US3920795A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Stabilization of sludge slurries
Assignee: Dravo Lime Co
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Filing: 1973-03-08
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Granted: 1975-11-18
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Expires: 1993-03-08
Abstract
Abstract The stabilization of aqueous sludge slurries containing calcium components is effected by the addition thereto of a granulated blast furnace slag. The aqueous sludge slurry should be dewatered such that the slurry contains about 25 to 60% solids and 75 to 40% aqueous portions, and the granulated blast furnace slag added thereto in an amount of about 1 to 20% based upon the amount of solids in the slurry.
Inventors
- 👤 Joseph G Selmeczi
- 👤 Donald H Marlin
- 👤 Daniel W Kestner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 23:51
CPC Classifications
C; C02; C02F; C02F11/00; C02F11/12; C02F11/008; C04; C04B; C04B28/00; C04B28/02; C04B28/08; Y; Y02; Y02W; Y02W30/00; Y02W30/50; Y02W30/91; Y10; Y10S; Y10S106/00; Y10S106/90
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
78 words
THE METHOD OF STABILIZING THE SOLIDS CONTENT OF AN QUEOUS SLUDGE SLURRY OF PREDOMINANTLY INORGANIC SOLIDS CONSISTING ESSENTIALLY OF CALCIUM SULFATES AND CALCIUM SULFITES, WHEREIN THE QUEOUS SLUDGE SLURRY COMPRISES 25-60% SOLIDS AND CORRESPONDING 75-40% AQUEOUS LIQOUR, COMPRISING ADDING TO AID AQUEOUS SLUDGE SLURRY AN AMOUNT OF BETWEEN 1-20 PERCENT, BASED UPON THE SOLIDS CONTENT OF THE SLURRY, OF A GRANULATED BLAST FURNACE SLAG, WHEREBY A STABLILZIED MASS OF SAID SOLIDS IS FORMED UPON SETTING OF SAID SOLIDS.
Claim 2
Independent Claim
78 words
THE METHOD OF STABILIZING THE SOLIDS CONTENT OF AN QUEOUS SLUDGE SLURRY OF PREDOMINANTLY INORGANIC SOLIDS CONSISTING ESSENTIALLY OF CALCIUM SULFATES AND CALCIUM SULFITES, WHEREIN THE QUEOUS SLUDGE SLURRY COMPRISES 25-60% SOLIDS AND CORRESPONDING 75-40% AQUEOUS LIQOUR, COMPRISING ADDING TO AID AQUEOUS SLUDGE SLURRY AN AMOUNT OF BETWEEN 1-20 PERCENT, BASED UPON THE SOLIDS CONTENT OF THE SLURRY, OF A GRANULATED BLAST FURNACE SLAG, WHEREBY A STABLILZIED MASS OF SAID SOLIDS IS FORMED UPON SETTING OF SAID SOLIDS.
Claim 3
Dependent Claim
34 words
The method as defined in claim 1 wherein said setting of said solids and formation of said stabilized mass is carried out while said solids are covered with supernatant aqueous liquor of the slurry.
Claim 4
Dependent Claim
40 words
The method as defined in claim 1 wherein said aqueous sludge slurry is the product of a wet scrubber system for the removal of sulfur dioxide from combustion gases and wherein said sludge solids contain calcium sulfite and calcium sulfate.
Claim 5
Dependent Claim
15 words
The method as defined in claim 3 wherein said sludge solids also contain fly ash.
Claim 6
Dependent Claim
35 words
The method as defined in claim 1 wherein said granulated blast furnace slag, prior to addition to said sludge slurry, is ground to a particle size of between 1800 to 4000 sq. cm per gram.
Claim 7
Dependent Claim
17 words
The method as defined in claim 1 wherein said sludge slurry solids are devoid of fly ash.
Claim 8
Dependent Claim
9 words
The product produced by the method of claim 1.
Claim 9
Dependent Claim
9 words
The product produced by the method of claim 4.
Claim 10
Dependent Claim
9 words
The product produced by the method of claim 6.
Claim 11
Independent Claim
99 words
The method of stabilizing the solids content of an aqueous sludge slurry of predominantly inorganic solids and consisting essentially of calcium sulfite, calcium sulfate and fly ash, wherein the aqueous sludge slurry comprises 25-60% solids and correspondingly 75-40% aqueous liquor, comprising: grinding a granulated blast furnace slag to a particle size in the range of 1800-4000 sq. cm. per gram and adding said ground granulated blast furnace slag to said aqueous slurry in an amount of 1-20%, based on the solids content of the slurry, whereby a stabilized mass of said solids is formed upon setting of said solids.
Claim 12
Independent Claim
99 words
The method of stabilizing the solids content of an aqueous sludge slurry of predominantly inorganic solids and consisting essentially of calcium sulfite, calcium sulfate and fly ash, wherein the aqueous sludge slurry comprises 25-60% solids and correspondingly 75-40% aqueous liquor, comprising: grinding a granulated blast furnace slag to a particle size in the range of 1800-4000 sq. cm. per gram and adding said ground granulated blast furnace slag to said aqueous slurry in an amount of 1-20%, based on the solids content of the slurry, whereby a stabilized mass of said solids is formed upon setting of said solids.
Claim 13
Dependent Claim
21 words
The method defined in claim 10 wherein said ground granulated blast furnace slag is intimately mixed with said sludge slurry solids.
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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) | 1978-11-17 | 1979-05-19 | 1979-11-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-11-17 | 1983-05-19 | 1983-11-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-11-17 | 1987-05-19 | 1987-11-18 | $7700.00 | Window Closed / Lapsed |