The preparation method of alumina base mullite homogeneous material
Technical field: the present invention is the processing and manufacturing technical field of the mineral compound of refractory raw material, is specifically related to a kind of preparation method of alumina base mullite homogeneous material.
Background technology: mullite (mullite) is an aluminium silicate mineral, have character such as refractoriness height, good thermal shock, chemical resistance of concrete, creep resistance, refractoriness under load height, volume stability be good, be the ideal high grade refractory, it is industrial to be widely used in metallurgy, glass, pottery, chemistry, electric power, national defence, combustion gas and cement etc.
Alumina base mullite homogeneous material refers to directly take alumina as raw material, through certain technology and the suitable synthesis material with uniform composition, structure and performance that makes of high-temperature calcination.Its principal crystalline phase is mullite, Al
2O
3Content is 50-80%, has the character such as refractoriness height, good thermal shock, creep resistant, refractoriness under load height, volume stability be good, is desirable high grade refractory.But alumina raw generally contains higher impurity, and the mullite purity of preparation is lower, and its sintering temperature is generally very high simultaneously, at 1600-1750 ℃.
A kind of method of artificial mullite synthesizing is provided in the Chinese invention patent application of publication number for CN98101568.9, it is mainly take alumine, kaolin, clay, silica, aluminium oxide as raw material, adopt preroast and the wet extract technology of sending out, this complex process, requirement condition height, the cost height is difficult to realize large-scale production.
A kind of synthetic method of mullite material is provided in the Chinese invention patent application of publication number for CN200410061029.7, and it mainly utilizes section bar factory industrial sludge and ferroalloy plant silica fume, makes through high temperature sintering.
Provide a kind of method of utilizing aluminous fly-ash sintering mullite synthesizing in the Chinese invention patent application of publication number for CN200410009081.8.It mainly utilizes power plant's discarded object aluminous fly-ash to be raw material, and adds a small amount of alumine, sintering synthesizing series mullite product.
A kind of method with preparing high-purity mullite at low temperature by mechanochemical process is provided in the Chinese invention patent application of publication number for CN200510040142.1, it mainly utilizes kaolin and aluminium hydroxide or aluminum oxide to be raw material, since its require material grinding to median size less than 1~2 μ m, cost is higher, and its industrial utilization is restricted.
A kind of method of synthetic mullite is provided in the Chinese invention patent of publication number for CN1312237A, he is to be raw material with one or more materials in alumine, kaolin, clay, silica, the aluminum oxide, through selecting materials, mate, pulverizing, moulding, dry, burn till, cool off, the method synthetic mullite that burns till with kiln.The alumina content of its main raw material alumine requires greater than 77%, is the resource that alumina demand each side all competes, and is more and more nervous from now on.Its firing temperature is also to 1800 ℃, and too high firing temperature not only can't scale operation, and cost can be very high.
Summary of the invention:
In order to overcome the deficiency that exists in the above-mentioned mullite preparation, the purpose of this invention is to provide a kind of is main raw material with alumine and coal gangue, add auxiliary material to improve the purity of alumina base mullite, reduce the preparation method of the alumina base mullite homogeneous material of mullite firing temperature:
Technical scheme of the present invention realizes in the following manner:
A kind of preparation method of alumina base mullite homogeneous material: take alumine as and gangue as raw material, add the agent of rare earth oxide and MgO composite sintering knot, adopt wet method or semidry method mixed grinding even, be pressed into the piece material, dry, burn till: it is characterized in that:
The weight percentage of a, each raw material is:
The alumine of 70-95%
The coal gangue of 5-30%
The 0.25-1.00% rare earth oxide of alumine and gangue total amount and the agent of MgO composite sintering knot
Rare earth oxide: MgO (mass ratio)=3-1: 1, rare earth oxide is CeO
2, La
2O
3Or Y
2O
3
B, grind size<0.088mm make the piece material, oven dry;
C, firing temperature are 1500-1600 ℃, are incubated 2-8 hour and burn till, and are cooled to room temperature and can make product.
Technical scheme of the present invention can also following manner realize:
A kind of preparation method of alumina base mullite homogeneous material: take alumine as and gangue as raw material, add the agent of rare earth oxide and MgO composite sintering knot, activated alumina, adopt wet method or semidry method mixed grinding even, be pressed into the piece material, dry, burn till: it is characterized in that:
The weight percentage of a, each raw material is:
The alumine of 70-95%
The coal gangue of 5-30%
The 0.25-1.00% rare earth oxide of alumine and gangue total amount and the agent of MgO composite sintering knot
The 1-4% activated alumina of alumine and coal gangue total amount
Rare earth oxide: MgO (mass ratio)=3-1: 1, rare earth oxide is CeO
2, La
2O
3Or Y
2O
3
B, grind size<0.088mm make the piece material, oven dry;
C, firing temperature are 1500-1600 ℃, are incubated 2-8 hour and burn till, and are cooled to room temperature and can make product.
Described alumine is alumine or the muck raw material such as II, Al after its igloss
2O
3Content is 60-78%, TiO
2≤ 4.0%, Fe
2O
3≤ 2.5%.
Al after the described gangue igloss
2O
3Content is 40-46%, TiO
2≤ 1.0%, Fe
2O
3≤ 0.8%.
Described alumina base mullite homogeneous material: principal crystalline phase is mullite; Chemical composition: Al
2O
3Be 58-75%, TiO
2≤ 3.0%, Fe
2O
3≤ 2.0%; The porosity≤3.0%, bulk density 〉=2.65g/cm
3
The invention has the advantages that:
The present invention with abundant idle mostly of China or alumine such as the II that piles up of going out of use and muck be main raw material, coal gangue also is the waste material of Coal Production association.This invention can improve the alumine resource utilization, makes the part coal gangue be used to produce high-grade refractory raw material, improves money former utilization ratio and added value of product.
2. by in alumine, adding an amount of gangue, and add activated alumina when needing and prepare stable components, the relatively low mullite of impurity content.
3. by adding the agent of rare earth oxide and MgO composite sintering knot, the sintering temperature of alumina base mullite homogeneous material can be down to 1500-1600 ℃ from 1650-1750 ℃, keeping simultaneously its load softening point is 1500-1650 ℃, is conducive to suitability for industrialized production.
4. the present invention utilizes the synthetic alumina base mullite homogeneous material of alumine resource of China, not only improve product specification and added value of product, and significantly improve the alumine resource utilization, and with the part gangue for the production of high-grade refractory material, improve the gangue economic benefit, for the comprehensive utilization of alumine and Coal Gangue Resource provides a better approaches and methods.
Specific implementation method:
Below in conjunction with example the present invention is further described, but is not limited to the following example.
Embodiment 1: plant experiment
With Dengfeng, Henan alumine and shanxi coal spoil is raw material, and its composition is shown in table 2.
The alumine of Dengfeng, table 1 Henan and the gangue chemical composition in Shanxi
Component | Al
2O
3 | SiO
2 | Fe
2O
3 | TiO
2 | R
2O
| Igloss |
Alumine | 66.84 | 12.50 | 1.62 | 3.01 | 0.39 | 14.12 |
Gangue | 37.41 | 42.60 | 0.30 | 0.49 | 0.08 | 17.65 |
Experimental size is 100Kg; Specific as follows:
76 parts of alumines and 24 parts of gangues are positioned in the ball grinder, wet-milling to granularity less than below the 0.044mm, add the 0.35% composite sintering knot agent of alumine and gangue total amount after the oven dry, in the complexing agent: CeO
2With the mass ratio of MgO be 3: 1, dry after the compression moulding;
Above-mentioned molding mass piece is put into the Industrial Stoves sintering, and sintering temperature is 1600 ℃, is incubated 6 hours.Naturally cool to room temperature then and take out, obtain alumina base mullite homogeneous material.
Through XRD analysis, the principal crystalline phase of product is mullite, and content is greater than 95%; The performance of mullite homogeneous material: AL
2O
3Content 69.80%, TiO
2Content 2.8%, Fe
2O
3Content 1.55%, the porosity 1.5%, bulk density 2.84g/cm
3
Embodiment 2
With alumine and coal gangue is raw material, and its composition is shown in table 2.
Table 2 alumine and gangue chemical composition
Component | Al
2O
3 | SiO
2 | Fe
2O
3 | TiO
2 | R
2O
| Igloss |
Alumine | 53.57 | 26.00 | 1.81 | 2.73 | 0.32 | 14.43 |
Gangue | 33.90 | 47.80 | 0.38 | 0.52 | 0.07 | 16.05 |
With 88 parts of alumines and 12 parts of gangues, add the 0.75% composite sintering knot agent of alumine and gangue total amount, composite sintering knot agent La
2O
3With the mass ratio of MgO be 1: 1, be positioned in the ball grinder wet-milling to 0.044mm, squeeze the mud moulding after, lower dry 24 hours at 110 ℃;
Above-mentioned molding mass piece is put into the kiln sintering, and sintering temperature is 1550 ℃, is incubated 3 hours.Naturally cool to room temperature then and take out, obtain alumina base mullite homogeneous material.
Through XRD analysis, the principal crystalline phase of product is a mullite, and content is greater than 95%.Al
2O
3Content 59.50%, TiO
2Content 2.88%, Fe
2O
3Content 1.92%, the porosity 2.0% of homogeneous material, bulk density 2.68g/cm
3
Embodiment 3
With alumine and coal gangue is raw material, and its composition is shown in table 2.
Table 2 alumine and gangue chemical composition
Component | Al
2O
3 | SiO
2 | Fe
2O
3 | TiO
2 | R
2O
| Igloss |
Alumine | 63.49 | 15.72 | 1.82 | 3.06 | 0.26 | 14.18 |
Gangue | 36.20 | 47.46 | 0.41 | 0.53 | 0.15 | 15.46 |
Experimentize at certain refractory factory, experimental size is 5000Kg.Specific as follows: as after 82 parts of alumines and 18 parts of gangues are mixed, to add 2% activated alumina and the agent of 1% composite sintering knot of alumine and gangue total amount, Y in the agent of composite sintering knot
2O
3With the mass ratio of MgO be 1: 2, put into the ball mill wet-milling to 0.044mm, then wet method extrusion modling after the oven dry, is put into the kiln sintering, sintering temperature is 1520 ℃, is incubated 8 hours.Naturally cool to room temperature then and take out, obtain alumina base mullite homogeneous material.
Through XRD analysis, the principal crystalline phase of product is a mullite, and content is greater than 95%.Al
2O
3Content 68.40%, TiO
2Content 2.90%, Fe
2O
3Content 1.81%, the porosity 1.0% of homogeneous material, bulk density 2.80g/cm
3