Roll crusher to produce high purity polycrystalline silicon chips

• US 20060070569A1
• Filed: 09/20/2005
• Published: 04/06/2006
• Est. Priority Date: 10/04/2004
• Status: Active Grant

• Current Assignee: Hemlock Semiconductor | Hemlock Semiconductor Operations LLC
• Original Assignee: Hemlock Semiconductor Corporation (Corning Incorporated)
• Inventors: Spencer, Roger Dale Jr., Horstman, Terence Lee, Andrejewski, Douglas, Dubay, Thomas
• Granted Patent: US 7,270,706 B2
• Time in Patent Office: Days
• US Class Current: 117/13
• CPC Class Codes: B02C 4/12 in the form of a plate
• CPC Class Codes: B02C 4/30 Shape or construction of rollers
• CPC Class Codes: C01B 33/02 Silicon forming single crystals or homogeneous polycrystalline material with defined structure C30B
• CPC Class Codes: C30B 15/00 Single-crystal growth by pulling from a melt, e.g. Czochralski method under a protective fluid C30B27/00
• CPC Class Codes: C30B 29/06 Silicon
• CPC Class Codes: Y10S 117/90 Apparatus characterized by composition or treatment thereof, e.g. surface finish, surface coating
• CPC Class Codes: Y10T 117/10 Apparatus
• CPC Class Codes: Y10T 117/1024 for crystallization from liquid or supercritical state

Abstract

A single roll crusher for comminuting high purity materials includes a roll with teeth spaced around the circumference of the roll. The roll is rotatably mounted inside a housing. The housing has a top with an entrance port, sides, and bottom with an exit port. The roll, teeth, and at least the inside surfaces of the top, sides, and bottom are fabricated from a material of construction that minimizes contamination of silicon. The material of construction may be tungsten carbide with a cobalt binder. The single roll crusher is used for processing polycrystalline silicon.

Claims

1. An apparatus comprising:

a roll,

teeth spaced around the circumference of the roll,

a shaft on which the roll is rotatably mounted

a housing having surfaces defining a cavity inside which the roll is mounted

an inlet port on top of the housing,

an exit port on bottom of the housing,

a plate inside the housing opposite the roll,

where the roll, teeth, plate, and housing surfaces defining the cavity are made from or clad with a material of construction that minimizes contamination of polycrystalline silicon.

2. The apparatus of claim 1, where the plate is flat.

3. The apparatus of claim 1, where the plate is tapered.

4. The apparatus of claim 1, where the plate is concave.

5. The apparatus of claim 1, where the plate has a longitudinal ridge.

6. The apparatus of claim 1, where the teeth span a full width of the roll.

7. The apparatus of claim 1, where the roll comprises a set of disks having teeth, and the teeth in the disks are offset from one another.

8. The apparatus of claim 1, where the material of construction is selected from the group consisting of carbides, cermets, ceramics, and combinations thereof.

9. The apparatus of claim 1, where the material of construction is selected from the group consisting of tungsten carbide;

tungsten carbide with a cobalt binder;

tungsten carbide with a nickel binder;

titanium carbide;

Cr₃C₂;

Cr₃C₂ with nickel-chrome alloy binder;

tantalum carbide;

niobium carbide;

silicon nitride;

silicon carbide in a matrix such as Fe, Ni, Al, Ti, or Mg;

aluminum nitride;

tantalum carbide;

niobium carbide;

titanium carbide with cobalt and titanium carbonitride;

nickel;

nickel-cobalt alloy;

iron; and

combinations thereof.

10. The apparatus of any one of claims 1 to 9, where the material of construction is tungsten carbide with a cobalt binder.

11. A method comprising:

a) comminuting polycrystalline silicon rods using the apparatus according to any one of claims 1 to 9,

b) sorting the product of step a), and

optionally c) removing impurities from the product of step a) or step b), or both, and

d) packaging resulting polycrystalline silicon pieces.

12. The method of claim 11, where step b) is performed using a step deck classifier or a rotary indent classifier.

13. The method of claim 11 or 12, where step c) is performed and includes exposing the product of step a) or step b), or both, to a magnetic field.

14. The method of any one of claims 11, 12, or 13 where the polycrystalline silicon pieces have particle size ranging from 0.2 to 250 millimeters.