US3712677A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Mining method
Assignee: Atlantic Richfield Co
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Filing: 1971-03-10
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Granted: 1973-01-23
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Expires: 1991-03-10
Abstract
Abstract A chamber mining technique whereby a series of horizontal slopes are formed between haulage and bleeder entries. Upon completion of a crosscut, the top and sides are drilled and blasted in a retreat operation and the broken ore is hauled out. The mined-out area need not be entered and there is no need for support or scaling since failure of walls between stopes will at no time endanger men and equipment.
Inventors
- 👤 A Janssen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 04:52
CPC Classifications
E; E21; E21C; E21C41/00; E21C41/16; E21C41/24
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
92 words
A method of mining thick-bedded minerals by a retreat chamber process comprising, a. driving a drift to a mining zone, b. driving haulage and bleeder entries into the mining zone, c. driving approximately parallel straight crosscuts between the haulage and bleeder entries, d. sectionally drilling and blasting radially outwardly from the walls and roof along the length of each crosscut, starting at the bleeder entry and working backward toward the haulage entry to enlarge the crosscut, leaving an unmined zone adjacent thereto, and e. removing the broken ore resulting from the blasting.
Claim 2
Independent Claim
92 words
A method of mining thick-bedded minerals by a retreat chamber process comprising, a. driving a drift to a mining zone, b. driving haulage and bleeder entries into the mining zone, c. driving approximately parallel straight crosscuts between the haulage and bleeder entries, d. sectionally drilling and blasting radially outwardly from the walls and roof along the length of each crosscut, starting at the bleeder entry and working backward toward the haulage entry to enlarge the crosscut, leaving an unmined zone adjacent thereto, and e. removing the broken ore resulting from the blasting.
Claim 3
Dependent Claim
22 words
A method according to claim 1 where ventilation flow is directed from the haulage entry through the crosscuts to the bleeder entry.
Claim 4
Dependent Claim
17 words
A method according to claim 1 where the resulting stopes are barricaded and backfilled with waste material.
Claim 5
Dependent Claim
25 words
A method according to claim 1 where a plurality of stopes are concurrently developed with new crosscuts being started when a stope is mined out.
Claim 6
Dependent Claim
14 words
A method according to claim 1 wherein the mineral being mined is oil shale.
Claim 7
Independent Claim
68 words
A method of mining thick-bedded materials by a retreat chamber mining process comprising, a. driving haulage and bleeder entries to define the longitudinal boundries of the chambers, b. driving a series of parallel straight crosscuts between the haulage and bleeder entries, c. drilling and blasting the top and sides of the crosscuts to form the chambers while retreating toward the haulage entry, and d. removing the broken ore.
Claim 8
Independent Claim
68 words
A method of mining thick-bedded materials by a retreat chamber mining process comprising, a. driving haulage and bleeder entries to define the longitudinal boundries of the chambers, b. driving a series of parallel straight crosscuts between the haulage and bleeder entries, c. drilling and blasting the top and sides of the crosscuts to form the chambers while retreating toward the haulage entry, and d. removing the broken ore.
Claim 9
Dependent Claim
23 words
A method according to claim 6 where the crosscuts are drilled and blasted so that adjacent chambers are in progressive stages of development.
Claim 10
Dependent Claim
24 words
A method according to claim 6 where a bulkhead is installed at at least one end of each chamber as it is mined out.
Claim 11
Dependent Claim
14 words
A method according to claim 6 where oil shale is the mineral being mined.
Claim 12
Dependent Claim
15 words
A method according to claim 9 where spent shale is deposited in the empty chambers.
References Cited (Backward Citations)
US494187A
Cited
US3588175A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-01-23 | 1976-07-24 | 1977-01-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-01-23 | 1980-07-24 | 1981-01-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-01-23 | 1984-07-24 | 1985-01-23 | $7700.00 | Window Closed / Lapsed |