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Publication numberUS3586379 A
Publication typeGrant
Publication dateJun 22, 1971
Filing dateSep 24, 1969
Priority dateSep 24, 1969
Publication numberUS 3586379 A, US 3586379A, US-A-3586379, US3586379 A, US3586379A
InventorsLambly Charles A R
Original AssigneeBechtel Int Corp
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Mining method
US 3586379 A
Abstract  available in
Images(4)
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Claims  available in
Description  (OCR text may contain errors)

United States Patent inventor Charles A. R. Lambly [56] RelerencesCited Sill Fl'flndsco, UNITED STATES PATENTS P 19.69 906,765 12/1903 Anderson 299/18 x g' 'ff it: 2,536,869 1/1951 Bucky 299/18 x Assignee Bechteumemfional corporation 3,349,848 10/1967 Burgh v. 299/8 X Primary Examiner-Ernest R. Purser Attorney-Eckh0fi and Hoppe MINING METHOD 4 Chin, 4 Drawing ABSTRACT: A method of mining an ore body in which a hau- U.S. Cl 299/8, lage level is established in the ore body and separate raises are 299/18, 299/19 driven into the ore body for men and equipment, ore and Int. Cl E2lc 41/00 waste. The ore body is classified as it is mined for movement Field of Search 299/18, 19, as either ore or waste through the appropriate raise for 8 separate removal from the haulage level.

QUIPMENT RA/5E Z E WASTE 5 5 9 1 1 I E l l 1 I 1 I g 1 E 1 17 5 1 i E I l L E P'I 1 L18 '2 J: 1 I 1 l 1 J 1 I I v d 1 7:: I I I H f: E 1 1 i 1 1- E l 1 a Z 5 1 I i 27: A I 4 i "'.f"\ i I E :3. V 1 [I l I -53 gf fik PATENTEU JUH22 I971 SHEET 2 OF 4 INVENTOR. CHAKLES AK. [AMBLV' I ATTOKNE Y5 PATENTEUJUN 2 2 I971 SHEET 3 OF 4 ATTOK/VEYS PATENTEU JUN22 I97! SHEET '4 BF 4 INVENTQR. CHAKLES A. R. LAMBLY ATTOKNEYS MINING METHOD SUMMARY OF THE INVENTION Present mining methods are generally designed to extract the maximum tonnage of material that contains recoverable minerals in excess of the predetermined cutoff values established to determine the outline and shape of the ore structure to be mined. While such an approach results in obtaining a maximum extraction of materials from the mineralized structure, such a mining method necessarily includes much waste and/or low grade material in the mine product. As a result, the mine product includes a high ratio of waste dilution with the result that greater tonnages of material must be beneficated for the recovery of the mineral values.

In accordance with the process of this invention, one is enabled to eliminate from the mine product most of the waste and low grade materials and so obtain a maximum extraction of the ore from the mineralized structure with the minimal inclusion of waste and low grade materials. Because of this reduction of the quantity handled, the capital investment required for underground and surface facilities is materially reduced. At the same time the overall metallurgical recoveries in the benefication plant are increased because a better mine product is treated. The overall result is that the cost per pound of concentrate or metal produced from a ton of mine product is substantially lowered. The end result is that the overall operating profit is increased because the pounds of concentrate or metal contained in the tons of mine product to maintain capacity operations and concentrate production is increased.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings accompanying and forming a part hereof:

FIG. 1 is a perspective view illustrating the raise complex provided in one method of ore extraction from an ore structure;

FIGS. 2 and 3 are respective views illustrating further steps in a steep dipping method of mining an ore structure; and

FIG. 4 is also a perspective view but illustrating a flat dipping method of mining an ore structure.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The ore extraction methods of the present invention are adapted to be applied to either a new ore body which has not been previously mined or to one which has an existing shaft, incline or tunnel entrance to the mine. The following description will deal with both circumstances.

Referring particularly to FIG. 1, one practicing this invention will either provide a shaft, incline or tunnel entrance to the mine and tunnels and raises exposing the ore body to be mined or will use that presently in existence. This will be referred to hereinafter-as raise 1 but it is not shown on the drawing. If not already in existence, one should establish one or more haulage levels in the ore structure, such haulage level being indicated in FIG. 1 as at 6. The ore haulage levels may be spaced at different elevations to suit the conditions and existing levels in the mine. From the haulage level, one then provides three additional raises indicated at 7, 8 and 9 in FIG. 1 and hereinafter termed as raise 2, raise 3 and raise 4. Raise 2 is used for raising and lowering equipment and manpower, suitable equipment being installed in it for this purpose; generally raise 2 is a raise approximately 7 by IO-feet in cross section and extends from the haulage level 6 to the desired haulage level above level 6 and from level to level to the top of the ore body. At the various elevations along raise 2, one then provides various stations indicated at l0, l1, l2, l3 and 14, these being sized to permit the use of the equipment to be used and the ore structure to be minedapproximately 9-feet by 9-feet and at approximately -foot intervals.

Raise 3 is provided in ore of the cross-sectional size approximately 6-feet by 6-feet and to one side and 6 or more feet away from the nearest wall and parallel to the raise 2 and intersects each 20-foot level. Raise 4 is provided in ore; it is also approximately 6-feet by 6-feet in cross section but is provided on the other side of raise 2 and intersects each 20-foot level cut. From raise 2 headings indicated at 16 through 20 are driven in each direction, sized to fit the structure to be extracted, each being approximately 8-feet by 9-feet and being cut into the ore structure. Using auto loading and transportation equipment that is sized to work in the desired opening, one removes the broken ore and Waste from the drift heading or stope face. Each load of material regardless of volume is classified and recorded as ore or waste. Each load classified as ore is dumped into the ore raise 3 and each load classified as waste is dumped into the waste raise 4.

After removing the broken ore and waste from each stope face on a given level, the loading equipment is moved to another level where the operation is repeated. If the ore structure is wider than the heading (of 9-feet by 8-feet), test holes can be drilled at the required location in ore on the hanging wall or in the ore on the footwall of the ore structure to determine the amount of ore remaining on the drift walls. This ore can then be mined and handled as previously outlined. Working from the haulage level up the ore structure, one should drift a tunnel in ore in each direction to the end of the ore structure. If the ore structure is of such great magnitude, it may be desirable to install additional raises (FIG. 1 raises 2, 3 and 4).

Upon completion of the levels, horizontal pillars of ore will remain between each level. The pillars will be about IO-feet thick and the width of the ore structure and the length of the ore structure, or about half the distance to the next raise complex. The ore location and values of the ore in the horizontal pillars will be known, based on the ore and waste information accumulated, recorded and mapped during the driving of the various levels.

In steep dipping ore structures, the first level above the haulage level 6 becomes a scram or scraping level (FIG. 2). Scrapers are installed so the ore from both sides of the raise complex 2 can be scraped to the'ore raise 3 and the ore transported from the ore chute to the surface. In preparing to mine the ore pillars in a steep dipping ore structure, one starts at the end of the first horizontal pillar farthest from the raise complex and retreats toward the raise complex. The first operation will be to remove a 10-foot long section of ore 30 from the horizontal pillar between the scram level 31 and the second level 32 in FIG. 2. One leaves a lO-foot long section of ore (or possible waste) as a pillar over the scram level, this being indicated at 33. This is repeated until the total length of the horizontal pillar has been cut into lO-foot long openings and separated by 10-foot long pillars 34-37 over the scram drift. The l0-foot pillars above the scram drift are not removed until the whole ore body has been extracted.

On the level at the drift face farthest away from the raise complex and at both ends of the level, one removes the ore section 38 of the horizontal pillar between the second and third levels. The broken ore will fall through the l0-foot openings between the lO-footpillars to the scram level and is then scraped to the ore raise 3 and transported from the surface. One does not remove any waste section during the extraction of the horizontal pillar, the waste being left in place as a waste pillar 39. This is repeated until the ore sections in all the horizontal pillars have been removed. If poor ground conditions exist, certain areas in the stopes may have to be supported in which case one can leave ore pillars as required.

The above procedure is continued until the whole ore structure has been removed and only the waste pillars and the ore pillars protecting the various raise complexes remain. At this time, observing mine safety procedures, one removes part or all of the orepillars protecting the raise complex to claim the maximum tons of ore.

Referring to FIG. 4. if the ore structure is flat dipping and the broken ore will not run, one then starts extracting the ore from the top of the ore structure to be mined by removing the ore pillars at level 41 which is below the top of the ore structure or below a permanent horizontal ore pillar. At the drift face farthest away from the raise complex and at both ends of the level, one removes the ore sections of the horizontal pillar below the level 41. The ore broken from the horizontal pillar will fall to the floor of the next level and will be loaded and transported by the loading equipment to the ore raise 3.

Using auto loading and transportation equipment that is sized to work in the desired opening, one removes the broken ore and waste from the drift heading or stope face. Each load of material regardless of volume is classified and recorded as ore or waste. Each load classified as ore is dumped into the ore raise 3 and each load classified as waste is dumped into the waste raise 4. Any waste section in the horizontal ore pillar being removed will not be mined but will be left as a waste pillar. Any broken ore that may hang up on the low dipping footwall will be moved to the level floor by the loading or scraping equipment. Any hang wall maintenance can be performed before the loading equipment ventures into the open stope area to remove the broken ore.

The above procedures enable the maximum tonnage of ore with minimum waste and low grade dilution to be obtained with the net result that maximum operating profits are secured. For example, two operating mines producing from the same ore bodies increased the metal content'in the mill heads by 50 percent to over 100 percent after establishing the foregoing mining operations. These results are shown in the following tabulation.

lclaim:

l. A method of mining an ore body comprising:

a. establishing a haulage level in the ore body for removal of separate lots of ore and of waste,

b. establishing a raise in the ore body for the movement of men and equipment from level to level,

c. establishing an ore raise in the ore body for movement of NO. 1 TEST-AMERICAN MINE (FLAT DIPPING) Room and pillar extraction N0. 2 TEST-CANADIAN MINE (STEEP DIPPING) Sub-level extraction 1967 grade mill feed 1968 grade mill feed 4. 79

Extraction by this invention 1969 (first half) grade mill feed 7. 00

ore by gravity to the haulage level, d. establishing a waste raise in the ore body or in waste for movement of waste by gravity to the haulage level, e. mining the ore body to provide loose material capable of being moved to either the ore raise or to the waste raise, classifying the loose material into separate lots either as ore to be beneficated or as waste,

g. and moving the separated lots of classified material to the appropriate raise for removal from the haulage level.

2. [n the mining method of claim 1 wherein a raise complex is provided including an ore raise, a waste raise and an equipment raise, the latter raise being between the ore raise and the waste raise.

3. [n the mining method of claim 2 wherein tunnels or stope headings are driven in the ore body at different elevations, each tunnel or stope heading starting from the raise complex at the required spacing and extending outwardly therefrom in the ore body, and mining each ore pillar from the outer end inwardly toward the raise complex.

4. In the mining method of claim 1 wherein the solid material in the ore body is classified in pillars as ore or waste.

Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3888543 *Sep 3, 1974Jun 10, 1975Robert W JohnsMethod for mining oil shales, tar sands, and other minerals
US3975053 *Dec 3, 1973Aug 17, 1976Kochanowsky Boris JMining methods as such and combined with equipment
US4103972 *Jul 15, 1976Aug 1, 1978Kochanowsky Boris JOpen pit mine
Classifications
U.S. Classification299/8, 299/19, 299/18
International ClassificationE21C41/22, E21C41/16, E21C41/00
Cooperative ClassificationE21C41/16
European ClassificationE21C41/16
Legal Events
DateCodeEventDescription
Sep 26, 1988AS02Assignment of assignor's interest
Owner name: BECHTEL GROUP, INC., 50 BEALE ST., SAN FRANCISCO,
Owner name: BECHTEL INVESTMENTS, INC., A CORP. OF NV
Effective date: 19880915
Sep 26, 1988ASAssignment
Owner name: BECHTEL GROUP, INC., 50 BEALE ST., SAN FRANCISCO,
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:BECHTEL INVESTMENTS, INC., A CORP. OF NV;REEL/FRAME:004951/0883
Effective date: 19880915
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:BECHTEL INVESTMENTS, INC., A CORP. OF NV;REEL/FRAME:4951/883
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:BECHTEL INVESTMENTS, INC., A CORP. OF NV;REEL/FRAME:004951/0883