US4238329A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for recovering heavy metal using insoluble starch-xanthates
Assignee: Industrial Filter Corp
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Filing: 1979-09-14
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Granted: 1980-12-09
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Expires: 1999-09-14
Abstract
Abstract A precoat layer comprising a mixture of insoluble starch-xanthate and a filter-aid is deposited on a filter leaf through which a solution containing a heavy metal flows in a continuous stream and insoluble starch-xanthate and filter-aid are continuously added upstream of the precoat layer.
Inventors
- 👤 James F. Zievers
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 23:53
CPC Classifications
C; C02; C02F; C02F1/00; C02F1/28; C02F1/288; B; B01; B01D; B01D37/00; B01D37/02; B01D37/03; C22; C22B; C22B3/00; C22B3/20; C22B3/22; C22B3/24; Y; Y02; Y02P; Y02P10/00; Y02P10/20
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
202 words
A process for recovering heavy metal from a continuous stream of water containing said metal in concentrations which vary from time to time between minimum and maximum levels, comprising causing said stream of water to flow through a filter element, coating said filter element with a mixture of diatomaceous earth and insoluble starch-xanthate, the relative amounts of diatomaceous earth and insoluble starch-xanthate combined in said mixture being in the range of 1.75 to 3.0 parts diatomaceous earth to one part insoluble starch-xanthate, continuously adding to said stream upstream of said filter element diatomaceous earth and insoluble starch-xanthate, the relative amounts of diatomaceous earth and insoluble starch-xanthate added to said stream being in the range of 1.75 to 3.0 parts diatomaceous earth to one part insoluble starch-xanthate, the amount of said insoluble starch-xanthate added to said stream upstream of said filter element being sufficient to react with all of said metal contained in said stream at said minimum concentration level to form upstream of said filter element a complex including all of the metal contained in said stream at said minimum concentration level, but said amount being insufficient to react with all of said metal in said stream at said maximum concentration level.
Claim 2
Dependent Claim
202 words
A process for recovering heavy metal from a continuous stream of water containing said metal in concentrations which vary from time to time between minimum and maximum levels, comprising causing said stream of water to flow through a filter element, coating said filter element with a mixture of diatomaceous earth and insoluble starch-xanthate, the relative amounts of diatomaceous earth and insoluble starch-xanthate combined in said mixture being in the range of 1.75 to 3.0 parts diatomaceous earth to one part insoluble starch-xanthate, continuously adding to said stream upstream of said filter element diatomaceous earth and insoluble starch-xanthate, the relative amounts of diatomaceous earth and insoluble starch-xanthate added to said stream being in the range of 1.75 to 3.0 parts diatomaceous earth to one part insoluble starch-xanthate, the amount of said insoluble starch-xanthate added to said stream upstream of said filter element being sufficient to react with all of said metal contained in said stream at said minimum concentration level to form upstream of said filter element a complex including all of the metal contained in said stream at said minimum concentration level, but said amount being insufficient to react with all of said metal in said stream at said maximum concentration level.
Claim 3
Dependent Claim
35 words
A process according to claim 1 where the amounts of diatomaceous earth and insoluble starch-xanthate in said mixture is in the range of about 1.75 to 2.0 parts diatomaceous earth to one part insoluble starch-xanthate.
Claim 4
Dependent Claim
11 words
A process according to claim 1 wherein said metal is copper.
Claim 5
Dependent Claim
11 words
A process according to claim 1 wherein said metal is nickel.
Claim 6
Dependent Claim
11 words
A process according to claim 1 wherein said metal is zinc.
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) | 1983-12-09 | 1984-06-09 | 1984-12-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-12-09 | 1988-06-09 | 1988-12-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-12-09 | 1992-06-09 | 1992-12-09 | $7700.00 | Window Closed / Lapsed |