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A corundum refractory product for a hydrogen-passing molybdenum rod heating furnace and its application method

A refractory product and heating furnace technology, applied in the field of refractory materials, can solve the problems of limited recycling, large fuel consumption, shortened kiln life, etc., and achieve densification of the microstructure, increase in mechanical strength, and low production energy consumption , good thermal shock resistance

Active Publication Date: 2020-12-25
CHANGXING KEAO POTTERY IND
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, at present, the purity of 99.3% of industrial alumina has basically reached the limit, and the cost of further purification is extremely high; firing at a high temperature of 1800°C will cause a large loss of fuel, and will also shorten the life of the firing kiln sharply
[0004] Industrial kilns such as hydrogen-passing molybdenum rod heating furnaces and tungsten-molybdenum product processing furnaces are mostly lined with corundum bricks and alumina hollow spherical bricks. After use, refractory bricks are polluted by tungsten and molybdenum, and traditional recycling is limited.

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0035] Embodiment 1: Weigh the electric fused white corundum (Al 2 o 3 ≥99.2%) 50kg, alumina fine powder (Al 2 o 3 ≥99.2%) 26kg, tungsten oxide fine powder (WO 3 ≥99.5%) 4kg, median diameter D 50 =10μm alumina powder (Al 2 o 3 ≥99.5%) 20kg, 4kg of PVA binding agent with a mass fraction of 5%, and the above-mentioned materials are fully mixed evenly in a roller type sand mixer. The mixture is formed into a 230mm×114mm×65mm standard brick on a 630-ton friction brick press. After the green body is dried at 110°C for 12 hours, it is fired in a gas-fired kiln at a maximum temperature of 800°C for 5 hours. During firing, the air-fuel ratio is adjusted to ensure that the CO concentration in the flue gas is less than 0.1%, and the kiln is kept in an oxidative atmosphere. After natural cooling, the corundum refractory product is obtained. The product w(Al 2 o 3)=96.0%, bulk density=3.15g cm -1 , Normal temperature compressive strength=60MPa, w(Al+O+W+Mo)=99.3%. This product ...

Embodiment 2

[0036] Embodiment 2: Weigh the tabular corundum (Al 2 o 3 ≥99.3%) 60kg, alumina fine powder (Al 2 o 3 ≥99.5%) 22kg, molybdenum oxide fine powder (MoO 3 ≥99.5%) 3kg, median diameter D 50 = 5μm alumina powder (Al 2 o 3 ≥99.5%) 15kg, 4kg of PVA binder with a mass fraction of 5%, and the above materials are fully mixed evenly in a roller type sand mixer. The mixture is formed into a 230mm×114mm×65mm standard brick on a 630-ton friction brick press. After the green body is dried at 110°C for 12 hours, it is fired in a gas-fired kiln at a maximum temperature of 1000°C for 5 hours. During firing, the air-fuel ratio is adjusted to ensure that the CO concentration in the flue gas is less than 0.1%, and the kiln is kept in an oxidative atmosphere. After natural cooling, the corundum refractory product is obtained. The product w(Al 2 o 3 )=97.0%, bulk density=3.20g cm -1 , Normal temperature compressive strength=75MPa, w(Al+O+W+Mo)=99.7%. This product is the working lining ref...

Embodiment 3

[0037] Embodiment 3: Weigh the fused white corundum (Al 2 o 3 ≥99.2%) 40kg, waste corundum brick broken granules with particle size less than or equal to 2mm and greater than 0.2mm (Al 2 o 3 =96.2%, W=3.1%) 30kg, alumina fine powder (Al 2 o 3 ≥99.2%) 20kg, crushed fine powder of waste corundum bricks (Al 2 o 3 =96.2%, W=3.1%) 4kg, tungsten oxide fine powder (WO 3 ≥99.5%) 1kg, median diameter D 50 =1μm alumina powder (Al 2 o 3 ≥99.5%) 10kg, 5kg of pulp waste liquid binder with a mass fraction of 10%, and the above materials are fully mixed evenly in a roller sand mixer. The mixture is formed into 230mm×114mm×65mm standard bricks on a 400-ton friction brick press. After the green body is dried at 110°C for 12 hours, it is fired in a gas-fired kiln at a maximum temperature of 1200°C for 3 hours. During firing, the air-fuel ratio is adjusted to ensure that the CO concentration in the flue gas is less than 0.1%, and the kiln is kept in an oxidative atmosphere. After natu...

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Abstract

Belonging to the field of refractory materials, the invention provides a corundum refractory product for a hydrogen introduced molybdenum rod heating furnace and an application method thereof. The corundum refractory product is a shaped refractory material subjected to high-temperature firing treatment, has a volume density of greater than or equal to 3.15g.cm<-1> and a normal-temperature compressive strength of greater than or equal to 60MPa; the components comprise Al2O3, the ratio of which is greater than or equal to 96.0%; the corundum refractory product for the hydrogen introduced molybdenum rod heating furnace contains one or two of tungsten and molybdenum elements, the sum of the mass fractions of the four elements aluminum, oxygen, tungsten and molybdenum in the corundum refractoryproduct for the hydrogen introduced molybdenum rod heating furnace is greater than or equal to 99.0%, the corundum refractory product for the hydrogen introduced molybdenum rod heating furnace is composed of particles, fine powder and micro powder, and is mainly applied to the hydrogen introduced molybdenum rod heating furnace with a working temperature of 1600-1900DEG C, and H2 with a concentration of larger than or equal to 99.0% is continuously introduced to serve as a protective gas during working. The corundum refractory product provided by the invention has the advantages of high mechanical strength and low production energy consumption, and at the same time can realize resource recycling of waste refractory materials.

Description

technical field [0001] The invention belongs to the field of refractory materials, and mainly relates to a corundum refractory product for a hydrogen-passing molybdenum rod heating furnace and an application method thereof. Background technique [0002] Tungsten and molybdenum are the most commonly used refractory metals. The melting point of tungsten is 3410±20°C, and the melting point of molybdenum is 2620°C. The industrial hydrogen-passing molybdenum rod heating furnace uses metal rods made of molybdenum or molybdenum-tungsten alloys as resistance heating elements. In order to prevent tungsten and molybdenum oxidation, circulating hydrogen is used as a protective gas, and refractory materials are used as furnace linings. The maximum operating temperature can reach 1900 ℃. The hydrogen molybdenum rod heating furnace needs to be baked and air-fired after the refractory materials are built and the components of the furnace body are installed. This process is to continuousl...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C04B35/101C04B35/634F27D1/00
CPCC04B35/1015C04B35/63416C04B2235/3256C04B2235/3258C04B2235/404C04B2235/5427C04B2235/5436F27D1/0006
Inventor 冯维银
Owner CHANGXING KEAO POTTERY IND