CN101743342A - Method for recovering elemental silicon from cutting remains - Google Patents
Method for recovering elemental silicon from cutting remains Download PDFInfo
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- CN101743342A CN101743342A CN200880020803A CN200880020803A CN101743342A CN 101743342 A CN101743342 A CN 101743342A CN 200880020803 A CN200880020803 A CN 200880020803A CN 200880020803 A CN200880020803 A CN 200880020803A CN 101743342 A CN101743342 A CN 101743342A
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- C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
- C22B7/00—Working up raw materials other than ores, e.g. scrap, to produce non-ferrous metals and compounds thereof; Methods of a general interest or applied to the winning of more than two metals
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Abstract
This invention relates to a method for recovering elemental silicon cutting remains containing silicon particles, wherein the method comprises manufacturing solid anodes from the cutting remains, arranging one or more manufactured anode(s) in an electrolytic cell with an electrolyte and one or more cathode(s), and applying a potential difference between the one or more anode(s) and cathode(s) to obtain an oxidation of metallic silicon in the one or more anode(s), transportation of dissolved silicon in the electrolyte, and reduction of the dissolved silicon to a metallic phase at the one or more cathode(s).
Description
Technical field
The present invention relates to be used to reclaim the method for the elemental silicon cutting residuum that contains the silicon particle.The present invention can be used for recycling the high purity silicon that is suitable as production photovoltaic cell raw material from the residuum of producing the photovoltaic wafer.
Background technology
Photovoltaic (PV) technology occurs as the important source of cleaning electric energy.The most frequently used base mateiral of photovoltaic cell is a silicon, under most situations, is the polycrystal ingot by directional solidification technique production perhaps, perhaps produces by proper Clusky (Czochralski) method to be single crystal.
In the polycrystal method, at first big ingot is cut into less piece.The amount of the material of removing in piece cutting can reach percentum of the amount that was processed into solar cell afterwards.
The piece cutting technique can use conventional equipment to carry out, for example band-saw diamond.Ingot cutting residuum will be coarse relatively, wet powder type, and polluting has a small amount of metal and abrasive particle from cutting technique.This material is dropped at present.
Perhaps, the piece cutting can use multi-thread saw to carry out.In wire cutting technology, to place under the tension force at the steel wire that turns round on the guide shaft, and be pushed on the silico briquette, will in cutting fluid, contain the abrasive thick liquid of abrasive particle (diameter is approximately 10-20 μ m) simultaneously, be fed in the cutting area between described gauze and described.What abrasives was the most frequently used is that silicon carbide and described cutting fluid generally are polyoxyethylene glycol or oil.This technology can be called as free abrasive material line cutting.Material from described cutting residuum is removed is dropped at present.
The cutting of wafer is undertaken by multi-thread cutting.In the prior art state of wafer cutting technique, wafer can be thick for 160-240 μ m, and the width of cut channel can be 180-220 μ m.Therefore, the amount suitable with the amount of the silicon that is processed into solar cell taken away by abrasive thick liquid.The exhausted slip will contain polyoxyethylene glycol or other cutting liquid, silicon carbide or other abrasives, silicon and from the metal of steel wire.The coarse part of cutting liquid and abrasive particle reclaims by various recovery technologies usually, for example at US 6,113, and disclosed technology or at US6 in 473, disclosed technology in 231,628.At present, contain abrasive material fine particle, silicon,, be dropped or sell as the inferior grade raw material from the slip residue of the metal of line of cut and residual cutting liquid.
In another kind of technology variant, steel wire is mixed with diamond, and the liquid that is fed to cutting area is only as refrigerant.This technology can be called as the cutting of fixed abrasive material line.Then, the cutting residuum is made up of silicon particle and the metal and the abrasive material that are suspended on a small quantity in the cooling fluid.This residual materials is dropped at present, or sells as the inferior grade raw material.
Monocrystalline silicon is a quadrate, and is cut into wafer.Though cutting can be used the cutting of fixed-abrasive line or other cutting technique, uses the multi-thread saw of free abrasive material to carry out usually.The cutting residuum is dropped at present, or sells as the inferior grade raw material.
The silicon raw material that is used for photovoltaic is an expensive material, therefore, is starved of and a kind ofly can recycles silicon inclusion residual materials from any or all above-mentioned sources as the method for the useful raw material of photovoltaic application.
Prior art
Since at least 10 years, had realized that, still up to the present also do not developed commercial or technical feasible method reclaiming the demand (referring to [1] such as for example Tsuo) of technology.
United States Patent (USP) 6,780,665 disclose from the method for the silicon production thin-film solar cells of cutting residuum recovery.Pneumatic flotation or electrostatic precipitation are carried out in, decant for example centrifugal by conventional isolation technique from the scroll saw slip or filtration then, come divided silicon.Do not provide embodiment, and can not obtain required silicon purity.
As the summary [2] of Elwell and Rao, produce the existing long history of silicon by fused salt electrolysis.But, do not find that also the silicon electrolyzation production technique used by commerce.
WO 02/099166 discloses a kind of technology, wherein passes through at CaO and CaCl
2Ionogen in, at about 800 ℃ of silicon electrolyzations, obtain the silicon of solar energy grade.A problem of this technology is that for example the deposition capability of boron and phosphorus is similar to silicon for element.Therefore, must use the silicon source of very pure and mild costliness.
At US 3,254, electrorefining is disclosed in 010, so that metalluragical silicon is upgraded to electronic-grade.In the method, with electric current from the negative electrode to the anode by containing the molten salt electrolyte of fluorochemical, anode is made of the alloy of impure silicon or germanium or these elements and precious metal.It is 99.9% pure that sedimentary silicon is at least.Ionogen is a fluorochemical, from alkaline metal fluoride cpd and alkaline-earth metal fluoride, contain maximum 10% treat the finishing metal oxide compound.According to statement, produced the silicon of 99.99% purity, but do not reported chemical analysis.
Sharma and Mukherjee[3] use KF-LiF-K described
2SiF
6Electrolytical silicon electrorefining.Method is containing 6-18mol%K
2SiF
6Etc. in mole KF and the LiF mixture, under the temperature between 650 to 800 ℃, carry out.In cathode current density is 0.135A/cm
2, 10mol%K
2SiF
6Under 750 ℃, obtained 92% current efficiency.Under comparatively high temps, can observe SiF
4Vaporization losses.The purity of silicon is upgraded to 99.99% from 97.5%, but residual boron amount is 6ppm.This is too high for the silicon solar cell of routine.
Summary of the invention
Target of the present invention
It is a principal object of the present invention to provide the method that from the cutting residuum that contains particle elements silicon, reclaims elemental silicon.
Another target of the present invention provides and reclaim the method for the silicon inclusion of photovoltaic quality as the raw material of photovoltaic application from the cutting residuum of the cutting technique of solar wafer production.
Target of the present invention can realize by the characteristics that propose in description of the invention below and/or the patent claims of enclosing.
Invention is described
The present invention is based on such understanding, promptly usually the metal pollutant in the cutting residuum than silicon inertia more, therefore might induce elemental silicon in the oxygen cutting residuum by utilizing electrochemistry, the silicon of oxidation is transported in ionogen, and the Si reduction of oxidation is become the elemental silicon of metallographic phase form in site away from the cutting residuum, obtain element specificity transportation from the silicon of cutting residuum.
Therefore, first aspect the present invention relates to from the method for cutting residuum recovery elemental silicon, and this method comprises:
-make solid anodes from described cutting residuum,
-anode of one or more manufacturings is arranged in the electrolyzer that contains ionogen and one or more negative electrodes, and
-between described one or more anodes and negative electrode, apply potential difference, in one or more anodes, to obtain the oxidation of Pure Silicon Metal, in ionogen, transport dissolved silicon, and described dissolved Si reduction is become metallographic phase at one or more negative electrodes place.
According to the electrolysis process of first aspect, will effectively remove than silicon inert element more because they at anode with not oxidized.Therefore these elements still are retained in the anode as solid.
Optional after the electrorefining technology can be the directional freeze step.The solvability of common metallic impurity in melt than high in the solid＞1000 times, the material that directional freeze is concentrated in such impurity final set effectively partly in.This part material can be dropped then.
When using term " cutting residuum " in this article, the present inventor is meant any solid part from the residual materials of the cutting of elemental silicon or sawing, wherein contains the solids of elemental silicon/sawdust.This solid part typical case is the surplus material that comes from cutting of the side of cutting (squaring), piece or wafer cutting, or from the mixtures of material in these sources, but also can be the solid part from other sawing/cutting technique of elemental silicon.Therefore, wish any liquid residue, cutting fluid etc. for example, actual to the greatest extent may, separate with the solid part of residual materials.The solid part of this residual materials promptly cuts residuum, contains usually by from the abrasive particle of cutting technique and the grain silicon of polluting from the little metal of saw.
Can be advantageously with the densification of cutting residuum, the electroconductibility when forming to be increased in anode.Can use at pottery and the known densification technology of powder metallurgical technology, comprise static pressure compacting, injection moulding, band castings etc. such as slurry casting, single shaft Xiang He.In general, it is favourable adding some processing aid, so that form green compact by required processing technology, the technology variant that does not use such additive certainly also within the scope of the invention.These processing aid scopes can arrive the wax and the tackiness agent of heavy addition under the injection moulding situation from a small amount of deflocculation agent that adds under the slurry casting situation.Optional, can be at the processing aid that in the cutting residuum, adds acceleration of sintering before the green compact formation.
The example that anode forms technology be mix with suitable tackiness agent by cut residuum, with mixture drying and dry-pressing anode precursor powder, make anode.Polyvinyl alcohol, other water-soluble polymers or latex are the adhesive materials that is fit to.Can use conventional drying plant with the mixture drying.Spraying drying is particularly advantageous.Be fit to the anodic densification at 75Mpa to the pressure in the 250Mpa scope.Pressure can use conventional hydropress or apply by isostatic pressing machine.
Another example that anode forms technology is the slurry casting.To cut residuum and mix, form poured into stream slurry with high solids loadings with water.Can choose for example 2-amino-2-methyl propyl alcohol of adding deflocculation agent wantonly, higher with the solid loadings that promotes the stream slurry.Anode forms by flowing to starch to be cast in the suitable material mould that for example gypsum is made.
In case formed green compact by suitable technology, and if necessary after the drying, in air, carried out heating cycle usually, be to help organic processing aid of being shaped and adding with the removal.This burn off method is generally undertaken by the temperature that carefully green compact is heated to 300-400 ℃.
Behind burn off,, make green compact fixed (sintering) to form anode by in non-oxidizable (being vacuum or rare gas element) atmosphere, heating.The selection of consolidation temperature depends on the type of the sintering aid of interpolation, and the open pores degree that needs in the anode.In general, need be higher than about 800 ℃ temperature.For the anode that the cutting residuum that never adds sintering aid is made, have been found that under 1300-1450 ℃ sintering temperature and the sintering temperature that 0.5 to 24 hour holding time (soak time) is fit to.
The another kind of density that anodic increases and the method for electroconductibility of obtaining is to add in the cutting residuum than silicon inert metal more.The metal that is fit to comprises Cr, Fe, Co, Ni and Cu.In this case, anode can be at the sintering temperature near the eutectic temperature of Si-M system.Have been found that the temperature in 100 ℃ of system's eutectic temperature is particularly suitable.For example, if use copper, the suitableeest sintering temperature will be about 800 ℃.
Can advantageously increase the silicon concentration in the cutting residuum,, cause the productivity of technology to increase and the energy expenditure reduction so that obtain the anode that silicone content increases.Increasing silicon concentration can partly obtain by the abrasive particle that removes in the cutting residuum.For example, by removing the conventional separating technology of abrasive particle in the cutting residuum, such as the present commercial separating technology that is used to reclaim abrasive particle and cutting fluid, combine by described technology being optimized the high yield and the high density that are used for residual materials silicon.Can use other known separation techniques, for example pneumatic flotation.Another kind is used for increasing the method from the silicon concentration of the cutting residuum of free abrasive material wafer cutting, be that material is mixed with cutting residuum from other cutting technique, the cutting residuum of described other cutting technique skill recently silicone content from the cutting residuum of free abrasive material wafer cutting is higher.
Anode can be made by casting process alternatively, wherein cut residuum and experienced other procedure of processing, with the volume fraction of silicon be increased to surpass about 70%, with the described cutting residuum temperature that direct heating melts to the metal ingredient that is enough to cause machined material under inert atmosphere.Fusing or directly carry out in being suitable for producing the mould of anode base is perhaps carried out in crucible, subsequently with melt transfer in casting die.Reduce temperature then, melt is solidified.After curing, the foundry goods shape is carried out controlled refrigeration cycle, to minimize the thermal stresses level.
The anode of agglomerating or casting can be chosen wantonly by grinding or mill machinery and be processed into their final shapes.
Negative electrode can from any conduction, to the chemical environment in described pond have resistance, from sedimentary silicon, separate and the low material manufacturing of velocity of diffusion in silicon easily.Negative electrode can advantageously be made by solar energy level silicon, but other material that is fit to comprises the high purity carbonaceous material, for example carbon, graphite or vitreous carbon, or transition metal or precious metal.
Ionogen must can dissolved oxygen silicon, and have macroion electroconductibility.Electrolytical metal ingredient must have than the obvious low inertia of silicon, avoiding in cathodic reduction, even and be dissolved in the silicon with lower concentration, can not have negative impact to the silicon character relevant with sun power efficient yet.Electrolytical suitable material standed for like this will be alkali metal halide, alkaline earth metal halide or its mixture.Described halogenide is preferably muriate, fluorochemical or mixture.
Composition advantageously concentration is the alkaline metal fluoride cpd that is selected from LiF, NaF and KF of 10-90mol% and the CaF that is selected from that concentration is 10-90mol%
2, SrF
2And BaF
2The mixture of alkaline-earth metal fluoride.Also can use the mixture of several alkaline metal fluoride cpds and/or several alkaline-earth metal fluorides.Have been found that and add BaF
2, SrF
2Or their combination is effective especially for reducing volatilization.Optional, the K that can add
2SiF
6Amount mostly be 20mol% most.The applicant has been found that in order to limit the resistance in described pond it is important avoiding oxide compound in ionogen, and this may cause owing to form electric insulation layer on one or two electrode surface.
Being used for the total pond reaction of silicon electrolyzation purified is:
Si(s)＝Si(s)????(1)
Therefore, the reversible cell voltage is 0V.The required cell voltage of operation process is the required voltage of resistance that overcomes in circuit, ionogen and the electrode, comprises the overvoltage at negative electrode and anode place.Therefore, among other factors, the suitableeest cell voltage is concrete characteristics, anode-cathode distance and the electrode of pond design and the function that ionogen is formed.Use term " overvoltage ", present inventor be meant working electrode be anode and negative electrode with the reference electrode of next-door neighbour's working electrode placement between potential difference.
The most general impurity element is an iron in the cutting residuum, but generally also has a spot of other transition metal, for example chromium, nickel and copper.Iron has the standard electrode potential than the high 1.02V of silicon.According to estimates, until the anode overvoltage of about 350mV, anode place ferric fluoride (III) still keeps below 10 with the thermodynamic activity ratio of iron
-9Therefore other transition metal has the standard electrode potential of similar scope, can avoid these metals to dissociate in the ionogen by making the anode overvoltage be lower than operation electrorefining technology under the situation of about 300mV.
The class impurity that can find in anode is the element lower than silicon inertia, for example alkaline-earth metal and basic metal.They will be dissolved in the ionogen, but be not easy in cathodic reduction.For example, according to estimates, until surpassing under the negative electrode overvoltage of 550mV, the ratio of the thermodynamic activity of negative electrode place Calcium Fluoride (Fluorspan) and calcium will be above 10
9, therefore can avoid codeposition by moving refinery practice under the situation that is lower than about 500mV in the negative electrode overvoltage.But the element that inertia is lower is accumulated in the ionogen as fluorochemical, may be accumulated to unacceptable level in some cases.If detrimental impurity runs up to unacceptable level, can replace part or all of ionogen with fresh electrolyte.
Element with reduction potential similar to silicon can not pass through the electrolysis tech refining.The concrete related example of this class impurity is boron and phosphorus.These elements also have solid in silicon and the relatively little shortcoming of difference between the liquid solubleness.In commercial metallurgical grade silicon and upgrading metallurgical grade silicon, the concentration of these elements is too high, can not comprise that directional freeze subsequently obtains high-quality solar energy level silicon by electrorefining.Use as starting material, owing to cut the intrinsic purity of silicon in the residuum, has overcome this shortcoming from the cutting residuum that cuts high purity silicon.
By adjusting process parameter suitably, might obtain refined silicon with the adventitious deposit on the negative electrode.Form is the function of cathode current density, but also is subjected to the influence of other processing parameter, for example electrolytical composition and temperature.Use and surpass about 0.05-0.20A/cm
2Higher cathode current density, obtain granular product usually.Granular disintegration can for example make use AlCl by known technology
3Solution washing is separated with the ionogen of remnants.These two kinds of settling forms all within the scope of the invention.
Electrolyzer is operated under the temperature of the electrolytical liquidus temperature that is higher than use.For the volatilization of minimization of silicon material, advantageously operate electrolyzer being higher than under the temperature of liquidus temperature＜50 ℃.According to selected ionogen, the temperature in described pond can be in 500-1200 ℃ scope.
The electrolytical container that accommodates fusing can be made from the known materials that a series of chemical environments to technology have resistance.The material that is fit to comprises silicon-dioxide, silicon nitride, silicon carbide, carbon, graphite and matrix material thereof.
Behind refinery practice (oxidation of Pure Silicon Metal), the residue in the anolyte compartment may comprise silicon carbide, silicon-dioxide and usually than silicon inert metal more.
Description of drawings
Fig. 1 is under 900 ℃, NaF-BaF
2-NaSiF
6In (28-68-4 quality %) mixture, (scanning speed=10mV/s) goes up the linear voltammogram of mapping to the Si electrode.
Fig. 2 has shown from the SEM Photomicrograph of the negative electrode of test 2, has had ultimate analysis.
Fig. 3 has shown the photo of the silicon that obtains in test 2.
Fig. 4 is the x-ray diffraction pattern of the silicon that is obtained that shows in Fig. 2.
Checking of the present invention
The present invention will describe in further detail by checking embodiment.These embodiment should not be considered to using electrorefining to be construed as limiting from the general theory that the cutting residuum extracts elemental silicon.
Make anodic embodiment from the cutting residuum
Exhausted line cutting slurry is handled by commercial process, with coarse part and the most of polyoxyethylene glycol of removing and reclaim silicon carbide.With the dry residue of about 365g, join in 1% aqueous solution of 300ml dispersion agent Dolapix A88 (2-amino-2-methyl propyl alcohol), and use the Ultra-Turrax decollator to disperse from this technology.With consequent about 55 weight % solid stream slurry, on jar forming roll grinding machine, roll and spend the night with several balls of milling.To flow slurry cast on the gypsum mold to the degree of depth be 15-20mm.After the drying, with anode 1415 ℃ of sintering 2 hours.The anode that obtains is machined into desired size.Geometric density is 1.55g/cm
3
The embodiment of electrorefining silicon
Carry out the electrorefining test, produced the possibility of pure elemental silicon with proof.In these processs of the test, silicon passes through electrochemical dissolution at the anode place, and in the galvanic deposit of negative electrode place.Ionogen is a fused salt, and silicon ion was dissolved in wherein before the beginning electrolysis.
Fused salt is contained in the vitreous carbon crucible, is placed in the inwall of graphite lining protection of the cylindrical vessel of being made by high temperature steel.The stainless steel cover that the pond is cooled with circulating water seals.Atmosphere is that the U level (is lower than 5ppm O
2) inert argon.Two are made by solar energy level silicon, surface-area is about 5cm
2Anode be placed on around the negative electrode.In two kinds of different fused salts, carry out two Si electrorefining tests.The actual conditions that uses in each test is listed in the table 1.
Table 1: test conditions
| Test | 6 salt are formed | Negative electrode | Cathodic surface area [cm 2] | Temperature [℃] | Time span [h] | Cathode current density [mA/cm 2] |
| ??1 | NaF-LiF (37-63 quality %) | Vitreous carbon | ??2 | ??800 | ??5 | ??75 |
| ??2 | ??NaF-BaF 2(29-71 quality %) | Silicon | ??5 | ??900 | ??24 | ??16 |
Before operation 2 beginnings, electrochemical techniques (linear voltammetry) on silicon electrode, have been carried out.Measured reference potential with respect to silicon electrode.Linear current-the voltage responsive of the voltammogram of Fig. 1 demonstrates at the highest 60mA/cm
2Current density under, there are not restriction in anodic dissolving or the deposition of silicon at the negative electrode place.
Operation is included in and applies the constant electric current between anode and the negative electrode.When end of run, from the pond, take out negative electrode, to reclaim sedimentary silicon.In operational process, find that cell voltage is a constant, near 100mV.
Settling part is made of the adhesion layer on the cathode substrate and the part silicon by particle form.With settling at room temperature at water-based AlCl
3Washing is 24 hours in the solution, so that dissolve adherent salt.At last, solution is filtered out also drying.SEM Photomicrograph from test 2 negative electrode is presented among Fig. 2.Can see the adventitious deposit of silicon.The EDS of sedimentary silicon analyzes and has only shown silicon and carbon, and this is because the illusion that is caused by the oil residue pollution in the microscopical vacuum chamber for example.Powder is presented among Fig. 3.Be presented at Fig. 4 from testing the 1 X-ray diffraction figure that obtains:, except the oxide compound that forms, in silicon, do not find impurity with after ionogen separates.
The quality of the silicon that the current efficiency of technology reclaims according to washing back and the given electric charge that passes through the ratio between the Theoretical Mass (according to Faraday's law calculating) that should obtain, calculate.Table 2 has shown that current efficiency is about 70% in test 1 and test 2.
Table 2: current efficiency
| Test | Theoretical Si quality [mg] | The Si quality [mg] that reclaims | Current efficiency [%] |
| ??1 | ??270 | ??196 | ??72.5 |
| ??2 | ??496 | ??340 | ??68.5 |
Reference
1.Y.S.Tsuo, J.M.Gee, P.Menna, D.S.Strebkov, A.Pinov and V.Zadde, " Environmentally benign silicon solar cell manufacturing, " presented at 2nd World Conference and Exhibition on Photovoltaic SolarEnergy Conversion; (the benign silicon solar cell manufacturing of environment is submitted in second world's photovoltaic solar conversion conference and exhibition) 6-10 July 1998; Vienna, Austria
2.D.Elwell and G.M.Rao, " Electrolytic production of Silicon, " (electrolysis production of silicon), J.Appl.Electrochem., 18 (1988) 15-22
3.Sharma and Mukherjee, " A Study on Purification of MetallurgicalGrade Silicon by Molten Salt Electrorefining ", (by the research of fused salt electrorefining purifying metallurgical grade silicon), Metallurgical Transactions, Vol.17B, 1986,395-397.
Claims (14)
1. reclaim the method for elemental silicon from the cutting residuum, wherein said method comprises:
-make solid anodes from described cutting residuum,
-anode of one or more manufacturings is arranged in the electrolyzer with ionogen and one or more negative electrodes, and
-between described one or more anodes and negative electrode, apply potential difference, in described one or more anodes, to obtain the oxidation of Pure Silicon Metal, in described ionogen, transport dissolved silicon, and described dissolved Si reduction is become metallographic phase at described one or more negative electrodes place.
2. the process of claim 1 wherein that the described electromotive force that applies is adjusted to the anode overvoltage that provides the negative electrode overvoltage that is lower than 500mV and be lower than 350mV.
3. claim 1 or 2 method, wherein said anode is formed by the cutting residuum by following step densification:
-will cut residuum mixes with tackiness agent,
-with this mixture drying,
This mixture of-dry-pressing, and
-in nonoxidizing atmosphere, be heated to above 800 ℃ temperature by mixture to make its sintering with described compacting.
4. claim 1 or 2 method, wherein said anode is formed by the cutting residuum by following step densification:
-by described cutting residuum is suspended in the water with optional deflocculation agent, form the stream slurry,
-described stream slurry is cast in the mould that gypsum or other suitable material make, and
-by being starched the temperature that is heated to above 800 ℃ in nonoxidizing atmosphere, described stream makes its sintering.
5. claim 3 or 4 method, wherein
-be heated to 1300 to 1450 ℃ of temperature in the scope by the anode that will form to make its sintering, and
-be between 0.5 to 24 hour in the time under the described sintering temperature.
6. claim 3 or 4 method, wherein
-one or more following granular metal: Cr, Fe, Co, Ni or Cu joined in the described cutting residuum and with it mix, and
-described sintering temperature on the eutectic temperature of system of silicon and add metal or under in 100 ℃.
7. any one method of claim 3-6 wherein before described cutting residuum is formed anode, removes at least a portion abrasive particle in described cutting residuum.
8. claim 1 or 2 method, wherein said negative electrode is made by one of the following: other silicon of solar level, the high purity carbonaceous material is carbon, graphite or vitreous carbon for example, or transition metal or precious metal.
9. claim 1 or 2 method, wherein said ionogen is made by one or more alkali metal halides and alkaline earth metal halide.
10. the method for claim 9, wherein said halogenide is one or more muriates and/or fluorochemical.
11. the method for claim 9, wherein said halogenide comprises:
-concentration is the alkaline metal fluoride cpd that is selected from LiF, NaF and KF of 10-90mol%, with
-concentration is the CaF that is selected from of 10-90mol%
2, SrF
2And BaF
2The mixture of alkaline-earth metal fluoride, optional
-wherein add the K of maximum 20mol%
2SiF
6
12. the method for claim 1 or 2, wherein said electrolyzer be higher than employed electrolytical liquidus temperature, but be lower than on the described liquidus temperature under 50 ℃ the temperature and operate.
13. any one method of aforementioned claim, the container that wherein contains described electrolyzer is made by silicon nitride, silicon carbide, carbon, graphite and matrix material thereof.
14. any one method of aforementioned claim, wherein said method also comprise the part of directional freeze step succeeded by the material of discharging final curing.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US94471607P | 2007-06-18 | 2007-06-18 | |
| US60/944,716 | 2007-06-18 | ||
| PCT/NO2008/000221 WO2008156372A2 (en) | 2007-06-18 | 2008-06-18 | Method for recovering elemental silicon from cutting remains |
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| Publication Number | Publication Date |
|---|---|
| CN101743342A true CN101743342A (en) | 2010-06-16 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN200880020803A Pending CN101743342A (en) | 2007-06-18 | 2008-06-18 | Method for recovering elemental silicon from cutting remains |
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|---|---|
| JP (1) | JP2010530637A (en) |
| CN (1) | CN101743342A (en) |
| DE (1) | DE112008001644T5 (en) |
| WO (1) | WO2008156372A2 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105384175A (en) * | 2015-12-25 | 2016-03-09 | 苏州格瑞动力电源科技有限公司 | Purification method of industrial waste silicon |
| CN108823637A (en) * | 2018-07-30 | 2018-11-16 | 孟静 | The device of purifying polycrystalline silicon |
| CN108842183A (en) * | 2018-09-10 | 2018-11-20 | 孟静 | The preparation method of polysilicon chip |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| RU2491374C1 (en) * | 2012-06-13 | 2013-08-27 | Федеральное государственное бюджетное учреждение науки Институт высокотемпературной электрохимии Уральского отделения Российской Академии наук | Electrochemical method of obtaining continuous layers of silicon |
| DE102013112004B4 (en) | 2013-10-31 | 2018-08-16 | variata Dorit Lang GmbH & Co. KG | Recycling of photovoltaic modules and / or solar modules |
Family Cites Families (8)
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|---|---|---|---|---|
| NL290209A (en) | 1962-03-14 | |||
| FR2480796A1 (en) * | 1980-04-21 | 1981-10-23 | Extramet Sarl | High purity silicon deposit formation - by electrolytic deposition from alkali (ne earth) metal halide melt contg. dissolved silicon |
| US4448651A (en) * | 1982-06-10 | 1984-05-15 | The United States Of America As Represented By The United States Department Of Energy | Process for producing silicon |
| US6113473A (en) | 1997-04-25 | 2000-09-05 | G.T. Equipment Technologies Inc. | Method and apparatus for improved wire saw slurry |
| US6231628B1 (en) | 1998-01-07 | 2001-05-15 | Memc Electronic Materials, Inc. | Method for the separation, regeneration and reuse of an exhausted glycol-based slurry |
| NO317073B1 (en) * | 2001-06-05 | 2004-08-02 | Sintef | Electrolyte and process for the manufacture or refining of silicon |
| US6780665B2 (en) | 2001-08-28 | 2004-08-24 | Romain Louis Billiet | Photovoltaic cells from silicon kerf |
| JP2007016293A (en) * | 2005-07-08 | 2007-01-25 | Kyoto Univ | Method for producing metal by suspension electrolysis |
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2008
- 2008-06-18 WO PCT/NO2008/000221 patent/WO2008156372A2/en active Application Filing
- 2008-06-18 DE DE200811001644 patent/DE112008001644T5/en active Pending
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105384175A (en) * | 2015-12-25 | 2016-03-09 | 苏州格瑞动力电源科技有限公司 | Purification method of industrial waste silicon |
| CN108823637A (en) * | 2018-07-30 | 2018-11-16 | 孟静 | The device of purifying polycrystalline silicon |
| CN108842183A (en) * | 2018-09-10 | 2018-11-20 | 孟静 | The preparation method of polysilicon chip |
Also Published As
| Publication number | Publication date |
|---|---|
| WO2008156372A3 (en) | 2009-02-19 |
| JP2010530637A (en) | 2010-09-09 |
| DE112008001644T5 (en) | 2010-09-09 |
| WO2008156372A2 (en) | 2008-12-24 |
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