US3947283A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for solidifying sludge
Assignee: Taiheiyo Cement Corp
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Filing: 1974-07-24
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Granted: 1976-03-30
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Expires: 1994-07-24
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 rapid hardening cement containing calcium haloaluminate.
Inventors
- 👤 Hiroshi Uchikawa
- 👤 Masao Shimoda
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 16:42
CPC Classifications
C; C02; C02F; C02F11/00; C02F11/008; C04; C04B; C04B28/00; C04B28/02; C04B28/06; Y; Y02; Y02W; Y02W30/00; Y02W30/50; Y02W30/91
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
179 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 contain a sugar, 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 the sludge and rapid hardening cement containing clinker consisting of 5 - 60% by weight of 11CaO.sup.. 7Al 2 O 3 .sup.. CaX 2 ; and 3CaO.sup.. SiO 2 solid solution, 2CaO.sup.. SiO 2 solid solution and 2CaO.sup.. Fe 2 O 3 -- 6CaO.sup.. 2Al 2 O 3 .sup.. Fe 2 O 3 ; and anhydrite or anhydrite and gypsum semihydrate in an amount such that the weight ratio of Al 2 O 3 /SO 3 in the cement is 0.4 - 1.8 and the weight ratio of water in the sludge to the cement is 0.8 - 2.5.
Claim 2
Independent Claim
179 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 contain a sugar, 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 the sludge and rapid hardening cement containing clinker consisting of 5 - 60% by weight of 11CaO.sup.. 7Al 2 O 3 .sup.. CaX 2 ; and 3CaO.sup.. SiO 2 solid solution, 2CaO.sup.. SiO 2 solid solution and 2CaO.sup.. Fe 2 O 3 -- 6CaO.sup.. 2Al 2 O 3 .sup.. Fe 2 O 3 ; and anhydrite or anhydrite and gypsum semihydrate in an amount such that the weight ratio of Al 2 O 3 /SO 3 in the cement is 0.4 - 1.8 and the weight ratio of water in the sludge to the cement is 0.8 - 2.5.
Claim 3
Dependent Claim
28 words
The method as claimed in claim 1, wherein the rapid hardening cement contains 15 - 30% by weight of 11CaO.sup.. 7Al 2 O 3 .sup.. CaX 2 .
Claim 4
Dependent Claim
44 words
The method as claimed in claim 1, wherein an organic carboxylic acid, a boric acid or a borate, a bicarbonate, a silicate and a silicofluoride is mixed with the rapid hardening cement in order to retard furthermore the setting time of cement thus produced.
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) | 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 |