US3915724A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for the manufacture of an improved anhydrite
Assignee: Nihon Hardon Kogyo KK
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Filing: 1974-03-01
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Granted: 1975-10-28
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Expires: 1994-03-01
Abstract
Abstract A method for the manufacture of an improved anhydrite which adjusts and accelerates elution of various components of the hydrates of hydraulic cements at normal temperature and at elevated hydration temperatures, comprising adding at least one of the compounds of metals or non-metals belonging to Groups II to VIII of the Periodic Table or such metals or non-metals which form compounds by burning, to a substance containing, as a main component, gypsum or a substance which forms anhydrite by burning, and burning the mixture to a temperature of 400*C to 1,000*C. The anhydrite of the invention provides hydrate of cement having a sufficiently long workability life at normal temperature and which hardens quickly at a desired time when heated to 60*C or above.
Inventors
- 👤 Hiroshi Kokuta
- 👤 Junichi Kasai
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 13:23
CPC Classifications
F; F16; F16H; F16H1/00; F16H1/006; C; C04; C04B; C04B11/00; C04B11/02; C04B11/024; C04B11/05; C04B22/00; C04B22/08; C04B22/14; C04B22/142; F16H37/00; F16H37/12; F16H37/14
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
112 words
A METHOD FOR THE MANUFACTURE OF AN IMPROVED ANHYDRITE WHICH ADJUSTS AND ACCELERATS ELUTION OF COMPONENTS OF HYDRAULIC CEMENT HYDRATES AT NORMAL TEMPERATURE AND AT HYDRATION TEMPERATURE, COMPRISING ADDING AT LEAST ONE OF THE COMPOUNDS SELECTED ROM THE GROUP CONSISTING IF MGSO4, 7H2O, NA2B4O7, 10H2O, ZNO, CAHPO4, ZRO(NO3E2, PBO, CR2O3, MNO2, CAF2 AND FE2O3, TO A NATURAL SUBSTANCE OR CHEMICAL COMPOSITION CONTAINING, AS A MAIN COMPONENT, GYPSUM OR A SUBSTANCE WHICH FORMS ANHYDRITE BY BRUNING, SAID COMPOUND BEING ADDED IN AN AMOUNT SUFFICIENT TO ACCELERATE ELUTION OF COMPOUNDS OF HYDRAULIC CEMENT HYDRATES WHEN THE RESULTANT ANHYDRITE IS MIXED WITH HYDRAULIC CEMEMT, AND BURNING THE MIXTURE TO A TEMPERATURE OF 400*C. TO 1,000*C.
Claim 2
Independent Claim
112 words
A METHOD FOR THE MANUFACTURE OF AN IMPROVED ANHYDRITE WHICH ADJUSTS AND ACCELERATS ELUTION OF COMPONENTS OF HYDRAULIC CEMENT HYDRATES AT NORMAL TEMPERATURE AND AT HYDRATION TEMPERATURE, COMPRISING ADDING AT LEAST ONE OF THE COMPOUNDS SELECTED ROM THE GROUP CONSISTING IF MGSO4, 7H2O, NA2B4O7, 10H2O, ZNO, CAHPO4, ZRO(NO3E2, PBO, CR2O3, MNO2, CAF2 AND FE2O3, TO A NATURAL SUBSTANCE OR CHEMICAL COMPOSITION CONTAINING, AS A MAIN COMPONENT, GYPSUM OR A SUBSTANCE WHICH FORMS ANHYDRITE BY BRUNING, SAID COMPOUND BEING ADDED IN AN AMOUNT SUFFICIENT TO ACCELERATE ELUTION OF COMPOUNDS OF HYDRAULIC CEMENT HYDRATES WHEN THE RESULTANT ANHYDRITE IS MIXED WITH HYDRAULIC CEMEMT, AND BURNING THE MIXTURE TO A TEMPERATURE OF 400*C. TO 1,000*C.
Claim 3
Dependent Claim
67 words
A method for the manufacture of a hydraulic cement which produces high strength and whose setting initiation time can be freely adjusted, comprising adding the improved anhydrite obtained by the method of claim 1 to a hydraulic cement containing as main components at least one of (1) a CaO.Al2O3 hydraulic component, (2) a CaO.SiO2 hydraulic component and (3) gypsum or a substance which forms anhydrite by burning.
Claim 4
Dependent Claim
71 words
A method for the manufacture of a hydraulic cement which produces high strength and elution of the components of which can be adjusted and accelerated, comprising adding the improved anhydrite obtained by the method of claim 1 to a hydraulic cement, causing the mixture to hydrate to form a hydrate having a sufficient workability life at normal temperature, and then heating the hydrate at a desired time to 60*C or above.
Claim 5
Dependent Claim
82 words
A method for the manufacture of a hydraulic cement which hardens quickly by application of heat producing high strength and whose workability life can be freely adjusted, comprising adding the improved anhydrite obtained by the method of claim 1 to a hydraulic cement containing as main components at least one of (1) a CaO.Al2O3 hydraulic component having halogen, (2) a CaO.SiO2 hydraulic component with or without an excess of free lime, and (3) gypsum or a substance which forms anhydrite by burning.
Claim 6
Dependent Claim
15 words
A method according to claim 2 further comprising adding an organic or inorganic chelating agent.
Claim 7
Dependent Claim
25 words
A method according to claim 4 further comprising adding a chelating agent, and then mixing together said anhydrite, said hydraulic cement and said chelating agent.
References Cited (Backward Citations)
US3510326A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-10-27 | 1979-04-28 | 1979-10-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-10-27 | 1983-04-28 | 1983-10-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-10-27 | 1987-04-28 | 1987-10-28 | $7700.00 | Window Closed / Lapsed |