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Method for firing volume-density controlled chromium oxide product

A technology of volume density and chromium oxide, which is applied in the field of controlling the volume density of chromium oxide products after firing, can solve the problems of difficulty in producing large overall products, high volume density of chromium oxide products, and polluting the environment, so as to achieve easy control of the process , easy to achieve, and low environmental pollution

Inactive Publication Date: 2011-09-21
SINOSTEEL LUOYANG INST OF REFRACTORIES RES
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Due to the adoption of H 2 O / H 2 、CO / CO 2 , N 2 / H 2 Mixed gas, it is difficult to control in actual industrial production, and the volume density of fired chromium oxide products is very high
The production of chromium oxide products by electromelting has the disadvantages of polluting the environment and high energy consumption. The bulk density of chromium oxide materials after electromelting is greater than 5.0g / cm 3 , and it is difficult to produce large-scale products as a whole, so it can only be used as aggregate of refractory materials

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0012] Chromium oxide products selection D 50 =1.8μm Cr 2 O 3 Micro powder with TiO added 2 Burning aid; its composition by weight percentage: Cr 2 O 3 :99%; TiO 2 :1%. After secondary molding, it is put into the nitriding kiln and controlled by a precision flow meter. 2 / O 2 The mixed gas flow rate makes the oxygen partial pressure in the mixed gas at 10 -6 Atm, while ensuring that the pressure in the nitriding kiln is between 10-50 Pa, it is fired at a temperature of 1500°C for 2 hours. The chromium oxide product obtained in this embodiment has a bulk density of 4.25 g / cm 3 , The apparent porosity is 16.7%.

Embodiment 2

[0014] Chromium oxide products selection D 50 =1.8μm Cr 2 O 3 Micro powder with TiO added 2 Burning aid; its composition by weight percentage: Cr 2 O 3 :97%; TiO 2 : 3%. After secondary molding, it is put into the nitriding kiln and controlled by a precision flow meter. 2 / O 2 The mixed gas flow rate makes the oxygen partial pressure in the mixed gas at 10 -4 Atm, while ensuring that the pressure in the nitriding kiln is between 10-50Pa, it is fired at 1450℃ for 3 hours. The volume density of the chromium oxide product obtained in this embodiment is 4.41 g / cm 3 , The apparent porosity is 13.2%.

Embodiment 3

[0016] Chromium oxide products selection D 50 =1.8μm Cr 2 O 3 Micro powder with TiO added 2 Burning aid; its composition by weight percentage: Cr 2 O 3 :94%; TiO 2 : 6%. After secondary molding, it is put into the nitriding kiln and controlled by a precision flow meter. 2 / O 2 The mixed gas flow rate makes the oxygen partial pressure in the mixed gas at 10 -2 Atm, while ensuring that the pressure in the nitriding kiln is between 10-50 Pa, it is fired at a temperature of 1400°C for 8 hours. The chromium oxide product obtained in this embodiment has a bulk density of 3.91 g / cm 3 , The apparent porosity is 26.7%.

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Abstract

The invention relates to a sintering method of chromium oxide product, of which the volume and density are controllable. Firstly, a mixed gas of N2O2 is filled into the nitriding kiln in which the chromium oxide products are prepared to be fired, meanwhile the flow of N2 and O2 is controlled to keep the oxygen partial pressure of the mixed gas between 10<-2>-10<-6>atm and ensure that the internal pressure is between 10pa to 50pa. Secondly, under the temperature between 1400 to 1500 degrees Centigrade, the chromium oxide product is treated with heat insulation for two to eight hours. The volume and density of chromium oxide product are between 3.8 to 4.8g / m<3>. The sintering method for chromium oxide product is characterized best in that the volume and density of the chromium oxide product can be controlled after sintering, and the production process is easy to control; the sintering temperature is fairly low with no pollution to chromium oxide products; in addition, the adoption of nitriding kiln contained with N2 in sintering technique is already mature at home, thus ensuring that the sintering method of chromium oxide product with controllable volume and density can be easily carried out in the industrial production.

Description

Technical field [0001] The invention relates to a firing method of chromium oxide products, and mainly relates to a method for controlling the volume density of chromium oxide products after firing by controlling the oxygen partial pressure of a mixed gas. Background technique [0002] Due to its excellent corrosion resistance, chromium oxide material has less pollution to molten glass and has a long service life. It is widely used as the hot surface lining material of alkali-free glass fiber tank kilns. As the key material for the lining of the hot surface of the tank kiln, there is currently no material that can replace it. However, with the accumulation of experience, it has been found that the bulk density of chromium oxide products is too high, and its thermal shock resistance is very poor, and cracks are prone to occur during the heating process, resulting in a significant decrease in the corrosion resistance of the crack area; at the same time, the bulk density is too high...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C04B35/64C04B35/66C04B35/12
Inventor 尹洪基耿可明徐延庆王金相范志辉石鹏坤胡飘孙红刚
Owner SINOSTEEL LUOYANG INST OF REFRACTORIES RES