KR100981134B1 - A high-purity silicon ingot with solar cell grade, a system and method for manufacturing the same by refining a low-purity scrap silicon - Google Patents

Abstract

According to the present invention, a system for continuously producing solar cell-grade high-purity silicon ingot by refining low-purity silicon scrap, comprising: a vacuum chamber; Disposed in the vacuum chamber, having a vertical axis, consisting of an upper crucible and a lower crucible, surrounded by an induction coil, the thermal crucible is not cooled, and is made of an electrically conductive nonmetallic material, Cold crucible has a water-cooled structure, the bottom open crucible made of a thermally conductive and electrically conductive metal material; Silicon scrap supply means disposed in the vacuum chamber and supplying the low purity silicon scrap to the lower open crucible; A plasma arc heating source disposed in the vacuum chamber and irradiating a plasma to the low purity silicon scrap supplied to the lower open crucible; and a reactive gas disposed in the vacuum chamber to obtain a reactive gas on the molten surface obtained from the low purity silicon scrap. A system is provided for continuous production of solar cell grade high purity silicon ingots comprising a reactive gas supply means for supplying.

Solar Cell, Silicon, Refining

Description

System and method for manufacturing solar-grade high-purity silicon ingot by refining low-purity silicon scrap, and a high-purity silicon ingot with solar cell grade, a system and method for manufacturing the same by refining a low-purity scrap silicon}

The present invention relates to a system, a method for producing a high purity silicon ingot, and a system, a method for producing a solar cell-grade high purity silicon ingot by refining a high purity silicon ingot obtained, and more particularly, a low purity silicon scrap. Solar cell grade high purity silicon ingot.

In recent years, the photovoltaic ("PV") industry faces a serious shortage of crystalline silicon, its main material. This is because waste from the microelectronics industry, a material source, is shrinking.

In order to increase the utilization rate of the silicon raw material, it is preferable to reuse the defective silicon substrate scrap (hereinafter referred to as "silicon scrap") which occurs during the manufacture of the silicon wafer from the silicon ingot or the printing of various circuits on the wafer. However, since silicon scrap contains impurities, it is essential to increase the purity before reuse.

Silicon scrap obtained from different sources may contain various other impurity elements such as, for example, boron, phosphorus, arsenic and antimony. Depending on the type of impurity element, the impurity refining method should be different. In addition, high purity silicon is not obtained when silicon scrap containing other impurity elements are mixed together during the melting step of the refining process. Furthermore, if the silicon scrap contains impurity elements that cannot be removed properly or at all by melting, the impurity elements eventually remain in the silicon after refining and no high purity silicon is obtained.

Attempts have been made to find alternative silicon sources for PV production, with the aim of investigating refining techniques for producing high-quality PV materials from low purity silicon. Its goal is to create polycrystalline wafers and photovoltaic cells that can compete with classical materials both in terms of conversion efficiency and cost. In one of these approaches, investigations have been made on refining upgraded metallurgical silicon.

Refining metallurgical-grade silicon using plasma has been studied by several research groups. A research group in France used an induced argon plasma with oxygen added as a reactive gas. All experiments were performed on low units (<250 g). Another research group in Japan has studied the removal of one of the impurities, boron, and developed a refining process that combines electron beam, arc plasma, and directional solidification. The electron beam was used to remove phosphorus, the plasma treatment used water to remove boron, and the two directional solidification steps removed metal impurities. The amount of xylocon treated in these studies amounted to 300 kg per batch. However, this process has the problem that although it is possible to manufacture solar cell grade silicon directly from metallurgical grade, it is not cost effective and has low productivity as a batch type.

In order to solve the problems of the prior art as described above, the present invention provides a system and method for manufacturing solar cell-grade high-purity silicon ingot by refining low-purity silicon scrap using a high melting efficiency continuous casting device. It aims to do it.

Moreover, an object of this invention is to provide the solar cell grade high purity silicon ingot obtained by refine | purifying low purity silicon scrap.

According to an aspect of the present invention for achieving the above object, a system for manufacturing a solar-grade high-purity silicon ingot by refining low-purity silicon scrap,

Vacuum chamber;

Disposed in the vacuum chamber, having a vertical axis, consisting of an upper crucible and a lower crucible, surrounded by an induction coil, the thermal crucible is not cooled, and is made of an electrically conductive nonmetallic material, The cold crucible has a water cooling structure and includes a bottom open crucible made of a thermally conductive and electrically conductive metal material;

Silicon scrap supply means disposed in the vacuum chamber and supplying low purity silicon scrap to the lower open crucible;

A plasma arc heating source disposed in the vacuum chamber and radiating plasma to the low purity silicon scrap supplied to the lower open crucible; and

A reactive gas supply means disposed in the vacuum chamber and supplying a reactive gas to a molten surface obtained from the low purity silicon scrap.

Preferably, the thermal crucible has an upper end integrated in the circumferential direction, and the lower end has a structure in which at least a portion of the circumferential direction is divided into segments by longitudinal slits, and the cold crucible has at least a portion in the circumferential direction. The slits in the longitudinal direction form a segment divided from the upper end to the lower end.

Preferably, at least some of the longitudinal slits run linearly across the hot crucible and the cold crucible.

Preferably, the electrically conductive nonmetallic material is graphite.

Preferably, the outside of the crucible is surrounded by a heat insulating material that transmits a magnetic field.

Preferably, the reactive gas is at least one selected from the group consisting of oxygen and hydrogen.

Preferably, the reactive gas is obtained by gasifying high purity water.

According to another aspect of the present invention, a method for continuously manufacturing solar-grade high-purity silicon ingot by refining low-purity silicon scrap is provided.

Feeding the low purity silicon scrap into a lower open crucible disposed in a vacuum chamber;

Applying induction heating heat to the lower open crucible and irradiating a plasma to the lower open crucible to melt the low purity silicon scrap and volatilize volatile impurities contained in the molten metal obtained from the low purity silicon scrap. ;

Supplying a reactive gas to the surface of the melt obtained from the low purity silicon scrap in order to react the nonvolatile impurities contained in the melt obtained from the low purity silicon scrap in the form of the volatile impurities; and

Slow cooling the molten metal from which the volatile impurities and the non-volatile impurities have been removed, and performing directional solidification;

Here, the lower open crucible has a vertical axis, consists of the upper crucible and the lower crucible, surrounded by an induction coil, the thermal crucible is not cooled, made of an electrically conductive non-metallic material, The cold crucible has a water cooling structure and is made of a thermally conductive and electrically conductive metal material.

Preferably, the volatile impurity is an impurity having a boiling point lower than Si and having an equilibrium partition coefficient that cannot be removed by directional solidification, and the nonvolatile material has a high boiling point than Si and cannot be removed by directional solidification It is an impurity having an equilibrium partition coefficient.

Preferably, the thermal crucible of the lower open crucible has an upper end integrated in the circumferential direction, and the lower end has a structure in which at least a portion of the circumferential direction is divided into segments by longitudinal slits, and the cold crucible At least a part of the direction forms a segment which is divided into segments from an upper end to a lower end by longitudinal slits.

Preferably, at least some of the longitudinal slits of the lower open crucible run straight across the hot crucible and the cold crucible.

Preferably, the electrically conductive nonmetallic material of the lower open crucible is graphite.

Preferably, the outside of the crucible is surrounded by a heat insulating material that transmits a magnetic field.

Preferably, the supplied reactive gas consists of a mixture of oxygen and hydrogen.

Preferably, the supplied reactive gas is obtained by gasifying high purity water.

A solar cell grade high purity silicon ingot according to another aspect of the invention is obtained using any of the above methods.

The present invention provides a system and method for producing solar cell-grade high-quality silicon ingots from low-purity silicon scrap, which are both satisfactory in terms of conversion efficiency and cost.

In addition, according to the present invention, a system and method for producing high quality silicon ingot of solar cell grade from low-purity silicon scrap having high productivity in continuous casting type can be obtained.

According to the present invention, solar cell grade high-quality silicon ingots can be obtained from low-purity silicon scrap.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

As shown in FIG. 1, a system for manufacturing solar cell-grade high purity silicon ingot by refining low purity silicon scrap according to the present invention,

Vacuum chamber (A); It is disposed in the vacuum chamber (A), has a vertical axis, consists of a hot crucible 10 of the upper and a cold crucible 2 of the lower, surrounded by an induction coil (1), the thermal crucible 10 is Crucible (B) that is not cooled, made of an electrically conductive nonmetallic material, the cold crucible (2) has a water-cooled structure, made of a thermally conductive and electrically conductive metal material; Silicon scrap supply means (C), disposed in the vacuum chamber (A), for supplying low-purity silicon scrap to the crucible (B); A plasma arc heating source (D) disposed in the vacuum chamber (A) and irradiating a plasma to the low purity silicon scrap supplied to the crucible (B); and disposed in the vacuum chamber (A), the low purity Reactive gas supply means (E) which supplies a reactive gas to the surface of the molten metal 5 obtained from the silicon scrap is included.

The silicon scrap supply means (C) is arranged in the vacuum chamber (A) to supply low purity silicon scrap to the crucible (B). With such silicon scrap supply means C, for example, parts made of iron are replaced with parts made of stainless steel in order to prevent the formation of rust in the hot-vacuum state and ordinary grease is used for use in a vacuum state. Commercially available vibratory component feeders (eg JA-type bulk hoppers from SANKI Co, Ltd), which have been adapted for use in hot-vacuum conditions in place of grease, can be used.

Then, a plasma arc heating source D is installed in the vacuum chamber A to help melt the low-purity silicon scrap and to volatilize impurities at a high temperature from the surface of the melt 5.

The plasma arc heating source D irradiates the plasma having high energy to the low purity silicon scrap supplied to the crucible B to melt the low purity silicon scrap. As a result, the low-purity silicon scrap is melted, and once melting begins, electromagnetic induction due to the current flowing in the induction coil 1 around the thermal crucible 10 causes the melting of the entire low-purity silicon scrap charge. Secured.

Among the impurities contained in the molten metal 5 obtained from the low-purity silicon scrap, boron and phosphorus, which are the most important elements, are particularly difficult to remove than other impurities. Boron and phosphorus have equilibrium distribution coefficients of 0.8 and 0.35, respectively, so that they are close to 1 compared to other impurities, and impurity segregation is less likely to occur in the crucible (B) by unidirectional coagulation system by slow cooling.

In order to remove boron and phosphorus, a method of applying high energy to volatilize these impurities at a high temperature and gasifying is used. However, phosphorus has a higher vapor pressure than silicon, but volatilizes it earlier than silicon by induction heating of plasma arc heating source (D) and crucible (B) before silicon is volatilized when high energy is applied. When high energy is applied, silicon has a problem of volatilizing before boron is volatilized. Therefore, the plasma arc heating source D has a limitation with respect to the removal of boron.

 Then, the reactive gas supply means E supplies boron by supplying a reactive gas, ie, a mixture of oxygen and hydrogen, to the surface of the molten metal 5 obtained from the low purity silicon scrap, which is suitable for promoting volatilization of impurities. It is to be installed on top of the melt of the crucible (B) in the vacuum chamber (A) to remove the. Preferably the mixture of oxygen and hydrogen can be readily supplied by gasifying purified high purity water. The reactive gas supplied in this way reacts with the impurities diffused and moved to the surface of the molten metal 5 by vortices formed in the molten metal 5 of the crucible B to help volatilize the impurities.

Boron (boiling point: 2820K) is less volatile than silicon (boiling point: 2540K), but it can become more volatile when the reactive gases, ie, oxygen and hydrogen, are added at the same time. Under these conditions, boron evaporates in the form of BHO (mainly), BO and BH2. At 1850 K, BOH is 10 times more volatile than BO, requiring hydrogen or water as well as oxygen for effective removal of boron.

On the other hand, the crucible (B) is disposed in the vacuum chamber (A) and is configured as follows for the high melting efficiency electromagnetic continuous casting of the lower open type.

1. The crucible (B), which corresponds to the upper part of the molten metal, whose heating effect is more important than the electromagnetic pressure effect, is a crucible of a structure that does not cool with a material having excellent electrical conductivity among nonmetallic materials having a high melting point (so-called "thermal crucible"). Was produced. Therefore, the amount of induction heat generated in the thermal crucible contributes to the heating of the molten metal.

2. The effect of electromagnetic pressure is more important than the heating effect, and at the bottom of the crucible (B) corresponding to the lower part of the molten metal which exits the induction coil (1) and starts to solidify, a high thermal conductivity conductive metal material A crucible (so-called "cold crucible") having a water-cooling structure was manufactured to prevent contact between the molten metal and the crucible.

Therefore, it is possible to keep the electromagnetic force greater than the hydrostatic pressure of the molten metal over the entire section of the molten metal while significantly improving the dissolution efficiency of the raw material.

 To this end, the crucible (B) has a vertical axis, consisting of a thermal crucible 10 of the upper portion and a cold crucible 2 of the lower portion, and is surrounded by an induction coil (1).

The thermal crucible 10 is not cooled and is made of an electrically conductive nonmetallic material. The cold crucible 2 has a water cooling structure and is made of a thermally conductive and electrically conductive metal material.

The thermal crucible 10 has a structure in which an upper end is integrated in the circumferential direction, and at least a portion of the lower end is divided into segments 4 by slits 3 in the longitudinal direction. Preferably, the cold crucible 2 has a structure in which at least a portion in the circumferential direction is divided into segments 4 from the upper end to the lower end by longitudinal slits 3.

The induction coil 1 is surrounded by the outside of the thermal crucible 10, and transmits a magnetic field generated as a current is applied to the inside of the thermal crucible 10 through the slits 3 of the thermal crucible 10. To dissolve the raw material by heating. In addition, by forming a vortex in the molten metal (5) obtained from the low-purity silicon scrap to diffuse the boron and phosphorus, the most important elements of the impurities to the surface of the molten metal (5) serves to help the removal process described below.

It is preferred that at least some of the longitudinal slits 3 extend linearly across the crucible 10 and the cold crucible 2.

The electrically conductive nonmetallic material of the thermal crucible 10 is preferably graphite. And, the crucible (B) preferably further comprises a magnetic field transparent cover of the heat insulating material surrounding the upper crucible 10.

For continuous casting, first, the low purity silicon scrap 6 is charged into the crucible B while the dummy bar 7 is closed under the crucible B, and the initial dome 5 is a crucible dome. (B) After forming up to 5 mm below the upper end, the low purity silicon scrap 6 is continuously replenished while the dummy bar 7 is lowered at a constant speed to continuously manufacture the ingot 8.

2-4 illustrate crucible structures of various aspects that can be used in a system according to a preferred embodiment of the present invention.

The crucible of the 1st aspect shown in FIG. 2 consists of a thermal crucible 10 of the upper part, and the cold crucible 2 of the lower part. That is, it is a structure in which the thermal crucible 10 of graphite material of 50 mm, an outer diameter of 80 mm, and a height of 30 mm was put on the upper part of the cold crucible 2.

The upper crucible 10, which has a heating effect rather than an electromagnetic pressure effect, is made of a high melting point non-metallic material having excellent electrical conductivity, and does not have a cooling structure. Therefore, the amount of induced heat generated in the thermal crucible 10 contributes to the heating of the molten metal 5.

On the contrary, the effect of electromagnetic pressure is more important than the heating effect, and the cold crucible 2 which exits the induction coil 1 and starts to solidify is made of a metal material of high thermal conductivity and electric conductivity and water cooled. It was made into a structure.

The cold crucible 2 has a structure in which at least a part of the circumferential direction is divided into segments 4 from the upper end to the lower end by the longitudinal slits 3.

The outside of the thermal crucible 10 was insulated using a heat insulating material 11 having no magnetic field shielding effect in order to improve the heating effect of the low-purity silicon scrap 6 and to protect the induction coil 1.

In the crucible of the first aspect, the induction calorific value generated in the thermal crucible 10 of the graphite material is not lost to the cooling water but contributes to the heating and melting of the low-purity silicon scrap 6, thereby enabling continuous dissolution process. The problem that contact with the crucible was not suppressed was observed. This is because the electromagnetic pressure is smaller than the hydrostatic pressure of the molten metal 5, so that it is difficult to maintain the molten metal 5 in a non-contact state with the crucible.

The crucible of the second aspect shown in FIG. 3 is divided into 12 segments 4 by twelve slits 3 in the longitudinal direction after the thermal crucible 10 of graphite material having an inner diameter of 50 mm, an outer diameter of 80 mm, and a height of 30 mm. Positioned above the cold crucible (2), the longitudinal slits (3) formed at the lower end of the thermal crucible (10) of the non-metallic material and the upper part of the cold crucible (2) of the electrically conductive material have electromagnetic force near the boundary of the two crucibles. It was made continuous to each other so as not to be stolen. The remaining conditions are the same as in the crucible of the first aspect of FIG.

In the crucible of the second aspect, the electromagnetic pressure was improved to prevent the contact between the molten metal 5 and the crucible, but as in the comparative example, when the low-purity silicon scrap 6 was introduced after the initial molten metal 5 was produced, the solidification A film was easily formed on the surface of the molten metal 5, and a continuous dissolution process could not be achieved. This is because about 50% of the total induction calorific value is lost in the crucible cooling process generated in the cold crucible (2).

The crucible of the third aspect shown in FIG. 4 has a structure in which a thermal crucible 10 of graphite material having an inner diameter of 50 mm, an outer diameter of 80 mm, and a height of 30 mm has a structure in which the upper end is integrated in the circumferential direction, and the lower end is in a slit 3 having a length of 20 mm. The longitudinal slits 3 formed at the lower end of the thermal crucible 10 of the non-metal material and the upper end of the cold crucible 2 of the electrically conductive material are formed in the two crucibles. The electromagnetic force was continuously connected to each other so as not to be stolen even near the boundary of. The remaining conditions are the same as the crucible of the first aspect of FIG. 2 and the crucible of the second aspect of FIG. 3.

In the crucible of the third aspect, it is possible to continuously melt-cast the low-purity silicon scrap 6 at a rate of 170 g / min or more while suppressing contact between the molten metal 5 and the crucible.

In other words, in the case of the crucible of the first embodiment using the thermal crucible 10 of the graphite material without the slit 3, the electromagnetic pressure is smaller than the hydrostatic pressure of the molten metal 5 so that the molten metal 5 is in contact with the crucible. On the other hand, even if the thermal crucible 10 is used as in the crucibles of the second and third aspects, the electromagnetic pressure is equal to or greater than the hydrostatic pressure of the molten metal 5 when the slits 3 in the longitudinal direction are at least partially from the lower end. It can be kept large.

Therefore, as the crucible of the third embodiment, the upper part of the crucible is made of a non-metallic material such as graphite, which has excellent electrical conductivity, and is not water cooled, but the lower part of the crucible is made of a high thermal conductivity electrically conductive metal material such as copper, and thus cooled. At this time, the upper part of the upper crucible is integrated in the circumferential direction and the lower part is divided into the plurality of segments 4 in the circumferential direction by the slits 3 in the longitudinal direction. It can efficiently and continuously cast by solar cell class high purity silicon ingot while maintaining contactless state.

On the other hand, a method for continuously manufacturing a solar cell-grade high-purity silicon ingot by refining low-purity silicon scrap according to another aspect of the present invention,

Feeding the low purity silicon scrap into a lower open crucible disposed in a vacuum chamber; Applying induction heating heat to the lower open crucible and irradiating a plasma to the lower open crucible to melt the low purity silicon scrap and volatilize volatile impurities contained in the molten metal obtained from the low purity silicon scrap. ; Supplying a reactive gas to the surface of the molten metal obtained from the low purity silicon scrap in order to react the nonvolatile impurities contained in the molten metal obtained from the low purity silicon scrap in the form of the volatile impurities; and the volatile impurities and the egg Slow cooling the molten metal from which volatile impurities have been removed, and performing directional solidification;

Here, the lower open crucible has a vertical axis, consists of the upper crucible and the lower crucible, surrounded by an induction coil, the thermal crucible is not cooled, made of an electrically conductive non-metallic material, The cold crucible has a water cooling structure and is made of a thermally conductive and electrically conductive metal material.

This will be described in more detail as follows.

First, a low purity silicon scrap containing impurities is fed to a lower open crucible disposed in a vacuum chamber.

Then, induction heating heat is applied to the lower open crucible and the plasma is irradiated to the lower open crucible to melt low purity silicon scrap and volatilize volatile impurities contained in the molten metal obtained from the low purity silicon scrap. do. Here, volatile impurities are impurities having a boiling point lower than Si and having an equilibrium partition coefficient that cannot be removed by directional solidification and refer to impurities such as phosphorus, for example. Low-purity silicon scrap is melted by induction heating heat of plasma and crucible with high energy, and volatile impurities, such as P, BHO, BO and BH2, contained in the molten metal obtained from the low-purity silicon scrap can be removed. Do.

Then, in order to react the nonvolatile impurities contained in the molten metal obtained from the low purity silicon scrap in the form of the volatile impurities, a reactive gas is supplied to the surface of the molten metal obtained from the low purity silicon scrap. The nonvolatile material refers to an impurity having a boiling point higher than that of Si and an equilibrium partition coefficient that is impossible to remove by directional solidification. By supplying a mixture of hydrogen and oxygen obtained from high purity water, for example, a reactive gas, boron, which is classified as nonvolatile impurities, is converted into BHO, BO, and BH2 forms, which are classified as volatile impurities, for easy removal by the step. do.

Thus, when boron and phosphorus are removed, and then the silicon molten metal 5 is directionally solidified, a silicon ingot in which impurities such as Al, Fe, Ti, and Cu are segregated is obtained, and only those parts where these impurities are segregated are removed by cutting. As a result, it is possible to continuously cast a solar cell class high purity silicon ingot as a final product.

1 is a side view for schematically illustrating a configuration of a system for manufacturing solar cell-grade high purity silicon ingot by refining low purity silicon scrap according to a preferred embodiment of the present invention.

2 is a cross-sectional view illustrating the crucible structure of the first aspect that may be used in a system according to a preferred embodiment of the present invention.

3 is a cross-sectional view illustrating a crucible structure of a second aspect that may be used in a system according to a preferred embodiment of the present invention.

4 is a cross-sectional view illustrating a crucible structure of a third aspect that may be used in a system according to a preferred embodiment of the present invention.

Claims (16)

A system for continuously manufacturing solar-grade high-purity silicon ingots by refining low-purity silicon scraps, Vacuum chamber; Disposed in the vacuum chamber, having a vertical axis, consisting of an upper crucible and a lower crucible, surrounded by an induction coil, the thermal crucible is not cooled, and is made of an electrically conductive nonmetallic material, Cold crucible has a water-cooled structure, the bottom open crucible made of a thermally conductive and electrically conductive metal material; Silicon scrap supply means disposed in the vacuum chamber and supplying the low purity silicon scrap to the lower open crucible; A plasma arc heating source disposed in the vacuum chamber and radiating plasma to the low purity silicon scrap supplied to the lower open crucible; and And a reactive gas supply means disposed in the vacuum chamber, the reactive gas supply means for supplying a reactive gas to the melt surface obtained from the low purity silicon scrap. The crucible of claim 1, wherein an upper end portion is integrated in a circumferential direction, and a lower end portion has a structure in which at least a portion of the circumferential direction is divided into segments by longitudinal slits. A system for producing solar cell-grade high purity silicon ingots, wherein at least a portion is structured into segments, from top to bottom, by longitudinal slits. 3. The system of claim 2, wherein at least some of the longitudinal slits run linearly across the thermal crucible and the cold crucible. The system of claim 1, wherein the electrically conductive nonmetallic material is graphite. The system of claim 1, wherein the exterior of the thermal crucible is surrounded by a heat insulator that transmits a magnetic field. 2. The system of claim 1, wherein the reactive gas supplied by the reactive gas supply means is a mixture of oxygen and hydrogen. 7. A system according to claim 6, wherein said reactive gas supplied by said reactive gas supply means is obtained by gasifying high purity water. As a method for continuously manufacturing solar-grade high-purity silicon ingot by refining low-purity silicon scrap, Feeding the low purity silicon scrap into a lower open crucible disposed in a vacuum chamber; Applying induction heating heat to the lower open crucible and irradiating a plasma to the lower open crucible to melt the low purity silicon scrap and volatilize volatile impurities contained in the molten metal obtained from the low purity silicon scrap. ; Supplying a reactive gas to the surface of the melt obtained from the low purity silicon scrap in order to react the nonvolatile impurities contained in the melt obtained from the low purity silicon scrap in the form of the volatile impurities; and Slow cooling the molten metal from which the volatile impurities and the non-volatile impurities have been removed, and performing directional solidification; Here, the lower open crucible has a vertical axis, consists of the upper crucible and the lower crucible, surrounded by an induction coil, the thermal crucible is not cooled, made of an electrically conductive non-metallic material, The cold crucible has a water-cooled structure, and is a method for continuously producing a solar cell-grade high purity silicon ingot made of a thermally conductive and electrically conductive metal material. 10. The method of claim 8, wherein the volatile impurities are lower boiling points than Si and have an equilibrium partition coefficient that is impossible to remove by directional coagulation. A method for continuously producing solar cell grade high purity silicon ingots which are impurities having an equilibrium distribution coefficient of degree. The crucible of claim 8, wherein the thermal crucible of the lower open crucible has an upper end integrated in the circumferential direction, and the lower end has a structure in which at least a portion of the circumferential direction is divided into segments by longitudinal slits. And wherein the at least a portion in the circumferential direction is divided into segments from the upper end to the lower end by longitudinal slits. The method of claim 10, wherein at least some of the longitudinal slits of the lower open crucible extend straight across the thermal crucible and the cold crucible. The method of claim 8, wherein the electrically conductive nonmetallic material of the lower open crucible is graphite. The method of claim 8, wherein the exterior of the thermal crucible is surrounded by a heat insulator that transmits a magnetic field. The method of claim 8, wherein the supplied reactive gas consists of a mixture of oxygen and hydrogen. 15. The method of claim 14, wherein the supplied reactive gas is obtained by gasifying high purity water. A solar cell grade high purity silicon ingot obtained using the method according to any one of claims 8 to 15.

Images