mass concentration of 1.0-2.0%, stir and soak for more than 1 hour;

[0020] 3. Add 2.3-2.8% magnesium oxide, 0.5-0.9% yttrium oxide and 4-8% binding agent based on the weight of the zirconia powder into the soaked zirconia powder, mix (preferably...

Embodiment 1

[0032] 1. Add ZrO 2 The fused desiliconized zirconia powder with a content of 99.0% is ground to a particle size of 14,500 mesh or more, accounting for 31.5wt%, 8,500-14,500-mesh powder accounts for 25.5wt%, and 4,500-8,500-mesh powder accounts for 41wt% %, powder below 4500 mesh accounts for 2wt%;

[0033] 2. Take the above-ground zirconia powder and carbonamide and mix them evenly at a weight ratio of 1:1.05, then seal them at 175°C and roast them at a constant temperature for 10 hours. The roasted zirconia powders are directly added to the prepared mass concentration Stir and soak in 1.0% dilute hydrochloric acid solution for 120min;

[0034] 3. Wash and dry the soaked zirconia powder, add 2.65% MgO and 0.75% Y 2 o 3 and 5% polyvinyl alcohol, after mixing evenly, carry out 6 times of roll granulation, and sieve until the 5-mesh sieve is completely passed;

[0035] 4. Press and sinter the powder obtained in step 3 under a pressure of 30-40 MPa to form a high-temperature ...

Embodiment 2

[0042] 1. Add ZrO 2 The fused desiliconized zirconia powder with a content of 99.0% is ground to a particle size of 14,500 mesh or more, accounting for 29.7wt%, 8,500-14,500-mesh powder accounts for 27.5wt%, and 4,500-8,500-mesh powder accounts for 40wt% %, powder below 4500 mesh accounts for 2.8wt%;

[0043] 2. Take the above-ground zirconia powder and carbonamide and mix them evenly in a weight ratio of 1:0.85, then roast at 135°C for 8 hours at a constant temperature in isolation from the air, and directly add the roasted zirconia powder to the prepared mass concentration Stir and soak in 1.5% dilute sulfuric acid solution for 60 minutes;

[0044] 3. Wash and dry the soaked zirconia powder, add 2.3% MgO and 0.5% Y 2 o 3 and 6% polyvinyl alcohol, after mixing evenly, carry out 5 roll granulation;

[0045] 4. Press and sinter the powder obtained in step 3 under a pressure of 30-40 MPa to form a high-temperature thermal shock-resistant zirconia nozzle brick. The sintering te...

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Abstract

The invention relates to a method for preparing a zirconium oxide nozzle brick with high temperature thermal shock resistance. Firstly, control over the grain size of electrofusion zirconium oxide powder and reasonable granularity distribution are conducted through the grinding process, then the surface of the zirconium oxide powder is modified and partial impurities in the powder are removed through carbamide mixed roasting and dilute acid soaking in sequence, and finally the zirconium oxide nozzle brick with low porosity, high volume density, low shrinking percentage and good high temperature thermal shock resistance and scouring resistance are prepared through the high-pressure firing technique. Tests prove that the porosity of the prepared zirconium oxide nozzle brick is between 1.5% and 3.5%, volume density is 5.55-5.70g / cm<3>, sample shrinking percentage is smaller than or equal to 10%, high temperature thermal shock resistance and erosion resistance are excellent, and the service cycle of a nozzle is 2-3 times that of an existing metering nozzle.

Description

[0001] This application is a divisional application with the application date as December 05, 2014, the application number 201410738261.3, and the invention patent named "a method for preparing zirconia nozzle brick" as the parent case. technical field [0002] The invention relates to the field of refractory materials, in particular to a method for preparing a high-temperature thermal shock-resistant zirconia nozzle brick. Background technique [0003] The sizing nozzle is the key refractory material for billet continuous casting. It plays a role in controlling the flow of molten steel and determines the casting speed of the billet in continuous casting. It is a necessary condition to ensure the normal operation of continuous casting. In recent years, as the service life of the tundish in steel mills has been significantly improved, it is difficult for ordinary zirconium low-volume-density nozzles to meet the use requirements. [0004] The existing zirconia powder productio...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C04B35/482C04B35/626
CPCC04B35/482C04B35/62605C04B35/6261C04B2235/3206C04B2235/3225C04B2235/77C04B2235/96
Inventor 包晓刚胡天喜颜玉萍张高平李有成
Owner SANXIANG ADVANCED MATERIALS