WO2006006436A1 - 金属の精製方法 - Google Patents
金属の精製方法 Download PDFInfo
- Publication number
- WO2006006436A1 WO2006006436A1 PCT/JP2005/012319 JP2005012319W WO2006006436A1 WO 2006006436 A1 WO2006006436 A1 WO 2006006436A1 JP 2005012319 W JP2005012319 W JP 2005012319W WO 2006006436 A1 WO2006006436 A1 WO 2006006436A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- metal
- silicon
- crucible
- cooling body
- molten
- Prior art date
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
- C22B9/00—General processes of refining or remelting of metals; Apparatus for electroslag or arc remelting of metals
- C22B9/02—Refining by liquating, filtering, centrifuging, distilling, or supersonic wave action including acoustic waves
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B33/00—Silicon; Compounds thereof
- C01B33/02—Silicon
- C01B33/037—Purification
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
- C22B61/00—Obtaining metals not elsewhere provided for in this subclass
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P10/00—Technologies related to metal processing
- Y02P10/20—Recycling
Definitions
- the present invention generally relates to a method for purifying a metal such as a metal or a semiconductor material, and more particularly to a method for producing a silicon raw material for a solar cell.
- Metal or semiconductor material elements such as iron, aluminum, copper, and silicon are generally single and rarely exist in nature, and most exist as compounds such as oxides. ing. Therefore, in order to use these metals or semiconductor material elements for applications such as structural materials, conductive materials, or semiconductor materials, it is often necessary to reduce oxides or the like to form a single metal or semiconductor material element. .
- refining means taking out impurities from a metal or semiconductor material element alone as another form, and depending on the physicochemical characteristics of the base metal or semiconductor material or impurity element, The objective is achieved by applying appropriate physicochemical methods.
- the ratio of the impurity concentration in a solid metal or semiconductor material in an equilibrium state to that in a molten metal or semiconductor material, so-called impurities Highly purified by so-called unidirectional solidification method, which reduces the concentration of impurities in solid copper by solidifying at a slow rate close to the equilibrium state by utilizing the segregation coefficient of The wire material has a low electrical resistance value.
- Heavy metal or semiconductor material impurity elements present in metal silicon include relatively large amounts of iron, aluminum, titanium, and the like. Typical values for impurity content in metallic silicon are 100 to 5000 ppmw for iron, 100 to 2000 ppmw for anoleminium, and:! To lOppmw for titanium.
- the solidification segregation method has an advantage that a large number of impurity elements can be simultaneously processed.
- the unidirectional solidification method uses a molten metal or a semiconductor material injected into a vertical shape. Because it solidifies at a slow speed that approaches the equilibrium state, the processing speed is non- Always slow.
- the initial solidification portion has a lower impurity concentration than before the solidification treatment (hereinafter referred to as a purification section), but the late solidification portion has a lower impurity concentration than before the solidification treatment.
- impurity concentration part There is a part with a large (hereinafter referred to as impurity concentration part).
- the proportion of the impurity concentrating portion varies depending on the impurity concentration before solidification treatment, the solidification rate, the degree of stirring of the molten metal or semiconductor material, etc., but occupies approximately 20 to 50% of the entire solidified mass. In other words, in order to perform the coagulation treatment two or three times, it is necessary to cut and eliminate a considerable amount of the impurity concentration part.
- aforementioned segregation coefficient values (iron 6 ⁇ 4 X 10_ 6, aluminum 2 ⁇ 8 X 10_ 3, titanium 7. 37 X 10- 6) is very slow solidification rate in the near equilibrium state This value is called the equilibrium segregation coefficient.
- the segregation coefficient in the actual solidification segregation process is larger than the equilibrium segregation coefficient.
- the segregation coefficient in this case is called the effective segregation coefficient, and the effective segregation coefficient ke and the equilibrium segregation coefficient ko are related by the following equation (1).
- Equation (1) shows that the effective segregation coefficient is determined by the solidification rate R, the impurity concentrated layer thickness ⁇ , and the impurity diffusion coefficient D.
- the impurity enriched layer is a portion where impurities are expelled to the molten metal or semiconductor material part when the molten metal or semiconductor material is solidified, and the impurity is concentrated near the solidification interface. This means a hypothetical thickness that can be handled by a mathematical formula that is not the actual thickness of the impurity concentration layer. From an industrial point of view, it is desirable to reduce the effective segregation coefficient while increasing the solidification rate, and it is effective to reduce the impurity concentrated layer thickness.
- the method is characterized in that the solidification rate can be increased while keeping the segregation coefficient small by agitating the molten metal or semiconductor material by rotating the cooling body to disperse the impurity concentrated layer.
- Japanese Patent Application Laid-Open No. 63-45112 only discloses a method of performing the purification treatment once.
- the heavy metal impurity concentration in metal silicon to 0.1 ppmw or less, which is required as a raw material for solar cells, it is necessary to perform purification using solidification segregation two or three times. Therefore, in order to produce a raw material for solar cells using this method, it is necessary to devise a new method for continuously performing the purification treatment.
- a typical value for the content in metal silicon is 30 to 50 ppmw.
- Japanese Patent Laid-Open No. 6-227808 discloses a method of dissolving metallic silicon under a reduced pressure of 1 OPa or less
- Each publication discloses a method of irradiating a molten metal silicon surface with an electron beam under reduced pressure. These increase the evaporation rate of phosphorus by using a vacuum with a relatively high vapor pressure of phosphorus, but in order to process a large amount of high-temperature molten silicon under vacuum, a large vacuum exhaust system is required. And there are problems such as limitation of usable in-furnace members.
- solar cells can be obtained by solidification segregation treatment two or three times, as in the case of removing heavy metal impurity elements such as iron and aluminum. It was found that the phosphorous concentration of 0.1 lppmw or less, which is the required specification as a raw material, can be realized.
- Patent Document 1 JP-A 63-45112
- Patent Document 2 JP-A-6-227808
- Patent Document 3 Japanese Patent Laid-Open No. 7-315827
- Patent Document 4 US Patent No. 4539194
- Patent Document 5 Special Table 2003-516295
- An object of the present invention is to provide a metal refining method for removing various metal or semiconductor materials, more specifically, impurity elements contained in metal silicon by a very efficient and inexpensive process. .
- the first step of holding the first molten metal containing impurities in the first crucible and the first melting held in the first crucible A second step of immersing the first cooling body in the metal while flowing a cooling fluid inside the cooling body to crystallize the first purified metal on the surface of the cooling body, and the first purified metal crystallizing out.
- the second cooling body is immersed in the second molten metal held in the step 5 while flowing a cooling fluid inside the cooling body, and the surface of the cooling body is immersed.
- a method for purifying metal is provided.
- the metal is a semiconductor material.
- the crucible in the fourth step is the second crucible in the fifth step.
- the mth step of holding the nth molten metal having a lower impurity concentration in the crucible than the molten metal in the (m-4) step is dissolved in the nth crucible together with the nth molten metal held in the mth step.
- the first cooling body after dissolving the first purified metal crystallized on the surface is used again as the first cooling body in the second step.
- the second cooling body after dissolving the second purified metal crystallized on the surface is used again as the second cooling body in the sixth step.
- n-th cooling body is used again as the n-th cooling body in the (m + 2) step.
- the sixth and seventh steps are performed a plurality of times while the first to fifth steps are repeated a plurality of times.
- the sixth and seventh steps are performed a plurality of times, and the mth to (m + 3) steps are further performed a plurality of times.
- the second molten metal is used as the first molten metal a predetermined number of times.
- the nth molten metal is used as the (n_l) th molten metal a predetermined number of times.
- a material that reduces the segregation coefficient of impurities is added to the molten metal.
- the molten metal is silicon
- the impurity is phosphorus
- the material that reduces the segregation coefficient of the impurity is calcium.
- the cooling body immersed in the molten metal is rotated.
- a method for purifying a metal such as a metal or a semiconductor material, which uses solidification segregation, is highly efficient, improves yield and throughput, and reduces manufacturing costs. Can be provided.
- FIG. 1 is a schematic sectional view of an apparatus applicable to the present invention.
- FIG. 2 is an enlarged sectional view of a shaft and a cooling body in the apparatus of FIG. 1 applicable to the present invention.
- Electromagnetic induction caloric heat equipment 41, 42, 43, 44, 45 Insulation, 51, 52, 53, 54, 55 Cooling fluid forward path, 511, 521, 531, 541, 551 Cooling P Fluid outlet, 61, 62 , 63, 64, 6 5 Cooling P fluid return path, 71, 72, 73, 74, 75 shaft, 81, 82, 83, 84, 85 Cooling body, 91 Raw material silicon charging machine, Dish, 102, 103, 104, 105 Molten silicon, 111, 112, 113, 114, 115 Purified silicon.
- the method for purifying a metal of the present invention includes a first step of holding a first molten metal containing impurities in a first crucible, and a first molten metal held in the first crucible.
- the first cooling body is immersed in the cooling body while flowing a cooling fluid therein, and a second step of crystallizing the first purified metal on the surface of the cooling body, and the first purified metal crystallizes.
- the second cooling body is immersed in the second molten metal held in this step while flowing a cooling fluid inside the cooling body, and is then placed on the surface of the cooling body.
- FIG. 1 is a schematic sectional view of an apparatus applicable to the present invention.
- the melting furnace 11 can be moved up and down by a graphite crucible 21 holding silicon, a heat insulating material 31, an electromagnetic induction heating device 41, a lifting mechanism, and has a cooling fluid forward path 51 and a cooling fluid return path inside.
- a cooling body 81 communicating with the cooling fluid return path 61 attached to the lower end of the shaft 71.
- the arrow in the figure indicates that the shaft 71 can rotate.
- Molten silicon 101 is held in the crucible 21.
- the crucible 2z is installed in the melting furnace lz.
- the purified silicon 111 is crystallized on the surface of the cooling body 81.
- the first step is a step of holding the first molten metal (silicon) containing impurities in the first crucible.
- a metal silicon lump is charged into the crucible 21 by a desired amount from a metal silicon charging machine 91 provided above the crucible 21.
- the temperature of the metal silicon charged in the crucible 21 is higher than the melting point of silicon, 1412 ° C, specifically 1412 ° C to: 1600 ° C. Raise to hold the metal silicon in a molten state.
- the second step is to immerse the first cooling body in the first molten metal (silicon) held in the first crucible while flowing a cooling fluid inside the cooling body.
- This is a step of crystallizing the first purified metal (silicon) on the surface. Specifically, using FIG.
- FIG. 2 is an enlarged cross-sectional view of the shaft 71 and the cooling body 81 in the apparatus of FIG. 1 applicable to the present invention.
- the arrow in a figure has shown the flow direction of the cooling fluid.
- a rotation drive mechanism is attached to the upper part of the shaft 71, and the shaft 71 can be rotated while the cooling body 81 is immersed in the molten silicon.
- the cooling body 81 is immersed in the molten silicon by lowering the shaft 71 while rotating it.
- a cooling fluid outlet 511 provided with a hole is provided at the lower end of the cooling fluid forward path 51, and the cooling fluid introduced from the cooling fluid outlet 51 is blown out of the cooling fluid outlet 511 to be cooled. It collides with the inner peripheral surface of 81. At that time, the cooling fluid absorbs heat from the inner peripheral surface of the cooling body 81, and then is discharged to the outside through the cooling fluid return path 61.
- the cooling fluid is typically not limited to a force that is an inert gas such as nitrogen or argon.
- the concentration of impurities formed near the interface between the purified silicon and the molten silicon crystallized on the surface of the cooling body 81 by rotating the shaft 71 to generate a fast flow in the molten silicon. It is possible to disperse the layers. At this time, if the baffle plate is immersed in the molten silicon, the flow generated in the molten silicon is disturbed and the effect of dispersing the impurity concentrated layer is improved, so that the effective segregation coefficient of impurities is further reduced.
- the cooling body 81 has a tapered shape in which the diameter of the lower end portion is smaller than that of the upper end portion.
- the shape of the cooling body 81 is not limited as long as purified silicon having a desired purity is crystallized. Les.
- the third step is a step of taking out the first cooling body from which the first refined metal (silicon) is crystallized from the first molten metal. Specifically, after the desired amount of the first purified silicon crystallizes in the second step, the shaft 71 is raised and the cooling body 81 immersed in the molten silicon is taken out.
- the fourth step is a step of holding the second molten metal (silicon) having an impurity concentration lower than that of the first molten metal (silicon) in the first step in the crucible.
- the concentration of heavy metal impurities such as iron and aluminum to 0.1 ppmw or less, which is the required value as raw material silicon for solar cells
- the melting furnace 12 has a configuration capable of coagulation segregation treatment similar to that of the melting furnace 11, but if it is limited to the role of the fourth step, it necessarily has a configuration capable of coagulation segregation processing. do not have to. That is, a crucible and a heating device for holding the molten silicon may be provided.
- the fifth step dissolves the first refined metal (silicon) crystallized in the second step, together with the second molten metal (silicon) held in the fourth step.
- This is a step of holding in the crucible of 2).
- the shaft 71 taken out in the third step is moved to above the crucible 22, the shaft 71 is lowered to dissolve the cooling body 81 in which the first purified silicon is crystallized.
- the first refined product is immersed in molten silicon (second molten metal) held in a crucible 22 attached to the furnace 12 and having a lower impurity concentration than the metal silicon used in the first step. Dissolve the silicon.
- the crucible holding the molten silicon is not necessarily the crucible 22 attached to the melting furnace 12.
- a separate melting furnace with only a crucible and a heating device is prepared, and molten silicon having an impurity concentration lower than that of the metal silicon used in the first step is held in the melting furnace, and if necessary, The purpose can also be achieved by pouring molten silicon into the crucible 22 attached to the melting furnace 12.
- the force dissolving method in which the first purified silicon is dissolved by being immersed in molten silicon is not particularly limited.
- a heating device may be provided separately to melt the first purified silicon by heating.
- the second cooling body in the sixth step, is immersed in the second molten metal held in the fifth step while flowing a cooling fluid inside the cooling body, and the second cooling body is immersed on the surface of the cooling body. This is a step of crystallizing the purified metal.
- the seventh step is a step of taking out the second cooling body obtained by crystallizing the second purified metal in the sixth step from the second molten metal. Specifically, after a desired amount of the second purified silicon crystallizes in the sixth step, the shaft 72 is raised and immersed in the molten silicon, and the cooled body 82 is taken out.
- the second purified silicon obtained through the first to seventh steps has been subjected to two solidification segregation treatments, and the concentrations of iron, aluminum, and other heavy metal impurities are the raw materials for solar cells.
- the required specification can be 0.1 ppmw or less.
- the first purified silicon is continuously produced by performing the first to fifth steps a plurality of times.
- the shaft 71 after dissolving the first purified silicon is immersed again in the crucible 21 used in the first step, and the surface of the cooling body 81 is coated with metallic silicon. Will crystallize out.
- the same amount of metal silicon as the crystallized first purified silicon is added to the crucible 21 and dissolved to produce the third purified silicon, that is, the shaft 71 When dipping in the crucible 21 again, the amount of molten silicon to be held is kept constant.
- the second purified silicon is continuously produced by performing the steps 6 to 7 a plurality of times.
- the shaft 72 after the second purified silicon is dissolved is again immersed in the crucible 22 used in the sixth step, and purified silicon is crystallized on the surface of the cooling body 82. Will be issued.
- the solidification segregation treatment may require three or more times.
- the mth step of holding the nth molten metal having a lower impurity concentration than the molten metal in the (m_4) step in the crucible —
- the (n-1) refined metal crystallized in step 3) is dissolved, and the (m +) retained in the nth crucible together with the nth molten metal held in the mth step.
- the nth cooling body is immersed in the molten metal held in the step (1) and the (m_3) step while flowing a cooling fluid inside the cooling body, and the nth cooling body is immersed in the surface of the cooling body.
- the nth cooling body that crystallizes the nth refined metal from the (m + 2) step of crystallizing the refined metal and the (m_2) step from the nth molten metal. It is preferable to further perform the (m + 3) step of taking out.
- m 4 (n_ l) and n is a natural number of 3 or more
- the eighth step of holding the third molten metal having a lower impurity concentration than the second metal in the third crucible, and the second purification A ninth step of melting the metal and holding it in the third crucible together with the third molten metal; a third cooling body in the third molten metal; and a cooling fluid in the cooling body.
- a tenth step in which the third refined metal is crystallized on the surface of the cooling body by dipping while flowing, and a third cooling body in which the third purified metal is crystallized is taken out from the third molten metal. 11 steps are further performed. As a result, the solidification segregation process is performed three times.
- a melting furnace 13 having the same configuration as the melting furnaces 11 and 12 is further installed, and after performing the first to seventh steps, a fourth furnace is further performed in the melting furnace 12.
- a fourth furnace is further performed in the melting furnace 12.
- the concentration of heavy metal impurities in the molten silicon held in the crucible 23 attached to the melting furnace 13 is the concentration of heavy metal impurities in the molten silicon held in the crucible 22 attached to the melting furnace 12.
- the second purified silicon, which is smaller than that, is dissolved and held in the crucible 23.
- the solidification segregation process may be required 4, 5, 6.
- the n-th purified silicon is continuously produced by performing the steps (m + 2) to (m + 3) a plurality of times. .
- the shaft 7n after dissolving the nth purified silicon is immersed again in the crucible 2n used in the (m + 2) step, and the surface of the cooling body 8n To crystallize purified silicon
- the first refined silicon is continuously crystallized and held in the crucible 21.
- the impurity concentration in the molten silicon increases from the impurity concentration in the metal silicon before the start of processing.
- the impurity concentration in the molten silicon held in the crucible 22 increases from the impurity concentration in the molten silicon before the start of processing. .
- the refined silicon is pulled up a predetermined number of times so that the impurity concentration in the molten silicon held in the crucible 22 does not exceed the impurity concentration in the metal silicon held in the crucible 21 before the start of processing. At this point, the crystallization of purified silicon is stopped. After stopping, the molten silicon in the crucible 21 is discharged out of the crucible 21, and the entire amount of molten silicon in the crucible 22 is poured into the crucible 21. By repeating the first to fifth steps a number of times not exceeding the capacity of the crucible 33, the second silicon having a lower impurity concentration than the first silicon can be stored in the crucible 22. Thereafter, the second purified silicon can be continuously produced again by repeating the first to seventh steps.
- the impurity concentrated part in the second solidified mass is used as the raw material for the first solidification segregation process. If this is the case, the process of crushing the impurity concentrating part for charging into the crucible and the process of dissolving the solid impurity concentrating part are added, resulting in problems such as increased capital investment, lower throughput, and increased energy input. Generated force In the method of the present invention, the impurity concentrating part is handled as a liquid, so that the steps of crushing and re-dissolving the impurity concentrating part become unnecessary, and the above problem can be solved.
- a phosphorus removal effect by solidification segregation by adding calcium as a material for reducing the segregation coefficient into the molten metal It is necessary to leave no phosphorus segregation part in the unidirectional solidification method described above or in molten silicon disclosed in JP-A-63-45112. It is preferable to adopt a method of growing the solidification interface while keeping the solidification interface smooth, such as a method of immersing the rolling cooling body and crystallizing high purity silicon on the outer peripheral surface of the rotation cooling body.
- examples of materials that can remove impurities by solidification segregation include iron, aluminum, and titanium.
- heavy metal impurities such as iron and aluminum can be reduced to 0.1 ppmw or less by two or three solidification segregation treatments. Therefore, calcium is added three times without adding calcium.
- other heavy metal impurity elements which are not only phosphorus and calcium, can be reduced to below the required specification of 0.1 lppmw as a raw material for solar cells.
- Metallic silicon was purified by the method of the present invention using the apparatus shown in FIG. First, 24 kg of metal silicon (made in China) was charged into a graphite crucible 21, and the inside of the melting furnace 11 was set to an argon gas atmosphere of 1 atm. Silicon was melted and held at 1550 ° C.
- the shaft 71 is lowered while rotating at 600 revolutions per minute, and when the cooling body 81 is immersed in molten silicon while introducing nitrogen gas as a cooling fluid from the cooling fluid forward passage 51 at 7600 liters per minute, cooling is performed.
- the first purified silicon crystallized on the surface of the body 81.
- the shaft 71 was raised, and the cooling body 81 was taken out of the molten silicon. Then, the introduction of nitrogen gas was stopped.
- the weight of the first purified silicon under the same conditions was measured in advance, and it was 3 kg. Thereafter, 3 kg of metallic silicon is charged into the crucible 21 and melted.
- the shaft 71 taken out from the melting furnace 11 is moved directly above the melting furnace 12, the shaft 71 is lowered and the cooling body 81 is held in the crucible 22.
- the first purified silicon crystallized on the surface of the cooling body 81 is dissolved.
- the shaft 71 is raised and moved again directly above the melting furnace 11. After that, the first refined silicon production is repeated in the melting furnace 11 under the same condition 'method as described above.
- the shaft 72 attached to the melting furnace 12 is lowered while rotating at 600 revolutions per minute, and nitrogen gas is introduced as a cooling fluid from the cooling fluid forward path 42 at 7600 liters per minute, while the cooling body When 82 was immersed in molten silicon, the second purified silicon crystallized on the surface of the cooling body 82.
- the second refined silicon production was repeated 50 times to produce 150 kg of the second refined silicon.
- 150 kg of the second purified silicon was dissolved again and the impurity concentration in the sample for impurity concentration analysis collected by the same procedure as above using a quartz suction tube was measured, iron and calcium were not detected. .
- the iron and power concentrations were less than 0.05 ppmw.
- Aluminum concentration is 0 ⁇ 09ppmw It was. All of the elements could be less than 0.1 ppmw required as a silicon raw material for solar cells.
- Example 1 the first purified silicon was produced 57 times, and the iron, aluminum, and calcium concentrations in 21 kg of molten silicon in the crucible 21 were 12000 ppmw, 3900 ppmw, and 150 ppmw, respectively. Therefore, the molten iron furnace 11 was turned on, and 21 kg of the molten silicon in the crucible 21 was completely discharged into the discharged silicon receiver disposed in the vicinity of the molten metal furnace 11.
- the iron, aluminum, and calcium concentrations in 21 kg of molten silicon in crucible 22 after the second purified silicon production 50 times in Example 1 were 140 ppmw, 170 ppmw, and 9 ppmw, respectively. It was. Subsequently, the melting furnace 12 was raised, and 21 kg of molten silicon in the crucible 22 was transferred into the crucible 21 attached to the melting furnace 11.
- 150 kg of second purified silicon was produced in the same procedure as in Example 1.
- the impurity concentration in 150 kg of the second purified silicon was measured in the same procedure as in Example 1, no element of iron, aluminum, or calcium was detected. That is, all the elements were less than 0.05 ppmw, and could be less than 0.1 ppmw required as a silicon raw material for solar cells.
- the molten silicon in crucible 21 after the first refined silicon production 57 times in Example 2 The concentration of iron, anoleminicum, and canolecium in 21 kg was 1000 ppmw, 1200 ppmw, and 63 ppmw, respectively.
- the iron, aluminum, and calcium concentrations in 21 kg of molten silicon in the crucible 22 after the second refined silicon production in Example 2 was reduced to 13 ppmw, 59 ppmw, and 4 ppmw, respectively.
- the molten silicon in ⁇ ⁇ 21 was removed, and all of the molten silicon in the crucible 22 was transferred to the crucible 21.
- 150 kg of second purified silicon was manufactured in the same procedure as in Example 1.
- the impurity concentration in 150 kg of the second purified silicon was measured in the same procedure as in Example 1, no element of iron, aluminum, or calcium was detected. That is, all the elements were less than 0 ⁇ 05 ppmw, and could be less than 0.1 ppmw required as a silicon raw material for solar cells.
- the yield of silicon is 88%, which is the same as that of Example 2.
- 534 kg of metallic silicon is used to obtain 450 kg of second purified silicon.
- silicon yield increased from 78% to 84%.
- Example 4 silicon was refined using an apparatus in which a melting furnace 13 having the same configuration as the melting furnace 11 was installed in addition to the melting furnaces 11 and 12. In the melting furnace 11, 24 kg of metallic silicon was melted in the same manner as in Example 1 and held. At this time, in addition to metallic silicon, 20 kg of metallic calcium was charged and dissolved.
- Example 2 the same procedure as in Example 1 was performed, and then 21 kg of the first purified silicon was held in the crucible 22 attached to the melting furnace 12. At this time, a quartz suction tube from which about 20 g of molten silicon was sampled from the crucible 22 was immediately immersed in water and rapidly solidified as an impurity concentration analysis sample. Phosphorus and calcium were analyzed by ICP emission spectrometry. When the concentration was measured, it was 1.5 ppmw and 1200 ppmw, respectively. [0100] After 16 kg of metallic calcium was charged in the crucible 22 and dissolved, a sample for impurity concentration analysis was taken again, and the calcium concentration was measured by ICP emission spectrometry. As a result, it was 15% by mass. Since a considerable amount volatilized when metallic calcium was dissolved, the calcium concentration was smaller than the calcium concentration (42% by mass) calculated from the amount of metallic calcium charged.
- the molten silicon force held in the crucible 21 attached to the melting furnace 11 is also pulled up by 3 kg of the first purified silicon per time, and in the crucible 2 2 attached to the melting furnace 12 Dissolved in and retained.
- the molten silicon held in the crucible 21 was charged with 3 kg of metal silicon and melted.
- the third purified silicon was pulled up from the molten silicon held in the crucible 23 attached to the melting furnace 13 at a time.
- the third refined silicon 150kg was pulled up.
- the impurity concentration in 150 kg of the third purified silicon was measured in the same procedure as in Example 1, phosphorus was not detected.
- the phosphorus concentration in the third purified silicon was less than 0.05 ppmw, and could be less than 0.1 ppmw required as a silicon raw material for solar cells.
- melting furnaces 14 and 15 having the same configuration as the melting furnace 11 are installed side by side.
- Example 4 3 kg of the third purified silicon was pulled up from the molten silicon held in the crucible 23 attached to the melting furnace 13 seven times, and the first was put into the crucible 24 attached to the melting furnace 14. 3 kg of purified silicon 21 kg was dissolved and retained. At this time, a quartz suction tube from which about 20 g of molten silicon was sampled from the crucible 24 was immediately immersed in water and rapidly solidified as a sample for impurity concentration analysis, and the calcium concentration was determined by ICP emission spectrometry. The measured value was 900 ppmw.
- the impurity concentration in the fifth purified silicon was less than 0.05 ppmw, which was less than 0.1 ppmw required as a silicon raw material for solar cells.
- Table 1 shows the concentrations of iron, aluminum, calcium, and phosphorus in 21 kg of molten silicon in crucibles 21, 22, 23, 24, and 25 after producing 150 kg of the fifth purified silicon in Example 5.
- the melting furnace 11 was tilted, and 21 kg of the molten silicon in the crucible 21 was completely discharged into the discharged silicon receiver disposed in the vicinity of the melting furnace 11. Subsequently, the melting furnace 12 was raised, and 21 kg of molten silicon in the crucible 22 was transferred into the crucible 21 attached to the melting furnace 11. In the same manner, 2 lkg of molten silicon was transferred from the crucible 23 to the crucible 22, from the crucible 24 to the crucible 23, and from the crucible 25 to the crucible 24, respectively.
- Example 4 As in Example 4, 140 g of metallic calcium was charged and dissolved in 21 kg of molten silicon in the crucible 23 so that the calcium concentration in the molten silicon in the crucible 23 was 13 mass%. Thereafter, in the same manner as in Example 5, 150 kg of fifth purified silicon was produced. When the iron, aluminum, calcium, and phosphorus concentrations in 150 kg of this fifth purified silicon were measured by ICP emission spectrometry, no element was detected. In other words, the impurity concentration in the fifth purified silicon was less than 0.05 ppmw, which was less than 0.1 ppmw required as a silicon raw material for solar cells.
- the yield of silicon is 88%, which is the same as that of Example 2. Similar to Examples 2 and 3, the silicon yield can be approached from 78% to 88% by repeating the procedure of this example.
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Organic Chemistry (AREA)
- Manufacturing & Machinery (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Inorganic Chemistry (AREA)
- Physics & Mathematics (AREA)
- Acoustics & Sound (AREA)
- Silicon Compounds (AREA)
Description
Claims
Priority Applications (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US11/631,287 US7811356B2 (en) | 2004-07-14 | 2005-07-04 | Method of purifying metal |
CN2005800308986A CN101018877B (zh) | 2004-07-14 | 2005-07-04 | 精制金属的方法 |
EP05765236A EP1777303A4 (en) | 2004-07-14 | 2005-07-04 | PROCESS FOR THE PURIFICATION OF A METAL |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2004-207591 | 2004-07-14 | ||
JP2004207591A JP4115432B2 (ja) | 2004-07-14 | 2004-07-14 | 金属の精製方法 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2006006436A1 true WO2006006436A1 (ja) | 2006-01-19 |
Family
ID=35783779
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2005/012319 WO2006006436A1 (ja) | 2004-07-14 | 2005-07-04 | 金属の精製方法 |
Country Status (5)
Country | Link |
---|---|
US (1) | US7811356B2 (ja) |
EP (1) | EP1777303A4 (ja) |
JP (1) | JP4115432B2 (ja) |
CN (1) | CN101018877B (ja) |
WO (1) | WO2006006436A1 (ja) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US7727502B2 (en) | 2007-09-13 | 2010-06-01 | Silicum Becancour Inc. | Process for the production of medium and high purity silicon from metallurgical grade silicon |
CN112429708A (zh) * | 2020-11-24 | 2021-03-02 | 中国电子科技集团公司第十三研究所 | 一种非金属半导体材料的提纯方法 |
Families Citing this family (16)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP4835867B2 (ja) * | 2007-04-20 | 2011-12-14 | 信越化学工業株式会社 | シリコンの精製方法 |
KR20100022516A (ko) * | 2007-06-08 | 2010-03-02 | 신에쓰 가가꾸 고교 가부시끼가이샤 | 금속 규소의 응고 방법 |
WO2009001547A1 (ja) * | 2007-06-26 | 2008-12-31 | Panasonic Corporation | 金属シリコンの精製方法とシリコン塊の製造方法 |
JP5886627B2 (ja) * | 2008-09-30 | 2016-03-16 | ヘムロック・セミコンダクター・コーポレーション | 汚染材料が高純度シリコンに寄与する不純物の量を決定する方法及び高純度シリコンを処理する炉 |
JP2012106886A (ja) * | 2010-11-17 | 2012-06-07 | Nippon Steel Materials Co Ltd | 金属シリコンの凝固精製方法及び装置 |
JP5194165B1 (ja) * | 2011-11-29 | 2013-05-08 | シャープ株式会社 | 金属精製塊の検査方法およびそれを含む高純度金属の製造方法 |
JP2013112574A (ja) * | 2011-11-30 | 2013-06-10 | Sharp Corp | シリコンの精製方法 |
JP5173013B1 (ja) * | 2011-12-12 | 2013-03-27 | シャープ株式会社 | シリコンの精製方法、結晶シリコン材料の製造方法、および、太陽電池の製造方法 |
JP5173014B1 (ja) * | 2011-12-12 | 2013-03-27 | シャープ株式会社 | シリコンの精製方法、結晶シリコン材料の製造方法、および、太陽電池の製造方法 |
WO2013088784A1 (ja) * | 2011-12-12 | 2013-06-20 | シャープ株式会社 | 金属の精製方法、金属、シリコンの精製方法、シリコン、結晶シリコン材料および太陽電池 |
CN103833038A (zh) * | 2014-03-08 | 2014-06-04 | 中国科学院等离子体物理研究所 | 一种从硅合金熔体中半连续结晶提纯硅的方法 |
JP6919633B2 (ja) * | 2018-08-29 | 2021-08-18 | 信越半導体株式会社 | 単結晶育成方法 |
CN112619198B (zh) * | 2020-12-07 | 2022-02-11 | 迈安德集团有限公司 | 一种冷却结晶箱 |
CN112921187B (zh) * | 2021-01-22 | 2022-09-27 | 浙江最成半导体科技有限公司 | 一种高纯铝的纯化方法 |
CN113718297B (zh) * | 2021-09-09 | 2023-01-20 | 中国铝业股份有限公司 | 一种从铝电解氟化物电解质中偏析除杂的系统和方法 |
CN114178788B (zh) * | 2021-12-06 | 2024-07-05 | 天津大学 | 一种基于表层区域熔炼调控杂质分布进而提升金属表面加工质量的方法 |
Citations (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS6345112A (ja) * | 1986-08-07 | 1988-02-26 | Showa Alum Corp | ケイ素の精製方法 |
JPH0417629A (ja) * | 1990-05-11 | 1992-01-22 | Showa Alum Corp | 金属の精製方法 |
JPH07206420A (ja) | 1994-01-10 | 1995-08-08 | Showa Alum Corp | 高純度ケイ素の製造方法 |
WO1997003922A1 (fr) * | 1994-01-10 | 1997-02-06 | Showa Aluminum Corporation | Procede pour produire du silicium tres pur |
JP2000351616A (ja) | 1999-06-07 | 2000-12-19 | Showa Alum Corp | 高純度シリコンの製造方法 |
JP2001172729A (ja) * | 1999-12-13 | 2001-06-26 | Showa Alum Corp | 金属の精製装置及び精製方法 |
US6398845B1 (en) | 2000-02-10 | 2002-06-04 | Sumitomo Chemical Company, Limited | Method for purifying aluminum |
JP2003516295A (ja) * | 1999-12-08 | 2003-05-13 | エルケム エイエスエイ | 冶金品位ケイ素の精製 |
Family Cites Families (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3543531A (en) * | 1967-05-08 | 1970-12-01 | Clyde C Adams | Freeze refining apparatus |
NO152551C (no) | 1983-02-07 | 1985-10-16 | Elkem As | Fremgangsmaate til fremstilling av rent silisium. |
US4854968A (en) * | 1986-12-25 | 1989-08-08 | Showa Aluminum Corporation | Method of preparing high-purity metal and rotary cooling member for use in apparatus therefor |
JP2905353B2 (ja) | 1993-02-04 | 1999-06-14 | 川崎製鉄株式会社 | 金属シリコンの精製方法 |
JP3140300B2 (ja) | 1994-03-29 | 2001-03-05 | 川崎製鉄株式会社 | シリコンの精製方法および精製装置 |
-
2004
- 2004-07-14 JP JP2004207591A patent/JP4115432B2/ja not_active Expired - Fee Related
-
2005
- 2005-07-04 WO PCT/JP2005/012319 patent/WO2006006436A1/ja active Application Filing
- 2005-07-04 CN CN2005800308986A patent/CN101018877B/zh not_active Expired - Fee Related
- 2005-07-04 US US11/631,287 patent/US7811356B2/en not_active Expired - Fee Related
- 2005-07-04 EP EP05765236A patent/EP1777303A4/en not_active Withdrawn
Patent Citations (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS6345112A (ja) * | 1986-08-07 | 1988-02-26 | Showa Alum Corp | ケイ素の精製方法 |
JPH0417629A (ja) * | 1990-05-11 | 1992-01-22 | Showa Alum Corp | 金属の精製方法 |
JPH07206420A (ja) | 1994-01-10 | 1995-08-08 | Showa Alum Corp | 高純度ケイ素の製造方法 |
WO1997003922A1 (fr) * | 1994-01-10 | 1997-02-06 | Showa Aluminum Corporation | Procede pour produire du silicium tres pur |
JP2000351616A (ja) | 1999-06-07 | 2000-12-19 | Showa Alum Corp | 高純度シリコンの製造方法 |
JP2003516295A (ja) * | 1999-12-08 | 2003-05-13 | エルケム エイエスエイ | 冶金品位ケイ素の精製 |
JP2001172729A (ja) * | 1999-12-13 | 2001-06-26 | Showa Alum Corp | 金属の精製装置及び精製方法 |
US6398845B1 (en) | 2000-02-10 | 2002-06-04 | Sumitomo Chemical Company, Limited | Method for purifying aluminum |
Non-Patent Citations (1)
Title |
---|
See also references of EP1777303A4 * |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US7727502B2 (en) | 2007-09-13 | 2010-06-01 | Silicum Becancour Inc. | Process for the production of medium and high purity silicon from metallurgical grade silicon |
CN112429708A (zh) * | 2020-11-24 | 2021-03-02 | 中国电子科技集团公司第十三研究所 | 一种非金属半导体材料的提纯方法 |
Also Published As
Publication number | Publication date |
---|---|
CN101018877B (zh) | 2010-12-15 |
EP1777303A4 (en) | 2009-03-18 |
CN101018877A (zh) | 2007-08-15 |
US20080289150A1 (en) | 2008-11-27 |
EP1777303A1 (en) | 2007-04-25 |
JP2006027940A (ja) | 2006-02-02 |
JP4115432B2 (ja) | 2008-07-09 |
US7811356B2 (en) | 2010-10-12 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
WO2006006436A1 (ja) | 金属の精製方法 | |
JP3325900B2 (ja) | 多結晶シリコンの製造方法及び装置、並びに太陽電池用シリコン基板の製造方法 | |
EP2467330B1 (en) | Method of purifying silicon utilizing cascading process | |
CN1873062A (zh) | 一种太阳能电池用高纯多晶硅的制备方法和装置 | |
EP2743359A1 (en) | Method for purifying high-purity aluminium by directional solidification and smelting furnace therefor | |
EP2089319B1 (fr) | Procede de purification de silicium metallurgique par solidification dirigee | |
JP3473369B2 (ja) | シリコンの精製方法 | |
JP6159344B2 (ja) | シリコンを精製するための方法 | |
TW201131031A (en) | Apparatus and method for continuous casting of monocrystalline silicon ribbon | |
JPH10194718A (ja) | 太陽電池用多結晶シリコン・インゴットの製造方法 | |
JPH07206420A (ja) | 高純度ケイ素の製造方法 | |
KR101074304B1 (ko) | 금속 실리콘과 그 제조 방법 | |
WO2003078319A1 (fr) | Procede pour purifier du silicium, silicium ainsi produit et cellule solaire | |
CN1204298A (zh) | 多晶硅的制造方法和装置以及太阳能电池用硅基片的制造方法 | |
CN109628995B (zh) | 利用梯度保温提高合金法提纯多晶硅收率的方法 | |
CN1083396C (zh) | 高纯度硅的制造方法 | |
WO2011113338A1 (zh) | 一种提纯硅的方法 | |
CN113753900A (zh) | 一种利用脉冲电流分离多晶硅中杂质元素的方法及多晶硅 | |
CN104071790A (zh) | 电磁搅拌硅合金熔体硅提纯装置及方法 | |
JP4365480B2 (ja) | 高純度シリコンの製造方法 | |
WO1997003922A1 (fr) | Procede pour produire du silicium tres pur | |
JP2010173911A (ja) | シリコンの精製方法 | |
JP2000351616A5 (ja) | ||
CN1269186C (zh) | 一种具有内吸杂功能的掺碳硅片的制备方法 | |
CN109850904B (zh) | 利用半固态法提高合金法提纯多晶硅收率的方法 |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AK | Designated states |
Kind code of ref document: A1 Designated state(s): AE AG AL AM AT AU AZ BA BB BG BR BW BY BZ CA CH CN CO CR CU CZ DE DK DM DZ EC EE EG ES FI GB GD GE GH GM HR HU ID IL IN IS KE KG KM KP KR KZ LC LK LR LS LT LU LV MA MD MG MK MN MW MX MZ NA NG NI NO NZ OM PG PH PL PT RO RU SC SD SE SG SK SL SM SY TJ TM TN TR TT TZ UA UG US UZ VC VN YU ZA ZM ZW |
|
AL | Designated countries for regional patents |
Kind code of ref document: A1 Designated state(s): BW GH GM KE LS MW MZ NA SD SL SZ TZ UG ZM ZW AM AZ BY KG KZ MD RU TJ TM AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IS IT LT LU LV MC NL PL PT RO SE SI SK TR BF BJ CF CG CI CM GA GN GQ GW ML MR NE SN TD TG |
|
DPEN | Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed from 20040101) | ||
121 | Ep: the epo has been informed by wipo that ep was designated in this application | ||
WWE | Wipo information: entry into national phase |
Ref document number: 11631287 Country of ref document: US |
|
NENP | Non-entry into the national phase |
Ref country code: DE |
|
WWW | Wipo information: withdrawn in national office |
Country of ref document: DE |
|
WWE | Wipo information: entry into national phase |
Ref document number: 2005765236 Country of ref document: EP |
|
WWE | Wipo information: entry into national phase |
Ref document number: 200580030898.6 Country of ref document: CN |
|
WWP | Wipo information: published in national office |
Ref document number: 2005765236 Country of ref document: EP |