US4255067A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Disposal of liquid waste and recovery of metals therefrom
Assignee: Individual
•
Filing: 1978-11-02
•
Granted: 1981-03-10
•
Expires: 1998-11-02
Abstract
Abstract Industrial liquid wastes containing low concentrations of heavy metals are applied to a soil bed where evaporation of the liquid occurs. The soil bed is lined with a liquid-impermeable liner of polymeric sheet material, bentonite clay or a laminate of the two to prevent escape of the liquid waste to the surrounding environment. After repeated applications of wastes to the bed, the concentration of metals in the bed reaches a level where the metals may be recovered by standard mining operations.
Inventors
- 👤 John C. Wright
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 11:01
CPC Classifications
C; C02; C02F; C02F11/00; C02F11/12; C02F11/16; E; E21; E21C; E21C41/00
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
63 words
A method of recovering heavy metals from industrial liquid wastes containing such metals comprising the steps of: preparing a soil bed to receive industrial liquid wastes containing heavy metals, the soil bed having a liquid-impermeable lining, applying said wastes to said soil bed, evaporating the water contained in the soil bed, and mining the soil bed to recover the heavy metals contained therein.
Claim 2
Independent Claim
63 words
A method of recovering heavy metals from industrial liquid wastes containing such metals comprising the steps of: preparing a soil bed to receive industrial liquid wastes containing heavy metals, the soil bed having a liquid-impermeable lining, applying said wastes to said soil bed, evaporating the water contained in the soil bed, and mining the soil bed to recover the heavy metals contained therein.
Claim 3
Dependent Claim
18 words
The method of claim 1 where the soil bed has a depth of from one to ten feet.
Claim 4
Dependent Claim
12 words
The method of claim 2 where said liquid-impermeable lining is bentonite clay.
Claim 5
Dependent Claim
25 words
The method of claim 2 further comprising the step of turning the soil in the soil bed frequently to enhance evaporation of the liquid waste.
Claim 6
Dependent Claim
26 words
The method of claim 4 wherein the steps of applying the liquid wastes and evaporating water contained therein is repeated prior to mining the soil bed.
Claim 7
Dependent Claim
29 words
The method of claim 5 wherein liquid wastes which collect at said liquid-impermeable liner are collected and conveyed to the surface where they are reapplied to said soil bed.
Claim 8
Dependent Claim
25 words
The method of claim 1 wherein said liquid wastes are pH adjusted to a pH of 4-8 prior to being applied to said soil bed.
Claim 9
Dependent Claim
36 words
The method of claim 7 wherein an acidic liquid waste is combined with a basic liquid waste in order to form a mixture having a pH of 4-8 prior to being applied to said soil bed.
Claim 10
Dependent Claim
16 words
The method of claim 2 where said liquid impermeable lining is a sheet of polymeric material.
Claim 11
Dependent Claim
22 words
The method of claim 2 where said liquid impermeable lining is a laminate of bentonite clay and a sheet of polymeric material.
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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) | 1984-03-09 | 1984-09-08 | 1985-03-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-03-09 | 1988-09-08 | 1989-03-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-03-09 | 1992-09-08 | 1993-03-10 | $7700.00 | Window Closed / Lapsed |