Method for purifying fluorine compound gas

Patent metadata

Field	Value
Publication number	US-10926211-B2
Application number	US-201716076536-A
Country	US
Kind code	B2
Filing date	Jan 27, 2017
Priority date	Feb 9, 2016
Publication date	Feb 23, 2021
Grant date	Feb 23, 2021

Abstract

Disclosed is a purification method for removing a metal component from a fluorine compound gas containing hydrogen fluoride and a metal component. This method includes a removing step for removing the hydrogen fluoride and the metal component therefrom by bringing the fluorine compound gas into contact with a solid metal fluoride to adsorb the hydrogen fluoride and the metal component on the metal fluoride. It is preferable for the fluorine compound gas to contain at least one kind selected from the group consisting of CIF, CIF3, IF5, IF7, BrF3, BrF5, NF3, WF6, SiF4, CF4, SF6 and BF3. It is also preferable for the metal fluoride to be an alkali metal fluoride or an alkali earth metal fluoride. Surprisingly, the presence of hydrogen fluoride in a fluorine compound gas makes it possible to remove a metal component therefrom as an impurity as a result of adsorption thereof by a metal fluoride.

First claim

The invention claimed is:

1. A method for purifying a fluorine compound gas by removing a metal component from a fluorine compound gas that contains hydrogen fluoride and the metal component, the method comprising the step of:
removing the hydrogen fluoride and the metal component by bringing the fluorine compound gas into contact with a solid metal fluoride to adsorb the hydrogen fluoride and the metal component on the metal fluoride.

2. The method for purifying the fluorine compound gas according to claim 1 , wherein the fluorine compound gas contains at least one fluorine compound selected from the group consisting of CIF, CIF 3 , IF 5 , IF 7 , BrF 3 , BrF 5 , NF 3 , WF 6 , SiF 4 , CF 4 , SF 6 and BF 3 .

3. The method for purifying the fluorine compound gas according to claim 1 , wherein before the removing step, a concentration adjusting step is performed for adjusting a content of the hydrogen fluoride contained in the fluorine compound gas to be in a range of 50 volume ppm to 1 volume %, relative to a total volume of a fluorine compound, the hydrogen fluoride and the metal component.

4. The method for purifying the fluorine compound gas according to claim 3 , wherein the concentration adjusting step is an addition step for adding the hydrogen fluoride to the fluorine compound gas.

5. The method for purifying the fluorine compound gas according to claim 1 , wherein the metal fluoride is at least one kind selected from the group consisting of an alkali metal fluoride and an alkali earth metal fluoride.

6. The method for purifying the fluorine compound gas according to claim 5 , wherein the metal fluoride is at least one kind selected from the group consisting of lithium fluoride, sodium fluoride, potassium fluoride, magnesium fluoride, calcium fluoride and barium fluoride.

7. The method for purifying the fluorine compound gas according to claim 1 , wherein in the removing step, a temperature at a time when the fluorine compound gas is brought into contact with the solid metal fluoride is a boiling point of a fluorine compound contained in the fluorine compound gas or higher to 50° C. or lower.

8. The method for purifying the fluorine compound gas according to claim 1 , wherein the metal component contained in the fluorine compound gas before the removing step contains at least one metal selected from the group consisting of Fe, Cr, Mn, Co, Ti, Mo, Cu and Ni.

9. The method for purifying the fluorine compound gas according to claim 1 , wherein a content of each of Fe, Cr, Mn, Co, Ti, Mo, Cu and Ni contained in the fluorine compound gas after the removing step is 10 mass ppb or less.

10. A method for purifying a fluorine compound gas by removing a metal component from a fluorine compound gas, wherein the fluorine compound gas is at least one kind selected from the group consisting of CIF, CIF 3 , IF 5 , IF 7 , BrF 3 , BrF 5 , NF 3 , WF 6 , SiF 4 , CF 4 , SF 6 and BF 3 , and contains hydrogen fluoride and at least one metal component selected from the group consisting of Fe, Cr, Mn, Co, Ti, Mo, Cu and Ni, the method comprising the step of:
removing the hydrogen fluoride and the metal component by bringing the fluorine compound gas into contact with at least one solid metal fluoride selected from the group consisting of lithium fluoride, sodium fluoride, potassium fluoride, magnesium fluoride, calcium fluoride and barium fluoride, to adsorb the hydrogen fluoride and the metal component on the metal fluoride,
wherein a content of each of Fe, Cr, Mn, Co, Ti, Mo, Cu and Ni contained in the fluorine compound gas after the removing step is 10 mass ppb or less.

11. A method for manufacturing a purified fluorine compound gas by removing a metal component contained in a fluorine compound gas, comprising the step of:
removing hydrogen fluoride and the metal component by bringing the fluorine compound gas containing the hydrogen fluoride and the metal component into contact with a solid metal fluoride to adsorb the hydrogen fluoride and the metal component on the metal fluoride.

12. The method for manufacturing the purified fluorine compound gas according to claim 11 , wherein a content of each of Fe, Cr, Mn, Co, Ti, Mo, Cu and Ni contained in the purified fluorine compound gas is 10 mass ppb or less.

13. The method for manufacturing the purified fluorine compound gas according to claim 11 , wherein a content of the hydrogen fluoride contained in the purified fluorine compound gas is 50 volume ppm or less, relative to a total volume of a fluorine compound, the hydrogen fluoride and the metal component.

Assignees

• Central Glass Co Ltd

Inventors

• Yao Akifumi
• Ooya Kohei
• Takeda Yuta
• Eto Jun

Classifications

• B01D53/0423 Primary

  Beds in columns · CPC title

• B01D2256/26

  Halogens or halogen compounds · CPC title

• C01D15/04

  Halides · CPC title

• Y02C20/30

  of perfluorocarbons [PFC], hydrofluorocarbons [HFC] or sulfur hexafluoride [SF6] · CPC title

• C01B21/083

  containing one or more halogen atoms · CPC title