US4042408A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hydraulic cements
Assignee: Associated Portland Cement Manufacturers Ltd
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Filing: 1976-04-05
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Granted: 1977-08-16
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Expires: 1996-04-05
Abstract
Abstract A method of making a special high strength cement of the Portland type containing alite of improved hydraulic activity, wherein argillaceous and calcareous materials are combined to form clinker by heating in a kiln and the resulting clinker is ground to form a cement, comprising the step of introducing into the kiln a combination of mineralizers which contains fluorine and sulphur, provided that an alkali metal compound which can be a component of the aforesaid combination of mineralizers is included in the combination of mineralizers at least when the condition that the lime saturation factor be at least 0.98 and the silica ratio be at least 4 is not met.
Inventors
- 👤 Ransom James Murray
- 👤 Arthur William Brown
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 09:09
CPC Classifications
C; C04; C04B; C04B7/00; C04B7/02; C04B7/36; C04B7/38; C04B7/42
Claims Analysis
Total Claims: 32
Claim 1
Independent Claim
150 words
In a method of making a high strength cement of the Portland type wherein argillaceous and calcareous materials are combined to form clinker by heating in a kiln and the resulting clinker is ground to form a cement, the improvement wherein the hydraulic activity attributable to the alite content is improved by introducing into the kiln a combination of mineralisers which contains fluorine and sulphur in which the mineralisers contain 0.1 to 2.0 percent fluorine by weight and 1 to 10 percent SO 3 by weight based on the clinker, provided that an alkali metal compound which can be a component of the aforesaid combination of mineralisers is included so that at least 0.5 percent sulphate is retained in the clinker as alkali metal sulphate at least when the condition that the lime saturation factor be at least 0.98 and the silica ratio be at least 4 is not met.
Claim 2
Dependent Claim
150 words
In a method of making a high strength cement of the Portland type wherein argillaceous and calcareous materials are combined to form clinker by heating in a kiln and the resulting clinker is ground to form a cement, the improvement wherein the hydraulic activity attributable to the alite content is improved by introducing into the kiln a combination of mineralisers which contains fluorine and sulphur in which the mineralisers contain 0.1 to 2.0 percent fluorine by weight and 1 to 10 percent SO 3 by weight based on the clinker, provided that an alkali metal compound which can be a component of the aforesaid combination of mineralisers is included so that at least 0.5 percent sulphate is retained in the clinker as alkali metal sulphate at least when the condition that the lime saturation factor be at least 0.98 and the silica ratio be at least 4 is not met.
Claim 3
Dependent Claim
14 words
A method according to claim 1, wherein the mineraliser containing flurorine is calcium fluorine.
Claim 4
Dependent Claim
33 words
A method according to claim 1, wherein the mineraliser containing sulphur is calcium sulphate or a hydrate thereof, an alkali metal sulphate or a double alkali metal calcium sulphate, or a mixture thereof.
Claim 5
Dependent Claim
20 words
A method according to claim 3, wherein the mineraliser containing sulphur is gypsum or potassium sulphate or a mixture thereof.
Claim 6
Dependent Claim
17 words
A method according to claim 1, wherein the mineraliser containing alkali metal is an alkali metal sulphate.
Claim 7
Dependent Claim
24 words
A method according to claim 5, wherein the alkali metal sulphate is potassium sulphate, a double alkali metal calcium sulphate or a mixture thereof.
Claim 8
Dependent Claim
23 words
A method according to claim 1, wherein components, containing fluorine, sulphate and alkali metal, of the mineralisers introduced, are retained in the clinker.
Claim 9
Dependent Claim
28 words
A method according to claim 7, wherein the clinker contains 0.01 to 1 percent fluoride and 0.1 to 5.0 percent SO 3 , by weight of the clinker.
Claim 10
Dependent Claim
20 words
A method according to claim 8, wherein the clinker contains 0.01 to 0.5 percent fluoride by weight of the clinker.
Claim 11
Dependent Claim
19 words
A method according to claim 1, wherein the lime saturation factor of the clinker is from 0.98 to 1.08.
Claim 12
Dependent Claim
18 words
A method according to claim 10 wherein the silica ratio of the clinker is from 4 to 20.
Claim 13
Dependent Claim
22 words
A method according to claim 11, wherein the alite content of the clinker is at least 65 per cent thereof by weight.
Claim 14
Dependent Claim
21 words
A method according to claim 11, wherein the alite content of the clinker is at least 70 percent thereof by weight.
Claim 15
Dependent Claim
18 words
A method according to claim 1, wherein the lime saturation factor of the clinker is less than 0.98.
Claim 16
Dependent Claim
17 words
A method according to claim 14, wherein the silica ratio of the clinker is less than 4.
Claim 17
Dependent Claim
25 words
A method according to claim 1, wherein mineraliser components from the material forming the clinker are recycled for use in the combination of further clinker.
Claim 18
Dependent Claim
24 words
A method according to claim 1, wherein the clinker is ground to a specific surface area of from 200 to 800 m 2 /kg.
Claim 19
Dependent Claim
24 words
A method acccording to claim 1, wherein the clinker is ground to a specific surface area of from 250 to 500 m 2 /kg.
Claim 20
Dependent Claim
28 words
A method according to claim 1, wherein the clinker formed is mixed with a clinker containing from 7 to 90 percent by weight C 12 A 7 .
Claim 21
Dependent Claim
36 words
A method according to claim 1, wherein the combination of mineralisers introduced to the kiln contains 0.2 to 0.5 percent fluorine by weight and 2 to 5 percent SO 3 by weight based on the clinker.
Claim 22
Dependent Claim
24 words
A method according to claim 1 wherein at least part of the combination of mineralisers is introduced to the kiln in the raw feed.
Claim 23
Dependent Claim
23 words
A method according to claim 1, wherein at least part of the combination of mineralisers is introduced to the kiln in the fuel.
Claim 24
Dependent Claim
14 words
A method according to claim 1, wherein the kiln is a fluidised bed kiln.
Claim 25
Dependent Claim
47 words
A method according to claim 1, wherein the clinker is ground with sufficient calcium sulphate in the form of a natural or synthetic gypsum, hemihydrate, soluble anhydrite or a mixture thereof, to give a total SO 3 content of up to 8 percent in the finished cement.
Claim 26
Dependent Claim
32 words
A method according to claim 24 wherein sufficient calcium sulphate of whatever form is incorporated in the cement to give a total SO 3 content in the range 2 to 5 percent.
Claim 27
Dependent Claim
14 words
A method according to claim 1, wherein the clinker is ground with an accelerator.
Claim 28
Dependent Claim
12 words
A method according to claim 26, wherein the accelerator is calcium chloride.
Claim 29
Dependent Claim
14 words
A method according to claim 1, wherein the clinker is ground with a retarder.
Claim 30
Dependent Claim
12 words
A method according to claim 28, wherein the retarder is citric acid.
Claim 31
Independent Claim
87 words
The method of obtaining a cement clinker containing at least 65% by weight alite, which comprises the steps of: a. forming a Portland cement raw feed mix; b. thermally converting said raw feed mix to clinker in the presence of mineralisers which contain an alkali metal, fluorine and sulphur, said mineralisers being present in amount sufficient to provide from 0.1-2.0% fluorine and 1-10% SO 3 by weight based on the clinker; and c. recovering a clinker containing at least 0.5% CO 3 combined with said alkali metal.
Claim 32
Independent Claim
87 words
The method of obtaining a cement clinker containing at least 65% by weight alite, which comprises the steps of: a. forming a Portland cement raw feed mix; b. thermally converting said raw feed mix to clinker in the presence of mineralisers which contain an alkali metal, fluorine and sulphur, said mineralisers being present in amount sufficient to provide from 0.1-2.0% fluorine and 1-10% SO 3 by weight based on the clinker; and c. recovering a clinker containing at least 0.5% CO 3 combined with said alkali metal.
References Cited (Backward Citations)
US1904640A
Cited
US3251701A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-08-15 | 1981-02-14 | 1981-08-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-08-15 | 1985-02-14 | 1985-08-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-08-15 | 1989-02-14 | 1989-08-16 | $7700.00 | Window Closed / Lapsed |