US4424062A
Expired / Lapsed
US
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Process and apparatus for chemically removing ash from coal
Assignee: Kanadevia Corp
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Filing: 1982-03-09
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Granted: 1984-01-03
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Expires: 2002-03-09
Abstract
Abstract Finely divided ash-containing coal is immersed in an aqueous solution of hydrochloric acid or citric acid, and acidic ammonium fluoride to cause the ash to react with the acid and the acidic ammonium fluoride, and the deashed coal is thereafter separated from the solution.
Inventors
- 👤 Yasumi Kamino
- 👤 Shigenori Onitsuka
- 👤 Takanobu Watanabe
- 👤 Katsuyuki Yano
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 17:11
CPC Classifications
C; C10; C10L; C10L9/00; C10L9/02
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
68 words
A process for chemically removing ash from coal comprising the steps of immersing finely divided ash-containing coal in an aqueous deashing solution containing an acid selected from the group consisting of hydrochloric acid and citric acid, and acidic ammonium fluoride to cause the ash to react with the acid and the acidic ammonium fluoride in the aqueous solution, and separating deashed fine coal particles from the aqueous solution.
Claim 2
Dependent Claim
68 words
A process for chemically removing ash from coal comprising the steps of immersing finely divided ash-containing coal in an aqueous deashing solution containing an acid selected from the group consisting of hydrochloric acid and citric acid, and acidic ammonium fluoride to cause the ash to react with the acid and the acidic ammonium fluoride in the aqueous solution, and separating deashed fine coal particles from the aqueous solution.
Claim 3
Dependent Claim
30 words
A process as defined in claim 1 wherein the deashing solution contains 1.0 to 12.0% by weight of hydrochloric acid and 1.25 to 10.0% by weight of acidic ammonium fluoride.
Claim 4
Dependent Claim
30 words
A process as defined in claim 1 wherein the deashing solution contains 1.0 to 10.0% by weight of citric acid and 1.0 to 10.0% by weight of acidic ammonium fluoride.
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) | 1987-01-02 | 1987-07-04 | 1988-01-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-01-02 | 1991-07-04 | 1992-01-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-01-02 | 1995-07-04 | 1996-01-03 | $7700.00 | Window Closed / Lapsed |