Controlled hydrolysis of hazardous silicon polymer residue

11958,022

17/065013

October 07, 2020

A polymer handling method for a polycrystalline silicon manufacturing device, wherein the polymer byproducts are treated in a manner that the silicon polymers are hydrolyzed. The method creates a heated treatment gas with a moisture content that both treats the polymer to a depth of about 0.25 mm to prohibit formation of the friction and shock sensitive layer near the polymer surface and keeps the hydrolyzed polymer humidified. Furthermore the polymer handling method includes inactivation of the polymer, removal of the polymer of the system and disposal of the polymer after removal.

Mitsubishi Polycrystalline Silicon America Corporation (MIPSA) (Theodore, AL, US); HIGH-PURITY SILICON CORPORATION (Yokkaichi, JP)

Mitsubishi Polycrystalline Silicon America Corporation (MIPSA) (Theodore, AL, US), HIGH-PURITY SILICON CORPORATION (Yokkaichi, JP)

1. A polymer handling method, comprising: providing a sealable vessel containing silicon polymers which are a byproduct of a production of polycrystalline silicon in a Siemens process or a byproduct from a silicon epitaxy reactor; sealing the vessel to close the vessel to prevent gas or fluid leaking from the vessel; filling the vessel with an atmosphere having an oxygen concentration in the range of 0.1 to 3 volume %; filling the vessel with a hydrolyzing gas having a range of about 90 to 120 grains of moisture over a temperature range of about 50 to 70° C.; whereby the silicon polymers are, in whole or in part, humidified.

2. The polymer handling method of claim 1 , wherein the silicon polymers are one or more polymers selected from the group consisting of: non-hydrolyzed Si 2 Cl 6 , non-hydrolyzed Si 2 HCl 5 , non-hydrolyzed Si 2 H 2 Cl 4 , non-hydrolyzed Si 3 Cl 8 , and non-hydrolyzed Si 4 Cl 10 .

3. The polymer handling method of claim 1 , wherein a flow rate of gas filling the vessel does not exceed about 0.15 m/s.

4. The polymer handling method of claim 1 , wherein when filling the vessel with the atmosphere having an oxygen concentration in the range of 0.1 to less than 3 volume %, the gas having the majority concentration is an inert gas.

5. The polymer handling method of claim 1 , wherein when filling the vessel with the atmosphere having an oxygen concentration in the range of 0.1 to less than 3 volume %, the gas having the majority concentration is a member selected from the group consisting of nitrogen, helium, neon, argon, krypton or xenon.

6. The polymer handling method of claim 1 , wherein filling the vessel with a hydrolyzing gas having a moisture content of about 100 grains of moisture.

7. The polymer handling method of claim 1 , wherein the vessel is filled with a hydrolyzing gas having a moisture content of about 100 grains of moisture at about 57° C.

8. The polymer handling method of claim 1 , wherein the humidification of silicon polymers is in an amount selected from the group consisting of: about 25%, about 35%, about 45% about 50%, about 65%, about 75%, about 85%, about 95% and about 100%.

9. The polymer handling method of claim 1 , further comprising: opening the vessel and treating the vessel with pressurized water; and collecting the water containing diluted polymer; and waste treating the water containing diluted polymer to remove wastes from the water.

10. A polymer handling method for a polycrystalline silicon manufacturing device, comprising: providing the polycrystalline silicon manufacturing device containing silicon polymers which are a byproduct of a production of polycrystalline silicon in a Siemens process or a byproduct from a silicon epitaxy reactor; sealing the polycrystalline silicon manufacturing device to close the polycrystalline silicon manufacturing device to prevent gas or fluid leaking from the polycrystalline silicon manufacturing device; filling the polycrystalline silicon manufacturing device with an atmosphere having an oxygen concentration less than 3 volume %; filling the polycrystalline silicon manufacturing device with a hydrolyzing gas having a range of about 90 to 120 grains of moisture over a temperature range of about 50 to 70° C.; whereby the silicon polymers are, in whole or in part, humidified; opening the polycrystalline silicon manufacturing device and treating the polycrystalline silicon manufacturing device with pressurized water; collecting the water containing diluted polymer; waste treating the water containing diluted polymer to remove wastes from the water; covering exhaust port openings of an exhaust system of the polycrystalline silicon manufacturing device with threaded polytetrafluoroethylene (PTFE) caps to allow for nitrogen to flow out of the caps; and placing a nitrogen purge on the exhaust system of the polycrystalline silicon manufacturing device.

11. The polymer handling method of claim 10 , wherein the silicon polymers are one or more polymers selected from the group consisting of: non-hydrolyzed Si 2 Cl 6 , non-hydrolyzed Si 2 HCl 5 , non-hydrolyzed Si 2 H 2 Cl 4 , non-hydrolyzed Si 3 Cl 8 , and non-hydrolyzed Si 4 Cl 10 .

12. The polymer handling method of claim 10 , wherein the flow rate of gas filling the polycrystalline silicon manufacturing device does not exceed about 0.15 m/s.

13. The polymer handling method of claim 10 , wherein when filling the polycrystalline silicon manufacturing device with the atmosphere having an oxygen concentration less than 3 volume %, the gas having the majority concentration is an inert gas.

14. The polymer handling method of claim 10 , wherein when filling the polycrystalline silicon manufacturing device with the atmosphere having an oxygen concentration less than 3 volume %, the gas having the majority concentration is a member selected from the group consisting of nitrogen, helium, neon, argon, krypton or xenon.

15. The polymer handling method of claim 10 , wherein filling the polycrystalline silicon manufacturing device with a hydrolyzing gas having a moisture content of about 100 grains of moisture.

16. The polymer handling method of claim 10 , wherein filling the polycrystalline silicon manufacturing device with a hydrolyzing gas having a moisture content of about 100 grains of moisture at about 57° C.

17. The polymer handling method of claim 10 , wherein the humidification of silicon polymers is in an amount selected from the group consisting of: about 25%, about 35%, about 45% about 50%, about 65%, about 75%, about 85%, about 95% and about 100%.

20090188532 July 2009 Endoh
20190002296 January 2019 Colomb
56114815 September 1981

Machine translation of JP-56114815-A (Year: 1981). cited by examiner

edspgr.11958022