Patent US3871986A successfully refreshed from Google Patents.
US3871986A
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Joint ramming cement for electrolytic reduction cell cathodes
Assignee: Reynolds Metals Co
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Filing: 1973-10-31
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Granted: 1975-03-18
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Expires: 1993-10-31
Abstract
Abstract A ramming cement suitable for joining a plurality of adjacent carbon blocks having joint spaces between them to form a continuous cell lining structure for an electrolytic cell, such as an aluminum reduction cell, is prepared from a mixture of a petroleum pitch having a cube-in-water softening point between about 40* and about 85*C, and containing not more than about 1% of quinoline-insoluble material, and an aggregate such as calcined anthracite.
Inventors
- 👤 Herbert K Reamey
- 👤 Jerry F Newman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 06:55
CPC Classifications
C; C25; C25C; C25C3/00; C25C3/06; C25C3/08
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
129 words
PROCESS FOR FORMING THE CATHODE LINING OF AN ELECTROLYTIC CELL, SAID LINING BEING MADE UP OF ADJACENT CARBONACEOUS BLOCKS HAVING JOINT SPACES THEREBETWEEN, COMPRISING THE STEPS OF INTRODUCING INTO SAID JOINT SPACES A RAMMING CEMENT COMPRISING A MIXTURE OF PITCH AND A CARBONACEOUS AGGREGATE, AT A TEMPERATURE SUFFICIENT TO MAINTAIN SUITABLE CONSISTENCY FOR COMPACTING THE CEMENT IN SAID SPACES, AND THEN BAKING THE BLOCKS AND CEMENTED JOINTS AT A TEMPERATURE AND FOR A PERIOD OF TIME SUFFICIENT TO CARBONIZE THE CEMENT AND TO FORM A CONTINUOUS LINING STRUCTURE, SAID MIXTURE CONTAINING FROM ABOUT 13 TO ABOUT 16.5% BY WEIGHT OF PETROLEUM PITCH CHARACTERIZED BY HAVING A CUBE-IN-WATER SOFTENING POINT BETWEEN ABOUT 40* AND ABOUT 85*C. AND HAVING A CONTENT OF MATERIAL INSOLUBLE IN QUINOLINE NOT GREATER THAN ABOUT 1%.
Claim 2
Dependent Claim
129 words
PROCESS FOR FORMING THE CATHODE LINING OF AN ELECTROLYTIC CELL, SAID LINING BEING MADE UP OF ADJACENT CARBONACEOUS BLOCKS HAVING JOINT SPACES THEREBETWEEN, COMPRISING THE STEPS OF INTRODUCING INTO SAID JOINT SPACES A RAMMING CEMENT COMPRISING A MIXTURE OF PITCH AND A CARBONACEOUS AGGREGATE, AT A TEMPERATURE SUFFICIENT TO MAINTAIN SUITABLE CONSISTENCY FOR COMPACTING THE CEMENT IN SAID SPACES, AND THEN BAKING THE BLOCKS AND CEMENTED JOINTS AT A TEMPERATURE AND FOR A PERIOD OF TIME SUFFICIENT TO CARBONIZE THE CEMENT AND TO FORM A CONTINUOUS LINING STRUCTURE, SAID MIXTURE CONTAINING FROM ABOUT 13 TO ABOUT 16.5% BY WEIGHT OF PETROLEUM PITCH CHARACTERIZED BY HAVING A CUBE-IN-WATER SOFTENING POINT BETWEEN ABOUT 40* AND ABOUT 85*C. AND HAVING A CONTENT OF MATERIAL INSOLUBLE IN QUINOLINE NOT GREATER THAN ABOUT 1%.
Claim 3
Dependent Claim
15 words
The process of claim 1 in which said electrolytic cell is an aluminum reduction cell.
Claim 4
Dependent Claim
12 words
The process of claim 1 in which said aggregate is calcined anthracite.
Claim 5
Dependent Claim
19 words
The process of claim 1 in which said aggregate is a mixture of calcined anthracite and calcined metallurgical coke.
Claim 6
Dependent Claim
23 words
The process of claim 1 in which said aggregate is predominantly finely divided material of which about 50% passes a 200 mesh screen.
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) | 1978-03-17 | 1978-09-16 | 1979-03-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-17 | 1982-09-16 | 1983-03-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-17 | 1986-09-16 | 1987-03-18 | $7700.00 | Window Closed / Lapsed |