CN103011170A - Method for purifying polysilicon through silicon alloy slagging - Google Patents
Method for purifying polysilicon through silicon alloy slagging Download PDFInfo
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- CN103011170A CN103011170A CN2012105908199A CN201210590819A CN103011170A CN 103011170 A CN103011170 A CN 103011170A CN 2012105908199 A CN2012105908199 A CN 2012105908199A CN 201210590819 A CN201210590819 A CN 201210590819A CN 103011170 A CN103011170 A CN 103011170A
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Abstract
The invention belongs to the technical field of metallurgical purification, and particularly relates to a polysilicon purification method. The method comprises the following steps: performing alloying smelting on metal and metallurgical silicon to obtain a silicon alloy; adding basic slagging agent into the silicon alloy used as a raw material, slagging, smelting, and purifying; and finally, keeping the temperature of the melt, cooling, and separating according to density difference to obtain high-purity silicon, the slagging agent and the silicon alloy, wherein the slagging agent and the silicon alloy can be recovered and used repeatedly. By adding a small amount of metal element into the metallurgical silicon, the metal element and the silicon can be formed into the alloy melt, thus effectively lowering the smelting temperature in the slagging and purifying process and reducing the crucible loss; in the cooling process, impurities have fractional condensation effect between the silicon and the alloy melt, thus effectively lowering the boron impurity content in the primary silicon and improving the purifying effect; and finally, based on the density difference among the silicon, the alloy and the slagging agent, the three phases are separated, thus obtaining the high-purity polysilicon, ensuring that the silicon alloy and the slagging agent can be used repeatedly, and avoiding the reagent consumption and alloy element loss in the subsequent acid washing and purifying process.
Description
Technical field
The invention belongs to the metallurgy purification technical field, particularly a kind of method of polycrystalline silicon purifying.
Background technology
As everyone knows, the energy and environment are the two large problems of face of mankind nowadays.Along with the exhaustion of traditional energy resource, the environmental problem that the fossil fuel burning brings are on the rise, human in the urgent need to exploitation cleaning, renewable energy source.Solar cell utilizes photovoltaic effect to convert solar energy into electrical energy, and possesses cleaning, reproducible energy characteristics, extensively is subjected to people's favor.At present, most widely used is silion cell.In order to guarantee its photoelectric transformation efficiency, the purity of its important composition silicon materials need to reach more than the 6N.The preparation of polycrystalline silicon used for solar battery has become one of bottleneck of heliotechnics widespread use.
The production method of solar-grade polysilicon adopts Siemens Method or improved Siemens more, i.e. chemical vapour deposition (CVD) method, and purifying industrial silicon obtains polysilicon.Its cardinal principle is that industrial silicon is processed into trichlorosilane (or silicon tetrachloride) with hydrochloric acid, purify behind the above-mentioned trichlorosilane (or silicon tetrachloride), in Siemens reactor (or Bed), obtain high purity polycrystalline silicon with High Purity Hydrogen reduction vapour deposition again.These methods mainly are for the production of electronic grade high-purity silicon.There is more shortcoming for the production of a large amount of solar-grade polysilicons.On the one hand, the technical process link is many, the time is long, and intermediate product severe toxicity, explosive easily leads to Serious Accident, and energy consumption is high, and is seriously polluted; On the other hand, the attaching problem of core technology and intellecture property has also seriously restricted the popularization of these techniques.
Compare with chemical method, metallurgy method purifying industrial silicon has the advantages such as technical process is relatively simple, energy consumption is low, environmental pollution is little, therefore enjoy people to pay close attention to.Metallurgy method need to realize in conjunction with multiple treatment technology the purification of industrial silicon usually, and these technology comprise (the CN 101122047A such as directional freeze, plasma melting, vacuum electron beam melting; CN87104483; CN1890177A; ZL96198989.0; ZL98105942.2; ZL98109239.3 and ZL95197920.5).Can realize the removal of most of impurity in the industrial silicon by directional solidification technique, but not obvious to the removal effect of boron impurities and phosphorus; And because the saturated vapor pressure of phosphorus is higher, can realize the removal of foreign matter of phosphor by vacuum melting.Directional freeze and vacuum melting technology are comparatively ripe purification techniquess, can be applicable to the purification of industrial silicon.Like this, the metallurgy method purifying industrial silicon key for preparing solar-grade polysilicon just is the removal of boron impurities.Slag refining, plasma oxidation refining and alloying fractional condensation etc. are mainly adopted in the removal of boron impurities.Slag refining, the part that can be removed boron impurities is subject to the partition ratio of boron between slag-Jin, be difficult to make the boron impurities content in the silicon up to standard, and the waste residue amount is large, and environmental problem is outstanding; Boron impurities can be effectively removed in the plasma oxidation refining, but equipment is complicated, service temperature is high, condition is harsh, only is confined at present bench scale.Alloying fractional condensation method reduces and the obvious rule that descends with temperature at the partition ratio of separating out between solid silicon and melt according to boron impurities, adopt suitable metal of alloying element and industrial silicon to carry out melting, after the cooling, remove alloy element and impurity by steps such as pickling, reach the purpose of purified silicon.Its shortcoming is that the alloy usage quantity is large, and reagent consumption is large, and Matter Transfer, energy consumption problem are given prominence to.
Summary of the invention
The present invention is for overcoming above deficiency, a kind of method of silicon alloy slag making purifying polycrystalline silicon is provided, the method utilizes silicon alloy fractional condensation process to strengthen the removal effect of boron in the metalluragical silicon, again by the further boron impurity of removing in the silicon alloy of slag making purification, finally according to density difference so that three phase separation, obtain low boron HIGH-PURITY SILICON.
The technical scheme that the present invention adopts for achieving the above object is: a kind of method of silicon alloy slag making purifying polycrystalline silicon is characterized in that: at first adopt metal and metalluragical silicon to carry out alloying smelting and obtain silicon alloy; Then take silicon alloy as raw material, add the basic slag agent, carry out the slag making melting and purify; To obtain HIGH-PURITY SILICON, slag agent and silicon alloy according to the density difference separation after melt insulation, the cooling at last, slag agent and silicon alloy recycle and reuse.
Described method concrete steps are as follows:
The first step alloying smelting: one or more in employing aluminium, tin, iron, copper, the titanium metal and metalluragical silicon carry out alloying smelting and obtain silicon alloy under 1000-1450 ℃ of argon shield condition;
Second step silicon alloy slag making melting: the silicon alloy that the first step is obtained is selected basic slag agent Na as raw material
2SiO
3-CaO-TiO
2, mix afterwards heat fused formation fused solution under 1300-1550 ℃ temperature;
The 3rd step Separation and Recovery: fused solution is incubated 0.5-4h, speed with 0.5-10 ℃/min is cooled to 1000-1200 ℃ again, and insulation is toppled over after HIGH-PURITY SILICON, slag agent and silicon alloy layering, obtain HIGH-PURITY SILICON, slag agent and silicon alloy, slag agent and silicon alloy reclaim and reuse.
The massfraction of described metal is 10%-50%, and its purity is 99%-99.9%.
The purity of described metalluragical silicon is 98%-99%, and boron-containing quantity is 10-50ppmw.
The density of described silicon alloy is 3-6g/cm
3
The basicity of described basic slag agent is 1.2-2.0, and density is 2.5-3g/cm
3
The mass ratio of described basic slag agent and silicon alloy is 0.5-5.
The content of boron is lower than 0.3ppmw in the described HIGH-PURITY SILICON.
Unusual effect of the present invention is by add a small amount of metallic element in metalluragical silicon, make itself and silicon form alloy melt, effectively reduced the smelting temperature of slag making purification process, reduce the crucible loss, and because in the process of cooling, impurity has dephlegmation between silicon and alloy melt, effectively reduce the content of boron impurity in the primary silicon, improve refining effect, utilize at last silicon, alloy, density difference between the slag agent is realized the separation of three-phase, obtains highly purified polysilicon, guarantee the recycling of silicon alloy and slag agent, and avoided the reagent consumption of follow-up pickling purification and the loss of alloying element.
Description of drawings
Fig. 1 is a kind of schema of method of silicon alloy slag making purifying polycrystalline silicon
Embodiment
Describe the present invention in detail below in conjunction with specific embodiments and the drawings, but the present invention is not limited to specific embodiment.
Embodiment 1
As shown in Figure 1, a kind of concise and to the point flow process of method of silicon alloy slag making purifying polycrystalline silicon is:
The first step alloying smelting: the metalluragical silicon that adopt that the total mass mark is 50%, purity is 99% aluminium and purity is 98%, boron-containing quantity is 50ppmw carries out alloying smelting and obtains silicon alloy under 1300 ℃ of argon shield conditions, the density of the silicon alloy that obtains is 3g/cm
3
Second step silicon alloy slag making melting: the silicon alloy that the first step is obtained is selected basic slag agent Na as raw material
2SiO
3-CaO-TiO
2, according to basic slag agent and the mass ratio of silicon alloy be 5 mix after under 1400 ℃ temperature heat fused form fused solution, wherein the basicity of basic slag agent is 1.2, density is 2.5g/cm
3
The 3rd step Separation and Recovery: fused solution is incubated 4h, speed with 10 ℃/min is cooled to 1000 ℃ again, insulation is after HIGH-PURITY SILICON, silicon alloy and slag agent layering, topple over, obtain HIGH-PURITY SILICON, slag agent and silicon alloy, silicon alloy and slag agent are reclaimed and are reused, and after testing, the boron content of the HIGH-PURITY SILICON that obtains is 0.29ppmw.
Embodiment 2
As shown in Figure 1, a kind of concise and to the point flow process of method of silicon alloy slag making purifying polycrystalline silicon is:
The first step alloying smelting: the metalluragical silicon that adopt that the total mass mark is 10%, purity is 99.3% aluminium, iron and copper and purity is 98.7%, boron-containing quantity is 24ppmw carries out alloying smelting and obtains silicon alloy under 1450 ℃ of argon shield conditions, the density of the silicon alloy that obtains is 3.2g/cm
3
Second step silicon alloy slag making melting: the silicon alloy that the first step is obtained is as raw material, and selecting the basic slag agent is Na
2SiO
3-CaO-TiO
2, according to basic slag agent and the mass ratio of silicon alloy be 2 mix after under 1300 ℃ temperature heat fused form fused solution, wherein the basicity of basic slag agent is 2.0, density is 3g/cm
3
The 3rd step Separation and Recovery: fused solution is incubated 2h, speed with 5 ℃/min is cooled to 1200 ℃ again, insulation is after HIGH-PURITY SILICON, silicon alloy and slag agent layering, topple over, obtain HIGH-PURITY SILICON, slag agent and silicon alloy, silicon alloy and slag agent are reclaimed and are reused, and after testing, the boron content of the HIGH-PURITY SILICON that obtains is 0.25ppmw.
Embodiment 3
As shown in Figure 1, a kind of concise and to the point flow process of method of silicon alloy slag making purifying polycrystalline silicon is:
The first step alloying smelting: the metalluragical silicon that adopt that the total mass mark is 40%, purity is 99.9% aluminium, tin and titanium and purity is 99%, boron-containing quantity is 10ppmw carries out alloying smelting and obtains silicon alloy under 1000 ℃ of argon shield conditions, the density of the silicon alloy that obtains is 6g/cm
3
Second step silicon alloy slag making melting: the silicon alloy that the first step is obtained is selected basic slag agent Na as raw material
2SiO
3-CaO-TiO
2, according to basic slag agent and the mass ratio of silicon alloy be 0.5 mix after under 1550 ℃ temperature heat fused form fused solution, wherein the basicity of basic slag agent is 1.8, density is 2.9g/cm
3
The 3rd step Separation and Recovery: fused solution is incubated 0.5h, speed with 0.5 ℃/min is cooled to 1100 ℃ again, insulation is after HIGH-PURITY SILICON, silicon alloy and slag agent layering, topple over, obtain HIGH-PURITY SILICON, slag agent and silicon alloy, silicon alloy and slag agent are reclaimed and are reused, and after testing, the boron content of the HIGH-PURITY SILICON that obtains is 0.21ppmw.
Claims (8)
1. the method for a silicon alloy slag making purifying polycrystalline silicon is characterized in that: at first adopt metal and metalluragical silicon to carry out alloying smelting and obtain silicon alloy; Then take silicon alloy as raw material, add the basic slag agent, carry out the slag making melting and purify; To obtain HIGH-PURITY SILICON, slag agent and silicon alloy according to the density difference separation after melt insulation, the cooling at last, slag agent and silicon alloy recycle and reuse.
2. the method for a kind of silicon alloy slag making purifying polycrystalline silicon according to claim 1, it is characterized in that: described method concrete steps are as follows:
The first step alloying smelting: one or more in employing aluminium, tin, iron, copper, the titanium metal and metalluragical silicon carry out alloying smelting and obtain silicon alloy under 1000-1450 ℃ of argon shield condition;
Second step silicon alloy slag making melting: the silicon alloy that the first step is obtained is selected basic slag agent Na as raw material
2SiO
3-CaO-TiO
2, mix afterwards heat fused formation fused solution under 1300-1550 ℃ temperature;
The 3rd step Separation and Recovery: fused solution is incubated 0.5-4h, speed with 0.5-10 ℃/min is cooled to 1000-1200 ℃ again, and insulation is toppled over after HIGH-PURITY SILICON, slag agent and silicon alloy layering, obtain HIGH-PURITY SILICON, slag agent and silicon alloy, slag agent and silicon alloy reclaim and reuse.
3. the method for arbitrary described a kind of silicon alloy slag making purifying polycrystalline silicon according to claim 1 and 2, it is characterized in that: the massfraction of described metal is 10%-50%, its purity is 99%-99.9%.
4. the method for arbitrary described a kind of silicon alloy slag making purifying polycrystalline silicon according to claim 1 and 2, it is characterized in that: the purity of described metalluragical silicon is 98%-99%, boron-containing quantity is 10-50ppmw.
5. the method for arbitrary described a kind of silicon alloy slag making purifying polycrystalline silicon according to claim 1 and 2, it is characterized in that: the density of described silicon alloy is 3-6g/cm
3
6. the method for arbitrary described a kind of silicon alloy slag making purifying polycrystalline silicon according to claim 1 and 2, it is characterized in that: the basicity of described basic slag agent is 1.2-2.0, density is 2.5-3g/cm
3
7. the method for arbitrary described a kind of silicon alloy slag making purifying polycrystalline silicon according to claim 1 and 2, it is characterized in that: the mass ratio of described basic slag agent and silicon alloy is 0.5-5.
8. the method for arbitrary described a kind of silicon alloy slag making purifying polycrystalline silicon according to claim 1 and 2, it is characterized in that: the content of boron is lower than 0.3ppmw in the described HIGH-PURITY SILICON.
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Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103276446A (en) * | 2013-06-06 | 2013-09-04 | 青岛隆盛晶硅科技有限公司 | Method for reutilization of slag agent after medium smelting |
| CN103708465A (en) * | 2013-12-06 | 2014-04-09 | 青岛隆盛晶硅科技有限公司 | Medium melting technology by utilization of mixed slag |
| CN103754882A (en) * | 2013-12-27 | 2014-04-30 | 福建兴朝阳硅材料股份有限公司 | Purifying method of slag-making agent with boron removal |
| CN104878226A (en) * | 2015-05-13 | 2015-09-02 | 大连理工大学 | Method for synthesizing massive silicon-titanium intermetallic compound |
| CN112811427A (en) * | 2021-01-12 | 2021-05-18 | 北京科技大学 | Method for converting and purifying impurity boron in metallurgical silicon based on superfine nitride |
| CN112938983A (en) * | 2021-01-27 | 2021-06-11 | 中国科学院过程工程研究所 | Regenerated silicon prepared based on crystalline silicon cutting waste and preparation method thereof |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101724900A (en) * | 2009-11-24 | 2010-06-09 | 厦门大学 | Device and method for purifying polycrystalline silicon |
| CN101920960A (en) * | 2010-06-29 | 2010-12-22 | 华南师范大学 | Method for preparing solar grade polysilicon by metallurgy method and polysilicon prepared thereby |
| CN102139879A (en) * | 2011-02-18 | 2011-08-03 | 厦门大学 | Method for purifying polysilicon by using silicon and tin alloy |
| WO2012050410A1 (en) * | 2010-10-14 | 2012-04-19 | Uab "Naujausių Technologijų Centras" | Method of purification of silicon |
| CN102807220A (en) * | 2011-05-31 | 2012-12-05 | 比亚迪股份有限公司 | Silicon purification method |
-
2012
- 2012-12-31 CN CN2012105908199A patent/CN103011170A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101724900A (en) * | 2009-11-24 | 2010-06-09 | 厦门大学 | Device and method for purifying polycrystalline silicon |
| CN101920960A (en) * | 2010-06-29 | 2010-12-22 | 华南师范大学 | Method for preparing solar grade polysilicon by metallurgy method and polysilicon prepared thereby |
| WO2012050410A1 (en) * | 2010-10-14 | 2012-04-19 | Uab "Naujausių Technologijų Centras" | Method of purification of silicon |
| CN102139879A (en) * | 2011-02-18 | 2011-08-03 | 厦门大学 | Method for purifying polysilicon by using silicon and tin alloy |
| CN102807220A (en) * | 2011-05-31 | 2012-12-05 | 比亚迪股份有限公司 | Silicon purification method |
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103276446A (en) * | 2013-06-06 | 2013-09-04 | 青岛隆盛晶硅科技有限公司 | Method for reutilization of slag agent after medium smelting |
| CN103276446B (en) * | 2013-06-06 | 2015-09-09 | 青岛隆盛晶硅科技有限公司 | A kind of method of slag agent recycling after medium melting |
| CN103708465A (en) * | 2013-12-06 | 2014-04-09 | 青岛隆盛晶硅科技有限公司 | Medium melting technology by utilization of mixed slag |
| CN103708465B (en) * | 2013-12-06 | 2015-11-04 | 青岛隆盛晶硅科技有限公司 | A kind of medium melting technology utilizing mixed slag |
| CN103754882A (en) * | 2013-12-27 | 2014-04-30 | 福建兴朝阳硅材料股份有限公司 | Purifying method of slag-making agent with boron removal |
| CN104878226A (en) * | 2015-05-13 | 2015-09-02 | 大连理工大学 | Method for synthesizing massive silicon-titanium intermetallic compound |
| CN112811427A (en) * | 2021-01-12 | 2021-05-18 | 北京科技大学 | Method for converting and purifying impurity boron in metallurgical silicon based on superfine nitride |
| CN112811427B (en) * | 2021-01-12 | 2022-08-02 | 北京科技大学 | Method for converting and purifying impurity boron in metallurgical silicon based on superfine nitride |
| CN112938983A (en) * | 2021-01-27 | 2021-06-11 | 中国科学院过程工程研究所 | Regenerated silicon prepared based on crystalline silicon cutting waste and preparation method thereof |
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Application publication date: 20130403 |