CN1387499A

CN1387499A - Pure fused silica, furnace and method

Info

Publication number: CN1387499A
Application number: CN00815425A
Authority: CN
Inventors: L·H·科塔斯卡; R·S·小帕夫利克
Original assignee: Corning Inc
Current assignee: Corning Inc
Priority date: 1999-09-10
Filing date: 2000-09-08
Publication date: 2002-12-25
Also published as: AU7364000A; JP2003508337A; EP1242324A1; KR20020029790A; WO2001017919A1

Abstract

An article of relatively pure silica, and a furnace (50) and method of producing the article. The article is produced by collecting molten silica particles in a refractory furnace (50) in which at least a portion of the refractory (32) has been exposed to a halogen-containing gas to react with contaminating metal ions in the refractory (32).

Description

Pure fused silica, kiln and method

The application requires to enjoy the title of submitting on September 10th, 1999 and is " being used to make the furnace roof fire resisting material of fused silica " (Lawrence H.Kotacska and Robert S.Pavilik, Jr.) right of priority of U.S. Patent application 60/153,422.The title that the application also relates on August 13rd, 1998 and submits to is " pure fused silica, kiln and method " (Robert S.Pavilik, Jr., Daniel R.Sempolinskiand Michael H.Wasilewski) U.S. Patent application 09/125,208, these patent applications are with reference to being incorporated into this.

Invention field

The present invention relates to the goods of purer fused silica, make the kiln and the method for this goods.

Background of invention

Purer fused silica is to make by the deposition of the thermolysis of its precursor and the oxide compound that produces.Precursor can be a steam form or by the steam load.Decompose by flame hydrolysis or pyrolysis.

A kind of method like this is that hydrolysis or pyrolysis silicon tetrachloride are made fused silica.The early stage patent that discloses this preparation silicon-dioxide method has: United States Patent (USP) 2,239,551 (Nordberg) and 2,273,342 (Hyde).The industrial application of flame hydrolysis is that formation and deposition of silica form larger object (vitreum (boule)).Such vitreum can directly use, or processes or assemble and become big optical body such as telescopical eyeglass.In this method, SiCl ₄Be hydrolyzed, the steam that hydrolysis forms feeds the melt granules of flame formation silicon-dioxide.These particle successive sedimentations are at the bait device or be deposited in the crucible that is known as cup the formation vitreum.

There is serious defective in this method, promptly need dispose by product HCl in environmentally safe mode.Therefore, at United States Patent (USP) 5,403, among 002 (Dobbins etc.), use a kind of silicon-containing compound of non-halogen thing to replace SiCl ₄The vapor reaction thing that concrete proposition uses polymethyl siloxane such as octamethylcyclotetrasiloxane to provide hydrolysis or pyrolytic process to use in this patent.

For introducing a kind of precursor of replacement, certainly, must avoid the tangible performance variation of fused silica product strictly speaking.Unfortunately, the precursor by propositions such as Dobbins substitutes the considerable change that causes performance.Its another shortcoming is fluorescence phenomenon to have occurred in the glass that produces, and this fluorescence phenomenon also increases when glass is subjected to shortwave irradiation to some extent.

These study announcement, a sodium content that factor is a glass of transmission loss.United States Patent (USP) 5,332,702 and 5,395,413 (Sempolinski etc.) have been described and have been reduced the remedial measures that sodium content adopted.These measures mainly are included in to build in the Vitrea stove of fused silica formation of deposits uses zirconia refractory.Particularly, in making the zirconia refractory component that this kiln uses, must use dispersion agent, tackiness agent and contain sodium ion few water of trying one's best.

The described methods of people's patent such as employing Sempolinski have obtained improved products.Yet the purposes of some fused silica obviously requires to further improve the strict demand of satisfying these purposes.A kind of purposes like this is the lens that are used for by the very short UV light transmission of excimer type laser apparatus emission.This laser apparatus emission wavelength is about the radiation of 193-248nm.

Discovery can't provide the transmission of qualified short wavelength radiation by the lens of commercially available fused silica manufacturing, and shows bad fluorescence phenomenon.Both of these case becomes more serious with passing duration of service.The transmission loss of glass or deepening generally are called UV and absorb damage.

Main purpose of the present invention provides a kind of fused silica material that addresses these problems.Second purpose provides the used improved fused silica glass of the especially meticulous lithography process of laser lens.The 3rd purpose provides the improvement kiln of the fused silica that is used to collect the vitreum form.The 4th purpose provides the method this improved collection kiln and make glass in this kiln of making.

Summary of the invention

The present invention includes the method for making fused silica glass.This method comprises the following steps: to provide silica material, and a furnace roof and a cup that mainly is made of aluminum oxide (aluminum dioxide) is provided, and furnace roof is positioned at the top of fixed non-porous fused silica glass body.Described method comprises also silica material is sent in the burner that is installed in the reactive site in the aluminum oxide furnace roof that in burner, silica material changes the fused silica dioxide granule into, again deposit and fixed is fused silica glass.

The present invention comprises that also the silica precursor raw material liq that will be not silicon-dioxide changes the fused silica glass kiln of fused silica glass into, and this kiln has the kiln inside that includes, and portion is the highest furnace operation temperature MFOT within it.Kiln inside has one to change the fixed position of deposition, and precursor raw material changes silica fume (silica soot) at this position, and the latter deposits and the fixed fused silica glass that becomes then.Kiln inside is positioned at alumina firebrick and by its thermal insulation, alumina firebrick sintering temperature FT＞1650 ℃ mainly is made up of Al and O.

One embodiment of the invention relate to by silicon-containing compound is fed flame, form the fused silica dioxide granule, and in the kiln that refractory materials is built, collect these particles and make improving one's methods of fused silica body, its improvement comprises at least a portion refractory materials of constructing kiln, be once be exposed to the reactive halogen gases that contains that to react with it, thereby pollution metal is removed in its purification.

A further aspect of the present invention relates to purer fused silica material, it is at least 99.5% to 248nm radiating transmissivity, the 193nm radiant ratio is at least 98%, this material bodies has qualified fluorescence volume when having at least a large portion to be exposed to such radiation, the pollution metal ion content of fused silica material is less than 100ppb.

The present invention also relates to the refractory materials kiln that collection fused silica particle becomes solid form on the other hand, and this kiln at least a portion is to be constructed by the refractory materials that contains the metal pollutant of wandering about as a refugee that is less than the 300ppb amount.

The accompanying drawing summary

Fig. 1 is that the present invention makes the equipment of fused silica glass and the synoptic diagram of method.

Fig. 2 is the vertical view of fused silica glass kiln refractory materials dome-shaped furnace roof of the present invention.

Fig. 3 is the sectional view of dome-shaped furnace roof of the present invention.

Fig. 4 is the sectional view of fused silica glass kiln cup of the present invention.

Fig. 5 is the synoptic diagram of carbon of the present invention-chlorination purification furnace treatment process.

Invention is described

The conventional vitreum manufacturing process that adopts in making fused silica is a single stage method.In this method, the carrier gas bubbling is by remaining on certain cryogenic SiCl ₄Raw material.SiCl ₄Steam just is transported to reactive site in carrier gas.Reactive site comprises several burners, is being higher than under 1600 ℃ of temperature burning and with SiCl ₄Vapor-phase oxidation deposits silicon-dioxide.

The major requirement of this ordinary method is: equipment and delivery system should be able to be transported to burner with vapor state with material gasification and with the raw material that gasifies.As described in people's such as Dobbins patent, its equipment and method the same with routine basically except a main difference just replaces SiCl with polymethyl siloxane ₄Raw material.Use this alternative materials can need to do some little adjustment, for example slightly high transmission temperature (as 100-150 ℃).This be because the vapour pressure of siloxanes a little less than SiCl ₄

Fig. 1 makes and deposits equipment and the method synoptic diagram that the fused silica particle is used for forming big fused silica glass body.This equipment generally is expressed as 10, comprises a raw material source 12.Use nitrogen or nitrogen/oxygen mixture as carrier gas.The by-pass flow 14 that feeds nitrogen is to prevent the saturated of steam flow.The vapor reaction thing arrives reactive site by a distribution apparatus, some burners 18 is arranged there near furnace roof 20.Reactant mixes with the fuel/oxygen mixture in these burners, being higher than burning and oxidation under 1600 ℃ of temperature, deposits silicon-dioxide.High-purity metal oxide soot and heat are carried downwards by refractory materials furnace roof 20.Silicon-dioxide deposits in the cup 26 of heat at once and is fixed is non-porous body 24.

Disclose as people's patents such as Sempolinski, the improvement of zirconia refractory can alleviate the effect that sodium ion pollutes in the fused silica goods.Yet, find except that sodium, in the refractory materials of stove, also to exist other pollutent.These pollutents comprise alkaline-earth metal and transition metal such as iron, lead, and phosphorus, sulphur, other basic metal and aluminium particularly can reduce the light transmissive free metal of the UV pollutent of glass.

These metal pollutants have volatility in various degree being higher than 1650 ℃ of (silicon-dioxide at this temperature deposition) temperature.Therefore, they can be present in the ring border, are entrained in wherein when silica deposit.If exist these pollutents can cause the transmission capacity of glass to descend, also can cause glass to form bad fluorescence phenomenon in the fused silica lens.And in the lens use, being subjected to short wavelength UV when the radiation, these shortcomings are also even more serious.

There is the metallic impurity and the different volatility of these metals of different amounts inherently in refractory materials.This feasible glass quality that is difficult to control in the fused silica collection kiln, even often be difficult to obtain qualified glass.When using polysiloxane as the precursor material of fused silica, it is particularly sharp-pointed that this problem becomes.Illustrated as people's patents such as Sempolinski, when using silxoane precursors, lost SiCl ₄Certainly the purification effect of the HCl by product that decomposes.

Pollution metal can be present in the raw material of making the oven refractory use.During the sintered refractory or operation subsequently also can carry metal secretly as during cutting or grinding.

We find, by building the stove of pollution metal content less than the refractory materials of 300ppm, can suppress to collect the metallic pollution in the kiln.Particularly, when finding to use zirconia refractory to build the collection kiln of fused silica deposition usefulness, this can do and obtain.Can reach this requirement according to the present invention by sintering kiln refractory materials in halogen-containing atmosphere.The reaction of halogen and pollution metal just can be removed pollution metal from these surfaces on the exposing surface of refractory materials at least.

We find that chlorine or fluorine itself or its sour gas form are especially suitable.Can use pure basically purification gas.Yet find, use that to be low to moderate concentration only be 5% purification gas in rare gas element such as helium or argon, effectively and easily, though need a little treatment time of length.Purification processes can be used successive halogen gas stream.Perhaps, can adopt pulse mode to handle, be to discharge after gas is fed purification chamber for some time, repeatedly repeats it then.

The purification effect can be low to moderate 700 ℃ of generations.Yet general preferred use is at 1100-1500 ℃ higher temperature.

Now the present invention is described referring to the each several part of refractory materials kiln.

Be preferably, earlier refractory body purified, and then build and dress up stove.Before block is dressed up stove, be in making refractory materials phase process, to carry out this processing.

The refractory materials of use chemical purification according to the present invention can provide several advantages.The deposition kiln of purifying can provide highly purified fused silica product, can also provide the molten silica glass that coagulates with qualified short wavelength UV radiation high-transmission rate and low fluorescence with the constant high yield.This glass in use can not increase UV and absorb damage and fluorescence.Do not need to change the structure of kiln or silicon-dioxide forms and deposition process just can reach these requirements.These advantages are very obvious, because these features are very serious to the homogeneity that obtains glass refraction.

Two groups of fused silica test pieces that comparison zirconia refractory kiln is made have confirmed the validity of purification processes.Take from sedimentary vitreum in the collection kiln of undressed zirconia refractory lay for one group.Another group is taken from sedimentary vitreum in the collection kiln of treated zirconia refractory lay.These two kilns are with agglomerating zirconia refractory lay furnace roof and cup lining, and are basic identical.The purification processes of zirconia refractory is to be incubated 8 hours in 1300 ℃ purification furnace, and the whole time keeps 5.7%Cl ₂Mobile atmosphere with 94.3% helium.

Mensuration is taken from the consolidation SiO that two kinds of kilns (through purification processes with without the refractory materials of purification processes) are made ₂The Vitrea relevant performance that compares the test piece at position.Table I is listed in the internal transmission factor (%) of 248nm and 193nm wavelength radiation mensuration.

Table I

	Be untreated	Handle
	Be untreated	Handle	????248nm	????99.08	????99.82
????193nm	????95.28	????99.18	????248nm	????99.08	????99.82

Also analyzed above-mentioned fused silica glass body, determine to have shown that the vitreum degree of depth of qualified low fluorescence accounts for it at the percentage ratio of collecting the cup degree of depth.Determine fluorescence by the intensity that integration is measured in the 400-700nm scope.It is qualified to become, and glass coupon must be subjected to 15mJ/cm ²And have less than 4.2 * 10 under the effect of 200Hz laser apparatus emitted laser ^-9Watt/centimetre ²Value.

Glass from the kiln that is untreated is defective fully.There is not fluorescent value to reach the part of qualified low value in the vitreum.And be qualified from the glass of handling stove in the degree of depth until 3.53 inches.This degree of depth is 59.3% of a total depth.

The present invention includes the method for making the fused silica body, is that a kind of silicon-containing compound is fed flame formation fused silica dioxide granule, collects the form of these particles with the fused silica body in the kiln of aluminum oxide refractory lining structure.Its improvement comprise structure collect at least a portion refractory materials of the kiln of silica dioxide granule be once accepted can with the processing that contains reactive halogen gases of its reaction, thereby pollution metal is removed in its purification.

The present invention includes the method for making fused silica glass.This method comprises provides silica material, and the furnace roof that mainly is made of aluminum oxide is provided, and this furnace roof is positioned at the top of fixed non-porous fused silica glass body.This method comprises the silica precursor raw material is sent in a plurality of reactive site burners that are installed in the aluminum oxide furnace roof that the silica precursor raw material changes silica dioxide granule in burner, deposits and be consolidated into the fused silica glass body.

Fig. 1-5 explanation the present invention makes the method for high-purity silicon dioxide glass.As shown in Figure 1, provide silica material from raw material source 12.Silica material better is transported to burner 18 with the vapor state form.Better be to produce the silica material steam, transmit raw material vapor by pipeline by carrier gas such as nitrogen and oxygen with feed vaporizer.This method comprises provides the furnace roof 20 that is made of aluminum oxide substantially.The aluminum oxide furnace roof 20 that provides is positioned at the top that fixed non-porous hot melt coagulates silicon dioxide body 24.The silica material steam is sent to the burner 18 of a plurality of reactive sites that are installed in aluminum oxide furnace roof 20.By the reaction flame/heat of burner, the raw material of input changes fine silica fume particle 30 into, and these particle depositions also are consolidated into fused silica glass body 24.This method has one to be used for splendid attire and the cup 26 that contacts silica glass 24 preferably in kiln.The cup 26 of kiln better mainly is made of aluminum oxide.The silica material that provides is that the pollution metal ion content is advisable less than the high-purity silicon dioxide raw material of 100ppb, and the pollution metal ion content of fixed like this fused silica glass body is just less than 100ppb.Silica material better is the not silica material of halide, preferably siloxanes.In another embodiment, silica material is the raw material of halide, better is SiCl ₄One preferably in the embodiment, providing silica material also to comprise provides one titanium doped dose of source, and the fused silica glass body is exactly the fused silica of Doped with Titanium as a result.

It better is to comprise the alumina firebrick of handling without Cl 32 is provided that aluminum oxide furnace roof 20 is provided, and is exposed to then in the gas 33 that contains reactive halogen.As shown in Figure 5, refractory brick 32 usefulness contain reactive halogen gases and carry out purification processes, produce the refractory brick 34 through the halogen purification processes.This method better comprises builds the alumina firebrick 34 of dress through the halogen purification processes, obtains the furnace roof 20 that is made of aluminum oxide substantially.Equally, providing aluminum oxide cup 26 to comprise provides the alumina refractory parts of handling without Cl 32, be exposed to then in the gas 33 that contains reactive halogen, generation is through the alumina refractory parts 34 of halogen purification processes, then they are built dress formation cup as shown in Figure 4, it mainly is made of aluminum oxide.In this better embodiment of present method, shaping/mechanical workout goes out aluminum oxide fireproof prefabricated 32.This prefabricated component better is to be configured as predetermined shape and size, they can be built dress up furnace roof 20 and cup 26.Better be prefabricated component to be machined into refractory component 32 with saw and drill bit, in one embodiment, the alumina refractory mechanical workout that wets.Preferably carry out mechanical workout/shaping earlier to refractory component 32, the purification processes that contains reactive halogen gases then, this purification processes are preferably built dress last step for the manufacturing processed before kiln cup 26 and the furnace roof 20 with the brick parts 34 of purifying.The purification processes that the present invention contains reactive halogen gases preferably comprises that the carbon-chlorination to the refractory brick parts purifies.As shown in Figure 5, the refractory brick parts are handled in carbon-chloridized stove 36.Carbon-chloridized stove 36 better is a crystal vessel 38, has at least one vacuum/processing gas feed/outlet 40, handles gas such as chlorine, helium, hydrogen and input of their mixture-controlled ground and discharge so that vacuumize in sealed vessel 38 and allow.One deck particle/powder carbon bed 42 is arranged in the graphite treatment heat size device preferably, and as the graphite carbon black powder, making has an an amount of carbon in the stove, be used for the carbon-chlorination of refractory component.Handle stove 36 and comprise suitable heating source such as inductive heating element or resistance heating element, make the inside of container 38 and the temperature of reaction that its inclusion can be heated to 1000-1500 ℃, better to 1200 ℃ inclusion is carried out carbon-chlorination at least.Except by with the halogens chlorine reagent react from refractory component is removed impurity, can also make the carbon in impurity and the stove react (carbon reduces to the metal pollutant in the refractory materials), reduce the metal pollutant of refractory materials.Carbon-chlorination purification processes operation preferably comprises refractory component and the carbon bed processing stove of packing into together.Furnace temperature is increased to range of reaction temperature 1000-1500 ℃ preferably (better being at least 1200 ℃), vacuumize simultaneously and keep certain hour, make suitably the reacting of oxide compound of carbon and existence, then, chlorine is handled gas import this container repeatedly, better be that chlorine body was handled lasting about 30-60 minute between each injection chlorine feed, under the temperature of reaction that raises, carry out handling in 30-60 minute, be preferably 2-5 time.Chlorine body is handled the Cl that atmosphere comprises 2.5-20% preferably ₂, be preferably 3-10%Cl ₂, 4-8%Cl more preferably ₂, be preferably 6 ± 1%Cl ₂, surplus is a helium.After such chlorine charging is sprayed, vacuumize once more and keep temperature simultaneously.Way is more than the carbon-chloridized of this vacuum-chlorine-vacuum form repeats once at least, to guarantee refractory component is carried out suitable carbon-chlorination purification processes preferably.Taken out at last after the vacuum, more handy purge gas such as helium or hydrogen purge processing vessel and inclusion thereof.After carbon-chlorination is purified, build and dress up before kiln, furnace roof and the cup, should reduce as far as possible to the processing of refractory component with contact.Preferably to carry out at least twice carbon-chloridized to the refractory brick parts.Adopt the refractory brick parts of carbon-chloridized of the present invention that highly purified fused silica can be provided, it is at least 99.9%/cm in the UV of KrF 248nm transmissivity, is at least 99.3%/cm at ArF 193nm, and even 99.7%+/cm.

As shown in Figure 1 and Figure 4, the present invention includes provides the kiln cup 26 that is made of aluminum oxide substantially, and this aluminum oxide cup is the usefulness of the fixed non-porous fused silica glass body 24 of splendid attire.

The refractory component 34 of aluminum oxide furnace roof and cup better is uncoated aluminum oxide.

The refractory component 34 of aluminum oxide furnace roof and cup better is not contain Si and SiO substantially ₂Aluminum oxide.SiO in the aluminum oxide ₂Content is preferably less than 2000ppm (weight).

Providing the refractory component 34 of aluminum oxide furnace roof and cup better to comprise provides without agglomerating alumina refractory precursor, at this alumina refractory precursor of at least 1660 ℃ of sintering, build dress and form and provide furnace roof and cup then through agglomerating alumina refractory parts 34.The alumina refractory precursor should better at least 1670 ℃, be preferably in 1675 ℃ of temperature and carry out sintering at least 1665 ℃ at least.

Shown in Fig. 2-3, the aluminum oxide furnace roof is provided, comprise better many porous alumina firebricks are provided and are furnace roof that the porosity of refractory brick is the 25-70% scope more fortunately with these fire-resistant brick dresses.Better shown in Fig. 2-3, aluminum oxide furnace roof 20 comprises provides many alumina firebricks 34, and these brick dresses is formed the arch furnace roof of self-supporting.Aluminum oxide furnace roof 20 usefulness is alumina refractory parts 34 preferably, its volume density＜3.9 gram per centimeters ³, better≤3 gram per centimeters ³, better≤2.5 gram per centimeters ³, best≤2 gram per centimeters ³With≤1.4 gram per centimeters ³The volume density of alumina refractory better 〉=1.2 gram per centimeters ³, in about 1.2-3.8 scope.Providing aluminum oxide furnace roof 20 better to comprise provides its 20-1200 ℃ Young's modulus to be at least the alumina refractory of 2 * 106psi.Provide aluminum oxide furnace roof 20 better to comprise and be provided at 1600 ℃ of creep percentage ratio＜5% of loading following 150 hours with 25psi, better≤2%, the alumina refractory 34 of better≤1.2%.Aluminum oxide furnace roof 20 is 1100 ℃ radiant ratio＜0.35 preferably.

The present invention better comprises and will avoid silica dioxide granule 30 to be deposited on the furnace roof 20.This be by control burner 18 cigarette ashes stream focus direction down and guarantee that they are fixing downward in furnace roof, so just can avoid and suppress silica dioxide granule and deposit and cover on the aluminum oxide furnace roof.

The present invention comprises that also stopping silica material imports burner 18, and the silica glass body 24 of cooling consolidation is taken aluminum oxide furnace roof 20 apart, and the use temperature that disposal is pulled down is higher than 1300 ℃ aluminum oxide furnace roof brick 34.

The present invention comprises that also the liquid silica precursor raw material that is used for not being silicon-dioxide changes the fused silica glass kiln of fused silica glass into.Fused silica glass kiln 50 has the kiln inside 52 that includes, this kiln inside has the highest furnace operation temperature MFOT, 52 comprise fixed position of deposition in the stove, change silica soot at this position precursor raw material, deposit and be consolidated into fused silica glass then.Kiln inside 52 is to be surrounded and adiabatic by many alumina firebricks 34, the sintering temperature FT of alumina firebrick 34＞1650 ℃, and alumina firebrick mainly is made of Al and O.

The sintering temperature FT of alumina firebrick 34 is preferably FT＞MFOT+20 ℃.The SiO of alumina firebrick 34 ₂Content is better less than 2000ppm (weight).The pollution metal ionic concn of alumina firebrick 34 is better less than 300ppm, and alumina firebrick 34 preferably Cl is handled the carbon-chlorating alumina firebrick of purifying.Alumina firebrick is Na concentration≤100ppm (weight) preferably, K concentration≤20ppm (weight), Fe concentration≤250ppm (weight) (better Fe≤150ppm).Alumina firebrick 34 better is the refractory brick that does not have tiny crack.Alumina firebrick 34 should be built and be fitted together the dome-shaped furnace roof that forms the self-supporting that is positioned at inner 52 tops of kiln.Alumina firebrick 34 also will be built and be fitted together the formation cup-shaped receptacle, splendid attire deposition and fixed fused silica glass in it, and this glass should be mobile shape in the cup inside of rotation.

The present invention includes fused silica glass kiln 50.Stove 50 comprises the dome-shaped furnace roof 20 (as shown in Figure 2, its cross section as shown in Figure 3) of self-supporting.Dome-shaped furnace roof 20 better is to be piled up by alumina firebrick 34 dislocations to form.Refractory brick 34 better mainly is made up of Al and O.The volume density of refractory brick 34 is the 1.2-3 gram per centimeter more fortunately ³Scope.Shown in Fig. 2-3, furnace roof 20 has the support ring 120 of a plurality of burner apertures 18 and steel metal ring structure, the latter is used for building encirclement furnace roof 20 and the position of maintenance brick 34 in the dome-shaped top construction between the dress/construction campaign, and furnace roof is on the foundation side wall that is positioned at stove during the furnace operation simultaneously.The sintering temperature of alumina firebrick better is higher than 1650 ℃.The dioxide-containing silica of alumina firebrick 34 is better less than 2000ppm (weight), and Fe content is better less than 250ppm (weight), and better less than 100ppm (weight), the Young's modulus of furnace roof alumina firebrick 34 better is at least 2 * 10 to Na content ⁶Psi, the creep percentage ratio after under 1600 ℃ and the 25psi load 150 hours is less than 5%.Furnace roof brick 34 should be built with herringbone pattern and be fitted together.

It will be understood by those of skill in the art that under without departing from the spirit and scope of the present invention and can carry out various modifications and changes the present invention.Therefore, present invention resides in modification and the change that provides within claims and its context of equal value.

Claims

1. the method for an improved manufacturing fused silica body, this method comprises: in the kiln that alumina refractory is built silicon-containing compound is fed flame formation fused silica particle, and collect described fused silica body particle, at least a portion that described improvement comprises the kiln of collecting silica dioxide granule once contacted and reacted with containing reactive halogen gases in advance, removed pollution metal in the refractory materials thereby purify.

2. method of making fused silica glass, described method comprises:

Silica material is provided,

Substantially the furnace roof that is made of aluminum oxide is provided, and described furnace roof is positioned at the top of fixed non-porous fused silica glass body,

Described silica material is transported in a plurality of reactive site burners that are installed in the aluminum oxide furnace roof, changes many silica dioxide granules into, deposit the also fixed described fused silica glass body that becomes at silica material described in the burner.

3. method as claimed in claim 2, it is characterized in that described method comprises provides the cup that substantially is made of aluminum oxide, the described fixed non-porous fused silica glass body of splendid attire in the described aluminum oxide cup.

4. method as claimed in claim 2 is characterized in that the described silica material that provides is the high-purity silicon dioxide raw material, and the pollution metal ion content of described fused silica glass body is less than 100ppb.

5. method as claimed in claim 2 is characterized in that the described silica material that provides comprises titanium doped dose of source material, and described fused silica glass body is the fused silica of titanium of having mixed.

6. method as claimed in claim 2 is characterized in that providing the step of described aluminum oxide furnace roof, and comprising provides many alumina firebricks of handling without Cl; To contain the purification processes of reactive halogen gases without the alumina firebrick that Cl handles, many alumina firebricks through the halogen purification processes will be provided; And build and adorn described alumina firebrick of purifying through the halogen processing, forming and providing described is the furnace roof of aluminum oxide substantially.

7. method as claimed in claim 3 is characterized in that providing the step of described aluminum oxide cup, and comprising provides many alumina refractory parts of handling without Cl; To contain the purification processes of reactive halogen gases without the alumina refractory parts that Cl handles, many alumina refractory parts through the halogen purification processes are provided, and build and adorn described alumina refractory parts of purifying through the halogen processing, form and provide the described cup of aluminum oxide that is substantially.

8. method as claimed in claim 2, it is characterized in that providing the step of described aluminum oxide furnace roof to comprise provides uncoated aluminum oxide furnace roof.

9. method as claimed in claim 2, it is characterized in that providing the step of described aluminum oxide furnace roof to comprise provides the aluminum oxide of the no silicon-dioxide that does not contain Si substantially furnace roof.

10. method as claimed in claim 2, it is characterized in that providing the step of described aluminum oxide furnace roof, comprise unsintered alumina refractory precursor is provided, at at least 1600 ℃ of described alumina refractory precursors of sintering, the agglomerating alumina refractory is provided, and build and adorn described agglomerating alumina refractory, form and provide described furnace roof.

11. method as claimed in claim 10 is characterized in that described alumina refractory precursor is at least 1665 ℃ of sintering.

12. method as claimed in claim 10 is characterized in that described alumina refractory precursor is at least 1670 ℃ of sintering.

13. method as claimed in claim 10 is characterized in that described alumina refractory precursor is at least 1675 ℃ of sintering.

14. method as claimed in claim 2, it is characterized in that providing the step of described aluminum oxide furnace roof to comprise provides many porous alumina firebricks, and with the described fire-resistant brick described furnace roof of dressing up, the porosity of described porous refractory brick is in the 25-70% scope.

15. method as claimed in claim 2, it is characterized in that providing the step of described aluminum oxide furnace roof to comprise provides many alumina firebricks, described fire-resistant brick dress is formed the furnace roof of dome-shaped.

16. method as claimed in claim 2, it is characterized in that providing the step of described aluminum oxide furnace roof to comprise provides its volume density＜3.9 gram per centimeters ³Alumina refractory.

17. method as claimed in claim 16 is characterized in that volume density 〉=1.2 gram per centimeters of described alumina glass material ³

18. method as claimed in claim 16, it is characterized in that providing the step of described aluminum oxide furnace roof to comprise provides its volume density≤3 gram per centimeters ³Alumina refractory.

19. method as claimed in claim 16, it is characterized in that providing the step of described aluminum oxide furnace roof to comprise provides its volume density≤2.5 gram per centimeters ³Alumina refractory.

20. method as claimed in claim 16, it is characterized in that providing the step of described aluminum oxide furnace roof to comprise provides its volume density≤2 gram per centimeters ³Alumina refractory.

21. method as claimed in claim 16, it is characterized in that providing the step of described aluminum oxide furnace roof to comprise provides its volume density≤1.4 gram per centimeters ³Alumina refractory.

22. method as claimed in claim 2, it is characterized in that providing the step of described aluminum oxide furnace roof to comprise provides Young's modulus to be at least 2 * 10 ⁶The alumina refractory of psi.

23. method as claimed in claim 2 is characterized in that providing the step of described aluminum oxide furnace roof to comprise being provided at the alumina refractory of creep percentage ratio＜5% that 1600 ℃ and 25psi load following 150 hours.

24. method as claimed in claim 2 is characterized in that providing the step of described aluminum oxide furnace roof to comprise being provided at the alumina refractory of creep percentage ratio≤2% that 1600 ℃ and 25psi load following 150 hours.

25. method as claimed in claim 2, the alumina refractory that it is characterized in that providing the step of described aluminum oxide furnace roof to comprise being provided at 1600 ℃ and 25psi to load following 150 hours back creep percentage ratio≤1.2%.

26. method as claimed in claim 2 is characterized in that described aluminum oxide furnace roof has at 1100 ℃＜0.35 radiant ratio.

27. method as claimed in claim 2 is characterized in that described method also comprises to avoid allowing silica dioxide granule be deposited on the described furnace roof.

28. method as claimed in claim 6, it is characterized in that described method comprises that also stopping silica material imports described burner, cool off the silica glass body of described consolidation, take the brick that removes described aluminum oxide furnace roof apart, dispose many service temperatures and be higher than 1300 ℃ described brick.

29. method as claimed in claim 2, it is characterized in that providing the step of silica material to comprise provides the not silica material of halide.

30. a fused silica glass kiln that is used for the silica precursor raw material is changed into fused silica glass,

Described fused silica glass kiln has the kiln inside that includes, it has the highest furnace operation temperature MFOT, a fixed position of transformation deposition is arranged in the described kiln inside, described precursor raw material changes silica fume at this position, the latter deposits and is consolidated into fused silica glass then

Described kiln inside is surrounded by many alumina firebricks and is adiabatic, the sintering temperature FT of described alumina firebrick＞1650 ℃, and described alumina firebrick mainly is made up of Al and O.

31. fused silica glass kiln as claimed in claim 30 is characterized in that the FT that described alumina firebrick has is FT＞MFOT+20 ℃.

32. fused silica glass kiln as claimed in claim 30 is characterized in that the SiO of described alumina firebrick ₂Content is less than 2000ppm weight.

33. fused silica glass kiln as claimed in claim 30 is characterized in that the SiO of described alumina firebrick ₂Content is less than 300ppm weight.

34. fused silica glass kiln as claimed in claim 30 is characterized in that described alumina firebrick is to handle the alumina firebrick of purifying through Cl.

35. fused silica glass kiln as claimed in claim 30 is characterized in that the Na concentration≤100ppm of described alumina firebrick.

36. fused silica glass kiln as claimed in claim 30 is characterized in that the K concentration≤20ppm of described alumina firebrick.

37. fused silica glass kiln as claimed in claim 30 is characterized in that the Fe concentration≤250ppm of described alumina firebrick.

38. fused silica glass kiln as claimed in claim 30 is characterized in that the Fe concentration≤150ppm of described alumina firebrick.

39. fused silica glass kiln as claimed in claim 30 is characterized in that described alumina firebrick is single non-microcracked refractory brick of planting oxide component.

40. fused silica glass kiln as claimed in claim 30 is characterized in that described alumina firebrick comprises that block is fitted together the aluminum oxide furnace roof brick that forms the dome-shaped furnace roof that is positioned at described kiln inner and upper.

41. fused silica glass kiln as claimed in claim 30, it is characterized in that described alumina firebrick comprises that block is fitted together the aluminum oxide cup brick that forms cup-shaped receptacle, the fused silica glass that described cup-shaped receptacle holds and contacts described deposition and be consolidated into.

42. fused silica glass kiln as claimed in claim 30, the volume density that it is characterized in that described alumina firebrick is at the 1.2-3 gram per centimeter ³Scope.

43. fused silica glass kiln, described kiln comprises the dome-shaped furnace roof of self-supporting, described dome-shaped furnace roof is that staggered the piling up of many alumina firebricks forms, and described alumina firebrick mainly is made up of Al and O, and its volume density is at the 1.2-3 gram per centimeter ³Scope.

44. fused silica glass kiln as claimed in claim 43 is characterized in that the temperature of the described alumina firebrick of sintering is higher than 1650 ℃.

45. fused silica glass kiln as claimed in claim 43, the dioxide-containing silica that it is characterized in that described alumina firebrick is less than 2000ppm weight.

46. fused silica glass kiln as claimed in claim 43, the Fe content that it is characterized in that described alumina firebrick is less than 250ppm weight.

47. fused silica glass kiln as claimed in claim 43, the Na content that it is characterized in that described alumina firebrick is less than 100ppm weight.

48. fused silica glass kiln as claimed in claim 43 is characterized in that the Young's modulus of described alumina firebrick is at least 2 * 10 ⁶Psi.

49. fused silica glass kiln as claimed in claim 43, it is characterized in that described alumina firebrick under 1600 ℃ and 25psi load 150 hours creep percentage ratio＜5%.

50. fused silica glass kiln as claimed in claim 43 is characterized in that described alumina firebrick is fitted together with the herringbone pattern block.