Treatment process of phosphorous pentafluoride

Patent metadata

Field	Value
Publication number	US-2016158696-A1
Application number	US-201414901548-A
Country	US
Kind code	A1
Filing date	May 26, 2014
Priority date	Jun 27, 2013
Publication date	Jun 9, 2016
Grant date	—

Abstract

A treatment process of PF 5 including an absorption step for inducing absorption of PF 5 by an acidic solution containing an acid to obtain a solution containing PF 5 A − , an adjustment step to adjust concentration of HCl in the solution, and a thermolysis step for heating the solution containing PF 5 A − ions obtained in the absorption step or the adjustment step to decompose the solution to an acidic mixture containing H 3 PO 4 and HF.

First claim

1 . A treatment process of PF 5 comprising:
an absorption step for inducing absorption of PF 5 by an acidic solution containing at least one acid selected from hydrogen fluoride (HF), hydrogen chloride (HCl), hydrogen bromide (HBr), hydrogen iodide (HI), phosphoric acid (H 3 PO 4 ), and fluorophosphoric acid compound (H 2 PO 3 F or HPO 2 F 2 ) to obtain a solution containing PF 5 A − which is an ion composed of an acid-based anion A − selected from F, Cl − , Br − , I − , H 2 PO 4 − , HPO 3 F − , and PO 2 F 2 − combined with PF 5 ; and a thermolysis step for heating the solution obtained in the absorption step to 35° C. or higher and 75° C. or lower for 2 to 96 hours to decompose PF 5 A − in the solution to form an acidic mixture containing at least one of F and PO 4 3− .

2 . A treatment process of PF 5 comprising:
an absorption step for inducing absorption of PF 5 by an acidic solution containing at least one acid selected from hydrogen fluoride (HF), hydrogen chloride (HCl), hydrogen bromide (HBr), hydrogen iodide (HI), phosphoric acid (H 3 PO 4 ), and fluorophosphoric acid compound (H 2 PO 3 F or HPO 2 F 2 ) to obtain a solution containing PF 5 A − which is an ion composed of an acid-based anion A − selected from F − , Cl − , Br − , I − , H 2 PO 4 − , HPO 3 F − , and PO 2 F 2 − combined with PF 5 ; an adjustment step for blowing in a gas containing 1 to 100 vol % of hydrogen chloride (HCl), or adding hydrochloric acid of a concentration of 1 to 36 wt % to the solution obtained in the absorption step to adjust concentration of HCl in the solution to 1 to 36 wt %; and a thermolysis step for heating the solution obtained in the adjustment step to 35° C. or higher and 75° C. or lower to decompose the solution.

3 . The treatment process according to claim 1 , wherein a concentration of PF 5 to be absorbed in the acidic solution in the absorption step is 0.00001 vol % (0.1 ppm) or higher and lower than 20 vol % (200,000 ppm).

4 . The treatment process according to claim 1 , wherein the acidic solution to be used in the absorption step contains 1 molar equivalent or higher of acid against an amount of PF 5 to be absorbed.

5 . (canceled)

6 . The process according to claim 2 , wherein the thermolysis step comprises heating the solution obtained in the adjustment step for 2 to 96 hours to decompose PF 5 A − in the solution to form an acidic mixture containing at least one of F and PO 4 3− .

7 . The treatment process according to claim 2 , wherein a concentration of PF 5 to be absorbed in the acidic solution in the absorption step is 0.00001 vol % (0.1 ppm) or higher and lower than 20 vol % (200,000 ppm).

8 . The treatment process according to claim 2 , wherein the acidic solution to be used in the absorption step contains 1 molar equivalent or higher of acid against an amount of PF 5 to be absorbed.

Assignees

• Kanto Denka Kogyo Kk

Inventors

• Saito Katsuhiro
• Mita Shinji
• Oya Hiromi
• Katayama shinsuke
• Sakurai Yoshimasa
• Masauji Shogo
• Kubota Yuuki
• Fujisawa Hidehito

Classifications

• C02F2101/14

  Fluorine or fluorine-containing compounds · CPC title

• B01D53/68 Primary

  Halogens or halogen compounds · CPC title

• C02F1/66

  by neutralisation; pH adjustment (for degassing C02F1/20; using ion-exchange C02F1/42; for flocculation or precipitation of suspended impurities C02F1/52; for removing dissolved compounds C02F1/58) · CPC title

• C02F1/70

  by reduction {(C02F1/4676 takes precedence)} · CPC title

• C02F1/025

  Thermal hydrolysis · CPC title