Patent US3893867A successfully refreshed from Google Patents.
US3893867A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnesia-base sintered article and process for producing the same
Assignee: NIHON KAISUIKAKO CO Ltd
•
Filing: 1973-10-25
•
Granted: 1975-07-08
•
Expires: 1993-10-25
Abstract
Abstract Finely divided magnesia or a substantially homogeneous mixture of finely divided magnesia with calcium oxide is blended with finely divided magnesium hydroxide or a mixture of both magnesium hydroxide and calcium hydroxide, and the resultant mixture is formed into a briquette. The thus prepared briquette is calcined to sinter same, thereby to produce a novel porous article having pores dispersed uniformly therein and having a low bulk density, high physical strength and excellent resistance to thermal shock. The approximate porosity value of the novel article can be predetermined by selection of the particle sizes and the blending ratios of the raw materials employed.
Inventors
- 👤 Kiyoshi Ogasawara
- 👤 Gentaro Kokubo
- 👤 Takashi Hojo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 19:48
CPC Classifications
C; C04; C04B; C04B38/00; C04B35/00; C04B35/01; C04B35/03; C04B35/04; C04B35/043; C04B35/06
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
136 words
A PROCESS FOR PRODUCING A LIGHT AND POROUS MAGNESIA-BASE SINTERED ARTICLE COMPRISING BLENDING A FINELY DIVIDED FIRST COMPONENT SELECTED FROM THE GROUP ONSISTING OF AGNESIA AND A SUBSTANTIALLY HOMOGENEOUS MIXTURE OF MAGNESIA AND CALCIUM OXIDE CONTAINING AT LEAST 70% BY WEIGHT OF MAGNESIA, WITH A FINELY DIVIDED SECOND COMPONENT SELECTED FROM THE GROUP CONSISTING OF MAGNESIUM HYDROXIDE AND A SUBSTANTIALLY HOMOGENEOUS MIXTURE OF MAGNESIUM HYDROXIDE WITH CALCIUM HYDROXIDE CONTAINING AT LEAST 70% BY WEIGHT OF MAGNESIUM HYDROXIDE, TO FORM A UNIFORMLY BLENDED MIXTURE CONTAINING FROM 20 TO 90% BY WEIGHT OF SAID FIRST COMPONENT AND THE BALANCE OF SAID MIXTURE CONSISTS ESSENTIALLY OF SAID SECOND COMPONENT, FORMING THE THUS-BLENDED MIXTURE INTO A SHAPED ARTICLE AND CALCINING THE ARTICLE AT A TEMPERATURE IN THE RANGE OF FROM ABOUT 1,400*C TO ABOUT 2,000*C TO FORM A SINTERED PRODUCT.
Claim 2
Dependent Claim
136 words
A PROCESS FOR PRODUCING A LIGHT AND POROUS MAGNESIA-BASE SINTERED ARTICLE COMPRISING BLENDING A FINELY DIVIDED FIRST COMPONENT SELECTED FROM THE GROUP ONSISTING OF AGNESIA AND A SUBSTANTIALLY HOMOGENEOUS MIXTURE OF MAGNESIA AND CALCIUM OXIDE CONTAINING AT LEAST 70% BY WEIGHT OF MAGNESIA, WITH A FINELY DIVIDED SECOND COMPONENT SELECTED FROM THE GROUP CONSISTING OF MAGNESIUM HYDROXIDE AND A SUBSTANTIALLY HOMOGENEOUS MIXTURE OF MAGNESIUM HYDROXIDE WITH CALCIUM HYDROXIDE CONTAINING AT LEAST 70% BY WEIGHT OF MAGNESIUM HYDROXIDE, TO FORM A UNIFORMLY BLENDED MIXTURE CONTAINING FROM 20 TO 90% BY WEIGHT OF SAID FIRST COMPONENT AND THE BALANCE OF SAID MIXTURE CONSISTS ESSENTIALLY OF SAID SECOND COMPONENT, FORMING THE THUS-BLENDED MIXTURE INTO A SHAPED ARTICLE AND CALCINING THE ARTICLE AT A TEMPERATURE IN THE RANGE OF FROM ABOUT 1,400*C TO ABOUT 2,000*C TO FORM A SINTERED PRODUCT.
Claim 3
Dependent Claim
27 words
The process according to claim 1 wherein the said first component consists essentially of dead burned magnesia and the said second component consists essentially of magnesium hydroxide.
Claim 4
Dependent Claim
35 words
The process according to claim 2 wherein the said first component and the said second component each have a particle size of less than 1 mm., and the calcining is carried out at 1,600*to 2,000*C.
Claim 5
Dependent Claim
39 words
The process according to claim 1 wherein said first and second components are blended in a dry state, and in the forming step a binder agent is blended into said mixture and the resulting composition is molded under pressure.
Claim 6
Dependent Claim
49 words
The process according to claim 2 wherein said first and second components are blended in a dry state, and in the forming step a binder agent is blended into said mixture and the resulting composition is molded under pressure and the calcining is carried out at 1,600* to 2,000*C.
Claim 7
Dependent Claim
30 words
The process according to claim 5 wherein the binder agent is selected from the group consisting of water, clay, magnesium chloride, magnesium sulfate, carboxymethyl cellulose, liquid paraffin and mixtures thereof.
Claim 8
Dependent Claim
27 words
The process according to claim 1, wherein the said first component consists essentially of dead burned dolomite clinker and said second component consists essentially of magnesium hydroxide.
Claim 9
Dependent Claim
40 words
The process according to claim 7 wherein said first and second components are blended in a dry state, and in the forming step a non-aqueous binder agent is blended into said mixture and the resulting composition is molded under pressure.
Claim 10
Dependent Claim
36 words
The process according to claim 8 wherein the non-aqueous binder agent is liquid paraffin and the said dead burned dolomite clinker and the said magnesium hydroxide each have a particle size of less than 1 mm.
Claim 11
Dependent Claim
56 words
The process according to claim 1 wherein said first component consists essentially of dead burned dolomite clinker having a magnesia content of at least 70% by weight and the said second component consists essentially of a substantially homogeneous mixture of magnesium hydroxide with calcium hydroxide having a magnesium hydroxide content of at least 70% by weight.
Claim 12
Dependent Claim
52 words
The process according to claim 10 wherein said first and second components are blended in a dry state, and in the forming step liquid paraffin is blended into said mixture as a binder agent and the resulting composition is molded under pressure, and the calcining is carried out at 1,600* to 2,000*C.
Claim 13
Dependent Claim
28 words
The process according to claim 1, in which the first component and the second component each have a particle size of less than 50 Mesh (Tyler screen size).
Claim 14
Dependent Claim
75 words
The process according to claim 12, in which the first component consists of a mixture of from 10 to 30 % by weight of particles having a size of from less than 50 to more than 100 mesh size, from 30 to 60 % by weight of particles having a size of from less than 100 to more than 200 mesh size and the balance is particles having a mesh size of less than 200.
Claim 15
Dependent Claim
47 words
The process according to claim 12, in which the first component contains from 20 to 70 % by weight of particles having a size of from less than 100 to more than 200 mesh size and the balance consists of particles of less than 200 mesh size.
Claim 16
Dependent Claim
30 words
The process according to claim 13 in which the size of the particles of the second component is not larger than the size of the particles of the first component.
Claim 17
Dependent Claim
30 words
The process according to claim 14 in which the size of the particles of the second component is not larger than the size of the particles of the first component.
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) | 1978-07-07 | 1979-01-06 | 1979-07-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-07-07 | 1983-01-06 | 1983-07-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-07-07 | 1987-01-06 | 1987-07-08 | $7700.00 | Window Closed / Lapsed |