Patent US4172025A successfully refreshed from Google Patents.
US4172025A
Expired / Lapsed
US
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Process for secondary recovery of bitumen in hot water extraction of tar sand
Assignee: Ontario Energy Corp
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Filing: 1978-05-11
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Granted: 1979-10-23
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Expires: 1998-05-11
Abstract
Abstract It has been found that tank-type air flotation cells are more efficient, when treating hot water process middlings containing in excess of about 3% bitumen, than trough-type air flotation cells. Also, it has been found that the trough-type cells are more efficient than the tank-type cells when treating middlings containing less than about 3% bitumen. Thus a secondary recovery circuit is proposed wherein the middlings are first treated in one or more tank-type cells in series and the underflow from the last tank-type cell is treated in one or more banks of trough-type cells.
Inventors
- 👤 Kenneth Porteous
- 👤 William Lavender
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 09:51
CPC Classifications
C; C10; C10G; C10G1/00; C10G1/04; C10G1/047
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
89 words
In the hot water extraction process for recovering bitumen from tar sand, wherein tar sand is conditioned in a tumbler, flooded with additional water, and subjected to flotation in a primary separation vessel to produce primary froth, middlings and tailings streams, the improvement comprising: recovering bitumen from the middlings stream by first subjecting the stream to air flotation in one or more tank-type flotation cells in series and then subjecting the underflow from the last tank-type cell to air flotation in one or more banks of trough-type flotation cells.
Claim 2
Dependent Claim
89 words
In the hot water extraction process for recovering bitumen from tar sand, wherein tar sand is conditioned in a tumbler, flooded with additional water, and subjected to flotation in a primary separation vessel to produce primary froth, middlings and tailings streams, the improvement comprising: recovering bitumen from the middlings stream by first subjecting the stream to air flotation in one or more tank-type flotation cells in series and then subjecting the underflow from the last tank-type cell to air flotation in one or more banks of trough-type flotation cells.
Claim 3
Dependent Claim
35 words
The improvement as set forth in claim 1 wherein: air flotation in the tank-type cell is continued until the underflow forwarded to the bank of trough-type cells contains less than about 3% bitumen by weight.
Claim 4
Dependent Claim
59 words
A circuit for recovering bitumen from hot water process middlings discharged from a primary separation vessel comprising, in combination and in sequence, one or more tank-type flotation cells in series operative to treat the middlings by air flotation; and one or more trough-type flotation cell banks operative to treat the underflow from the last tank-type cell by air flotation.
Claim 5
Dependent Claim
59 words
A circuit for recovering bitumen from hot water process middlings discharged from a primary separation vessel comprising, in combination and in sequence, one or more tank-type flotation cells in series operative to treat the middlings by air flotation; and one or more trough-type flotation cell banks operative to treat the underflow from the last tank-type cell by air flotation.
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) | 1982-10-22 | 1983-04-23 | 1983-10-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-10-22 | 1987-04-23 | 1987-10-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-10-22 | 1991-04-23 | 1991-10-23 | $7700.00 | Window Closed / Lapsed |