Note: Descriptions are shown in the official language in which they were submitted.
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RAISE BORE MINING METHOD AND APPARATUS FOR
CARRYING oU~ THE ~ETHOD
This invention relates to a raise bore mining method
and an apparatus for carrying out the method.
Raise boring has been successful in virtually all t~pes
of rock. Modern raise boring machines are able to drive
10-12 ~t. diameter raises at a rate of up to 1000 ft. per
month. The known raise boring machines are capable of
drilling a pilot hole o~ up to 300 meters and then reaming
the pilot hole out to 10-12 ft. On completion of the. raise
reaming, a rail such as the one developed by Linden-
Alimak AB i8 installed on th~ hanging wall of the rais~
and a drill rig such as the one developed by Tamrock,
Finland for the Swedish Viscaria Mine, i8 mounted on the
rail. Using the Tamrock-Viscaria rig, horizontal or
inclined fan pattern of blastholes are drilled from the
rig. The drill rig has an automatic rod changer which
allows up to 100 feet of 4 inch diameter blastholes to
be drilled. The drill is normally controlled by a
microprocessor. Drill patterns are fed to the
microprocessor via a line from a central office. Thus the
operator does not have to control the azimuth or depth of
the blastholes.
The Tamrock-Viscaria rig drills off an ore block at
higher rate than any prior art conventional devices.
Varying ore shapes can be accommodated by varying the
length and azimuth of the blastholes. Loading of
blastholes is mechanized and highly productiva. However,
the Tamrock-Vi~caria rig has several disadvantages:
1. The Linden-Alimak rail attached on the hanging
wall of the raise can only handle a veight o~ 10 tons or
so and, there~ore, the drill rig has to he quite light.
2. To save on weiyht, the drill riy is su~pended
below the rig and is thus difficult tG service.
3. A cable winch is required to move the Tamrock-
Viscaria rig. Thus, there is the potential for a broken
cable, winch pxoblem, sheave failures, etc.
4. Drill vibrations can cause failure of the rail or
the anchoring bolts and thus there i~ an additional
potential for failure.
5. The shape o~ the raise is not optimum ~or
collaring drill holes.
It is therefore the object of the present invention to
provide a new method and apparatus for the mechanization
of bulk mining. The method, called raise bore mining, is
suitable to mine large tabular and steeply dipping ore
bodies, both primary mining and pillar recovery, rapidly
and economically.
The method, in accordance with the present invention,
comprises the steps of boring a raise from one drift level
to the next with a conventional raise boring machine using
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a string of drill pipes, on completion of the raise
boring, attaching a mining as6embly to the end of the
drill string of the sa~e or a different raise boring
machine ~or moving the mining assembly up and down the
bored raise, and performing regular mining activities such
as drilling, blasting, ground support, etc, from such
mining assembly.
The distance between adjacent bored raises depends on
the size and geometry of the ore body and the extent of
the blasthole drill pattern. Permissible dip depends on
the angle of repose of the muck.
By using the drill string of a raise boring machine to
suspend the mining assembly, large capacity drills may be
used to drill the blastholes. Aftar reaming ~he raisa, a
less expen~ive raise boring machine may be substituted for
the purpo~e o~ raising or lowering the mining assembly.
The raise bore apparatus comprises a raise boring
machine adapted to drill a raise using a string of drill
pipes, a mining assembly attached to the end of the drill
string of the raise boring machine for moving the mining
assembly up and down the bored raise, and means for
performing regular mining activities such as drilling,
blasting, ground support, from said mining assembly.
Fail sa~e security may be provided to the mining
assembly by means of spring loaded and hydraulically
! released gripper pads which fix the mining a~sembly to the
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wall of the bored raise while performing mining activities
or to support the assembly while removing or adding
sections of drill string pipes to the boring machine.
The mining assembly is g~nerally made in two superposed
sections interconnected by hydraulic or air cylinders to
permit a blasthole drill mounted on the lower section to
be displaced along the raise without moving the mining
assembly as a whole. The inherent advantage of such a
system is to permit the adjustment of the blasthole drill
elevation and the drilling of more than one row of blast-
holes, and to allow greater accuracy in collaring holes.
Each ~ection i5 provided with spring loaded and
hydraulically released gripper pads. By alternately
gripping and releasing the gripper pads of one section
versus tho~e of the other ~ection, and using the
cylinders, the mining assembly can also be moved along the
bored raise if required.
Access of personnel and supply to and from the mining
assembly may be by conventional Linden-Alimak raise
climbers traveling upon a rail attached to the bored raise
wall. An alternative method is by using a mobile service
rig capable of traveling along the drill string of the
raise boring machine as disclosed and claimed in
Canadian application No. ~ 9~ 5 filed ~o JQ~Y I~ Iq~
Additional stability of the stope walls may be achieved
by cable bolting during the production phase by extending
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the regular blastholes for the installation o~ cable
bolts.
The in~ention will now be disclosed, by way of example,
- with referance to the accompanying drawings in which:
Figure 1 is a cross section view of a raise bore stope,
Figure 2 is view ~f a first embodiment of a mining
assembly; and
Figure 3 is a view of a second embodiment of a mining
a~sembly~
Referring to Figure 1, there is shown a raise bore
stope 10 through which has been bored a raise 12. It is to
be understood however that a raise may be driven long
enough to ~ervice several stopes along its length. The
angle of dip of the raise depends on the angle of repose of
the muck. The raise is bor~d by a xaise boring machine 14
suitably located in an access drift at a predetermined
height above the top of the stope so as to leave a crown
pillar above the stope. The raise boring machine is
provided with conventional equipment capable of delivering
a string of drill pipes 16 for drilling a pilot hole down
the stope. The pilot hol~ is subsequently reamed by
additional equipment attached to the drill string to
enlarge the pilot hole between an upper access drift 18
and a lower access drift which is later undercut as
indicated at 20. A haulage drift 22 provides access to the
stope undercut. A mining assembly 24 is attached to the
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end of the drill string 16. A service rig 26 is mounted on
a rail (not ~hown) attached to the hanging wall of the
raise to provide access of personnel and supply to the
mining assembly.
Referring to Yigure 2 there is shown a mining assembly
comprising a drill deck 30 and an operator's deck 32
supported by two rings 34 and 36 respectively. A platform
38 is attached to the top ring by three support columns 40
Qpaced at 120C. The top ring is attached to the drill
string 16 by means of a swivel attachment 42 which
prevents any rotation in the drill string to be
transmitted to the mining assembly. A platform 44 is
attached to the lower ring by thre~ hollow tubes 46
also spaced at 120C.
The drill deck 30 is suspended under the operator's
deck by hydraulic or air cylinders 48 mounted on lower
ring 34 and having their pistons 50 connected to the
platform 38. This permits the drill deck to move along the
raise independently of the operator's deck and thus
adjustment o~ the elevation o~ the drilling eguipment and
drilling of more than one row of blastholes without
having to move the mining assembly as a whole.
Spring loaded and hydraulically released gripper pads
52 are mounted on the upper and lower rings. The gripper
pads fix the mining assembly to the wall of the bored
raise while performing mining activities and are used to
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support the assembly while removing, or adding sections of
drill string pipes to the boring machine. Furthermore, by
alternately gripping and releasing the gripper pads o~ the
lower riny with respect to thosa of the top ring and
operating the cylinders 48, the mining ass~mbly can be
moved along the bored raise if required. Thare is at all
times at least one set of grippers act:ivated to ensure the
6afety to the mining assembly. Support columns 40 extend
to the bottom of the drill deck through tubes 46 and serve
as guides to the lower ring.
The platform 38 of the operator's deck 32 may be
provided with rollers 53 to guide its pa~sage along the
bored rai3e wall in inclined raises. An operator's cabin
54 is mounted on three cylinders 56 which serve to level
the cabin ln inclined bored raises. A power unit 58 i8
also mounted on aylinders 60 for the same purpose.
Ladders 62 connect the two decks of the mining
assembly.
A conventional drill rig 64 i~ suspended from the lower
ring via an articulated arm 66. The arm may be rotated in
a horizontal plane by means of a shaft 68 and locked in
position with a disk brake 70. The drill rig may be
pivoted in the vertical plane by means of an articulated
arm 72 and cylinder 74. A cylinder 76 operating a pad 78
applies a compensating force on the bored raise wall while
drilling.
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As shown in Figure 1 of the drawings, the blast
hole drill may be used to drill holes eor installing cable
bolts 79.
Referring to Figure 3, there is shown a second
embodiment of a mining assembly comprisiny an upper ring
80 and a lower ring 82 connected by cylinders 84
permitting the lower ring 82 to move independently of the
top ring 80 ~or the same purpose as in the ~irst
embodiment of the mining assembly. Three support columns
86 spaced at 120DC are fixed to the lower ring and pass
through the upper ring to serve as guides for the movement
o~ the upper ring. Each ring is mounted with ~ail safe
sprlnq loaded and hydraulically released grippar pad~ 88
which serve to fix the mining assembly to the bored
raise wall. Rollers 90 mounted on each ring permit the
movement of the rings without damaging the pads. As in the
first embodiment, by alternately gripping and releasing
the gripper pads on the lower ring with respect to those
of the top ring and operating the cylinders, the mining
assembly can be moved along th~ bored raise if required.
The drill string 16 of the raise boring machine is
attached to the upper ring B0 of the mining assembly
through a swivel attachment 92 which prevents any rotation
of the drill string to be transmitted to the mining
assembly.
A power unit 94 is mounted on the lower ring~
A drill ring 96 and an ~perator's cabin 98 are
supported underneakh the lower ring. Both drill and
operator's cabin are able to rotate in a horizontal plane
via a turntable loo. A ball and socket attachment 102 and
a pair of levelling cylinders 104 serve~ to level the
turntable. A work platform 106 is also ~uspended under the
lower ring via columns 108. The work platform can be
leveled by ball and socket attachment 110 and cylinders
112.
The blasthole drill mounting assembly is designed to
permit a horizontal offset 60 that obstacles such as
columns 108 can be avoided. The blasthole drtll is of
conventional type.
Drilling is preferably carried out ~rom higher to lower
elevations and controlled by a microprocesBor 80 that the
operator doe~ not ha~e to set the azimuth or depth of the
blastholes. Drill pattern~ may be fed to the
microprocessor via a line from a central office.
At the start of the drilling cycle, the gripper pads
on the upper and lower sections o~ tha mining assembly are
extended against the rock. Once a complete row of blast-
hole is drilled off, the gripper pads on the lower
section of the mining assembly are retracted and the
cylinders are extended to the preset location of the next
row of blasthole~ and so on until full extension of the
cylinders is reached. Once the full extension of the
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cylinders has been reached, the gripper pads on the lower
section are applied and those on the upper section
retracted so as to allow the raise boring machine to add
additional raise bore drill pipes for lowering the mining
assembly. The above drilling operation can be completely
mechanized and automatedO
once the complete stope is drilled off, the mining
assembly may be removed and replaced by a blasting
platform but the mining assembly is preferably used for
loading the blastholes and blasting. Loading and blasting
is pre~srably carried out from the bottom to the top of
the raise. Loading and blasting can also be mechanized by
u~ing bulk explosive which would be blown through a hose
from one level above and detonated using conventional
detonators, thus minimizing material handling.
The main feature of the present invention is that it
permits mining of an ore body from a bored raise using a
mining assembly which is suspended from the drill string
of a raise boring machine. ~he mining assembly may be
moved up and down the bored raise using the raise boring
machine. This feature allows no practical weight
limitation for the mining assembly. This is a marked
improvement over the Tamrock-Viscaria rig which is limited
by the load handling capacity Q~ the Alimak rail used to
support the drill rig in the bored raise.
Another advantage of the pre~ent invention is the use
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of a mining asembly having two indendepent sections
interconnected by cylinders which allow drilling o~
several rows of blastholes without moviny the mining
assembly as a whole.
Additional advantages of the present invention are as
follow :
1~ Mining assembly is completely mechanized and can
be automated with present technology.
2. Mining method is suitable for remote control
mining such as in radio active or high stres areas.
3~ Fewer accesses are re~uired thus reducing
development C08t. This becomes significant in high stress
or high temperature areas where conditioning of accesses
is a major expense.
4. Driving of a bored raise is fast and safe. A bored
raise is also easier to condition than conventional drill
and blast raises.
5. Collaring of drill holes will be easier eince a
drill located in the center o~ a circular bored raise will
always be at right angle to the raise wall. Ease at
collaring increase blast hole accuracy.
6. The platform under the drill rig on the mining
assembly provide~ access to drill for sampling and
maintenance.
7. Different options exist for driving the raise such
as reaming from top to bottom~ or bottom to top, driving a
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box hole raise, or using a tunnel boring rig, all of which
giveæ more flexibility to the methodO
8. During the moving cycle, the mi.ning assembly is
always supported by two methods: either two sets of
grippers pads both of which are designed to support the
total weight of the mining assembly plus the raise boring
machine drill stringl or the boring machine drill string
plus one set of gripper pads while a portion of the drill
a6semb1y i5 being moved.
