US4015997A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for stabilizing aqueous coal sludges
Assignee: Dravo Lime Co
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Filing: 1975-07-22
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Granted: 1977-04-05
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Expires: 1995-07-22
Abstract
Abstract The solids content of aqueous coal sludge slurries such as coal washings are stabilized in a hardened state by concentrating the solids content thereof, adding to the concentrated coal sludge 2-50% by weight of the solids of granulated blast furnace slag, with intimate mixing, and maintaining the mixture in a quiescent state and in the presence of excess water to produce a sedentary mass having load supportive properties suitable as landfill.
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 17:27
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: 6
Claim 1
Independent Claim
112 words
A process for converting an aqueous coal processing waste sludge, containing finely divided coal particles and waste materials from the beneficiation of coal, into a sedentary mass of improved load supportive properties comprising: a. providing a concentrated aqueous coal processing waste sludge having a solids content in the range of 20-80 weight percent solids; b. adding to the concentrated sludge between 2-50 percent by weight, based on the weight of said solids, of granulated blast furnace slag; c. intimately mixing the combined concentrated sludge and granulated blast furnace slag; and d. maintaining the resulting mixture in a substantially quiescent stage and in the presence of excess water to produce a sedentary mass.
Claim 2
Dependent Claim
112 words
A process for converting an aqueous coal processing waste sludge, containing finely divided coal particles and waste materials from the beneficiation of coal, into a sedentary mass of improved load supportive properties comprising: a. providing a concentrated aqueous coal processing waste sludge having a solids content in the range of 20-80 weight percent solids; b. adding to the concentrated sludge between 2-50 percent by weight, based on the weight of said solids, of granulated blast furnace slag; c. intimately mixing the combined concentrated sludge and granulated blast furnace slag; and d. maintaining the resulting mixture in a substantially quiescent stage and in the presence of excess water to produce a sedentary mass.
Claim 3
Dependent Claim
56 words
The process of claim 1 wherein said aqueous coal processing waste sludge contains less than 20 weight percent solids and wherein mechanical separation of a portion of the water in said sludge is made to increase the solids content thereof to the range of 20-80 weight percent prior to addition of said granulated blast furnace slag.
Claim 4
Dependent Claim
22 words
The process of claim 1 wherein said granulated blast furnace slag is added in an amount of between 5-25 percent by weight.
Claim 5
Dependent Claim
25 words
The process defined in claim 1 where said granulated blast furnace slag is ground to a particle size of between 1800-5000 sq. cm. per gram.
Claim 6
Dependent Claim
65 words
The process defined in claim 1 wherein said granulated blast furnace slag comprises a mixture of a first portion ground to a particle size of between 1800-5000 sq. cm. per gram and a second portion having a particle size coarser that 2500 sq. cm. per gram, with said first portion comprising 50-75 percent by weight of the total mixture of said granulated blast furnace slag.
References Cited (Backward Citations)
US3920795A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-04-04 | 1980-10-04 | 1981-04-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-04-04 | 1984-10-04 | 1985-04-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-04-04 | 1988-10-04 | 1989-04-05 | $7700.00 | Window Closed / Lapsed |