US3775984A

US3775984A - Mining method and method of land reclamation

Info

Publication number: US3775984A
Authority: US
Inventors: C Livingston
Original assignee: Individual
Current assignee: Individual
Priority date: 1971-08-18
Filing date: 1971-08-18
Publication date: 1973-12-04
Anticipated expiration: 1990-12-04

Abstract

A mining method including land reclamation and hydropower and water resources development including removing the ore from the ore body in a predetermined pattern so that the remaining ore body defines a grid network of cellular units, the ore removal being performed progressively such that adjacent cellular units are in various stages of development simultaneously and filling the mined-out cells with overburden from adjacent ore body; constructing terrace ponds above the elevation of the top of the mined-out cells, the terrace ponds being constructed from overburden material; constructing dams between adjacent terrace ponds, the dams overlying an elevated portion of the ore body previously used as a plant pillar or access entry pillar; and selectively filling the terrace ponds and pillar ponds with mill tailing slurry to a predetermined reclaimed surface elevation so that the reclaimed surface consists predominantly of a slime fraction suited to agricultural re-use of the land.

Description

United States Patent 1 [111 3,775,984 Livingston 1 Dec. 4, 1973 MINING METHOD AND METHOD OF 1965, pages 3-8.

LAN 1D RECLAMATION [76] Inventor: Clit'ton W. Livingston, 624

Panorama Dr., Grand Junction, Colo. 81501 [22] Filed: Aug. 18, 1971 21 Appl. No.: 172,711

Related US. Application Data [62] Division of Ser. No. 14,166, Feb. 25, 1970.

References Cited UNITED STATES PATENTS 7/1914 Dorr 61/35 X 1,924,721 8/1933 Leubuscher 61/] 2,874,945 2/1959 McWhorter 299/19 X FOREIGN PATENTS OR APPLICATIONS 1,385,793 12/1964 France 102/23 OTHER PUBLICATIONS Lang-Mining ltabirite Canadian Mining Journal, Nov.

HIGH TERRACE TERRACE INTERMEDIATE TERRACE FUTURE PILLAR Pouo OPEN CELL WATER STORAGE LOWE R ACCESS ROAD RAM

Primary Examiner-Jacob Shapiro Attorney-Sherman & Shalloway [57] ABSTRACT A mining method including land reclamation and hydropower and water resources development including removing the ore from the ore body in a predetermined pattern so that the remaining ore body defines a grid network of cellular units, the ore removal being performed progressively such that adjacent cellular units are in various stages oi development simulta" neously and filling the mined-out cells with overburden from adjacent ore body; constructing terrace ponds above the elevation of the top of the mined-out cells, the terrace ponds being constructed from overburden material; constructing dams between adjacent terrace ponds, the dams overlying; an elevated portion of the ore body previously used as a plant pillar or access entry pillar; and selectively filling the terrace ponds and pillar ponds with mill tailing slurry to a predetermined reclaimed surface elevation so that the reclaimed surface consists predominantly of a slime fraction suited to agricultural re-use of the land.

20 Claims, 36 Drawing Figures HIGHWALL ACTIVE MINING CELLS ":JTERRACE POND/1 :1:

INTERMEDIATE TERRACE PATENTEDUEC 41973 SHEEI OlUF 21 E C N A B R U T 5 D SHOCK FRONT PATENTEBUEC M973 SHEET OEUF 21 PATENTEU 41975 397 750984 SHEEI 03UF 21 H615 I H 1 5 APPARENT I TRUE CRATER fi/g] APPARENT 76: 8

APPARENT CRATER PATENTEDDEC 4W3 SHEEI UHF 21 PAIENTEUBEE 41975 I 3,775,984

SHEET OSUF 21 Q O 8 o a O o u n H O l 1 0 3 q I0 X n a II LBS. 04,1958 SNOWSURFACE S 10 LBS. C-4, ICE

10 LBS. A 60 TR ENCH SNOW C3 CHURCHILL TILL //' ATLAS 6c. KEWEENAW SILT ENERGY UTILIZATION NUMBER, A

DEPTH RATIO A F/G. I00

PAH-,NTED 41% 3.775995% saw 050? 21 PAIENIED U975 SIYYEISBA SHEEI' 980i 21 d SCALED CHARGE DEPTH W 0 I I u 2 "I 0 f 25$ 4 5 d 6 k I I I I I 8 I l I I 8 1 I I I I I l I I I I 7 I 1 I I 7 I I RADIAL I I CRACKS I I I 6 I I I I 6 I/ SECOND RING I I I I l CRACKS I I I 3 5 5 -INCREMENT ,I I N I b A1 A0 T3,: I I I 3 i I I I I I i 4 I CRATER 1 4 "7, I I C LIMIT I a B I '2 C I I I 1 I 3 3 3 (n y I /I/ I i o I I j I I I I /I I I I g FRAGMENTATION RANGE. I DOMING RANGE I AB. I an; PR. IsII UPLIFT REGION J REGJ; l I R, T I I I I I I I AIRBLAST 8.5.0. V/W R. CR] PRECONDITIONING l I I I 4 I I I I r PS. 4 I l I ,3 W I 3 I V I 9 2 8 IV x I I h w I N I I I 0 .LI I7 I I v 0 I I O I CRATERING SCALED BURDEN d I 0 I 4 o% I 4 I I I 0 I 2 3 4 5 6 LEGEND:

AB. REG. Airbiost Region 850. Bond SIreng'Ih Destruction SR. Secondary Region V/W R. V/W Region P. R. Primary Region CR. Course Region SH.R. Shear Region AU B Auiogenous Blasting RS. Puriicle Size CB. Conventional Blosiing FIG. l5

PATENTEB M975 SJYSBBfi SHEET UQUF 21 4 m V m T m 0.8 I i u.: 5.0 lb. O i E 0.s- I Lateral extent of bond 2 strength destruction 5 I (gas bubble radius) 8 0.4 2' l I I i I 0.2 N 1 I l I I O 1 I I O 2 O 4 O 6 O 8 I O DEPTH RATIO A PAI-ENIED DEC 4 75 ORIENT PARALLEL t0 MAJOR JOINT'SYSTEM END LINE A (PRIMACORD LOOP BURDEN CONTROL LINE 8 j 4I3 EN SHEET 10 0F 21 DIRECTION OF ADVANCE FACE DO NOT REDUCE MINIMUM SLIDING RESISTANCE PR IMACORD LOOP LINE OF SYMMETRY D REPLACE LINE D WITH LINE C, ADD LINES FOR COMPOSITE BLASTS B AND A ON OPENING SHOT SHORT PERIOD BACK LINE E PRIMAcoRD LOOP DELAY N0.

CODE V4 V2 V3 8-1 5-2 B3 54 8'5 5'5 57 5-9 SYM Q Q C) G9 6' 0 g Q Q W DIA. IN. 9.875 9.875 9.975 9.875 9.875 9.875 9.875 9.975 9.575 5.025 5.625 SUB. FT 5.91 6.17 5.27 5.17 5.79 5.47 4.97 4.97 5.18 4.50 3.70

DEPTH ft. 40.91 40.17 40.27 40.17 39.78 39.74 33.97 39.97 39.18 33.50 37.70

PATENTED 41975 3 7?5 98% SHEEI 12 [1F 21 PATENTED 41573 3.775884 FIG. 20b H6 200 I PATENTEDJQ mm sum mar 21 IHIIIIHIIHH Ill Him]! III CODE 5 CODE 4 CODE 3 CODE 2 CODE PATENTEDBEB 419B 3.775.984 sum mar 21 PATENTEBUED M973 sum 18% 21 KN 6Q

Claims

1. In the method of land reclamation including removing overburden from an extended area of ore, removing the ore from the ore body in a predetermined pattern so that the remaining ore body defines a grid network of cellular units, said ore removal being performed progressively such that adjacent cellular units are in various stages of development simultaneously and filling the mined-out cells with overburden from adjacent ore body; the improvement comprising: a. constructing terrace ponds above the elevation of the top of the mined-out cells, said terrace ponds being constructed from overburden material; b. constructing dams between adjacent terrace ponds said dams overlying an elevated portion of the ore body previously used as a plant pillar or access entry pillar; and c. selectively filling the terrace ponds and pillar ponds with mill tailing slurry to a predetermined reclaimed surface elevation so that the reclaimed surface consists predominantly of a slime fraction suited to agricultural re-use of the land.

2. The method of claim 1, wherein the over-burden material used to construct the terrace and pillar ponds is blasted to a predetermined required size by product control blasting.

3. The method as defined in claim 1, further including the step of mining the pillars separating the cellular units of the ore body by cut-and-fill mining.

4. The method as defined in claim 3, wherein the fill material for the cut-and-fill mining steps is mill tailing slurry from an ore processing plant.

5. The method as defined in claim 1, wherein the predetermined reclaimed surface is effectively established by the height of the dykes forming the terrace and pillar ponds and the height of the terrace and pillar ponds are pre-planned to accommodate the swell factor of the material being mined, said swell factor being determined by a measurement of the volume of the material to be disposed of for a given area after the mining process is complete, as compared to the volume of the material for the area in its original state.

6. A method of mining, land reclamation and hydropower and water resources development wherein a mining layout is established including a cellular mining grid having an even number of rows of mining cells, the rows being divided equally by a processing plant pillar, the processing plant pillar being a mass of the ore to be mined and centrally positioned within the cellular mining grid, the cells being separated by barrier pillars perpendicular to the plant pillar and access entry pillars parallel to the plant pillars separating the rows of cells on either side of the plant pillars, the barrier pillars and access entry pillars being of the same ore body material and having essentially the same shape and height, the said cells being mined in a step arrangement such that various adjacent cells are in different stages of mining completion, mining commencing at a face barrier pillar and proceeding parallel to the plant pillar towards an ultimate mining limit, large diameter bore holes in the form of entries being driven from the face barrier pillar into the entry and plant pillars and therethrough, cross-entries being driven from the entries perpendicular to the plant and access entry pillars through the cellular units, the level of the entries and cross-entries being designed to perform trajectory control blasting in the overburden and product control blasting in the predefined cellular units, the entries and cross-entries providing communication between adjacent cellular units after the mining has proceeded to the point that the ore is removed from the predefined cells, a processing plant for the ore mined from the predefined cells being positioned at the top of the ore body height on the processing plant pillar and adjacent the face barrier pillar, whereby the material removed from the cells may be passed upwardly to the processing plant and the refined ore recovered and the by-products, including tailings, being passed further upwardly to disposal areas, the mined-out cells being filled with overburden from the ore body adjacent the previously mined cells, and terrace ponds formed above the cells by dykes to provide chambers for disposal of the tailings, the area defined by adjacent plant pillars and bound by the face barrier pillar and the mining limit defining a hydropower and water resources development unit, termed a hydropower unit, a number of cell mining units being constructed during the course of the mining with certain of the cellular units having been completely exhausted of the ore material by cut-and-fill operations to define larger pillar recovery units separated by boundary pillars and the various cell recovery units establishing water control chambers, providing for underground water storage, the improvements comprising constructing a lower pool lake bed having a water level below the face barrier pillar, access slots on the face barrier pillar for access to the plant pillars and access pillars and ramps leading from the lower pool elevation to the access slots to provide passage for motor vehicles to pillar mining entries and cross-entries, drainage tunnels, and water quality control tunnels.

7. The method as defined in claim 6, further including leaving at least one mining cell adjacent the face barrier pillar open and free of any filling overburden or other material for use as an open cell water storage area, and further constructing tunnels and raises through the face barrier pillar communicating the lower pool with the upper portion of the open cell water storage area.

8. The method as defined in claim 7, further including constructing a power generation system adjacent the lower pool water level for generating power due to the passage of water from the open cell water storage tank to the lower water level.

9. The method as defined in claim 8, further including means for sUpplying water to the processing plant constructed on the processing plant pillar.

10. The method as defined in claim 8, further including reclaiming water from the ore processing plant tailings by downward percolation of the water into broken overburden-filled mining cells, thence through filter beds placed in the bottom of the mining cells and finally draining the water into the lower pool.

11. The method as defined in claim 10, further including constructing an overflow structure and mine spillway tunnels to transfer upper pool water from one hydropower unit to another.

12. The method of claim 2 wherein the product control blasting is conducted by: i. conducting test crater blasts at various depths to determine the breakage limits of the material in response to the blasts; ii. preparing a chart by plotting the slant distance to each of the types of fractures in the blasting failure process and to the doming limit from test crater blasts; iii. establishing a grid over the crater formed by each test blast and measuring the particle size of the broken material touched by the grid; iv. preparing a chart by plotting the variation of the predominant particle size with various charge depths at scaled depth ratios Delta ; v. determining in the range Delta d to Delta o from the chart of (iv) the value in the controlling burden direction at which the desired predominant particle size can be achieved, Delta d is the Delta value at which doming begins and Delta o is the value of do/N for the given charge weight, do being the depth of placement of a charge of the given weight which produces upon explosion of the charge maximum pressure rise within the material, and N being the depth of placement of a charge of the given weight which first begins to produce upon explosion of the charge fractures on the surface of the material in which the charge is placed; or in the range Delta o to Delta equals 0 the value at which the desired particle size can be achieved where predominant particle size from autogenous blasting ranges from near zero to that measured at Delta 0 of the crater tests; vi. decreasing the crater chart value (v) by subtracting for bench geometry a Delta increment adjustment ranging linearly from a maximum at Delta bo - Delta o for a controlling burden of magnitude Delta o to zero for a controlling burden Delta a or less or for a controlling burden Delta ss or greater, Delta increment being Delta bo minus Delta o, Delta bo being the value of dbo/N for the given charge weight, dbo being the perpendicular distance from the vertical free face to the center of gravity of explosive charge which produces upon explosion of said charge maximum pressure rise within the material, a is the Delta value at which the volume of the apparent crater is maximum, and Delta ss being the Delta value at which cratering begins; vii. placing the charge at a distance from the controlling burden toward the face of the bench corresponding to the adjusted Delta value; viii. placing the charge at a distance from the non-controlling free face at the crater test determined value; and i. detonating the charge.

13. A mining method including: a removing overburden from the ore body by trajectory control blasting; b. establishing a cellular grid structure including planned ore body cells separated by barrier pillars perpendicular to entry pillars; c. driving entries in the ore body perpendicular to the free face in said entry pillars; d. driving cross-entries from said entries through said planned ore body cells perpnedicular to said entries and at the same ore body level; e. constructing over cells filled with overburden and mill tailing, ramps and terraces forming an embankment to re-establish the terrain of the mined region; f. placing explosive charges in said cross-entries wIthin the area defined by the planned ore body cells for product control blasting; and g. detonating said explosive charges.

14. The method of claim 13, wherein the trajectory control blasting is conducted by controlling the trajectory of material formed as bench geometry surrounding a blast charge in response to explosion of the charge by: i. placing a charge of weight W at a vertical depth Delta v, wherein Delta v dv/N wherein dv is the vertical depth, N being the depth of placement of a charge of given weight which first begins to produce upon explosion of the charge fractures on the surface of the material in which the charge is placed; ii. positioning said charge of weight W along a rearward extension of a line perpendicular to the bench free face at a burden Delta b wherein Delta b db/N wherein db is the burden distance and Delta b Delta v + Delta diff wherein Delta diff is a predetermined positive value, the trajectory being substantially in a vertical direction when Delta v is less than Delta b and substantially in the horizontal face direction when Delta b is less than v; and iii. detonating the charge.

15. The method of claim 13, wherein the material for constructing the embankment is produced by product control blasting.

16. A mining method including: a. clearing overburden from an extended area of underlying ore; b. excavating in a stepped fashion a grid of cellular units in the exposed ore body, said units separated by barrier pillars; c. forming ramps in the pillars as mining progresses downwardly for access to the ore; and d. providing means for removing water from streams adjacent the area being mined during periods of high stream flow to an upper pool formed as a reuslt of the mining operation and returning the water to the stream during low flow periods.

17. The mining method claim 16, further including removing water contained within the overburden and ore body and storing the removed water in drainage collection cells and void storage cells which are constituted as previously mined cells filled with broken overburden.

18. The mining method of claim 17, further including constructing terrace ponds and pillar ponds above the previously filled mining cells for collecting surface run-off water and passing the surface run-off water downwardly into the previously mined cells filled with broken overburden.

19. The mining method of claim 18, further including controlling the flow of water from the drainage collection cells by valves positioned within the entries and cross-entries communiating between the mining cells to thereby direct the water through filter beds and water quality and drainage tunnels for use in irrigation and the milling process and collection of portions of the water in a lower pool for return as desired to augment low stream flow.

20. A mining method including: a. clearing overburden from an extended area of underlying ore; b. excavating in a stepped fashion a grid of cellular units in the exposed ore body, said units separated by barrier pillars; c. forming ramps in the pillars as mining progresses downwardly for access to the ore; d. drilling drain holes through the barrier pillars to provide water control tunnels communicating between said cells; and e. recovering water used in the ore processing plant by pumping a slurry of tailings to terrace and pillar ponds constructed above previously mined cells and filtering water from the slurry into void storage cells.