US4167477A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Separation of plastics by flotation
Assignee: United States Department of the Interior
•
Filing: 1978-01-17
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Granted: 1979-09-11
•
Expires: 1998-01-17
Abstract
Abstract Individual components of mixtures of plastic materials are separated by flotation employing sodium silicate as a wetting agent and fatty amines as promoters.
Inventors
- 👤 Espiridion G. Valdez
- 👤 Wayne J. Wilson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 18:03
CPC Classifications
B; B29; B29B; B29B17/00; B29B17/02; B03; B03D; B03D1/00; B03D1/001; B03D1/002; B03D1/004; B03D1/01; C; C08; C08J; C08J11/00; C08J11/04; C08J11/06; B03D2201/00; B03D2201/007; B03D2201/02; B29B2017/0203; B29B2017/0213; B29B2017/0217; B29B2017/0248; B29K; B29K2025/00; B29K2055/00; B29K2055/02; B29K2077/00; B29L; B29L2031/00; B29L2031/30; B29L2031/3055; Y; Y02; Y02W; Y02W30/00; Y02W30/50; Y02W30/62
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
55 words
A process for separation of polystyrene plastic from polyamide plastics comprising conditioning a mixture of the plastic materials in an aqueous solution of sodium silicate at a pH of about 9 to 9.3 and subjecting the resulting mixture to froth flotation, whereby the polystyrene plastics is floated and the polyamide plastic remain in the tailings.
Claim 2
Dependent Claim
55 words
A process for separation of polystyrene plastic from polyamide plastics comprising conditioning a mixture of the plastic materials in an aqueous solution of sodium silicate at a pH of about 9 to 9.3 and subjecting the resulting mixture to froth flotation, whereby the polystyrene plastics is floated and the polyamide plastic remain in the tailings.
Claim 3
Dependent Claim
46 words
The process of claim 1, comprising the additional step of conditioning the tailings in an aqueous solution of a primary fatty amine, or salt thereof, at a pH of about 4.5 to 5.0, and subjecting the resulting mixture to froth flotation to separate individual polyamide plastics.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-09-10 | 1983-03-12 | 1983-09-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-09-10 | 1987-03-12 | 1987-09-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-09-10 | 1991-03-12 | 1991-09-11 | $7700.00 | Window Closed / Lapsed |