US4333816A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for the production of needle coke
Assignee: FA RUTGERSWERKE AG
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Filing: 1980-08-18
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Granted: 1982-06-08
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Expires: 2000-08-18
Abstract
Abstract Coal tar pitch is liquified at temperature of from about 135° C. to 280° C. The liquid coal tar pitch is filtered through a sieve with apertures from about 100 to 220 μm and with a closed surface area of at least 75 percent of the total sieve surface under pressures of from about 2 to 10 bar until a filter cake of a height of from about 40 to 80 mm forms above the sieve for separating ash, soot and quinoline insoluble particles from the liquid. Then the filtrate obtained is subjected to a coking process. The needle cokes resulting in accordance with the invention provide excellent materials for the production of graphite electrodes.
Inventors
- 👤 Georg Kolling
- 👤 Ingo Romey
- 👤 Hellmut Kokot
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 21:40
CPC Classifications
C; C10; C10C; C10C3/00; C10B; C10B55/00
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
100 words
A method for production of needle coke, comprising the steps of liquifyng coal tar pitch at temperatures from aboout 135° C. to 280° C.; filtering the liquified coal tar pitch through a sieve having apertures from about 100 to 220 μm and a closed surface of at least 75 percent of the total sieve surface, under pressures from about 2 to 10 bar, until a filter cake of a height of from about 40 to 80 mm forms above the sieve for separating ash, soot and quinoline-insoluble parts from the liquid; and subjecting the filtrate obtained to a coking process.
Claim 2
Independent Claim
100 words
A method for production of needle coke, comprising the steps of liquifyng coal tar pitch at temperatures from aboout 135° C. to 280° C.; filtering the liquified coal tar pitch through a sieve having apertures from about 100 to 220 μm and a closed surface of at least 75 percent of the total sieve surface, under pressures from about 2 to 10 bar, until a filter cake of a height of from about 40 to 80 mm forms above the sieve for separating ash, soot and quinoline-insoluble parts from the liquid; and subjecting the filtrate obtained to a coking process.
Claim 3
Dependent Claim
36 words
The method for production of needle coke according to claim 1, comprising recirculating the filtrate obtained until a filter cake height of from about 2 to 5 mm is present to the liquefied coal tar pitch.
Claim 4
Dependent Claim
33 words
The method for production of needle coke according to claim 1, wherein the pressure above the sieve increases during filtration continuously from about 1 to 3 bar to about 6 to 10 bar.
Claim 5
Dependent Claim
34 words
The method for production of needle coke according to claim 1, wherein the pressure above the sieve increases during filtration in steps from about 1 to 3 bars to about 6 to 10 bar.
Claim 6
Dependent Claim
29 words
The method for production of needle coke according to claim 1, wherein an auxiliary filtering material is added to the liquefied coal tar pitch before filtering through the sieve.
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) | 1985-06-07 | 1985-12-07 | 1986-06-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-06-07 | 1989-12-07 | 1990-06-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-06-07 | 1993-12-07 | 1994-06-08 | $7700.00 | Window Closed / Lapsed |