US4235562A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Land reclamation system
Assignee: Individual
•
Filing: 1978-12-08
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Granted: 1980-11-25
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Expires: 1998-12-08
Abstract
Abstract An improved procedure is disclosed for reclaiming land as it is surface mined; more particularly, reclamation of mined-out phosphate-containing land is disclosed where strata comprising a sandy component, a phosphate pebble component and a slime component are excavated, and the sandy component and the slime component are returned after extraction of the phosphate pebble component and dewatering by the dewatering system of the present invention. The volume of returned material is equal to or less than the volume of mined material, and the returned material forms a stable and agronomically sound soil. This result is obtained by accelerating dewatering of the slimes component of a specially treated backfill prior to and after deposition in the mined-out pit.
Inventors
- 👤 Alberto L. Ribas
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 23:01
CPC Classifications
E; E02; E02D; E02D3/00
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
192 words
A method of reclamation of a tract of land in the surface mining of an ore-bearing stratum and an overburden stratum overlying the ore-bearing stratum comprising the steps of: (a) dividing said tract into a plurality of parallel strips, numbered consecutively from an edge of said area as the first strip, second strip, and the like; (b) excavating and storing the overburden stratum from said first strip; (c) forming a first strip mined-out pit by excavating and transporting to a processing plant the ore-bearing stratum from said first strip, said processing plant being adapted to separate said ore-bearing stratum into an ore and a waste product of said first strip and treat said waste product to produce a dewatered waste product; (d) initiating excavation of said overburden from said third strip; (e) mixing said overburden from said third strip with said dewatered waste product of said first strip to form a backfill; (f) transporting said backfill to said first strip mined-out pit while said third strip is being excavated; (g) repeating sequentially steps (c) through (f) for all odd-numbered strips; and (h) repeating sequentially steps (c) through (f) for all even-numbered strips.
Claim 2
Independent Claim
192 words
A method of reclamation of a tract of land in the surface mining of an ore-bearing stratum and an overburden stratum overlying the ore-bearing stratum comprising the steps of: (a) dividing said tract into a plurality of parallel strips, numbered consecutively from an edge of said area as the first strip, second strip, and the like; (b) excavating and storing the overburden stratum from said first strip; (c) forming a first strip mined-out pit by excavating and transporting to a processing plant the ore-bearing stratum from said first strip, said processing plant being adapted to separate said ore-bearing stratum into an ore and a waste product of said first strip and treat said waste product to produce a dewatered waste product; (d) initiating excavation of said overburden from said third strip; (e) mixing said overburden from said third strip with said dewatered waste product of said first strip to form a backfill; (f) transporting said backfill to said first strip mined-out pit while said third strip is being excavated; (g) repeating sequentially steps (c) through (f) for all odd-numbered strips; and (h) repeating sequentially steps (c) through (f) for all even-numbered strips.
Claim 3
Dependent Claim
20 words
The method of claim 1 wherein said processing plant includes a washer plant, a filtration plant, and a dewatering system.
Claim 4
Dependent Claim
87 words
The method of claim 2 wherein said dewatering system includes a thickener comprising at least one cylindrical tank partially filled with sand and having an axial vertical shaft with radially attached rake arms for rotation about said shaft, said rake arms having netting for exerting mechanical action on said waste product in said tank, said tank having above said rake arms a disk formed of a plurality of vertical tubes bonded together, said disk being submerged in the upper portion of said waste product in said tank.
Claim 5
Dependent Claim
15 words
The method of claim 3 wherein said rake arms are vertically adjustable on said shaft.
Claim 6
Dependent Claim
10 words
The method of claim 4 wherein said netting is nylon.
Claim 7
Dependent Claim
16 words
The method of claim 5 wherein said waste product comprises a suspension of clay in water.
Claim 8
Dependent Claim
20 words
The method of claim 6 wherein said clay is selected from a group consisting of montmorillonite, attapulgite, and mixtures thereof.
Claim 9
Dependent Claim
11 words
The method of claim 7 wherein said ore is phosphate ore.
Claim 10
Dependent Claim
13 words
The method of claim 8 wherein said overburden stratum is substantially quartz sand.
Claim 11
Dependent Claim
22 words
The method of claim 9 wherein said waste product is mixed with said overburden in a mixing cone to form a slurry.
Claim 12
Dependent Claim
19 words
The method of claim 10 wherein said slurry is transported to a floating deck discharge in said mined-out pit.
Claim 13
Dependent Claim
13 words
The method of claim 11 wherein gypsum is added to said waste product.
Claim 14
Dependent Claim
24 words
The method of claim 12 wherein said gypsum is added as a slurry at a predetermined level to the waste product entering said thickener.
Claim 15
Dependent Claim
17 words
The method of claim 12 wherein said gypsum is added to said overburden entering said mixing cone.
Claim 16
Dependent Claim
26 words
The method of claim 10 wherein said slurry from said mixing cone is placed in an above ground storage reservoir before transporting to said mined-out pit.
Claim 17
Dependent Claim
61 words
The method of claim 10 wherein said mixing cone comprises an upwardly opening conical surface, a plurality of inlet lines for discharging said waste product in said mixing cone, an axially disposed inlet pipe for discharging said overburden downwardly within said conical surface, and a conical deflector pointed upwardly for deflecting said overburden from said inlet pipe onto said conical surface.
Claim 18
Dependent Claim
25 words
The method of claim 16 wherein a level control sensor and a level control valve regulate the flow of said waste product into said thickener.
Claim 19
Dependent Claim
32 words
The method of claim 11 wherein said floating deck discharge comprises a floating deck platform having submerged wings, a plurality of buoyant floats, and a deflecting plate adapted to deflect incoming backfill.
Claim 20
Dependent Claim
15 words
The method of claim 18 wherein a a clarifier and thickener are connected in series.
Claim 21
Dependent Claim
15 words
The method of claim 12 wherein said gypsum is added dry to the waste product.
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) | 1983-11-25 | 1984-05-26 | 1984-11-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-11-25 | 1988-05-26 | 1988-11-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-11-25 | 1992-05-26 | 1992-11-25 | $7700.00 | Window Closed / Lapsed |