CN102351522A - Method for preparing homogeneous mullite material from kyanite - Google Patents

Abstract

The invention relates to a method for preparing a homogeneous mullite material from kyanite. The method is characterized in that the method comprises the following steps: 1, weighing 60-100 wt% of kyanite containing equal to or greater than 40% of Al2O3, 0-40 wt% of high bauxitic clay containing equal to or greater than 85% of Al2O3, 0-40% of industrial alumina containing equal to or greater than 98% of Al2O3, a sintering agent rare earth oxide which accounts for 0-1.5% of the sum of weight percentages of above raw materials, and 0-1.5% of MgO with the purity of equal to or greater than 98.5%, wherein the rare earth oxide is anyone of CeO2, La2O3 or Y2O3; 2, cogrinding mixing through a wet process or a dry process until the granularity is less than 0.074mm, extruding into a blocky blank through semi-dry extrusion or wet extrusion, and drying to the water content of less than 1.0%; and 3, calcining the dried blank under conditions of a temperature of 1460-1600DEG C, insulating for 8-16h, and cooling to room temperature to prepare products with the Al2O3 content of 45-70% and the volume density of 2.3-2.8g/cm<3>.

Description

A kind of preparation method who prepares mullite homogeneous material with kyanite

Technical field

The invention belongs to technical field of inorganic nonmetallic materials, specifically relate to its preparation method of the synthetic preparation of the natural blue spar ore of a kind of usefulness mullite homogeneous material.

Background technology

It is mineral that kyanite (Kyanite) belongs to aluminium silicon, and its chemical formula is: Al ₂O ₃-SiO ₂, it has at high temperature irreversible mullite and the SiO of becoming ₂, and be attended by comparatively large vol expansible characteristic.The application of kyanite mainly is in the matrix of aluminium silicon system (comprising clay matter, high alumina matter, mullite and corundum matter) refractory materials, to add a small amount of kyanite (< 10%) improves refractory materials as swelling agent performance; In lightweight refractory, add a small amount of kyanite (≤12%) to increase the content of mullite phase in the goods.After in refractory materials, adding kyanite; Because of its mullitization reaction at high temperature can form the network structure that good high temperature substrate constitutes mutually; Thereby significantly improve the high-temperature behavior of refractory materials, as: high volume stability (minimizing shrinkage crack), high temperature creep, thermal shock resistance, refractoriness under load etc.Yet, only limit to concentrate (Al in the utilization of the present blue spar ore of China ₂O ₃>=55%), and account for total reserves more than 90% in low-grade blue spar ore idle, comprehensive utilization as yet.

Mullite is an aluminium silicate mineral, is Al ₂O ₃-SiO ₂Unique stable compound in the two component system belongs to high grade refractory, widespread use in hot industry.Industrial mullite mainly adopts the preparation of sintering process and electric smelting method, and the raw material of use mainly contains bauxitic clay, clay, commercial alumina, coal gangue, glass sand, flyash etc., synthesize the preparation mullite with in them one or more, when preparing Al ₂O ₃Its sintering temperature was usually 1650～1700 when content was>=60% mullite ^oC.And adopt kyanite is the mullite that starting raw material prepares; Not only the content of its mullite phase is high, crystal shape is good, the high-temperature behavior of composition and even structure, product is better; And can make a large amount of idle in low-grade blue spar ore obtain utilizing, increase substantially the utilization ratio of resource.

Do not retrieve as yet at present with blue spar ore (low-grade blue spar ore particularly) and make raw material, add document and patent of invention that the used sintering aid of the present invention prepares the mullite aspect.

Summary of the invention

The present invention seeks to do raw material, develop that a kind of mullite phase content is high, crystal shape is good, the preparation method of chemical constitution and uniform microstructure, mullite that high-temperature behavior is good with natural blue spar ore.

Characteristics of the present invention are to make raw material with natural blue spar ore, and part adds bauxitic clay and/or commercial alumina and micro-sintering aid, adopt wet method or dry method to grind altogether, mix, and make product of the present invention through moulding, drying, sintering.

The preparation method who prepares mullite homogeneous material with kyanite of the present invention comprises the steps:

A, get by weight percentage: Al ₂O ₃The kyanite 60 ~ 90% of content>=40%, Al ₂O ₃The alumine 0 ~ 40% of content>=85%, Al ₂O ₃The commercial alumina 0 ~ 40% of content>=98%, and above-mentioned raw materials weight percent sum as the rare earth oxide 0 ~ 1.5% of agglutinant, the MgO 0 ~ 1.5% of purity>=98.5%; Described rare earth oxide is CeO ₂, La ₂O ₃Or Y ₂O ₃In any one;

B, employing wet method or dry method are ground mixing altogether, and granularity is＜0.074mm, are squeezed into block base substrate with semidrying machine pressure or wet method, dry to moisture＜1.0%;

It is roasting under 1460 ~ 1600 ℃ the condition that c, the base substrate after will drying place temperature, is incubated 8 ~ 16 hours, is cooled to room temperature then and can makes Al ₂O ₃Content 45～70%%, volume density 2.3～2.8g/cm ³Product.

The mullite homogeneous material Al of the present invention's preparation ₂O ₃Content is 45 ~ 70%, and its principal crystalline phase is that (relative content is 60～95% to mullite.

 

Beneficial effect of the present invention is following:

1, used blue spar ore source is abundant, particularly idle in the utilization of low-grade blue spar ore, increased substantially the utilization ratio of resource;

2, utilize kyanite to be converted into the characteristics of mullite phase, the product mullite phase content of the present invention's preparation is high, crystal shape is good, the high-temperature behavior of composition and even structure, product is good;

3, manufacture craft is simple, and firing temperature is relatively low, and is energy-conservation, suitability for mass industrialized production.

Embodiment

To combine embodiment to further describe below the present invention, but not limit the present invention.

The preparation method who prepares mullite homogeneous material with kyanite of the present invention comprises the steps:

A, get by weight percentage: Al ₂O ₃The kyanite 60 ~ 90% of content>=0%, Al ₂O ₃The alumine 0 ~ 40% of content>=85%, Al ₂O ₃The commercial alumina 0 ~ 40% of content>=98%, and above-mentioned raw materials weight percent sum as the rare earth oxide 0 ~ 1.5% of agglutinant, the MgO 0 ~ 1.5% of purity>=98.5%; Described rare earth oxide is CeO ₂, La ₂O ₃Or Y ₂O ₃In any one;

B, employing wet method or dry method are ground mixing altogether, and granularity is＜0.074mm, are squeezed into block base substrate with semidrying machine pressure or wet method, dry to moisture＜1.0%;

It is roasting under 1460 ~ 1600 ℃ the condition that c, the base substrate after will drying place temperature, is incubated 8 ~ 16 hours, is cooled to room temperature then and can makes Al ₂O ₃Content 45～70%, volume density 2.3～2.8g/cm ³Product.

The mullite homogeneous material Al of the present invention's preparation ₂O ₃Content is 45 ~ 70%, and its principal crystalline phase is mullite (relative content is 60～95%).

Embodiment 1:

Get by weight percentage: Al ₂O ₃Content is 46%, granularity<0.074mm kyanite 100%,, in wet-type ball mill, mix, squeeze clay moulded pottery not yet put in a kiln to bake through filter-press dehydration, vacuum, go into kiln after the drying, 1470 ℃ of insulations 8 hours, be cooled to room temperature and promptly obtain product.

Embodiment 2:

Get by weight percentage: Al ₂O ₃Content is 53%, granularity<0.074mm kyanite 100%, driedly be mixed evenly, add water 6% (or spent pulping liquor 8%), machine is pressed into base, goes into kiln after the drying, 1500 ℃ of insulations 10 hours, is cooled to room temperature and promptly obtains product.

Embodiment 3:

Get by weight percentage: Al ₂O ₃Content is 56%, granularity<0.074mm kyanite 100%, add 0.4% CeO ₂, in wet-type ball mill, mix, squeeze the clay moulded pottery not yet put in a kiln to bake that gets through filter-press dehydration, vacuum, go into kiln after the drying, 1550 ℃ of insulations 8 hours, be cooled to room temperature and promptly obtain product.

Embodiment 4:

Get by weight percentage: Al ₂O ₃The kyanite 70% of content 45%, Al ₂O ₃The alumine 30% of content>=85%, granularity is＜0.074mm, adds 0.5% Y ₂O ₃MgO with 0.6% mixes in wet-type ball mill, squeezes the clay moulded pottery not yet put in a kiln to bake that gets through filter-press dehydration, vacuum, goes into kiln after the drying, 1540 ℃ of insulations 8 hours, is cooled to room temperature and promptly obtains product.

Embodiment 5:

Get by weight percentage: Al ₂O ₃The kyanite 70% of content 55%, Al ₂O ₃The alumine 20% of content>=88%, commercial alumina 10%, granularity is＜0.074mm, adds 1.0% La ₂O ₃MgO with 0.8% mixes in wet-type ball mill, squeezes the clay moulded pottery not yet put in a kiln to bake that gets through filter-press dehydration, vacuum, goes into kiln after the drying, 1580 ℃ of insulations 16 hours, is cooled to room temperature and promptly obtains product.

Embodiment 6:

Get by weight percentage: Al ₂O ₃The kyanite 65% of content 56%, commercial alumina 35%, granularity is＜0.074mm, adds 1.3% CeO ₂MgO with 1.3% mixes in wet-type ball mill, squeezes the clay moulded pottery not yet put in a kiln to bake that gets through filter-press dehydration, vacuum, goes into kiln after the drying, 1600 ℃ of insulations 14 hours, is cooled to room temperature and promptly obtains product.

Claims (1)

1. one kind prepares the preparation method of mullite homogeneous material with kyanite, and it is characterized in that: said preparation method comprises the steps:

A, get by weight percentage: Al ₂O ₃The kyanite 60 ~ 100% of content>=40%, Al ₂O ₃The alumine 0 ~ 40% of content>=85%, Al ₂O ₃The commercial alumina 0 ~ 40% of content>=98%, and above-mentioned raw materials weight percent sum as the rare earth oxide 0 ~ 1.5% of agglutinant, the MgO 0 ~ 1.5% of purity>=98.5%; Described rare earth oxide is CeO ₂, La ₂O ₃Or Y ₂O ₃In any one;

B, employing wet method or dry method are ground mixing altogether, and granularity is＜0.074mm, are squeezed into block base substrate with semidrying machine pressure or wet method, dry to moisture＜1.0%;

It is roasting under 1460 ~ 1600 ℃ the condition that c, the base substrate after will drying place temperature, is incubated 8 ~ 16 hours, is cooled to room temperature then and can makes Al ₂O ₃Content 45 ~ 70%%, volume density 2.3 ~ 2.8g/cm ³Product.