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Patent US4929435A successfully refreshed from Google Patents.
US4929435A
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US
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Manufacture of high purity low arsenic anhydrous hydrogen fluoride
Assignee: Honeywell International Inc
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Filing: 1988-07-11
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Granted: 1990-05-29
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Expires: 2008-07-11
Abstract
Abstract A process for manufacturing high purity anhydrous hydrogen fluoride (HF) having low levels of arsenic impurity by contacting anhydrous hydrogen fluoride product, or an intermediate product obtained during the manufacture of HF, with hydrogen peroxide to oxidize the arsenic impurity in the presence of a catalyst which comprises a catalytic amount of a component selected from the group consisting of molybdenum, a molybdenum compound, vanadium, and a vanadium compound, and a phosphate compound. The volatile trivalent arsenic impurity in the anhydrous hydrogen fluoride is oxidized to a non-volatile pentavalent arsenic compound and the resultant mixture is distilled to recover high purity anhydrous hydrogen fluoride with reduced levels of arsenic impurity. In one embodiment, an oxidizing agent such as nitric acid or a nitrate salt is added to the reaction mixture to oxidize organic compounds.
Inventors
- 👤 Barry J. Boghean
- 👤 Somanahalli N. Subbanna
- 👤 Charles L. Redmon
- 👤 Christian A. Wamser
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 03:34
CPC Classifications
C; C01; C01B; C01B7/00; C01B7/19; C01G; C01G28/00; C01B7/191; C01B7/195; C01B7/196
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
120 words
A process for manufacturing anhydrous hydrogen fluoride with reduced levels of arsenic impurity from arsenic contaminated anhydrous hydrogen fluoride which comprises the steps of: (a) contacting said anhydrous hydrogen fluoride with an effective amount of hydrogen peroxide to oxidize the arsenic impurity in the presence of a catalyst which comprises a catalytic amount of (i) a component selected from the group consisting of an organic molybdenum compound, vanadium, and a vanadium compound and, (ii) a phosphate compound, at a temperature and for a period of time sufficient to oxidize volatile trivalent arsenic impurities in the anhydrous hydrogen fluoride to non-volatile pentavalent arsenic compounds, and (b) distilling the resulting mixture and recovering anhydrous hydrogen fluoride with reduced levels of arsenic impurity.
Claim 2
Dependent Claim
120 words
A process for manufacturing anhydrous hydrogen fluoride with reduced levels of arsenic impurity from arsenic contaminated anhydrous hydrogen fluoride which comprises the steps of: (a) contacting said anhydrous hydrogen fluoride with an effective amount of hydrogen peroxide to oxidize the arsenic impurity in the presence of a catalyst which comprises a catalytic amount of (i) a component selected from the group consisting of an organic molybdenum compound, vanadium, and a vanadium compound and, (ii) a phosphate compound, at a temperature and for a period of time sufficient to oxidize volatile trivalent arsenic impurities in the anhydrous hydrogen fluoride to non-volatile pentavalent arsenic compounds, and (b) distilling the resulting mixture and recovering anhydrous hydrogen fluoride with reduced levels of arsenic impurity.
Claim 3
Dependent Claim
32 words
The process of claim 1 in which the arsenic contaminated hydrogen fluoride is free of an amount of organic contaminants which would interfere with the hydrogen peroxide oxidation of said arsenic impurities.
Claim 4
Dependent Claim
31 words
The process of claim 2 wherein more than the stoichiometric amount of hydrogen peroxide is used which is required for oxidation of said trivalent arsenic impurities to said pentavalent arsenic compounds.
Claim 5
Dependent Claim
20 words
The process of claim 3 wherein the anhydrous hydrogen fluoride starting material has a purity of 99.95% HF or better.
Claim 6
Dependent Claim
19 words
The process of claim 3 wherein the hydrogen peroxide is 50% to 70% by weight commercial grade hydrogen peroxide.
Claim 7
Dependent Claim
14 words
The process of claim 1 wherein said component (i) is an organic molybdenum compound.
Claim 8
Dependent Claim
11 words
The process of claim 1 wherein said component (i) is vanadium.
Claim 9
Dependent Claim
14 words
The process of claim 1 wherein said component (i) is an organic vanadium compound.
Claim 10
Dependent Claim
14 words
The process of claim 1 wherein said component (i) is an inorganic vanadium compound.
Claim 11
Dependent Claim
12 words
The process of claim 1 wherein said component (i) is ammonium vanadate.
Claim 12
Dependent Claim
12 words
The process of claim 1 wherein said component (i) is sodium vanadate.
Claim 13
Dependent Claim
20 words
The process of claim 3 wherein the amount of hydrogen peroxide used is at least 3 times the stoichiometric amount.
Claim 14
Dependent Claim
24 words
The process of claim 3 wherein the reaction is carried out at a temperature in the range of about 15° to about 75° C.
Claim 15
Dependent Claim
45 words
The process of claim 3 wherein the amount of the metal component in the catalyst is at least about 3.7 ppm based on 100% HF and the amount of the phosphate component in the catalyst is at least about 3.5 ppm based on 100% HF.
Claim 16
Dependent Claim
26 words
The process of claim 3 wherein the amount of said metallic compound in the catalyst is about 10 to about 65 ppm based on 100% HF.
Claim 17
Dependent Claim
139 words
A process for manufacturing anhydrous hydrogen fluoride with reduced levels of arsenic impurity from arsenic and organic material contaminated anhydrous hydrogen fluoride which comprises the steps of: (A) contacting said anhydrous hydrogen fluoride with: (1) an effective amount of hydrogen peroxide to oxidize the arsenic impurity, in the presence of a catalyst which comprises a catalytic amount of: (a) a component selected from the group consisting of an organic molybdenum compound, vanadium, and a vanadium compound, and (b) a phosphate compound, and (2) an effective amount of an oxidizing agent to oxidize the organic material present, at a temperature and for a period of time sufficient to oxidize volatile trivalent arsenic impurities in the anhydrous hydrogen fluoride to non-volatile pentavalent arsenic compounds, and (B) distilling the resulting mixture and recovering anhydrous hydrogen fluoride with reduced levels of arsenic impurity.
Claim 18
Dependent Claim
139 words
A process for manufacturing anhydrous hydrogen fluoride with reduced levels of arsenic impurity from arsenic and organic material contaminated anhydrous hydrogen fluoride which comprises the steps of: (A) contacting said anhydrous hydrogen fluoride with: (1) an effective amount of hydrogen peroxide to oxidize the arsenic impurity, in the presence of a catalyst which comprises a catalytic amount of: (a) a component selected from the group consisting of an organic molybdenum compound, vanadium, and a vanadium compound, and (b) a phosphate compound, and (2) an effective amount of an oxidizing agent to oxidize the organic material present, at a temperature and for a period of time sufficient to oxidize volatile trivalent arsenic impurities in the anhydrous hydrogen fluoride to non-volatile pentavalent arsenic compounds, and (B) distilling the resulting mixture and recovering anhydrous hydrogen fluoride with reduced levels of arsenic impurity.
Claim 19
Dependent Claim
16 words
The process of claim 16 wherein the oxidizing agent is nitric acid or a salt thereof.
Claim 20
Dependent Claim
12 words
The process of claim 16 wherein the oxidizing agent is nitric acid.
Claim 21
Dependent Claim
15 words
The process of claim 16 wherein the oxidizing agent is a salt of nitric acid.
Claim 22
Dependent Claim
12 words
The process of claim 16 wherein the oxidizing agent is sodium nitrate.
References Cited (Backward Citations)
DE62309C
Cited
FR1335675A
Cited
US3166379A
Cited
US3663382A
Cited
US3689370A
Cited
US3687622A
Cited
US4032621A
Cited
JPS5354463A
Cited
US4083941A
Cited
EP0027607A1
Cited
US4491570A
Cited
JPS61151002A
Cited
US4752379A
Cited
US4752380A
Cited
US4756899A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-05-28 | 1993-11-27 | 1994-05-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-05-28 | 1997-11-27 | 1998-05-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-05-28 | 2001-11-27 | 2002-05-29 | $7700.00 | Window Closed / Lapsed |