US4375986A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for treating liquids wastes possessing a strong acidity
Assignee: Individual
•
Filing: 1981-04-08
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Granted: 1983-03-08
•
Expires: 2001-04-08
Abstract
Abstract Waste material having a pH not exceeding 2, and which have previously caused a serious disposal problem, are converted into stable, solid, useful, non-polluting products by first mixing the waste material with fly ash using about 30 to 260 parts of weight of ash for 100 parts of waste material, then neutralizing the resultant mixture using lime or calcium carbonate containing materials, next adding a calcium containing binder such as lime or Portland cement, and then solidifying the resultant mixture.
Inventors
- 👤 Philippe Pichat
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 14:08
CPC Classifications
C; C04; C04B; C04B18/00; C04B18/04; C04B18/0418; C02; C02F; C02F11/00; C02F11/008; Y; Y02; Y02W; Y02W30/00; Y02W30/50; Y02W30/91; Y10; Y10S; Y10S106/00; Y10S106/01
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
66 words
A process for treating liquid wastes diluted in water and possessing strong acidity (pH 2) to obtain stable solid materials that are non-polluting and resistant to water leaching, the process comprising the steps of: first, mixing the wastes with coal fly ash to form a pasty mass; then, neutralizing the pasty mass to neutral pH; and finally, adding a lime-containing substance to obtain a treated product.
Claim 2
Dependent Claim
66 words
A process for treating liquid wastes diluted in water and possessing strong acidity (pH 2) to obtain stable solid materials that are non-polluting and resistant to water leaching, the process comprising the steps of: first, mixing the wastes with coal fly ash to form a pasty mass; then, neutralizing the pasty mass to neutral pH; and finally, adding a lime-containing substance to obtain a treated product.
Claim 3
Dependent Claim
48 words
Process according to claim 1 wherein said step of mixing the wastes and fly ash is performed at regular pressure and at a temperature ranging from below 0° C. to 100° C., using about 30 to 260 parts by weight of ash for 100 parts of the waste.
Claim 4
Dependent Claim
28 words
Process according to either claim 1 or 2 wherein said neutralizing step is effected using lime or products containing lime until a pH close to 7 is obtained.
Claim 5
Dependent Claim
42 words
Process according to claim 3 wherein said neutralizing step comprises first adding a product rich in calcium carbonate to attain a pH of about 4, and then adding lime to the mixture in an amount sufficient to obtain a pH of neutrality.
Claim 6
Dependent Claim
48 words
Process according to claim 4 wherein, in said neutralizing step, said product rich in calcium carbonate consists of a composition selected from the group consisting of ground chalk, ground limestone and residues derived from calcium carbonate base, and wherein said lime consists of either quicklime or slaked lime.
Claim 7
Dependent Claim
60 words
Process according to claim 1 wherein said lime containing substance used in said final adding step is selected from the group consisting of quicklime, slaked lime, Portland cement, lime manufacture wastes and blast furnace slags, and wherein the amounts of said lime-containing substance and fly ash are such that there is a ratio of fly ash to Ca(OH) 2 ≧4.
Claim 8
Dependent Claim
20 words
Process according to claim 1, wherein, after addition of said lime containing substance, raw clay is added to the mixture.
Claim 9
Dependent Claim
20 words
A process in accordance with claim 6 wherein said ratio of fly ash to Ca(OH) 2 approximates 10 or more.
Claim 10
Dependent Claim
20 words
A process in accordance with claim 1 wherein said treated product is deposited on a final disposal site before setting.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-03-07 | 1986-09-06 | 1987-03-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-03-07 | 1990-09-06 | 1991-03-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-03-07 | 1994-09-06 | 1995-03-08 | $7700.00 | Window Closed / Lapsed |