US3947284A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for solidifying sludge
Assignee: Taiheiyo Cement Corp
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Filing: 1974-09-03
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Granted: 1976-03-30
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Expires: 1994-09-03
Abstract
Abstract A sludge having a water/solid high ratio and containing a substance having a harmful influence upon the setting of portland cement is solidified by mixing the sludge with hydraulic portland cement and at least one substance selected from the group consisting of alkali sulphate, gypsum dihydrate and insoluble gypsum anhydride.
Inventors
- 👤 Kyoichi Kitsugi
- 👤 Seizo Kozeki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 14:54
CPC Classifications
C; C02; C02F; C02F11/00; C02F11/008; C04; C04B; C04B28/00; C04B28/02; C04B28/04; Y; Y02; Y02W; Y02W30/00; Y02W30/50; Y02W30/91; Y10; Y10S; Y10S210/00; Y10S210/902; Y10S210/911; Y10S210/912
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
145 words
A method for solidifying a sludge having a high water/solid ratio and containing a substance having a harmful influence upon the setting of portland cement, where said sludge is: 1. a sand, a silt, a clay or colloidal particles which contains a sugar; a cracked petroleum substance; a fat; a humic substance; an oxide, a sulfide, a chloride or a hydroxide of copper, lead or zinc; a phosphoric acid; an inorganic phosphate or an organic phosphorous compound, or 2. a mud which contains substances discharged from a metal mine, said method comprising mixing 90 - 70% by weight of the sludge and 10 - 30% by weight of a mixture which consists of 95 - 50% by weight of a hydraulic portland cement and 5 - 50% by weight of sodium sulphate, potassium sulphate, gypsum dihydrate, gypsum hemihydrate, soluble gypsum anhydride or insoluble gypsum anhydride.
Claim 2
Independent Claim
145 words
A method for solidifying a sludge having a high water/solid ratio and containing a substance having a harmful influence upon the setting of portland cement, where said sludge is: 1. a sand, a silt, a clay or colloidal particles which contains a sugar; a cracked petroleum substance; a fat; a humic substance; an oxide, a sulfide, a chloride or a hydroxide of copper, lead or zinc; a phosphoric acid; an inorganic phosphate or an organic phosphorous compound, or 2. a mud which contains substances discharged from a metal mine, said method comprising mixing 90 - 70% by weight of the sludge and 10 - 30% by weight of a mixture which consists of 95 - 50% by weight of a hydraulic portland cement and 5 - 50% by weight of sodium sulphate, potassium sulphate, gypsum dihydrate, gypsum hemihydrate, soluble gypsum anhydride or insoluble gypsum anhydride.
Claim 3
Dependent Claim
45 words
The method as claimed in claim 1, wherein said hydraulic portland cement is at least one portland cement selected from the group consisting of normal portland cement, high early strength portland cement, superhigh early strength portland cement, moderate heat portland cement and mixed portland cement.
Claim 4
Dependent Claim
35 words
The method as claimed in claim 1, wherein 10 - 30% by weight of sodium sulphate, potassium sulphate, gypsum dihydrate, gypsum hemihydrate, soluble gypsum anhydride or insoluble gypsum anhydride is added to the hydraulic cement.
Claim 5
Dependent Claim
26 words
The method as claimed in claim 1, wherein 10 - 30% by weight of gypsum dihydrate or insoluble gypsum anhydride is added to the hydraulic cement.
References Cited (Backward Citations)
US196971A
Cited
CA574081A
Cited
CA574088A
Cited
US1760713A
Cited
US2806530A
Cited
US3720609A
Cited
JPS4731869U
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-03-30 | 1979-09-29 | 1980-03-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-03-30 | 1983-09-29 | 1984-03-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-03-30 | 1987-09-29 | 1988-03-30 | $7700.00 | Window Closed / Lapsed |