JP2015182112A - Casting apparatus for ingot and casting method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a casting apparatus for ingots that can reduce entrainment of oxide and prepare stably a plurality of uniformly-shaped molten cast ingots at low costs and a casting method.SOLUTION: A casting apparatus 10 for ingots casts ingots by inpouring molten metal 21 produced by heating and melting a metal material 20 into a mold main body 3 through nozzles 6 and 6 of a raw material dumping tank 11. The mold main body 3 comprises a plurality of chambers 32 and 32 for ingot casting, where a space between bottom parts of the chambers 32 and 32 for ingot casting is communicated with a flowing groove 41 of a carbon sheet 12. Further, at an upper part of the mold main body 3 is formed an exhausting groove 36 that overflows the molten metal 21 flowing into the chambers 32 and 32 for ingot casting at a predetermined height.

Description

  The present invention relates to an ingot casting apparatus and a casting method apparatus capable of stably producing a plurality of melt-cast ingots with less oxide entanglement and uniform shape at low cost.

  When compound semiconductors such as bismuth tellurium and indium antimony are synthesized in large quantities at the mass production level, it is necessary to prepare a large number of metal raw materials (ingots) of a certain shape in advance in order to shorten the time for weighing the input raw materials. Is done. In order to produce a metal ingot having a fixed shape, it is necessary to provide a process such as casting. In that process, however, oxide entrainment, variation in shape, and the like may occur. For this reason, shortening of the weighing time may not be sufficiently achieved.

Further, when taking out a plurality of ingots obtained by melting and casting metal raw materials from a mold, the following problems may occur.
(1) Since the oxide adhering to the raw material is caught in the cast ingot, the oxygen concentration in the ingot does not decrease. If there is an oxygen concentrating part in part, time and labor are required because it is necessary to remove it in a later process.
(2) In order to make the sizes of the plurality of ingots the same, it is necessary to provide a molten metal through hole in the mold. However, if the through hole is large, the molten metal in the through hole is also solidified when the cast ingot is solidified. The work which cut | disconnects the solidification part of a through-hole is required after ingot casting.
(3) When the cast ingot is taken out from the mold, a part of the ingot is fixed to the mold surface, and in the case of a brittle metal, the ingot may be damaged.

  In addition, about the reduction | decrease of an impurity, it is shown by patent document 1, and in the refinement | purification method and refiner | purifier, the solution is aimed at by heating a metal in a mold in vacuum.

JP 2002-212647 A

  However, according to the conventional purification method and the purification apparatus of Patent Document 1, although the reduction of impurities is eliminated, there is a problem that other problems described above are not solved.

  Therefore, the present invention has been made in view of such problems, and provides an ingot casting apparatus and a casting method capable of stably producing a plurality of melt-cast ingots having a uniform oxide shape and a uniform shape at a low cost. The purpose is to do.

  To achieve the above object, the present invention according to claim 1 is an ingot casting apparatus for forming a plurality of metal ingots having a low oxygen concentration, a high purity, and a uniform shape, wherein the metal raw material is heated and melted. A plurality of ingot casting chambers for pouring the molten metal into an ingot, communicating the ingot casting chambers at the bottom, and a discharge groove at the top for overflowing the molten metal flowing into the ingot casting chamber at a predetermined height An ingot casting apparatus characterized by being formed is provided.

  In order to achieve the above object, the present invention according to claim 2 is an ingot casting apparatus for forming a plurality of metal ingots having a low oxygen concentration, a high purity, and a uniform shape. There are a raw material charging tank containing the metal raw material and a plurality of ingot casting chambers connected to the raw material charging tank, and the molten metal heated and melted from the raw material charging tank into the ingot casting chamber overflows into the drainage section. A mold body having a discharge groove formed on the top, a carbon sheet having a flow groove formed on the bottom surface of the mold body and formed to communicate with the bottom of adjacent ingot casting chambers, and a carbon sheet And a bottom plate for closely contacting the mold body.

  In order to achieve the above object, according to a third aspect of the present invention, in the ingot casting apparatus according to the first or second aspect, the raw material charging tank, the mold body, the carbon sheet, and the bottom plate are formed of high-purity carbon. It is characterized by being.

  In order to achieve the above object, according to a fourth aspect of the present invention, in the ingot casting apparatus according to any one of the first to third aspects, the ingot casting chamber is expanded toward the upper side or the bottom side. It is characterized by having a tapered shape.

  In order to achieve the above object, the present invention according to claim 5 is an ingot casting method for forming a plurality of metal ingots having a low oxygen concentration, a high purity, and a uniform shape, wherein a metal raw material is reduced in an atmosphere. Alternatively, the step of heating and melting in an inert atmosphere, the step of allowing the heated and melted melt to flow into a plurality of ingot casting chambers that communicate with each other at the bottom, and the overflowing of the molten metal that has flowed into the ingot casting chamber at a predetermined height And an ingot casting method characterized in that it comprises a step.

  In order to achieve the above object, the present invention according to claim 6 is an ingot casting method for forming a plurality of metal ingots having a low oxygen concentration and a high purity and uniform shape. A step of accommodating a metal raw material in a raw material charging tank, a step of flowing molten metal obtained by heating and melting the metal raw material in a reducing atmosphere or an inert atmosphere into a plurality of ingot casting chambers connected to the raw material charging tank, and an adjacent ingot A step of causing the molten metals to flow into each other through a flow groove formed so as to communicate the bottoms of the casting chambers, and an oxide contained in the molten metal that has flowed into the ingot casting chamber and floated above the molten metal to a predetermined height. The step of causing the ingot to overflow, the step of solidifying the molten metal flowing into the ingot casting chamber by cooling, and the ingot It provides an ingot casting method comprising configured and a step of issuing Ri.

  In order to achieve the above object, according to a seventh aspect of the present invention, in the ingot casting method according to the fifth or sixth aspect, the ingot casting chamber is formed in a tapered shape that is expanded toward the upper side or the bottom side. Thus, the formed ingot can be easily taken out.

  According to the ingot casting apparatus and the casting method of the present invention, the molten metal obtained by heating and melting the metal raw material for casting into the ingot is caused to flow into the ingot casting chamber communicating at the bottom, and the molten metal that has flowed into the ingot casting chamber is allowed to flow. Since it was decided to make it overflow at a predetermined height, the oxide contained in the molten metal floats up to the upper part of the molten metal and is removed from the ingot casting chamber by the storage chamber and overflow, so that an ingot with less oxide entanglement is produced. can do. Further, since the shape of the ingot casting chamber is constant, there is an effect that a large number of melting and casting ingots having a uniform shape can be stably manufactured at low cost. Furthermore, the weighing time when an alloy is synthesized using the manufactured ingot can be shortened.

  Further, since the raw material charging tank, the mold body, the carbon sheet and the bottom plate constituting the casting mold are formed of high purity carbon, there is an effect that the ingot is prevented from being contaminated.

  Furthermore, since the ingot casting chamber is formed in a tapered shape that expands toward the upper side or the bottom side, even if the formed ingot is a brittle metal, it can be easily taken out without being damaged. .

It is sectional drawing which shows one Embodiment of the ingot casting apparatus which concerns on this invention. It is BB sectional drawing of the ingot casting apparatus shown in FIG. It is a flowchart which shows each process of the ingot casting method using the ingot casting apparatus shown in FIG.

  Hereinafter, an ingot casting apparatus and a casting method according to the present invention will be described in detail based on a preferred embodiment. FIG. 1 is a cross-sectional view showing an embodiment of an ingot casting apparatus according to the present invention, and a BB cross-sectional view of the ingot casting apparatus shown in FIG.

[Configuration of ingot casting machine]
The ingot casting apparatus 10 according to the illustrated embodiment is roughly composed of a raw material charging tank 11 for storing a metal raw material 20 for casting into an ingot, and a plurality of molten metal 21 in which the metal raw material 20 is heated and melted (this embodiment). (In the form, a total of 16 4 × 4 chambers) ingot casting chambers 32 and 32 are disposed, and the flow is disposed on the bottom surface of the mold body 3 and communicates with the bottoms of the adjacent ingot casting chambers 32 and 32. The carbon sheet 12 in which the grooves 41 are formed and the square plate-like bottom plate 5 that causes the carbon sheet 12 to be in close contact with the mold body 3 are provided.

  A plurality of nozzles 6, 6 are provided in the raw material charging tank 11 so as to communicate with the ingot casting chambers 32, 32 in order to pour a molten metal 21 obtained by heating and melting the metal raw material 20 into the ingot casting chambers 32, 32. It is attached. The mold body 3 is provided with partition-shaped partition members 34, 34 for dividing the plurality of ingot casting chambers 32, 32 into a cross-beam shape, and a drainage portion 33 is provided on the outer periphery of the mold body 3. Side wall portions 35 and 35 are formed upright.

  On the upper side of the mold body 3, there are provided discharge grooves 36, 36 that allow a part of the molten metal 21 that has flowed into the bottoms of the ingot casting chambers 32, 32 through the flow grooves 41 to overflow into the drainage part 33. Yes. The ingot casting chambers 32, 32 are separated from each other except that they are communicated with each other by a flow groove 41. In addition, the discharge grooves 36 and 36 that allow the molten metal 21 to overflow into the liquid discharge part 33 have the same height on the upper side of the mold body 3 in order to make the ingots cast in the ingot casting chambers 32 and 32 uniform. In the position. Further, even if oxides are contained in the molten metal 21 stored in the ingot casting chambers 32, 32, the oxide is discharged to the outside by overflowing the upper layer portion of the molten metal 21, so that there are few impurities. Ingots can be manufactured. The discharge grooves 36 and 36 connected to the four ingot casting chambers 32 and 32 located on the innermost side are formed in the partition members 34 and 34. Moreover, the drainage part 33 is arrange | positioned so that the casting_mold | template main body 3 may be surrounded. In the above configuration, each of the raw material charging tank 11, the mold body 3, the carbon sheet 12, and the bottom plate 5 is made of high-purity carbon in order to prevent contamination of the ingot.

  The ingot casting chambers 32, 32 are provided with a taper that expands toward the bottom so that the ingot after casting can be easily taken out from the ingot casting chambers 32, 32. In addition, when the raw material charging tank 11 is formed so as to be removable, it can be formed so as to be taken out from the upper side by providing a taper that expands toward the upper side of the ingot casting chambers 32, 32.

  The carbon sheet 12 is a plate-like member made of high-purity carbon, and in the predetermined area of the carbon sheet 4, opening-shaped flow grooves 41 and 41 are provided. The carbon sheet 12 is firmly fixed to the bottom surface of the mold body 3 by a plurality of bolts (carbon bolts) 7 and 7 so that the molten metal 21 does not leak out of the mold.

[Ingot casting method]
Next, the operation of the ingot casting apparatus 10 and the ingot casting method will be described with reference to FIG. FIG. 3 is a flowchart showing each step of the ingot casting method using the ingot casting apparatus shown in FIG.

  First, the metal raw material 20 is stored in the raw material charging tank 11, and the ingot casting apparatus 10 storing the metal raw material 20 is stored in a resistance heating furnace (not shown). After making the atmosphere in the resistance heating furnace (not shown) a reducing atmosphere or an inert atmosphere, the ingot casting apparatus 10 is heated to a temperature equal to or higher than the melting point of the metal raw material 20 to melt the metal raw material (step S1).

  When the metal raw material 20 is melted in the raw material charging tank 11, it becomes a molten metal 21, and the oxide floats in the upper part of the molten metal 21 in the raw material charging tank 11. 6 flows into each ingot casting chamber 32, 32 (step S2). Then, the molten metal 21 uniformly flows into the ingot casting chambers 32 and 32 through the flow grooves 41 formed in the carbon sheet 12 attached to the lower surface of the mold body 3. And the excess molten metal 21 is made to overflow through the discharge grooves 36 and 36 formed in the upper part of each ingot casting chamber 32 and 32 (step S3). Since the excess molten metal 21 is discharged to the drainage parts 33, 33, the height of the ingot formed in each ingot casting chamber 32, 32 is constant, and the size of the ingot to be cast can be made uniform. Moreover, the oxide which floated on the upper part of the molten metal 21 is effectively removed by making the upper layer part of the molten metal 21 overflow through the discharge grooves 36 and 36. Further, the carbon sheet 12 prevents the molten metal 21 from leaking from the lower part of the mold body 3 to the outside.

  In addition, when using the carbon sheet 12 with a small thickness, the depth of the flow groove 41 becomes shallow, so that it may take time to flow into the ingot casting chambers 32 and 32. Accordingly, the diameters of the nozzles 6 and 6 of the raw material charging tank 11 in order to balance the molten metal 21 injected from the raw material charging tank 2 into the ingot casting chambers 32 and 32 and the molten metal 21 flowing into each other through the flow grooves 41. It is preferable to carry out adjustments such as changing the size appropriately.

  Thereafter, the molten metal flowing into the ingot casting chambers 32, 32 is cooled to solidify to form an ingot (not shown) (step S4). Then, after separating the raw material charging tank 11 and the mold body 3, the mold body 3 and the ingots in the ingot casting chambers 32, 32 are pushed out by a dedicated device or manually, and the ingot is removed from the mold body 3 and the ingot casting chambers 32, 32. Remove (step S5) and move to storage location. At this time, since the ingot casting chambers 32 and 32 are provided with a taper, they can be easily taken out by pushing in the expanding direction. This completes the ingot casting.

  As described above, according to the ingot casting apparatus and the casting method of the present invention, the molten metal 21 is poured from the raw material charging tank 11 into the ingot casting chambers 32 and 32, and the carbon sheet 12 having the flow grooves 41 is provided below the molten metal 21. As a result, it is possible to stably produce a large number of melt-cast ingots having a uniform shape and a smaller shape than conventional ones at a low cost.

  Next, the Example which cast the ingot using the ingot casting apparatus 10 mentioned above is described. The present inventors used the ingot casting apparatus 10 shown in FIGS. 1 and 2 and made a 4N-Te raw material having a size of about 50 × about 45 × about 35 mm with a lower end of 24.8 × 24.8 and an upper end of 25 Melting casting of 16 Te ingots having a taper shape with a size of 0.0 × 25.0 and a height of 125 mm was performed. First, 20 pieces of about 500 g of 4N-Te blocks were put into the raw material charging tank 11, and the ingot casting apparatus 10 was set inside a resistance heating furnace (not shown). Then, after evacuating the inside of the furnace, 5N hydrogen gas was allowed to flow for 30 minutes to sufficiently replace the atmosphere in the furnace with hydrogen, and then the temperature was raised to 650 ° C. at a temperature rising rate of 10 ° C./1 minute. The Te block starts melting at 450 ° C. or higher during the temperature increase. The molten metal 21 is poured into the ingot casting chambers 32 and 32 through nozzles 6 and 6 provided at the lower part of the raw material charging tank 11.

  The molten metal 21 poured into each ingot casting chamber 32, 32 passes through a flow groove 41 of a carbon sheet 4 having a thickness of 0.5 mm provided at the lower part of each ingot casting chamber 32, 32, and adjacent each ingot casting chamber 32, 32. Thereafter, the molten metal 21 overflows into the drainage part 33 through the discharge groove 36 provided in the upper part of the ingot casting chambers 32, 32, whereby the height of the molten metal 21 in each ingot casting chamber 32, 32 is made uniform. Oxides floating on the upper layer of the molten metal 21 are excluded.

  Then, after holding the temperature of 650 ° C. for 60 minutes, the heater power supply of the resistance heating furnace is turned off and the furnace is cooled down. Removed inside. Thereafter, the bolts 7 and 7 were removed, the raw material charging tank 2 was separated from the mold body 3, and the carbon sheets 12 at the lower portions of the ingot casting chambers 32 and 32 were further removed. At this time, the molten metal 21 accumulated in the flow groove 41 is solidified to have a convex shape, but the convex portion has a thin plate shape with a thickness of about 1 mm, and therefore can be easily removed by using a spatula. Can do. After removing the convex portions, by pushing the lower part of the ingot, the ingots (16 pieces) in the ingot casting chambers 32 and 32 could be easily taken out without being damaged.

  With regard to the oxygen concentration of the 16 ingots cast as described above, a sample was cut out from the upper part and subjected to gas analysis by the LECO method (infrared absorption spectroscopy). As a result, good results of 30 ppm or less were obtained. Table 1 shows the measured values of the heights of the 16 ingots cast according to this example. The average value was 125.05 mm, and the variation was a standard deviation with a very small variation of 0.27 mm (the relative variation coefficient of the height of the ingot cast in this example was 0.216). %Met). On the other hand, when the oxygen concentration was analyzed in the same manner for the upper portion of the Te ingot after being solidified in the ingot casting chambers 32 and 32 without overflowing from the discharge groove 36, the average was about 70 ppm.

3 Mold body 5 Bottom plate 6 Nozzle 7 Bolt 10 Ingot casting apparatus 11 Raw material charging tank 12 Carbon sheet 20 Metal raw material 21 Molten metal 31 Reservoir chamber 32 Ingot casting chamber 33 Drainage portion 34 Partition member 35 Side wall portion 36 Discharge groove 41 Distribution groove

Claims (7)

An ingot casting apparatus for forming a plurality of metal ingots having a low oxygen concentration and high purity and uniform shape,
A plurality of ingot casting chambers for pouring molten metal obtained by heating and melting a metal raw material into an ingot are provided, the ingot casting chambers communicate with each other at the bottom, and the molten metal flowing into the ingot casting chamber has a predetermined height. An ingot casting apparatus characterized in that a discharge groove for overflowing is formed in the upper part. An ingot casting apparatus for forming a plurality of metal ingots having a low oxygen concentration and high purity and uniform shape,
A raw material charging tank for storing a metal raw material for casting into an ingot;
A plurality of ingot casting chambers communicated with the raw material charging tank, and a discharge groove is formed in the upper part for overflowing the molten metal that has been heated and melted from the raw material charging tank into the ingot casting chamber to the drainage part. Molded mold body,
A carbon sheet formed on the bottom surface of the mold body and formed with a flow groove formed so as to communicate with the bottoms of adjacent ingot casting chambers;
A bottom plate for closely attaching the carbon sheet to the mold body;
An ingot casting apparatus comprising: In the ingot casting apparatus according to claim 1 or 2,
The ingot casting apparatus, wherein the raw material charging tank, the mold main body, the carbon sheet and the bottom plate are made of high purity carbon. In the ingot casting apparatus according to any one of claims 1 to 3,
The ingot casting chamber is an ingot casting apparatus characterized in that the ingot casting chamber has a taper shape expanding toward the upper side or the bottom side. An ingot casting method for forming a plurality of metal ingots having a low oxygen concentration, high purity, and uniform shape,
Heating and melting a metal raw material in a reducing atmosphere or an inert atmosphere;
Flowing the melted heat into a plurality of ingot casting chambers that communicate with each other at the bottom; and
Overflowing the molten metal flowing into the ingot casting chamber at a predetermined height;
An ingot casting method, comprising: An ingot casting method for forming a plurality of metal ingots having a low oxygen concentration, high purity, and uniform shape,
Storing a metal raw material for casting into an ingot in a raw material charging tank;
Flowing the molten metal obtained by heating and melting the metal raw material in a reducing atmosphere or an inert atmosphere into a plurality of ingot casting chambers connected to the raw material charging tank;
Flowing the molten metal into each other through a flow groove formed so as to communicate with the bottoms of adjacent ingot casting chambers;
Overflowing the oxide contained in the molten metal flowing into the ingot casting chamber and floating above the molten metal at a predetermined height;
Solidifying the molten metal flowing into the ingot casting chamber by cooling it into an ingot;
Removing the ingot;
An ingot casting method, comprising: In the ingot casting method according to claim 5 or 6,
An ingot casting method characterized in that the ingot casting chamber is formed in a tapered shape that expands toward the upper side or the bottom side, so that the formed ingot can be easily taken out.

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