Method for preparing high-purity mullite material by taking molten silicon dioxide as silicon source

A technology of fused silica and silica, which is applied in the field of high-temperature ceramic materials, can solve the problems of high synthesis temperature of high-purity mullite, complex reaction methods, difficulty in meeting production requirements, etc., and achieve good high-temperature mechanical properties , high production efficiency, and the effect of improving high temperature toughness

Active Publication Date: 2020-09-04
临沂利发耐火材料有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Using sol-gel or spark plasma sintering can effectively reduce the firing temperature of high-purity mullite materials, but these methods have high preparation costs and low production efficiency, and it is difficult to meet industrial production requirements
In short, the synthesis temperature of high-purity mullite is high, and the method of improving the reactivity of raw materials is relatively complicated.

Method used

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  • Method for preparing high-purity mullite material by taking molten silicon dioxide as silicon source
  • Method for preparing high-purity mullite material by taking molten silicon dioxide as silicon source

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0021] Step 1): Preparation of fused silica raw material;

[0022] Mix 90.5wt% natural quartz, 8.5wt% kaolinite and 1.0 wt% magnesia according to the mass percentage, and put them in a planetary ball mill (rotating speed 280r / min) for 3 hours, particle size ≤325 mesh, then mix The material is pressed into a green body under a pressure of 100 MPa, and the green body is dried and calcined at 1530° C. for 0.6 hours, and cooled to obtain a fused silica raw material.

[0023] Step 2): Use fused silica raw materials to prepare high-purity mullite materials;

[0024] Crush the fused silica raw material synthesized in step 1 and γ-Al 2 O 3 Fine powder press Al 2 O 3 / SiO 2 Ingredients with a molar ratio of 3:2. After the raw materials are co-milled (particle size ≤325 mesh), 4wt% of the above-mentioned raw material mass is added as a binder, molded at 120MPa, and calcined at 1600°C for 3 hours. Obtain high-purity mullite material.

[0025] The technical index of the high-purity mullite mater...

Embodiment 2

[0027] Step 1): Preparation of fused silica raw material;

[0028] According to the mass percentage, 94 wt% silica, 5.5 wt% γ-Al 2 O 3 Mix it with 0.5wt% yttrium oxide, put it into a planetary ball mill (rotating speed 280r / min), ball mill for 3 hours, particle size ≤325 mesh, then press the mixture into a green body under a pressure of 100MPa, and dry the green body at 100°C It is calcined at 1560°C for 0.5 hours and cooled to obtain a fused silica raw material.

[0029] Step 2): Use fused silica raw materials to prepare high-purity mullite materials;

[0030] Crush the fused silica raw material synthesized in step 1 and α-Al 2 O 3 Fine powder press Al 2 O 3 / SiO 2 Ingredients with a molar ratio of 3:2. After the raw materials are co-milled (particle size ≤325 mesh), 4wt% silica sol of the sum of the above raw materials is added as a binding agent, molded at 120MPa, and calcined at 1630°C for 4 hours. Pure mullite material.

[0031] The technical index of the high-purity mullite mat...

Embodiment 3

[0033] Step 1): Preparation of fused silica raw material;

[0034] Mix 86.6wt% of natural quartz, 12.8wt% of coal gangue and 0.6wt% of zinc oxide according to mass percentage, and then wet ball mill the mixture for 5 hours, with a particle size of ≤325 mesh, and press it into a blank under a pressure of 120MPa The green body is dried at 100°C and calcined at 1550°C for 0.6 hours. After cooling, the fused silica raw material is obtained.

[0035] Step 2): Use fused silica raw materials to prepare high-purity mullite materials;

[0036] Crush the fused silica raw material synthesized in step 1 and α-Al 2 O 3 Fine powder according to Al 2 O 3 / SiO 2 Ingredients with a molar ratio of 3:2. After the raw materials are co-milled (particle size ≤325 mesh), 4wt% of the above-mentioned raw material masses and 4wt% of the pulp waste liquid are added as a binding agent, molded at 120MPa, and calcined at 1630°C for 5 hours. High-purity mullite material.

[0037] The technical index of the high-pu...

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Abstract

The invention discloses a method for preparing a high-purity mullite material by taking molten silicon dioxide as a silicon source. The method is characterized by comprising the following steps: a, mixing, in percentage by mass, 75-94 wt% of a silicon dioxide raw material, 4-20 wt% of an aluminum-silicon raw material and 0.1-2 wt% of a sintering aid; carrying out ball milling, drying and forming,conducting calcining in a 1500-to-1600 DEG C high-temperature furnace for 0.5-1 hour, firing the mixed raw materials to a molten state, and conducting cooling to obtain a molten silicon dioxide raw material; b, crushing the molten silicon dioxide raw material prepared in the step a, mixing the crushed molten silicon dioxide raw material with an alumina raw material according to a molar ratio of Al2O3 / SiO2 of 3: 1, co-grinding the mixed raw materials, adding a binding agent accounting for 4 wt% of the total weight of the raw materials, carrying out molding under a pressure of 80-150 MPa, carrying out calcining at 1550-1650 DEG C for 3-8 hours, and carrying out cooling to obtain the high-purity mullite crystal material. According to the invention, molten silicon dioxide is used as a siliconsource, the sintering temperature for synthesizing the high-purity mullite material is low, the addition amount of the sintering aid is small, and columnar mullite and lamellar mullite crystals are formed; and the high-purity mullite material has the characteristics of low impurity content, high density and good high-temperature mechanical properties.

Description

Technical field [0001] The invention belongs to the technical field of high-temperature ceramic materials, and specifically relates to a fused silica (SiO 2 ) It is a method for preparing high-purity mullite materials from silicon sources. Background technique [0002] As an ideal high temperature ceramic material, mullite has good high temperature creep resistance, excellent thermal shock resistance, high load softening temperature, good mechanical properties at room temperature, and strong electrical insulation. It is widely used High-temperature engineering materials, refractory materials, electric power and national defense and other fields. [0003] It is very difficult to prepare high-purity mullite materials by the reaction sintering method, which requires higher firing temperature and longer firing time. For example, the invention patent "a processing technology of high-purity mullite" (Patent Publication No. CN 101314547A) discloses a method for synthesizing high-purity m...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C04B35/185C04B35/622C04B35/626C04B35/63C04B35/634
CPCC04B35/185C04B35/622C04B35/62204C04B35/62665C04B35/63C04B35/6316C04B35/6303C04B35/63416C04B2235/322C04B2235/349C04B2235/3418C04B2235/3206C04B2235/3225C04B2235/3284C04B2235/3217C04B2235/3218C04B2235/3229C04B2235/3227C04B2235/3208C04B2235/3248C04B2235/3262C04B2235/656C04B2235/6567C04B2235/77C04B2235/96C04B2235/9607
Inventor 赵飞朱先忠李可可刘新红徐恩霞杨力远葛铁柱
Owner 临沂利发耐火材料有限公司
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