Patent US3867519A successfully refreshed from Google Patents.
US4146568A
Expired / Lapsed
US
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Process for reducing radioactive contamination in waste product gypsum
Assignee: Olin Corp
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Filing: 1977-08-01
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Granted: 1979-03-27
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Expires: 1997-08-01
Abstract
Abstract A process for reducing the radioactive contamination in waste product gypsum in which waste product gypsum is reacted with a dilute sulfuric acid containing barium sulfate to form an acid slurry at an elevated temperature, the slurry is preferably cooled, the acid component is separated from the solid, and the resulting solid is separated into a fine fraction and a coarse fraction. The fine fraction predominates in barium sulfate and radioactive contamination. The coarse fraction predominates in a purified gypsum product of reduced radioactive contamination.
Inventors
- 👤 Paul H. Lange, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 23:14
CPC Classifications
G; G21; G21F; G21F9/00; G21F9/28
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
89 words
A process for reducing the radioactive contamination in waste product gypsum which comprises: (a) admixing waste product gypsum containing radioactive contamination with dilute sulfuric acid containing barium sulfate at an elevated temperature to form an acid slurry having a solid component comprised of a fine fraction and a coarse fraction, and (b) separating said fine fraction of solids from said coarse fraction, (c) whereby said fine fraction predominates in said barium sulfate and said radioactive contamination, and (d) whereby said coarse fraction predominates in gypsum of reduced radioactive contamination.
Claim 2
Dependent Claim
89 words
A process for reducing the radioactive contamination in waste product gypsum which comprises: (a) admixing waste product gypsum containing radioactive contamination with dilute sulfuric acid containing barium sulfate at an elevated temperature to form an acid slurry having a solid component comprised of a fine fraction and a coarse fraction, and (b) separating said fine fraction of solids from said coarse fraction, (c) whereby said fine fraction predominates in said barium sulfate and said radioactive contamination, and (d) whereby said coarse fraction predominates in gypsum of reduced radioactive contamination.
Claim 3
Dependent Claim
29 words
The process of claim 1 wherein said solid component is separated from said acid slurry and washed with water prior to separating said fine fraction from said coarse fraction.
Claim 4
Dependent Claim
17 words
The process of claim 2 wherein said acid slurry is admixed at a temperature above 60° C.
Claim 5
Dependent Claim
25 words
The process of claim 3 wherein said acid slurry is admixed at a temperature in the range of about 80° C. to the boiling point.
Claim 6
Dependent Claim
26 words
The process of claim 3 wherein said acid slurry is cooled to a temperature below about 60° C. before separating said acid from said solid component.
Claim 7
Dependent Claim
31 words
The process of claim 4 wherein said acid slurry is cooled to a temperature in the range of from about 15°-40° C. prior to separating said acid from said solid component.
Claim 8
Dependent Claim
15 words
The process of claim 2 wherein said fine fraction is less than about 150 microns.
Claim 9
Dependent Claim
15 words
The process of claim 3 wherein said fine fraction is less than about 80 microns.
Claim 10
Dependent Claim
15 words
The process of claim 6 wherein said fine fraction is less than about 80 microns.
Claim 11
Dependent Claim
26 words
The process of claim 3 wherein the proportion of said barium sulfate in said acid slurry ranges from about 0.01 to about 1.0 percent by weight.
Claim 12
Dependent Claim
26 words
The process of claim 8 wherein the proportion of said barium sulfate in said acid slurry ranges from about 0.03 to about 0.3 percent by weight.
Claim 13
Dependent Claim
35 words
The process of claim 3 wherein the concentration of said dilute sulfuric acid used to form said acid slurry ranges from about 10 to about 50 percent by weight of H 2 SO 4 .
Claim 14
Dependent Claim
32 words
The process of claim 11 wherein the concentration of said dilute sulfuric acid used to form said acid slurry ranges from about 15 to about 35 percent by weight of sulfuric acid.
Claim 15
Dependent Claim
40 words
The process of claim 3 wherein the concentration of said waste product gypsum added to said acid slurry, based upon anhydrous calcium sulfate equivalent, is in the range from about 50 to about 500 grams per liter of acid solution.
Claim 16
Dependent Claim
36 words
The process of claim 13 wherein the concentration of waste product gypsum added to said acid slurry, based upon anhydrous calcium sulfate equivalent, is in the range from about 150-350 grams per liter of acid solution.
Claim 17
Dependent Claim
17 words
The process of claim 15 wherein said fine fraction is separated from said coarse fraction by screening.
Claim 18
Dependent Claim
22 words
The process of claim 15 wherein said fine fraction is separated from said coarse fraction in an aqueous suspension in a hydrocyclone.
Claim 19
Dependent Claim
29 words
The process of claim 4 wherein said solid component, after admixing with water for washing, is de-watered and dried prior to separating said fine fraction from said coarse fraction.
References Cited (Backward Citations)
US3949047A
Cited
GB1394734A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-03-26 | 1982-09-25 | 1983-03-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-03-26 | 1986-09-25 | 1987-03-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-03-26 | 1990-09-25 | 1991-03-27 | $7700.00 | Window Closed / Lapsed |