Patent US4491570A successfully refreshed from Google Patents.
US4491570A
Expired / Lapsed
US
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Removal of arsenic from hydrogen fluoride
Assignee: Arkema Inc
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Filing: 1984-05-03
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Granted: 1985-01-01
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Expires: 2004-05-03
Abstract
Abstract Arsenic impurities are removed from anhydrous hydrogen fluoride by treating the hydrogen fluoride with elemental chlorine and anhydrous hydrogen chloride or a fluoride salt or both and then separating the purified anhydrous hydrogen fluoride, preferably by distillation, from the nonvolatile arsenic compounds.
Inventors
- 👤 Gregory A. Wheaton
- 👤 David M. Gardner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 03:47
CPC Classifications
C; C01; C01B; C01B7/00; C01B7/19; C01B7/191; C01B7/195
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
64 words
A process for removing arsenic from arsenic contaminated anhydrous hydrogen fluoride which comprises intimately contacting said anhydrous hydrogen fluoride for an effective period of time and in effective amounts with elemental chlorine and a substance selected from the group consisting of anhydrous hydrogen chloride, a fluoride salt and mixtures thereof, and then recovering the anhydrous hydrogen fluoride having a substantially reduced amount of arsenic.
Claim 2
Dependent Claim
64 words
A process for removing arsenic from arsenic contaminated anhydrous hydrogen fluoride which comprises intimately contacting said anhydrous hydrogen fluoride for an effective period of time and in effective amounts with elemental chlorine and a substance selected from the group consisting of anhydrous hydrogen chloride, a fluoride salt and mixtures thereof, and then recovering the anhydrous hydrogen fluoride having a substantially reduced amount of arsenic.
Claim 3
Dependent Claim
19 words
The process of claim 1 wherein the anhydrous hydrogen fluoride is contacted with elemental chlorine and anhydrous hydrogen chloride.
Claim 4
Dependent Claim
17 words
The process of claim 2 wherein the anhydrous hydrogen fluoride is also contacted with a fluoride salt.
Claim 5
Dependent Claim
18 words
The process of claim 3 wherein the fluoride salt is an alkali metal or alkaline earth metal fluoride.
Claim 6
Dependent Claim
29 words
The process of claim 1 wherein the anhydrous hydrogen fluoride is recovered by first distilling off chlorine and hydrogen chloride, if present, and then distilling off anhydrous hydrogen fluoride.
Claim 7
Dependent Claim
27 words
The process of claim 2 wherein the amounts of chlorine and hydrogen chloride are each at least about 0.5% based on the weight of anhydrous hydrogen fluoride.
Claim 8
Dependent Claim
15 words
The process of claim 6 wherein the amounts range from about 1 to about 4%.
Claim 9
Dependent Claim
28 words
The process of claim 3 wherein the fluoride salt is present in an amount ranging from 0.01 to 0.75% based on the weight of the anhydrous hydrogen fluoride.
Claim 10
Dependent Claim
18 words
The process of claim 2 wherein the hydrogen chloride is generated in situ from an inorganic acid chloride.
Claim 11
Dependent Claim
22 words
The process of claim 3 wherein the fluoride salt is generated in situ from the salt of a halogen other than fluorine.
Claim 12
Dependent Claim
94 words
A process for removing arsenic from arsenic contaminated anhydrous hydrogen fluoride which comprises intimately contacting said anhydrous hydrogen fluoride for an effective period of time, at a temperature ranging from ambient to about 30° C. with from about 1% to about 4% elemental chlorine and from about 1% to about 4% of anhydrous hydrogen chloride, said amounts based on the weight of anhydrous hydrogen fluoride, and then recovering the anhydrous hydrogen fluoride with a substantially reduced arsenic content by first distilling off chlorine and hydrogen chloride and then distilling off said anhydrous hydrogen fluoride.
Claim 13
Dependent Claim
94 words
A process for removing arsenic from arsenic contaminated anhydrous hydrogen fluoride which comprises intimately contacting said anhydrous hydrogen fluoride for an effective period of time, at a temperature ranging from ambient to about 30° C. with from about 1% to about 4% elemental chlorine and from about 1% to about 4% of anhydrous hydrogen chloride, said amounts based on the weight of anhydrous hydrogen fluoride, and then recovering the anhydrous hydrogen fluoride with a substantially reduced arsenic content by first distilling off chlorine and hydrogen chloride and then distilling off said anhydrous hydrogen fluoride.
Claim 14
Dependent Claim
40 words
The process of claim 11 wherein the anhydrous hydrogen fluoride is also contacted with an alkali metal or alkaline earth metal fluoride in an amount from about 0.01% to about 0.75% based on the weight of the anhydrous hydrogen fluoride.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-01-01 | 1988-07-02 | 1989-01-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-01-01 | 1992-07-02 | 1993-01-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-01-01 | 1996-07-02 | 1997-01-01 | $7700.00 | Window Closed / Lapsed |