CN102030470A - Gel cast fused quartz crucible and manufacturing method thereof - Google Patents

Abstract

The invention discloses a gel cast fused quartz crucible which contains the following components by mass percentage: more than 99.74% of silica, less than 40ppm of ferric oxide, less than 1000ppm of alumina, and the balance inevitable impurities such as potassium, sodium, magnesium or calcium oxides. A green body of the gel cast fused quartz crucible is high in strength and density, and even in structure, and can be used for producing large-sized crucibles. The invention also discloses a manufacturing method of the gel cast fused quartz crucible.

Description

A kind of notes congeal into type fused silica crucible and manufacture method thereof

Technical field

The present invention relates to a kind of fire-resistant kiln furnitures, belong to metallurgy industry.Relate in particular to a kind of quartz crucible and manufacture method thereof, particularly a kind of notes congeal into type fused silica crucible and manufacture method thereof.

Background technology

The fused quartz ceramic crucible is the easily-consumed products in the polycrystalline silicon ingot casting process, every annual about 120 of ceramic side's crucible that needs of polycrystalline furnace.07 year domestic crucible demand about 120,000 every year is as being explosive growth again in nearest 2 years of this year.The mainstream technology injection forming (slipcasting) of fused silica crucible in the market.Injection forming is traditional moulding process, is characterized in product density height (1.89～2.0g/cm ³), intensity is higher.But slip-casting shaping process has many shortcomings that can't overcome: 1, and the plaster mould quality instability of grouting,, there is fluctuation in time so that influences the crucible quality; 2, the green strength of injection forming is low, and production large size crucible difficulty is very big; 3, the injection forming structure is inhomogeneous, even interlayer is arranged, and intensity is lower; 4 mould access times are limited, and die cost is very high; 5, burn till the back crucible bottom cost of need polishing and increase substantially; 6, the requirement of mold temperature humidity etc. is very high.Present 880 crucibles are market mainstreams, but 1024 crucibles even bigger crucible are the directions that in the future develops.It is very big that large-scale like this crucible difficulty is done in the injection forming moulding, highlights the limitation of slip casting method.

The notes type (gelcasting) that congeals into is novel ceramic preparation technology, but this technology has remarkable advantages such as green strength height, once shaped with short production cycle, produces large-scale fused silica crucible and has incomparable advantage.Domestic seldom producer prepares quartz ceramic crucible with annotating the type that congeals into, and compare with the crucible of injection forming production, the crucible density (about 1.80g/cm3) on the low side that notes congeal into type, low excessively density has a strong impact on the performance of crucible, so annotate the share of market atrophy year by year of congealing into the type crucible.Therefore, the density that how to improve the fused quartz ceramic crucible is to annotate key one ring that can the type that congeal into be successfully applied to the sector.

In the disclosed patent No. be: 200910101334.7, patent name is: in the patent documentation of a kind of high-purity silica pot and manufacture method thereof, a kind of high-purity silica pot and manufacture method thereof are disclosed, its fused quartz crystal of selecting three kinds of variable grain specification SiO2 for use is a main raw material, by weight percentage with particle diameter c1) 0.381mm 30%-40%, c1) 0.173mm 10%-15%, c1) the ratio proportioning of 0.0065mm 60%-45%, other adds the interpolation wedding agent, deionized water is mixed with slurry, slurry is cast in the plaster mould behind the ball mill ball milling, the demoulding, the oven dry back is sintering the quartz crucible finished product in the push-plate type oil kiln automatically.It has improved the intensity and the easy crumbliness of quartz crucible, but the problem that does not relate to crucible density and produce large-scale crucible.

Summary of the invention

The technical problem to be solved in the present invention is: a kind of notes congeal into type fused silica crucible and manufacture method thereof are provided, and the crucible that it can production green strength height, density is high, and even structure, intensity high energy are produced large-scale crucible.

In order to solve the problems of the technologies described above, the invention provides a kind of notes type fused silica crucible that congeals into, the congeal into quality percentage composition of composition of type fused silica crucible of these notes is:

Silicon-dioxide＞99.74%,

Ferric oxide＜40ppm,

Aluminum oxide＜1000ppm,

All the other are unavoidable impurities such as potassium oxide compound, na oxide, magnesium oxide or calcium oxide.

Further, the congeal into quality percentage composition of composition of type fused silica crucible of described notes is:

Silicon-dioxide＞99.85%,

Ferric oxide＜30ppm,

Aluminum oxide＜500ppm,

All the other are unavoidable impurities such as potassium oxide compound, na oxide, magnesium oxide or calcium oxide.

Further be that the congeal into quality percentage composition of composition of type fused silica crucible of described notes is:

Silicon-dioxide＞99.9%,

Ferric oxide＜10ppm,

All the other are potassium oxide compound, na oxide, magnesium oxide or calcium oxide class unavoidable impurities.

According to the notes of the present invention type fused silica crucible that congeals into, the volume density that is preferably described fused silica crucible is 1.89～1.98g/cm ³, more than the room temperature bending strength 20MPa, coefficient of linear expansion about 0.6 * 10 ^-6/ ℃, apparent porosity is less than 15%.

A kind ofly make the method that above-mentioned notes congeal into the type fused silica crucible, may further comprise the steps:

1) grind to form slurry with adding water in high-purity fused quartz sand input shredder, the granularity of described quartz sand is controlled in 30 microns;

2) above-mentioned slurry ageing is after 8 to 12 days, again to material with 50～100 microns of middle adding granularities, 250～350 microns fused quartz sand, add the acrylamide chemical reagent then, fully stir and reach 30～45 degrees centigrade until slurry temperature, pressure injects stainless steel mould after the froth in vacuum, is aided with slight vibrations simultaneously, about 20～40 times/minute of vibration frequency, about 2～5 millimeters of amplitude, behind the casting complete static 15～30 minutes;

3) then in the baking oven of the stainless steel mould after the cast as for 40～100 degree, be incubated 1～5 hour;

4) after the demoulding earlier humidity greater than 80% environment under dry 1～12 hour, in the baking ovens of 100～200 degree dry 20～30 hours then;

5) dried green compact being put into kiln burns till; in oxidizing atmosphere, protect 6～10 hours earlier, then in reducing atmosphere, protect 5～50 hours; firing temperature 1000～1300 degree, firing time is 15～56 hours, the gained crucible is the fused quartz ceramic crucible.

Beneficial effect of the present invention is:

1, green strength height, the qualification rate height;

2, the density height of crucible is with injection forming gained crucible consistent in density;

3, cast is convenient, shaping cycle is short;

4, once shaped need not multi-processing, so cost is far below injection forming;

5, even structure, intensity height;

6, produce large-scale crucible (1024mm and above size) and have incomparable advantage;

7, less investment, instant effect, risk are low, compare with injection forming, are that place or equipment are all few a lot.

Embodiment

Below, for a more detailed description with embodiment to the present invention.These embodiment only are the descriptions to best mode for carrying out the invention, scope of the present invention are not had any restriction.

Embodiment 1

(mass percent of its component is: silicon-dioxide＞99.75% with 50 parts of block glass sands, ferric oxide＜38ppm, aluminum oxide＜950ppm, other are unavoidable impurities, as the potassium oxide compound, na oxide, magnesium oxide or calcium oxide etc.) drop in the ball mill and carry out wet ball grinding, particle diameter is controlled in 10 microns, ageing adds 60 microns again after 8 days, each 25 parts in high-purity fused quartz sand of 220 microns, adding acrylamide monomer reagent then fully stirs, fully stir and reach 35 degrees centigrade until slurry temperature, after the physical and chemical index detection is qualified, pressure injects stainless steel mould after the froth in vacuum, be aided with slight vibrations simultaneously, vibration frequency 30 times/minute, 3 millimeters of amplitudes.Behind the casting complete static 20 minutes.After 50 degrees centigrade drying rooms are placed 5 hours, take out the demoulding, green compact humidity greater than 80% environment under dry 10 hours, then under 200 degrees centigrade environment dry 25 hours.Dried green compact are put into kiln burn till, earlier in oxidizing atmosphere protection 8 hours, protection of reducing atmosphere 45 hours then.Firing temperature 1100 degree, firing time is 55 hours, the gained crucible is fused quartz ceramic crucible sample 1.

Embodiment 2

(mass percent of its component is: silicon-dioxide＞99.8% with 45 parts of block glass sands, ferric oxide＜25ppm, aluminum oxide＜400ppm, other are unavoidable impurities, as the potassium oxide compound, na oxide, magnesium oxide or calcium oxide etc.) drop in the ball mill and carry out wet ball grinding, particle diameter is controlled in 20 microns, ageing adds high-purity fused quartz sand of 20 parts 80 microns after 10 days, high-purity fused quartz sand of 35 parts 300 microns, adding reagent such as acrylamide monomer then fully stirs, fully stir and reach 40 degrees centigrade until slurry temperature, after the physical and chemical index detection is qualified, pressure injects stainless steel mould after the froth in vacuum, be aided with slight vibrations simultaneously, vibration frequency 38 times/minute, 5 millimeters of amplitudes.Behind the casting complete static 25 minutes.After 80 degrees centigrade drying room is placed 3 hours, take out the demoulding then, green compact humidity greater than 80% environment under dry 6 hours, then under 180 degrees centigrade environment dry 21 hours.Dried green compact are put into kiln burn till, earlier in oxidizing atmosphere protection 10 hours, protection of reducing atmosphere 30 hours then.Firing temperature 1200 degree, firing time is 30 hours, the gained crucible is fused quartz ceramic crucible sample 2.

Case 3

(mass percent of its component is: silicon-dioxide＞99.95% with 40 parts of block glass sands, aluminum oxide＜10ppm, other are unavoidable impurities, as the potassium oxide compound, na oxide, magnesium oxide or calcium oxide etc.) drop in the ball mill and carry out wet ball grinding, particle diameter is controlled in 25 microns, ageing adds high-purity fused quartz sand of 25 parts 90 microns after 12 days, high-purity fused quartz sand of 35 parts 330 microns, adding reagent such as acrylamide monomer then fully stirs, fully stir and reach 45 degrees centigrade until slurry temperature, after the physical and chemical index detection is qualified, pressure injects stainless steel mould after the froth in vacuum, be aided with slight vibrations simultaneously, vibration frequency 25 times/minute, 2 millimeters of amplitudes.Behind the casting complete static 15 minutes.After 100 degrees centigrade drying room is placed 2 hours, take out the demoulding then, green compact humidity greater than 80% environment under dry 3 hours, then under 120 degrees centigrade environment dry 28 hours.Dried green compact are put into kiln burn till, earlier in oxidizing atmosphere protection 6 hours, protection of reducing atmosphere 10 hours then.Firing temperature 1200 degree, firing time is 30 hours, the gained crucible is fused quartz ceramic crucible sample 3.

Above-mentioned quartz crucible product is carried out Performance Detection, and its main performance index sees Table 1

Table 1

Test item	Sample 1	Sample 2	Sample 3
				Bending strength (MPa)	26.7	33.1	29.2

Volume density (g/cm 3)	1.90	1.94	1.92
				Apparent porosity (%)	12.5	12.1	12.8
Coefficient of linear expansion (10 -6/℃)	0.59	0.6	0.6

Claims (5)

1. notes type fused silica crucible that congeals into is characterized in that: the congeal into quality percentage composition of composition of type fused silica crucible of these notes is:

Silicon-dioxide＞99.74%,

Ferric oxide＜40ppm,

Aluminum oxide＜1000ppm,

All the other are potassium oxide compound, na oxide, magnesium oxide or calcium oxide class unavoidable impurities.

2. the notes according to claim 1 type fused silica crucible that congeals into is characterized in that: the congeal into quality percentage composition of composition of type fused silica crucible of described notes is:

Silicon-dioxide＞99.85%,

Ferric oxide＜30ppm,

Aluminum oxide＜500ppm,

All the other are potassium oxide compound, na oxide, magnesium oxide or calcium oxide class unavoidable impurities.

3. the notes according to claim 1 type fused silica crucible that congeals into is characterized in that: the congeal into quality percentage composition of composition of type fused silica crucible of described notes is:

Silicon-dioxide＞99.9%,

Ferric oxide＜10ppm,

All the other are potassium oxide compound, na oxide, magnesium oxide or calcium oxide class unavoidable impurities.

4. the notes according to claim 1 type fused silica crucible that congeals into, it is characterized in that: the volume density of described fused silica crucible is 1.89～1.98g/cm ³, more than the room temperature bending strength 20MPa, coefficient of linear expansion is 0.6 * 10 ^-6/ ℃, apparent porosity is less than 15%.

5. make the method that the described notes of claim 1 congeal into the type fused silica crucible for one kind, it is characterized in that: this method may further comprise the steps:

1) grind to form slurry with adding water in high-purity fused quartz sand input shredder, the granularity of described quartz sand is controlled in 30 microns;

2) above-mentioned slurry ageing is after 8 to 12 days, again to material with 50～100 microns of middle adding granularities, 250～350 microns fused quartz sand, add the acrylamide chemical reagent then, fully stir and reach 30～45 degrees centigrade until slurry temperature, pressure injects stainless steel mould after the froth in vacuum, is aided with slight vibrations simultaneously, about 20～40 times/minute of vibration frequency, about 2～5 millimeters of amplitude, behind the casting complete static 15～30 minutes;

3) then in the baking oven of the stainless steel mould after the cast as for 40～100 degree, be incubated 1～5 hour;

4) after the demoulding earlier humidity greater than 80% environment under dry 1～12 hour, in the baking ovens of 100～200 degree dry 20～30 hours then;

5) dried green compact being put into kiln burns till; in oxidizing atmosphere, protect 6～10 hours earlier, then in reducing atmosphere, protect 5～50 hours; firing temperature 1000～1300 degree, firing time is 15～56 hours, the gained crucible is the fused quartz ceramic crucible.