Graphitization furnace and method for producing graphite

1. A graphitization furnace for obtaining graphite from powder as a carbon source, comprising:

an electrically conductive crucible including a hollow configured to house the powder;

a first electrode including a columnar shaft and a head provided at an end of the shaft, the head having a shape selected from the group consisting of a sphere, a hemisphere, a column with a rounded edge, a cone, and a cone with a rounded tip, the first electrode being disposed above the crucible;

a second electrode disposed below the crucible;

a first vertical moving device configured to move the first electrode vertically relative to the crucible between a first position and a second position of the first electrode;

a second vertical moving device configured to move the second electrode vertically relative to the crucible between a first position and a second position of the second electrode; and

a power source configured to apply electric current to the powder through the crucible, the first electrode, and the second electrode,

wherein in the first position of the first electrode, the head of the first electrode is above the hollow of the crucible, and in the second position of the first electrode, the head of the first electrode is inserted into the hollow, and

wherein in the first position of the second electrode, the second electrode is free of contact with a bottom surface of the crucible, and in the second position of the second electrode, the second electrode is in contact with the bottom surface of the crucible.

2. The graphitization furnace of claim 1 , wherein the first head of the electrode at least in part projects radially outward from the shaft.

3. The graphitization furnace of claim 1 , further comprising:

an induction coil so disposed as to heat at least an upper face of the powder.

4. The graphitization furnace of claim 1 , wherein the crucible is made thinner toward a lowermost end of the hollow.

5. The graphitization furnace of claim 1 , further comprising:

a chamber so dimensioned as to enclose the crucible and configured to place the powder under a controlled atmosphere, the chamber including a first end and a second end, each of the first end and the second end including an opening capable of being closed;

conveyance means for conveying the crucible from the first end toward the second end; and

a first heater for preheating the powder.

6. The graphitization furnace of claim 1 , further comprising:

a second heater for preheating the electrode.

7. A method for producing graphite from powder as a carbon source, comprising:

housing the powder in a hollow of an electrically conductive crucible;

bringing a first electrode into contact with the powder via a first elevator device, the first electrode including a columnar shaft and a head provided at an end of the shaft, the head having a shape selected from the group consisting of a sphere, a hemisphere, a column with a rounded edge, a cone, and a cone with a rounded tip, the first electrode being disposed above the crucible;

bringing a second electrode in contact with a bottom surface of the crucible via a second elevator device, the second electrode being disposed below the crucible; and

applying electric current to the powder through the crucible, the first electrode, and the second electrode from a power source.

8. The method of claim 7 , further comprising:

sinking the head of the first electrode into the powder by a controlled distance to regulate density distribution of the powder.

9. The method of claim 7 , further comprising:

enclosing the crucible with a chamber so as to place the powder under a controlled atmosphere, the chamber including a first end and a second end, each of the first end and the second end including an opening capable of being closed;

preheating the powder; and

conveying the crucible from the first end toward the second end.

10. The method of claim 7 , further comprising:

preheating the first electrode.

11. The graphitization furnace of claim 1 , further comprising an insulating wall which surrounds the crucible, the insulating wall including a first opening through which the first electrode passes and a second opening through which the second electrode passes.