US4100065A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for removing of multivalent heavy metals from metal plating waste effluents
Assignee: Purdue Research Foundation
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Filing: 1976-12-22
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Granted: 1978-07-11
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Expires: 1996-12-22
Abstract
Abstract An exfoliated vermiculite cation-exchange column is used to remove multivalent heavy metals (copper, zinc, nickel, chromium, etc.) from metal plating wastes. The exfoliated vermiculite may be either chemically or relatively low-temperature thermally expanded vermiculite ore. It preferably has a cation exchange capacity of over 80 meq/100g. Exfoliated vermiculite particle sizes of less than approximately 10 mesh are preferred as the column packing. The ion-depleted vermiculite from the exchange column after use can be further expanded thermally and used as a lightweight filling material.
Inventors
- 👤 James E. Etzel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 01:59
CPC Classifications
B; B01; B01J; B01J39/00; B01J39/02; C; C25; C25D; C25D21/00; C25D21/16; C25D21/22; Y; Y10; Y10S; Y10S210/00; Y10S210/902; Y10S210/911; Y10S210/912; Y10S210/913
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
86 words
A method for removing multivalent heavy metal ions from metal plating waste effluents to avoid polluting the water supplies comprising passing a metal plating waste effluent having a multivalent heavy metal ion concentration of 25 mg/l or less through a cation-exchange column packed with exfoliated vermiculite particles, whereby the multivalent heavy metal ions are exchanged for a non-polluting magnesium ion and the heavy metal ions are retained by the vermiculite lattice so as to prevent polluting the water supplies with the discharged metal plating waste effluent.
Claim 2
Independent Claim
86 words
A method for removing multivalent heavy metal ions from metal plating waste effluents to avoid polluting the water supplies comprising passing a metal plating waste effluent having a multivalent heavy metal ion concentration of 25 mg/l or less through a cation-exchange column packed with exfoliated vermiculite particles, whereby the multivalent heavy metal ions are exchanged for a non-polluting magnesium ion and the heavy metal ions are retained by the vermiculite lattice so as to prevent polluting the water supplies with the discharged metal plating waste effluent.
Claim 3
Dependent Claim
18 words
The method of claim 1 wherein said exfoliated vermiculite particles have a cation-exchange capacity of over 80 mg/100g.
Claim 4
Dependent Claim
18 words
The method of claim 2 wherein said exfoliated vermiculite particles are less than approximately 10 mesh in size.
Claim 5
Dependent Claim
24 words
The method of claim 3 wherein said exfoliated vermiculite particles are ones which have been thermally expanded by heat treatment at approximately 550° C.
Claim 6
Dependent Claim
22 words
The method of claim 3 wherein said exfoliated vermiculite particles are ones which have been chemically expanded by treatment with hydrogen peroxide.
Claim 7
Dependent Claim
25 words
The method of claim 3 wherein said multivalent heavy metal ions are ions of metals selected from the group consisting of copper, zinc and nickel.
Claim 8
Dependent Claim
19 words
The metal of claim 6, wherein said effluent is passed through said column at 0.7 gal/min/ft 2 or less.
Claim 9
Dependent Claim
18 words
The method of claim 3 wherein said effluent has a copper ion concentration of 25 mg/l or less.
Claim 10
Dependent Claim
36 words
The method of claim 1 wherein said exfoliated vermiculite is, after completion of the ion-exchange process, removed from said column and heated to over 700° C to expand it and produce a lightweight expanded vermiculite material.
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) | 1981-07-10 | 1982-01-09 | 1982-07-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-07-10 | 1986-01-09 | 1986-07-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-07-10 | 1990-01-09 | 1990-07-11 | $7700.00 | Window Closed / Lapsed |