JP2009143795A - Continuous casting apparatus, continuous casting method, and ingot - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a continuous casting method and continuous casting apparatus in which high quality ingots are obtained without mingling in the ingots of inclusions such as oxides or impurity elements, the drawing out velocity is raised, and the production efficiency can be sharply raised, and to provide the ingots obtained by the same. <P>SOLUTION: A continuous casting apparatus 10 which continuously manufactures an ingot 2 obtained by making a molten metal 1 solidified in one direction includes: a molten metal holding part 20 holding the molten metal 1, and a template 30 in which the horizontal one side end is located below the molten metal holding part 20, wherein the template 30 has a base part 31 which inclines and extends to the horizontal plane so as to gradually go down as going to the horizontal direction on the other side, a cooling means 35 is disposed in the base part 31, the molten metal 1 fed from the molten metal holding part 20 is made to be solidified in one direction by the cooling means 35, and the resulting ingot 2 is continuously drawn out along the base part 31 of the template 30. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a continuous casting apparatus, a continuous casting method, and an ingot obtained thereby, for continuously producing an ingot obtained by unidirectionally solidifying a molten metal such as silicon.

Since silicon used as a material for solar cells is a metal that expands during solidification, when casting is performed, it is required to solidify in one direction so that the molten metal does not remain inside the ingot.
Moreover, since the impurity element is discharged from the solid phase (ingot) to the liquid phase (molten metal) by unidirectional solidification, it is possible to obtain an ingot with high purity.

Conventionally, as a casting apparatus for unidirectionally solidifying silicon, for example, as disclosed in Patent Document 1, a molten metal is supplied from an upper opening portion of a cylindrical mold and cooled from a side wall of the mold. There has been proposed a method in which an ingot is drawn downward from the lower opening.
However, in the casting apparatus described in Patent Document 1, since the crystal is grown from the lower side to the upper side and the resulting ingot is drawn downward, the crystal growth rate becomes rate-limiting, and the drawing is performed. It has been difficult to increase production efficiency by increasing speed.

Therefore, in Patent Document 2, in order to efficiently produce a unidirectionally solidified silicon ingot, the side wall of the solidification tank in which the molten metal is held is opened, and the solidified silicon is released horizontally through the opened side wall. A method of casting silicon that is drawn obliquely upward with respect to the direction is disclosed.
In the silicon casting method described in Patent Document 2, since the crystal growth direction and the ingot drawing direction are different, the crystal growth rate is not hindered, and the drawing rate can be increased.
Japanese Patent Laid-Open No. 08-310898 Japanese Patent Laid-Open No. 10-182286

By the way, in the casting method described in Patent Document 2, the molten metal is held by the side wall of the coagulation tank and the ingot by opening the side wall of the coagulation tank and pulling the ingot obliquely upward from the opened portion. It is supposed to be configured. Thereby, the solidification interface between the ingot and the molten metal is inclined with respect to the horizontal direction.
As a result, inclusions such as oxide floating in the molten metal are trapped at the solidification interface and are easily taken into the ingot, and the quality of the ingot may be significantly deteriorated. In addition, the impurity element in silicon is discharged from the solid phase (ingot) to the liquid phase (molten metal), but since the solidification interface is inclined with respect to the horizontal plane, the concentration of this impurity element is There was a possibility of fluctuation in the thickness direction of the ingot.

  The present invention has been made in view of the above-described circumstances, and a high-quality ingot can be obtained without inclusion of inclusions such as oxides or impurity elements in the ingot, and the drawing speed can be increased. It is an object of the present invention to provide a continuous casting method, a continuous casting apparatus, and an ingot obtained thereby, which can greatly improve production efficiency.

  In order to solve this problem, a continuous casting apparatus according to the present invention is a continuous casting apparatus that continuously produces an ingot obtained by unidirectionally solidifying a molten metal, and holds the molten metal. And a mold having one end in the horizontal direction positioned below the molten metal holding part, and the mold is inclined with respect to the horizontal plane so as to gradually go downward as it goes to the other side in the horizontal direction. The bottom surface portion is provided with a cooling means, and the molten metal supplied from the molten metal holding portion is solidified in one direction by the cooling means, and the obtained ingot is obtained. The mold is continuously drawn along the bottom surface of the mold.

  In the continuous casting apparatus having this configuration, the molten metal holding part is located at the one end in the horizontal direction of the mold having the bottom part gradually inclined downward toward the other side in the horizontal direction. Since the cooling means is provided, the molten metal supplied from the supply part of the molten metal holding part is cooled and solidified by the cooling means provided on the bottom part of the mold. The solidification interface extends in the horizontal direction due to the balance of heat input from the holding part.

Thereby, inclusions floating in the molten metal in the molten metal holding part are located away from the ingot solidified below the molten metal holding part, and mixing of inclusions into the ingot can be prevented. Moreover, the impurity element discharged | emitted from a solid phase (ingot) to a liquid phase (molten metal) will be concentrated in the molten metal holding | maintenance part located above an ingot, and a high purity ingot can be obtained. it can.
Furthermore, since the crystal growth direction and the ingot drawing direction are different, the drawing speed can be increased without being limited by the crystal growth speed, and the production efficiency can be greatly improved.
Moreover, since the mold and the molten metal do not contact each other and only the solidified ingot contacts the mold, the deterioration of the mold can be prevented and the casting cost can be greatly reduced.

Here, the molten metal holding portion may be held by electromagnetic force.
In this case, it is possible to suppress contact between the refractory and the molten metal by holding the molten metal with electromagnetic force. Thereby, reaction of a molten metal and a refractory can be suppressed and generation | occurrence | production of inclusions, such as an oxide, and generation | occurrence | production of gas, such as SiO, can be prevented. In addition, when the molten metal is held by electromagnetic force, the molten metal is also heated secondarily, so that the temperature difference between the molten metal and the ingot can be increased to promote unidirectional solidification.

Moreover, you may comprise so that the surface temperature of the said bottom face part may differ in the extension direction.
In this case, by setting the surface temperature of the bottom surface along the extending direction of the bottom surface, that is, the drawing direction of the ingot, it is possible to control the crystal growth and obtain a high quality ingot. For example, below the molten metal holding portion, the surface temperature of the bottom surface portion on the side where the molten metal holding portion and the bottom surface portion are close to each other is increased, and the surface temperature of the bottom surface portion is decreased as the molten metal holding portion and the bottom surface portion are separated from each other. By adjusting to, the solidification interface between the molten metal and the ingot can be kept stable and horizontal. In addition, by increasing the surface temperature of the bottom surface portion of the portion where the molten metal holding portion and the bottom surface portion are close to each other, the ingot is prevented from growing into the molten metal holding portion, and the ingot is pulled out. It can be done smoothly.

Further, the surface temperature of the bottom surface of the mold may be set so as to gradually become lower toward the other side in the horizontal direction and the lower side.
In this case, as the ingot is pulled out toward the other side in the horizontal direction and downward, the temperature of the bottom surface portion becomes lower, so that the isothermal surface of the ingot solidified in one direction becomes horizontal, and the level of the solidification interface Can be improved.

Here, the maximum surface temperature of the bottom surface of the mold may be set immediately below the melting point of the ingot.
In this case, by setting the maximum temperature of the surface temperature of the bottom portion directly below the melting point of the ingot, it is possible to prevent the molten metal from being rapidly cooled at one side portion in the horizontal direction of the bottom portion and to smoothly draw the ingot. be able to.

Moreover, it is good also as a structure which heat-insulates the side part of the said casting_mold | template.
In this case, the molten metal in the mold is not cooled from the side surface portion, and the ingot in which the crystal is grown only from the bottom surface portion and solidified in one direction can be reliably produced.

Furthermore, you may provide the discharge means which discharges the said molten metal outside in the said molten metal holding | maintenance part.
In this case, as the solidification progresses, the impurity element concentrates in the molten metal holding part, and when the impurity concentration rises to a predetermined value, the molten metal in the molten metal holding part is discharged to obtain a high purity ingot. It can be produced for a long time. Further, inclusions floating in the molten metal in the molten metal holding part can be discharged, and inclusions can be reliably prevented.

Further, the mold is configured such that a plurality of divided units are connected in the extending direction of the mold, the units are sequentially fed from the molten metal holding part side, and the unit is combined with the ingot. You may comprise so that it may pull out.
In this case, by pulling out the unit together with the ingot, the sliding contact between the mold and the ingot can be suppressed, and surface defects of the ingot can be prevented. Moreover, since the unit on the side of the molten metal holding part is sequentially updated, it is possible to prevent the deterioration of the ingot quality due to the deterioration of the mold.

  Furthermore, the continuous casting method according to the present invention uses the above-described continuous casting apparatus to incline the unidirectionally solidified ingot with respect to the horizontal plane so as to gradually go downward as it goes to one side in the horizontal direction. It is characterized by being pulled out.

  According to the continuous casting method of this configuration, the solidification progresses so that the solidification interface between the molten metal in the molten metal holding portion and the ingot in the mold extends in the horizontal direction, so that inclusion inclusions and impurity elements can be prevented. A few high quality ingots can be obtained. Further, by making the crystal growth direction (solidification progress direction) different from the ingot drawing direction, it is possible to increase the drawing speed and greatly improve the production efficiency.

  Further, the ingot according to the present invention is produced by the above-described continuous casting apparatus, and is configured such that the crystal growth direction intersects with the thickness direction of the ingot at an angle θ. Is set within a range of 0 ° <θ ≦ 20 °.

  In the ingot produced by the continuous casting apparatus described above, the crystal grows from the bottom surface portion toward the molten metal holding portion side between the bottom surface portion provided with the cooling means and the molten metal holding portion. Is inclined with respect to the thickness direction of the ingot. The crystal growth direction is the direction of a vector parallel to the major axis of the crystal grains constituting the ingot growing from the lower surface to the upper surface of the ingot and upward from the lower surface, and the angle θ is the vector and the ingot. It is an angle made with the normal line of the lower surface of. Here, this inclination angle θ coincides with the angle formed by the extending direction of the bottom surface and the extending direction (horizontal direction) of the solidification interface. Here, by setting the angle θ formed by the crystal growth direction and the ingot thickness direction to 20 ° or less, the drawing speed can be reliably improved. Furthermore, when the ingot is cut in the thickness direction, the number of crystal grain boundaries intersecting the cut surface can be suppressed.

  According to the present invention, a high-quality ingot can be obtained without inclusion of impurities such as oxides or impurity elements in the ingot, and the production speed can be greatly improved by increasing the drawing speed. A continuous casting method, a continuous casting apparatus, and a high quality ingot obtained thereby can be provided.

Embodiments of the present invention will be described below with reference to the accompanying drawings. 1 and 2 show a continuous casting apparatus 10 according to a first embodiment of the present invention.
A continuous casting apparatus 10 according to this embodiment is for continuously producing a silicon ingot 2 having a purity of 6 to 7 N class used as a material for a solar cell, and a molten metal for holding a molten silicon 1. A holding unit 20 and a mold 30 located below the molten metal holding unit 20 are provided.

Above the molten metal holding unit 20, as shown in FIG. 1, a raw material hopper 5 that stores metallic silicon powder, and a melting furnace 6 that melts the metallic silicon powder supplied from the raw material hopper 5 to generate molten silicon 1. Are arranged.
Here, the melting furnace 6 is a so-called skull melting furnace in which metal silicon powder is induction-heated using a divided water-cooled copper crucible, and since no refractory is used, impurities are mixed into the silicon melt 1. It is suppressed. A bottom 7 of the melting furnace 6 is provided with a discharge port 7 for discharging the molten silicon 1 to the molten metal holding unit 20, and is configured to adjust the discharged state of the molten silicon 1 using a freezing valve. .

The molten metal holding part 20 has a holding electromagnetic coil 22 and is configured to hold the molten silicon 1 using a pinch force generated by an interaction between an electric current and a magnetic field. That is, the silicon melt 1 is not held in a container made of a refractory material or the like, but the silicon melt 1 is held in a suspended state.
In the present embodiment, a discharge control electromagnetic coil 23 for discharging the molten silicon 1 held in the molten metal holding unit 20 is provided, and a storage unit 24 in which the discharged molten silicon 1 is stored is disposed. Has been.

  A carbon heater 25 for keeping the temperature of the molten silicon 1 is disposed on the upper part of the molten metal holding unit 20. A hole 26 is formed in a part of the carbon heater 25, and the molten silicon 1 discharged from the melting furnace 6 is supplied to the molten metal holding unit 20 through the hole 26. An air gap is defined between the carbon heater 25 and the molten silicon 1 held by the molten metal holding part 20, and an inert gas is introduced to circulate an inert gas (Ar gas in FIG. 1) through the air gap. Means 27 are provided.

  The molten metal holding unit 20 is provided with a supply unit 21 that supplies the molten metal downward, and the supply unit 21 is positioned on one side in the horizontal direction of the mold 30 (left side in FIG. 1). Has been. The horizontal length (the horizontal length in FIG. 1) of the supply unit 21 is set within a range of 3000 mm to 300 mm, and is 1500 mm in the present embodiment.

  As shown in FIG. 1, the mold 30 is inclined with respect to the horizontal plane so as to gradually move downward from one horizontal side where the molten metal holding portion 20 is disposed toward the other horizontal side (right side in FIG. 1). 2 and a main body 33 having a U-shaped cross section comprising a side wall 32 extending so as to be orthogonal to the bottom surface portion 31 as shown in FIG. And a lid portion 34 disposed to face the bottom surface portion 31. In addition, the cover part 34 is arrange | positioned only at the horizontal direction other side part of the casting_mold | template 30 as shown in FIG.

  Here, the angle θ formed by the extending direction of the bottom surface portion 31 of the mold 30 and the horizontal plane is set in a range of 0 ° <θ ≦ 20 °, and in this embodiment, θ = 7.66 °. Has been. Further, the width of the bottom surface portion 31 (the length in the left-right direction in FIG. 2) is set within a range of 150 mm to 3000 mm, and is 1000 mm in the present embodiment. Further, the height of the side wall 32 (length in the vertical direction in FIG. 2) is set within a range of 20 mm to 500 mm, and is set to 200 mm in the present embodiment.

  Panel-shaped cooling means 35 is provided on the bottom surface portion 31 of the mold 30. By this cooling means 35, the surface temperature of the bottom surface portion 31 is adjusted to be different in the extending direction of the bottom surface portion 31 (mold 30). In this embodiment, the surface temperature of the bottom surface portion 31 of the horizontal one side portion (arrow U in FIG. 1) of the cooling means 35 is set to the highest, and is set to 1410 ° C., which is directly below the melting point of silicon. The surface temperature of the bottom surface portion 31 of the other side portion in the horizontal direction (arrow V in FIG. 1) is 800 ° C.

In addition, as shown in FIG. 2, a heat insulating material 36 is disposed on the side of the mold 30, and heat dissipation from the side wall 32 portion of the mold 30 is suppressed.
Furthermore, as shown in FIG. 1, a temperature controller 9 for adjusting the temperature of the produced silicon ingot 2 is provided on the downstream side of the mold 30 in the drawing direction.

Next, the continuous casting method by the continuous casting apparatus 10 which is this embodiment is demonstrated.
Metal silicon powder is supplied from the raw material hopper 5 to the melting furnace 6. In the melting furnace 6, the metal silicon powder is melted by induction heating to generate the molten silicon 1. Then, the molten silicon 1 is supplied to the molten metal holding unit 20 from the outlet 7 provided at the bottom of the melting furnace 6.

In the molten metal holding unit 20, the molten silicon 1 is held by the pinch force of the holding electromagnetic coil 22, and the supply unit 21 is directed to the bottom surface 31 of the mold 30.
Here, heat is removed by the cooling means 35 provided on the bottom surface portion 31 of the mold 30, so that solidification proceeds in one direction from the bottom surface portion 31 side.

  At this time, the surface temperature of the bottom surface portion 31 of the mold 30 is adjusted to be different in the extending direction of the bottom surface portion 31 (mold 30). In this embodiment, the horizontal one side portion of the cooling means 35 (FIG. 1). The surface temperature of the arrow U) is 1410 ° C., and the surface temperature of the other horizontal portion of the cooling means 35 (arrow V in FIG. 1) is 800 ° C., so that the silicon ingot 2 (solid phase) The solidification interface with the molten silicon 1 (liquid phase) is horizontal as shown in FIG. 1 and is located at the supply unit 21 of the molten metal holding unit 20.

  In this way, solidification proceeds in one direction from the bottom surface portion 31 side of the mold 30, whereby the impurity element of the silicon ingot 2 (solid phase) is discharged to the silicon melt 1 (liquid phase) in the molten metal holding portion 20. The Therefore, as time passes, the impurity elements of the molten silicon 1 in the molten metal holding part 20 are concentrated. Therefore, when a predetermined time has elapsed, the silicon melt 1 is discharged to the storage unit 24 by the discharge control electromagnetic coil 23, and the silicon melt 1 is newly supplied from the melting furnace 6 to the molten metal holding unit 20. Yes.

  The silicon ingot 2 formed by unidirectional solidification is along the mold 30 (bottom surface portion 31), that is, toward the other side in the horizontal direction (the right side in FIG. 1) and gradually down toward the horizontal plane. It is pulled out in the direction of inclination. The temperature of the drawn silicon ingot 2 is adjusted by the temperature controller 9. As a result, a plate-shaped silicon ingot 2 having a thickness t (200 mm) and a width W (1000 mm) is continuously produced.

  In the silicon ingot 2 produced in this way, as shown in FIG. 3, the crystal growth direction intersects the thickness direction of the silicon ingot 2 (vertical direction in FIG. 3) at an angle θ. It is configured. That is, in the silicon ingot 2 produced by the continuous casting apparatus 10 of the present embodiment, crystals are melted from the bottom surface portion 31 to the molten metal holding portion 20 between the bottom surface portion 31 provided with the cooling means 35 and the molten metal holding portion 20. The angle θ formed by the extending direction of the bottom surface portion 31 and the extending direction of the solidification interface (horizontal direction) with respect to the thickness direction of the silicon ingot 2. It will be inclined at.

  According to the continuous casting apparatus 10 of the present embodiment, since the solidification interface extends in the horizontal direction as shown in FIG. 1, inclusions floating in the silicon melt 1 in the molten metal holding part 20 are present. In addition, it exists in a place away from the silicon ingot 2 that solidifies below the molten metal holding portion 20, and inclusions of inclusions in the silicon ingot 2 can be prevented. Further, the impurity element discharged from the solid phase (silicon ingot 2) to the liquid phase (silicon molten metal 1) is surely discharged to the molten metal holding part 20 located above the silicon ingot 2, A silicon ingot 2 of high purity and good quality can be obtained.

Since the solidification direction (crystal growth direction) and the drawing direction of the silicon ingot 2 are different, the drawing speed of the silicon ingot 2 can be increased without being limited by the solidification rate (crystal growth rate). , Production efficiency can be greatly improved.
Further, since the mold 30 and the silicon melt 1 are not in contact with each other and only the solidified silicon ingot 2 is in contact with the mold 30, deterioration of the mold 30 can be prevented, and the casting cost can be greatly reduced.

  Furthermore, since the molten metal holding part 20 is configured to hold the molten silicon 1 by the pinch force of the holding electromagnetic coil 22, the contact between the refractory and the molten silicon 1 can be suppressed. The reaction with the refractory can be suppressed and the generation of inclusions such as oxides can be prevented. Further, when the silicon melt 1 is held by the pinching force of the holding electromagnetic coil 22, the silicon melt 1 is also heated secondarily, so that there is a temperature difference between the silicon melt 1 and the silicon ingot 2. Can be provided to promote unidirectional solidification.

  Further, the surface temperature of the bottom surface portion 31 of the mold 30 is configured to be different in the extending direction. In particular, in the present embodiment, the bottom surface of the horizontal one side portion of the mold 30 where the molten metal holding portion 20 is located. Since the surface temperature of the portion 31 is 1410 ° C. and in the vicinity of the melting point of silicon, the silicon ingot 2 is prevented from growing into the molten metal holding portion 20 and the silicon ingot 2 is smoothly pulled out. Can be done. Further, the solidification interface can be extended in the horizontal direction by adjusting the surface temperature of the bottom surface portion 31.

  In addition, the molten metal holding unit 20 is provided with a discharge control electromagnetic coil 23 for discharging the molten silicon 1 and is configured to discharge the molten silicon 1 in the molten metal holding unit 20 when a predetermined time has elapsed. By discharging the silicon melt 1 in which the impurity element is concentrated and obtaining a new silicon melt 1 from the melting furnace 6, a high-purity silicon ingot 2 can be produced for a long time. In addition, inclusions floating in the molten metal holding unit 20 can be discharged at the same time, and inclusions can be reliably prevented.

Further, in the present embodiment, an inert gas introduction means 27 for introducing an inert gas (Ar gas) is provided in a gap defined between the molten silicon 1 of the molten metal holding unit 20 and the carbon heater 25. Therefore, the silica gas (SiO) produced | generated from the silicon molten metal 1 can be discharged | emitted to the exterior of the molten metal holding | maintenance part 20, and the purity of the silicon ingot 2 can be raised further.
In addition, since the carbon heater 25 is disposed on the molten metal holding unit 20, the temperature of the molten silicon 1 can be maintained, and a temperature difference is provided between the molten silicon 1 and the silicon ingot 2. Directional solidification can be promoted.

  In addition, the silicon ingot 2 produced by the continuous casting apparatus 10 according to the present embodiment is configured such that the crystal growth direction intersects with the thickness direction of the silicon ingot 2 at an angle θ. Since the angle θ is set in the range of 0 ° <θ ≦ 20 °, the number of crystal grain boundaries intersecting the cut surface can be suppressed when the silicon ingot 2 is cut in the thickness direction. . Therefore, when a plate material for a solar cell is molded, it can be configured such that no crystal grain boundary exists in the thickness direction of the plate material, and a high-quality plate material can be provided.

Next, a second embodiment of the present invention will be described with reference to the accompanying drawings. In addition, the same code | symbol is attached | subjected to the component same as 1st Embodiment, and detailed description is abbreviate | omitted. In FIG. 4, the continuous casting apparatus 50 which is the 2nd Embodiment of this invention is shown.
In the continuous casting apparatus 50 which is 2nd Embodiment, the casting_mold | template 60 is comprised by the several units 63 and 64 being connected in the extension direction.

  When casting by this continuous casting apparatus 50, the units 63 and 64 are sequentially fed from the side where the supply part 21 of the molten metal holding part 20 is located, and the units 63 and 64 are pulled out together with the silicon ingot 2. It is configured. That is, the units 63 and 64 constituting the mold 60 are sequentially updated, and the silicon ingot 2 and the mold 60 are pulled out integrally.

  According to the continuous casting apparatus 50 having this configuration, by sliding the units 63 and 64 in contact with the silicon ingot 2 together with the silicon ingot 2, sliding between the silicon ingot 2 and the mold 60 can be prevented. 2 surface defects can be prevented. In addition, since the units 63 and 64 located on the molten metal holding unit 20 side are sequentially updated, it is possible to obtain a high-quality silicon ingot 2 that is stable and does not deteriorate for a long time.

As mentioned above, although embodiment of this invention was described, this invention is not limited to this, It can change suitably in the range which does not deviate from the technical idea of the invention.
For example, the silicon ingot for solar cells has been described as being produced, but the present invention is not limited to this, and an ingot obtained by unidirectionally solidifying other metals or semiconductors is produced. Also good.

Moreover, although the molten metal holding | maintenance part was demonstrated as what hold | maintains a molten metal with the pinch force of an electromagnetic coil, it is not limited to this, The molten metal holding | maintenance part comprised with the refractory etc. may be sufficient. What is necessary is just to select suitably considering the reactivity of the molten metal to hold | maintain and a refractory.
Further, the metal silicon powder has been described as being configured to generate a molten silicon by melting in a so-called skull melting furnace, but the present invention is not limited to this and may be melted by other melting methods.
Further, the size of the supply part of the molten metal holding part and the size of the mold are not limited to this embodiment, and these dimensions can be arbitrarily set.

It is a schematic explanatory drawing of the continuous casting apparatus which is the 1st Embodiment of this invention. It is XX sectional drawing in FIG. It is sectional drawing along the drawing direction of the ingot produced by the continuous casting apparatus shown in FIG. It is a schematic explanatory drawing of the continuous casting apparatus which is the 2nd Embodiment of this invention.

Explanation of symbols

1 Silicon melt (melt)
2 Silicon ingot (ingot)
10, 50 Continuous casting apparatus 20 Molten metal holding part 22 Electromagnetic coil 23 Discharge control coil (discharge means)
30, 60 Mold 31 Bottom portion 35 Cooling means 63, 64 Unit

Claims (10)

A continuous casting apparatus for continuously producing an ingot obtained by unidirectionally solidifying a molten metal,
A molten metal holding part that holds the molten metal, and a mold in which one horizontal end is positioned below the molten metal holding part,
The mold has a bottom surface portion that is inclined with respect to a horizontal plane so as to gradually go downward as it goes to the other side in the horizontal direction, and cooling means is provided on the bottom surface portion,
A continuous casting apparatus, wherein the molten metal supplied from the molten metal holding part is solidified in one direction by the cooling means, and the obtained ingot is continuously drawn along the bottom surface part of the mold.   The continuous casting apparatus according to claim 1, wherein the molten metal holding unit is configured to hold the molten metal by electromagnetic force.   The continuous casting apparatus according to claim 1 or 2, wherein a surface temperature of the bottom surface portion of the mold is set to be different in an extending direction thereof.   4. The surface temperature of the bottom surface of the mold is set so as to gradually become lower toward the other side in the horizontal direction and the lower side, according to claim 1. Continuous casting equipment.   The continuous casting apparatus according to claim 4, wherein a maximum surface temperature of the bottom surface portion of the mold is set immediately below the melting point of the ingot.   The continuous casting apparatus according to any one of claims 1 to 5, wherein a side surface portion of the mold is thermally insulated.   The continuous casting apparatus according to any one of claims 1 to 6, wherein the molten metal holding portion is provided with a discharging means for discharging the molten metal to the outside.   The mold is configured by connecting a plurality of divided units in the extending direction of the mold. The units are sequentially fed from the molten metal holding part side, and the unit is pulled together with the ingot. The continuous casting apparatus according to any one of claims 1 to 7, wherein the continuous casting apparatus is pulled out.   Using the continuous casting apparatus according to any one of claims 1 to 8, the unidirectionally solidified ingot is inclined with respect to a horizontal plane so as to gradually go downward as it goes to one side in the horizontal direction. A continuous casting method, wherein the continuous casting method is drawn out in a direction to perform.   Produced by the continuous casting apparatus according to any one of claims 1 to 8, wherein the crystal growth direction intersects with the thickness direction of the ingot at an angle θ, The ingot is characterized in that the angle θ is set within a range of 0 ° <θ ≦ 20 °.

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