CN103043665B - Preparation method for silicon powder - Google Patents
Preparation method for silicon powder Download PDFInfo
- Publication number
- CN103043665B CN103043665B CN201310026873.5A CN201310026873A CN103043665B CN 103043665 B CN103043665 B CN 103043665B CN 201310026873 A CN201310026873 A CN 201310026873A CN 103043665 B CN103043665 B CN 103043665B
- Authority
- CN
- China
- Prior art keywords
- silicon
- preparation
- silica flour
- slag
- boron
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Abstract
The invention discloses a preparation method for silicon powder, relates to a process of removing boron by industrial silicon and a preparation method for high-purity superfine silicon powder. The invention provides the preparation method for the silicon powder capable of remarkably reducing the content of the boron. The silicon powder can be used as an ideal low-boron material for a later process, namely pickling and impurity-removing process of purifying solar polycrystalline silicon by a metallurgy method. The preparation method comprises the following steps of: (1), adopting a metallurgical-grade silicon material as the material, putting the material silicon to a crucible, electromagnetically heating up the silicon material to melt the silicon material by an inductive coil; (2), adding a slag former to control the heating power when the silicon material is molten, so that the temperature of the molten silicon is kept to 1550 DEG C to 1850 DEG C in a reaction process, stewing the molten silicon to remove the slag former on the upper layer of the molten silicon after slagging and refining; and (3), controlling the temperature of the molten silicon to 1500 DEG C to 1700 DEG C, and then opening the valve and starting an atomizer; guiding the molten silicon to the atomizer by a guide tube, adjusting the air pressure of the air outlet of the atomizer so that the molten silicon is sprayed out of the atomizer in the forms of mists to enter an atomizing chamber; and collecting the silicon powder by a supporting rotary plate.
Description
Technical field
The present invention relates to industrial silicon except the preparation method of boron technique and high pure and ultra-fine silica flour, especially relate to the preparation method of a kind of silica flour that is applicable to prepare solar cell silicon material.
Background technology
Face increasingly serious energy dilemma and environmental degradation situation, national governments fall over each other tapping a new source of energy as prior development direction.China belongs to one of abundant country of solar energy resources reserves, and year sunshine time is greater than the regional area of 2000 hours and accounts for the more than 2/3rds of national total area, and solar electrical energy generation is huge in China's development potentiality.At present, solar cell mainly contains the types such as crystal silicon solar energy battery, thin-film solar cells, dye sensitization solar battery, quantum dot array solar cell.Wherein, crystal silicon cell accounts for more than 90%, be at present and from now on one period of paramount importance solar cell types.
Preparing crystal silicon solar energy battery needs purity to be not less than the silicon material of 6N, and wherein the content of impurity element boron is less than 0.3ppmw.Boron is a kind of main recipient element in semiconductor silicon, and the boron oxygen complex body that it forms in silicon is seriously restricting the minority carrier life time of solar cell, and the generating efficiency of solar cell is had to baneful influence.Therefore, except boron is the mission critical in various silicon methods of purification.In chemical method, (improvement siemens, silane thermal decomposition process etc.) are to obtain low boron high purity polycrystalline silicon by steps such as silicide rectifying, reduction.And in metallurgy method process, because boron has higher segregation coefficient (0.8) and lower high temperature saturated vapor pressure in silicon, adopt traditional directional freeze or vacuum melting to be difficult to reach removal object, need to adopt the method for slag refining to purify.
Slag refining by adding slag former, forms slag phase in molten state, removes the boron impurity in silicon, obtains the method for HIGH-PURITY SILICON.Its key factor depends on the partition ratio of basicity, oxygen gesture and the boron of smelting temperature, slag liquid.By Theoretical Calculation and experimental verification, the segregation coefficient of the oxide compound of boron in slag phase and silicon is far smaller than the segregation coefficient of boron in silicon.Suzuki and the Sano of Japan, the Viana Teixeira of Tokyo Univ Japan and Kazuki Morita(Leandro Augusto Viana Teixeira and Kazuki Morital, Removal of Boron from Molten Silicon Using CaO – SiO
2based Slags, ISIJ International, Vol.49 (2009), No.6, pp.783 – 787.) all carried out exploitative experiment research, under the condition of 1823K, can obtain partition ratio and be 2.4 except effect of boron.Xiamen University's metallurgical laboratory (high-purity metalluragical silicon removes the progress of boron for Cai Jing, Luo Xuetao etc., material Leader, and 2009,23(12): 81-84) adopt CaO-SiO
2-CaF
2the pilot plant test of-BaO slag making system shows, at slag silicon, than at 1650～1750 ℃ of 2: 1～1: 2, temperature, successfully B content is reduced to 0.15～0.35ppmw.2011, the people such as Luo Xuetao (Chinese patent ZL201110040875.0; Chinese patent ZL201110000994.3) adopt slag making in conjunction with the method for pickling, the boron in Pure Silicon Metal is reduced to below 0.3ppmw from 8ppmw.2012, Kunming University of Science and Technology's Marvin's can wait people to adopt CaO-SiO
2-Li
2o and CaO-SiO
2-LiF slag system, under the condition of 1823K, can be reduced to 1.3ppmw from 22ppmw by the content of boron.
F.A.Trumbore, the people's such as G.L.Vick result of study shows, below 1500K, the solid solubility of boron in silicon significantly reduces along with the reduction of temperature, and the easy segregation of impurity residues in crystal boundary.Conventionally, the silicon liquid after slag refining is poured cooled and solidified in ingot mould into and is become large silicon ingot, then carries out pickling impurity removal operation after fragmentation, abrasive dust, tends to cause metal secondary pollution and increase tooling cost in the powder course of processing.Therefore, traditional slag refining method exists certain limitation.
Summary of the invention
Object of the present invention is mainly for slagging boron removal technique the deficiencies in the prior art, and the preparation method that can significantly lower a kind of silica flour of boron content is provided.The later process that gained silica flour can be used as metallurgy method purifying solar energy level polysilicon is the desirable low boron raw material of pickling impurity removal operation.
Technical scheme of the present invention is first to adopt high temperature slag making purifying polycrystalline silicon, after slag making reaction finishes, removes slag liquid; Then by silicon liquid by the atomizing of spraying gun, form the silica flour of low boron.The content of boron can disposablely be reduced to 0.05～0.2ppmw, and the later process that can meet metallurgy method purifying solar energy level polysilicon is the requirement of pickling impurity removal technique.
The present invention includes following steps:
1) adopt metallurgical silicon material as raw material, raw silicon is placed in crucible, by ruhmkorff coil Electromagnetic Heating, melted silicon material;
2) when silicon material melts, add slag former, control heating power, make the temperature of silicon liquid in reaction process remain on 1550～1850 ℃, after slag refining finishes, standing, remove the slag former that floats on silicon liquid upper strata;
3) silicon liquid temp is controlled to 1500～1700 ℃, then starts spraying gun, silicon liquid enters spraying gun via thrust-augmenting nozzle, adjusts the air pressure of spraying gun air outlet, makes silicon liquid be the spray form spraying gun that flies out and enters spray chamber, by accepting rotating disk, collects and obtains silica flour.
In step 1) in, described metallurgical grade silicon can be silica flour or silico briquette, and its purity is preferably more than 99%, and the content of boron can be 5～30ppmw; Described crucible is preferably plumbago crucible.
In step 2) in, the mass ratio of described slag former and silicon material can be 3: 1～and 1: 2; When silicon material is no more than 20kg, the slag refining time is 15～30min; When silicon material is during at 20～50kg, the slag refining time is 30～60min; When silicon material is during at 50～100kg, the slag refining time is 60～120min; Described time of repose can be 10～20min.Described slag former can adopt the mixture of silicon-dioxide, Sodium Fluoride and sodium salt, and by mass percentage, silicon-dioxide can be 25%～40%, and Sodium Fluoride can be 8%～20%, and sodium salt can be 40%～60%; Described sodium salt can adopt sodium carbonate or sodium bicarbonate.
In step 3) in, the diameter of described thrust-augmenting nozzle can be 2～8mm; The spraying gun gas adopting can be the mixed gas that nitrogen, oxygen, argon gas or above-mentioned three kinds of gases form, and when gas flows out from spraying gun air outlet, air pressure can be 0.5～3MPa; Spraying gun liquid exit to the vertical range of accepting rotating disk is 0.3～1.5m, and the temperature of accepting rotating disk can be 25 ℃～100 ℃.
Compared with the prior art, mechanism of the present invention and beneficial effect are as follows:
Theoretical according to Physical Chemistry of Metallurgy, under high temperature, the boron simple substance in silicon and the oxygen free plasma under molten state, oxygen effect, with boratory form enter slag mutually in.By regulating the formula of slag former, change its basicity, thereby adjust oxygen free plasma concentration and oxygen gesture in melt, consider the loss of silicon and except boron level of response, select Optimal Temperature and smelting time to carry out melting.
High temperature silicon liquid, after standing, enters spraying gun through thrust-augmenting nozzle, by adjusting the air pressure of spraying gun air outlet, makes silicon liquid under the effect of atomizing gas, be atomized into tiny drop.In atomization process, silicon liquid, under the effect of gas, has overcome surface tension and viscous force, and distortion, fragmentation become drop particle, therefore, the ratio between atomizing gas mass flow rate and metal flow rate (GMR) is the important parameter of the last silica flour quality of impact.This parameter is determining mass distribution, size-grade distribution, speed of cooling of atomizing cone etc., thereby directly affects silica flour quality.When the diameter of thrust-augmenting nozzle is certain, silicon liquid mass flow rate can be regarded certain value as.Regulate the ratio (GMR) between atomizing gas mass flow rate and metal flow rate just only to need to control the air pressure of spraying gun air outlet.
High temperature silicon liquid becomes liquid particle under the effect of gas, is accepting chilling on rotating disk.By chilling effect, suppressed silicon liquid in temperature-fall period, boron from a small amount of slag contrary of remnants to be diffused into silicon mutually.On the other hand, (B) element of the boron in high temperature silicon liquid and airborne oxygen and moisture generation chemical reaction, generate B
xo
yh
zcompounds, this compounds mainly contains B
3o
6h
3and BO
2h, and also have a small amount of BO
3h
3with BOH etc., the B of generation
xo
yh
zcompounds can with the form of gas from silicon mutually volatilization rapidly, thereby reach further the object except boron.In addition, by control, accept the temperature of rotating disk, suitable condensate depression can be provided for the process of setting of drop, improve nucleation probability and the crystallization rate of silicon liquid.
The present invention is by verifying removing the technological experiment of B impurity in industrial silicon, determined key parameter: as slag making temperature of reaction, reaction times, spraying gun air outlet air pressure, spraying gun liquid exit to accept rotating disk vertical range, accept the setting range of the temperature etc. of rotating disk, result shows significantly to have reduced B content in industrial silicon, has broad application prospects.
The present invention proposes a kind of preparation technology of silica flour, by the silicon liquid after slag refining is carried out to atomization, obtain the low silica flour of boron content, can be directly as the raw material of pickling process.
Accompanying drawing explanation
Fig. 1 is device and the schematic flow sheet that various embodiments of the present invention are prepared silica flour.
Fig. 2 is the structural representation of the spraying gun in Fig. 1.
Embodiment
Referring to Fig. 1 and 2, the device that various embodiments of the present invention are prepared silica flour comprises ruhmkorff coil 1, plumbago crucible 2, warming plate 3, valve 4, thrust-augmenting nozzle 5, spraying gun 6, spray chamber 7 and accepts rotating disk 8.Label P1 in Fig. 1 is silicon liquid, and label P2 is silica flour.
Warming plate 3 is wrapped in plumbago crucible 2 outer walls, ruhmkorff coil 1 is centered around warming plate 3 peripheries, valve 4 is positioned at thrust-augmenting nozzle 5 upper ends, thrust-augmenting nozzle 5 is positioned at plumbago crucible 2 centers, bottom, spraying gun 6 is positioned at plumbago crucible 2 belows, spray chamber 7 is positioned at spraying gun 6 belows, accepts rotating disk 8 and is positioned at spray chamber 7 and is positioned at spraying gun 6 belows.
Spraying gun 6 comprises outer wall 61, air bag 62, air outlet 63, liquid exit 64.Air bag 62 is wrapped up by outer wall 61, and the gas in air bag 62 is flowed out by air outlet 63, reacts, by the atomization of silicon liquid with the silicon liquid flowing out from liquid exit 64.
Adopt said apparatus to prepare the preparation method embodiment of silica flour of the present invention as follows:
Embodiment 1
Get B content and be the metallurgical silicon material of 5.1ppmw and put into plumbago crucible melting.During the fusing of silicon material, add slag former (sodium bicarbonate 50%, silicon-dioxide 30%, Sodium Fluoride 20%), slag refining, except boron time 0.5h, is controlled the interior temperature of plumbago crucible at 1600 ℃～1650 ℃, standing 10～20min.Remove the slag former that floats on silicon liquid upper strata; Open valve, silicon liquid flows into spraying gun from thrust-augmenting nozzle, and draft-tube diameter is 5mm, and controlling spraying gun air outlet air pressure is 0.5MPa, and spraying gun liquid exit is 0.3m with the distance of accepting rotating disk.In the silica flour obtaining, boron content is 0.24ppmw.Silica flour median size is 55 μ m.
Through simultaneous test, adopting B content in the prepared silicon of ordinary skill (identical slag refining temperature, time and formula) is 0.55ppmw.In the silica flour that visible the present embodiment obtains, boron content significantly reduces.
Embodiment 2
Technological process is with embodiment 1, difference is, slag former formula is sodium bicarbonate 40%, silicon-dioxide 40%, Sodium Fluoride 20%, when slag refining removes boron, control the interior temperature of plumbago crucible at 1650 ℃～1700 ℃, slag refining time 1h, draft-tube diameter is 4mm, controlling spraying gun air outlet air pressure is 1MPa, and spraying gun liquid exit is 0.5m with the distance of accepting rotating disk.Recording boron content in gained silica flour is 0.21ppmw.Silica flour median size is 48 μ m.
Through simultaneous test, adopting boron content in the prepared silicon of ordinary skill (identical slag refining temperature, time and formula) is 0.51ppmw.In the silica flour that visible the present embodiment obtains, boron content significantly reduces.
Embodiment 3
Technological process is with embodiment 1, difference is, slag former formula is sodium carbonate 60%, silicon-dioxide 32%, Sodium Fluoride 8%, when slag refining removes boron, control the interior temperature of plumbago crucible at 1650 ℃～1700 ℃, slag refining time 0.5h, draft-tube diameter is 6mm, controlling spraying gun air outlet air pressure is 1.5MPa, and spraying gun liquid exit is 0.75m with the distance of accepting rotating disk.Recording boron content in gained silica flour is 0.19ppmw.Silica flour median size is 41 μ m.
Through simultaneous test, adopting boron content in the prepared silicon of ordinary skill (identical slag refining temperature, time and formula) is 0.49ppmw.In the silica flour that visible the present embodiment obtains, boron content significantly reduces.
Embodiment 4
Technological process is with embodiment 1, difference is, slag former formula is sodium bicarbonate 60%, silicon-dioxide 25%, Sodium Fluoride 15%, when slag refining removes boron, control the interior temperature of plumbago crucible at 1700 ℃～1750 ℃, slag refining time 1h, controlling spraying gun air outlet air pressure is 2MPa, spraying gun liquid exit is 1m with the distance of accepting rotating disk.Recording boron content in gained silica flour is 0.15ppmw.Silica flour median size is 38 μ m.
Through simultaneous test, adopting boron content in the prepared silicon of ordinary skill (identical slag refining temperature, time and formula) is 0.38ppmw.In the silica flour that visible the present embodiment obtains, boron content significantly reduces.
Embodiment 5
Technological process is with embodiment 1, difference is, slag former formula is sodium carbonate 40%, silicon-dioxide 40%, Sodium Fluoride 20%, when slag refining removes boron, control the interior temperature of plumbago crucible at 1700 ℃～1750 ℃, slag refining time 1h, controlling spraying gun air outlet air pressure is 3MPa, spraying gun liquid exit is 1.5m with the distance of accepting rotating disk.Recording boron content in gained silica flour is 0.12ppmw.Silica flour median size is 33 μ m.
Through simultaneous test, adopting boron content in the prepared silicon of ordinary skill (identical slag refining temperature, time and formula) is 0.35ppmw.In the silica flour that visible the present embodiment obtains, boron content significantly reduces.
Claims (7)
1. a preparation method for silica flour, is characterized in that it comprises the following steps:
1) silicon material fusing: adopt metallurgical silicon material as raw material, raw silicon is placed in crucible, by ruhmkorff coil Electromagnetic Heating, melted silicon material;
2) slag refining removes boron: during the fusing of silicon material, add slag former, control heating power, make the temperature of silicon liquid in reaction process remain on 1550～1850 ℃, and after slag refining finishes, standing, remove the slag former that floats on silicon liquid upper strata; Described slag former adopts the mixture of silicon-dioxide and sodium salt; By mass percentage, silicon-dioxide is 25%～40% to described slag former; Described sodium salt adopts the mixture of Sodium Fluoride and sodium carbonate, or Sodium Fluoride and sodium bicarbonate mixture; By mass percentage, Sodium Fluoride accounts for slag former 8%～20%; Sodium carbonate or sodium bicarbonate account for slag former 40%～60%;
3) silicon liquid temp is controlled to 1500～1700 ℃, then opens valve, start spraying gun; Silicon liquid enters spraying gun via thrust-augmenting nozzle; Adjust the air pressure of spraying gun air outlet, make silicon liquid be the spray form spraying gun that flies out, enter spray chamber, by accepting rotating disk, collect and obtain described silica flour.
2. the preparation method of a kind of silica flour as claimed in claim 1, is characterized in that step 1) in, described silicon material is silica flour or silico briquette, and purity is more than 99%, and boron content is 5～30ppmw.
3. the preparation method of a kind of silica flour as claimed in claim 1, is characterized in that in step 1) in, described crucible is plumbago crucible.
4. the preparation method of a kind of silica flour as claimed in claim 1, is characterized in that in step 2) in, when silicon material is no more than 20kg, the slag refining time is 15～30min; When silicon material is during at 20～50kg, the slag refining time is 30～60min; When silicon material is during at 50～100kg, the slag refining time is 60～120min; Described time of repose is 10～20min.
5. the preparation method of a kind of silica flour as claimed in claim 1, is characterized in that in step 3) in, the diameter of described thrust-augmenting nozzle is 2～8mm.
6. the preparation method of a kind of silica flour as claimed in claim 1, is characterized in that in step 3) in, the gas that described spraying gun adopts is the mixed gas that nitrogen, oxygen, argon gas or above-mentioned three kinds of gases form; When gas flows out from spraying gun air outlet, air pressure is 0.5～3MPa.
7. the preparation method of a kind of silica flour as claimed in claim 1, is characterized in that in step 3) in, described in to accept rotating disk be 0.3～1.5m apart from the vertical range of spraying gun liquid exit, the temperature of accepting rotating disk is 25～100 ℃.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201310026873.5A CN103043665B (en) | 2013-01-24 | 2013-01-24 | Preparation method for silicon powder |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201310026873.5A CN103043665B (en) | 2013-01-24 | 2013-01-24 | Preparation method for silicon powder |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN103043665A CN103043665A (en) | 2013-04-17 |
| CN103043665B true CN103043665B (en) | 2014-11-26 |
Family
ID=48056558
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201310026873.5A Expired - Fee Related CN103043665B (en) | 2013-01-24 | 2013-01-24 | Preparation method for silicon powder |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN103043665B (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103771419B (en) * | 2014-01-10 | 2016-03-30 | 合盛硅业股份有限公司 | A kind of method removing boron in polysilicon |
| CN106477583B (en) * | 2016-12-09 | 2019-06-18 | 成都斯力康科技股份有限公司 | A kind of modified silicon liquid transferring device for silicon melting |
| CN110395739A (en) * | 2019-07-24 | 2019-11-01 | 黄冈师范学院 | A kind of ultrasonic atomization prepares the production method and device of ball-shaped silicon micro powder |
| CN112794332B (en) * | 2021-01-12 | 2022-05-24 | 北京科技大学 | Method for removing boron impurities in metallurgical silicon by nitridation-purification |
| CN112875707B (en) * | 2021-01-29 | 2023-04-18 | 有研亿金新材料有限公司 | High-purity low-oxygen silicon powder and preparation method thereof |
| CN113699378B (en) * | 2021-08-26 | 2023-09-15 | 枣阳市一鸣化工有限公司 | Method and system for treating organic silicon waste residues |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3592391A (en) * | 1969-01-27 | 1971-07-13 | Knapsack Ag | Nozzle for atomizing molten material |
| US4534917A (en) * | 1983-03-29 | 1985-08-13 | Alfred Walz | Metal powders and a process for the production thereof |
| CN1043112A (en) * | 1988-12-08 | 1990-06-20 | 埃尔凯姆公司 | Silica flour and production method thereof |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE10059594A1 (en) * | 2000-11-30 | 2002-06-06 | Solarworld Ag | Method and device for producing globular grains from ultrapure silicon with diameters from 50 mum to 300 mum and their use |
| DE102011100884B4 (en) * | 2011-05-08 | 2015-03-05 | Centrotherm Photovoltaics Ag | METHOD AND DEVICE FOR REMOVING CONTAMINATION FROM METALLURGICAL SILICON |
| DE102011112662B4 (en) * | 2011-05-08 | 2015-04-09 | Centrotherm Photovoltaics Ag | Process for treating metallurgical silicon |
-
2013
- 2013-01-24 CN CN201310026873.5A patent/CN103043665B/en not_active Expired - Fee Related
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3592391A (en) * | 1969-01-27 | 1971-07-13 | Knapsack Ag | Nozzle for atomizing molten material |
| US4534917A (en) * | 1983-03-29 | 1985-08-13 | Alfred Walz | Metal powders and a process for the production thereof |
| CN1043112A (en) * | 1988-12-08 | 1990-06-20 | 埃尔凯姆公司 | Silica flour and production method thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| CN103043665A (en) | 2013-04-17 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN103043665B (en) | Preparation method for silicon powder | |
| CN101585536B (en) | Device and method for purifying solar energy level polysilicon | |
| CN102145894B (en) | Method and device for smelting and purifying polysilicon by using electron beams and adopting slag filtering | |
| CN101481112B (en) | Direct oxidation refining purification method for industrial silicon melt | |
| CN103387236B (en) | Refining device and method of high purity silicon | |
| CN102126725B (en) | Method and equipment for purifying polycrystalline silicon by melting in electron beam shallow pool | |
| CN102219219B (en) | Method and equipment for purifying polycrystalline silicon by directional solidification and filter slag melting | |
| CN101495681A (en) | Device and method for production of semiconductor grade silicon | |
| CN106115717B (en) | A kind of method of impurity in removal metallurgical grade silicon | |
| CN103395787B (en) | Apparatus and preparation method for high purity silicon from silicon ore | |
| CN101671024B (en) | Production technology and device for boron-removing and purification of polysilicon by adopting electromagnetic induction melting assisted with high-temperature plasma | |
| CN102874816B (en) | Method and device for preparing polysilicon by electromagnetically separating aluminum-silicon alloy solution | |
| CN103011167B (en) | Preparation device and preparation method for silicon ball | |
| CN102001661A (en) | Method for slagging, boron removal and purification of metalluragical silicon | |
| CN102120578B (en) | Method and device for coupling and purifying polysilicon and removing phosphorus and metal with electron beams | |
| CN102101671B (en) | Method for removing boron and phosphorus impurities from industrial silicon by using magnesium-containing compound | |
| CN102275929A (en) | Method for improving purity of metallurgical silicon and apparatus for realizing method | |
| CN103570023A (en) | Slag-making and boron-removing method for industrial silicon | |
| CN202063730U (en) | Electron beam and slag filter smelting polycrystalline silicon purifying equipment | |
| CN102616787B (en) | Method for removing boron-phosphorus impurities from silicon metal | |
| CN103101912B (en) | Polycrystalline silicon preparation method | |
| CN102408112A (en) | Method and equipment for purification of polysilicon by using electron beam melting under action of high purity silicon substrate | |
| CN103539125B (en) | Medium melting is connected the method for purifying polycrystalline silicon with preliminary directional freeze | |
| CN103011169B (en) | Preparation method for sheet silicon | |
| CN207244047U (en) | A kind of high density sapphire crystal quick process units of high purity aluminium oxide crystal block |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20141126 Termination date: 20220124 |