U.S. patent number 3,790,214 [Application Number 05/293,401] was granted by the patent office on 1974-02-05 for hydraulic mining system.
Invention is credited to Oliver B. Kilroy.
United States Patent |
3,790,214 |
Kilroy |
February 5, 1974 |
HYDRAULIC MINING SYSTEM
Abstract
This specification discloses an hydraulic mining system
including a method and apparatus whereby energy derived from a
downflowing column of water utilized to conduct underground mining
operations is mechanically transferred to a pump which drives a
column of slurry containing mined ore upwardly to a separator on
the ground surface.
Inventors: |
Kilroy; Oliver B. (Tucson,
AZ) |
Family
ID: |
23128935 |
Appl.
No.: |
05/293,401 |
Filed: |
September 29, 1972 |
Current U.S.
Class: |
299/8; 60/398;
299/17; 299/18; 299/19; 405/75; 406/96; 406/106; 406/146 |
Current CPC
Class: |
E21C
37/00 (20130101); E21F 13/04 (20130101); E21C
25/60 (20130101); E21C 35/20 (20130101); E21F
13/042 (20130101); E21C 41/22 (20130101) |
Current International
Class: |
E21C
35/00 (20060101); E21C 35/20 (20060101); E21C
37/00 (20060101); E21F 13/00 (20060101); E21C
41/16 (20060101); E21F 13/04 (20060101); E21C
41/00 (20060101); E21C 25/00 (20060101); E21C
25/60 (20060101); E21c 041/00 (); E21c
045/00 () |
Field of
Search: |
;299/8,17,18,56,57,64-68,19 ;60/398 ;61/19 ;302/14,15,16 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Purser; Ernest R.
Attorney, Agent or Firm: Robertson; John A. Schellin; Eric
P.
Claims
1. In hydraulic mining, the method including the steps of:
a. storing water in a surface reservoir;
b. downflowing a column of water to an underground reservoir;
c. mining ore at an underground level;
d. converting mined ore into slurry at said underground level by
combining it with water from said underground reservoir;
e. pumping said slurry upwardly by a pump that is mechanically
driven by a turbine that is actuated by said downflowing column of
water, with the assistance of an auxillary net power input system,
and
2. The method of claim 1 in which the ore is mined hydraulically by
water
3. The method of claim 1 in which the slurry is delivered under
pressure to an ore separator, including a pressure autoclave, at
the ground surface
4. The method of claim 1 in which the ore is mined hydraulically by
water
5. The method of claim 4 in which the pressurized water is conveyed
from the downflowing column to jet nozzles by a flexible tube and
water and
6. The method of claim 5 together with the step of conveying excess
water
7. The method of claim 6 together with the steps of separating fine
particles from the water that is conveyed from the locality of the
water jets to the underground reservoir and transferring said
particles to the
8. In hydraulic mining, apparatus installed in a ground formation
having an upper surface and a lower mining level,
a. a surface reservoir immediately below said upper surface;
b. an underground reservoir below said mining level;
c. a downflow tube extending between said reservoirs;
d. a turbine included in said tube at a level closely adjacent to
said underground reservoir;
e. a slurry mix tank at said lower level;
f. an upflow slurry tube having a lower end communicating with said
slurry mix tank and an upper end at said ground surface;
g. a pump included in said slurry tube;
h. mechanical driving connections between said turbine and
pump;
i. net power input apparatus including a motor connected to said
pump;
j. ore mining devices at said lower level;
k. means for conveying ore from ore mining devices to said slurry
mix tank;
l. a pipe communicating between said underground reservoir and said
slurry mix tank, and
9. The mining apparatus of claim 8 together with a separator,
including a pressure autoclave, at said upper ground surface
communicating with said slurry tube and a tube between said
separator and said surface reservoir.
10. The mining apparatus of claim 8 in which said mining devices
comprise jet nozzles, together with a flexible tube extending from
said jet nozzles to said downflow tube and communicating therewith
between said turbine and said underground reservoir and in which
the means for conveying mined ore
11. The mining apparatus of claim 10 together with a drain pipe
communicating between the locale of said water jets and said
underground
12. The mining apparatus of claim 11 together with a settling tank
included in said drain pipe, together with a transfer tube
communicating between
13. The mining apparatus of claim 8 in which the means for
conveying spent water to said surface reservoir includes a return
tube extending from said underground reservoir to said surface
reservoir and including an
14. The mining apparatus of claim 8 in which the mining devices are
mechanical and the means for conveying ore from the mining devices
to the
15. The mining apparatus of claim 8 in which the mining devices are
jet nozzles connected to said downflow tube by a flexible tube, the
mined ore is conveyed to the slurry mix tank by a mechanical
conveyor and water is delivered from said underground reservoir to
said slurry mix tank by a pump that is actuated by an hydraulic
motor connected to said downflow
16. The mining apparatus of claim 15 together with a return tube
communicating between said underground reservoir and said
surface
17. The mining apparatus of claim 8 in which said mining devices
comprise jet nozzles, together with a flexible tube extending from
said jet nozzles to said underground reservoir and being driven by
a pump located thereat.
18. The method of claim 1 in which the step of returning spent
water to the surface reservoir includes the pumping of water from
said underground reservoir to said surface reservoir.
Description
The present invention relates to hydraulic mining and is concerned
primarily with the mechanical transfer of energy derived from a
downflowing column of water to a pump which actuates an upward
moving column of ore-containing slurry.
BACKGROUND OF THE INVENTION
At the present time, with the costs of underground mining increased
yearly, the use of hydraulic mining is being reconsidered. It may
be the only practical method for mining under certain
conditions.
The use of underground tunnels and other types of excavations, such
as modified mine workings, for storage reservoirs of water,
especially for hydroelectric pump storage projects, is well
known.
Also, it is a known technique to break up rock formations by jets
of water, the pressure of which can be derived from the head
provided by a downflowing tube which communicates at its upper end
with a storage pond or lake at or immediately below the ground
surface.
The practicality of conveying mined ore in slurry form is now
recognized as is the feasibility of raising an ore-containing
slurry from an underground mining site to a separator at or
immediately below the ground surface.
The use of pressure autoclaves, where the metal values are leached
from the ore which are then substantially stripped from the leach
solution, is well known in mining.
It is also important to note that in many localities, the rates for
electric power are lower at night than during the normal daytime
working hours.
The present invention is founded on the basic concept of
mechanically transferring energy derived from a downflowing column
of water to a pump for driving an upflowing column of
ore-containing slurry. It is based on the theoretical calculations
that a given volume of water flowing downwards into a mine area,
then being enslurried with ore, and then returning to the surface,
will require a net power input, supplementing the mechanically
transferred energy, at a cost which represents substantial
operating savings over conventional haulage equipment used in
underground mines.
OBJECTS OF THE INVENTION
With the foregoing conditions in mind, the present invention has in
view the following objectives:
1. To provide, in a method of hydraulic mining, the step of
mechanically driving a pump for an upflowing column of
ore-containing slurry by energy mechanically derived from a
downflowing column of water used in hydraulic mining
operations.
2. To provide, in a method of the type noted, the steps of
operating a turbine from a downflowing column of water and
mechanically driving a pump which moves an ore-containing slurry
upwardly from said turbine. Also, to provide, in a preferred
method, the supply of auxillary net power input to the system.
3. To provide, in a method of the character described, the step of
operating high pressure, rock breaking jets from the downflowing
column of water.
4. To provide, in a method of the kind described, the step of
conveying mined ore and water used in the mining thereof to a
slurry mixing tank.
5. To provide, in a method of the type noted, the step of conveying
water from the mining operation to an underground reservoir into
which excess water from the downflowing column also empties.
6. To provide, in a method of the character aforesaid, the step of
conveying water from the underground reservoir to the reservoir at
the ground surface.
7. To provide, in a method of the kind described, the steps of
separating fine particles from the water which is conveyed from the
mining operation to the underground reservoir and delivering such
separated particles to the slurry mixing tank.
8. To provide, in a method the type noted, the steps of separating
the metal values from the slurry by a pressure autoclave located at
or directly beneath the ground surface, separating the spent ore
material from the leach solution, stripping the metal values from
the leach solution, and returning water from this separating system
to the reservoir at the ground surface.
9. To provide, in a method of the type noted, the steps of mining
the ore by mechanical mining apparatus, crushing the mined ore and
conveying the mined ore to a slurry mixing tank.
10. To provide a method of the kind described in which the slurry
mixing tank and pump which delivers water thereto from the
underground reservoir is operated by an hydraulic motor which in
turn is actuated by the downflowing column of water.
11. To provide apparatus for carrying out the above method.
Various other more detailed objects and advantages of the
invention, such as arise in connection with carrying out the above
ideas in a practical embodiment, will, in part, become apparent,
and, in part, be hereafter stated as the description of the
invention proceeds.
SUMMARY OF THE INVENTION
The foregoing objects are achieved by providing a water reservoir
in the form of a lake or pond which is located at or immediately
beneath the ground surface. Extending downwardly from this
reservoir and preferably in a direction which is substantially
vertical is a downflow tube, the lower end of which empties into an
underground reservoir located at the lower level of the mining
operation. Included in this tube at a location fairly close to the
underground reservoir, speaking with reference to the overall
length of the tube, is a turbine which is driven by the downflowing
column of water in the tube. This turbine is mechanically connected
to a pump which drives a column of slurry in an upflow tube. As an
auxillary to the mechanically driven pump is a system for boosting
the power requirements to drive the slurry upwards. This is
necessary where underground reservoir capacity is not large enough
to hold the additional volume of water necessary to provide the net
input power requirement by mechanical transfer. This auxillary
system may be driven by electricity, gas, fuel oil, or other forms
of energy. The lower end of this tube communicates with a slurry
mix tank and the upper end with an ore separating system that
includes a pressure autoclave. Water from the latter is conveyed to
the reservoir at the ground surface, preferably under gravity
action. Rock breaking jets are provided on a mobile carrier and are
operated by the pressure of water in a flexible tube that is
connected to the downflow tube immediately beneath the turbine
therein. Mined ore and water are conveyed by another flexible tube
to the slurry mix tank under the influence of a pump which is
driven by a motor operating on one of the above auxillary energy
forms. Excess water from the mining operation is conveyed by
gravity action through a tube to the underground reservoir. A
settling tank is included in this tube for the purpose of
separating fine particles from the water and these fine particles
are delivered to the slurry mix tank. Water for the slurry mix tank
is drawn from the underground reservoir by a pump which is driven
by a motor operating on one of the above auxillary energy forms.
Excess water from the underground reservoir is returned to the
surface reservoir by an upflow tube under the influence of a pump
that is driven by a motor operating on one of the above energy
forms, but electricity is preferred.
In a somewhat modified and perhaps more simplified form of the
invention, the ore is mined by conventional mining apparatus,
crushed and conveyed to the slurry mix tank. The mining apparatus,
rock crusher and conveyor are driven by motors operating on one or
more of the above auxillary energy forms.
In another embodiment of the invention, all of the underground
operations including the breaking of rocks by water jets,
conveyance thereof to the slurry mix tank and the operation of the
slurry mix tanks are driven from an hydraulic motor which is in
turn actuated by the head of water in the downflow tube. In the
latter case, both of the reservoirs should be extensive to allow
for the return of water from the underground reservoir to the
surface reservoir at night when electric power is less expensive,
if available. In addition, the volume of water needed to provide
the net power input, provided by other energy forms in the
preferred embodiment, will be substantially greater than that used
in said preferred embodiment.
For a full and more complete understanding of the invention,
reference may be had to the following description and the
accompanying drawings wherein:
FIG. 1 is a vertical section through a ground formation with parts
broken away and largely diagrammatic of mining apparatus used to
carry out the method of this invention;
FIG. 2 is a view similar to FIG. 1 of a modified embodiment,
and
FIG. 3 is another view similar to FIGS. 1 and 2 of still another
modified embodiment.
Before referring to FIG. 1, it is important to note that each of
the three embodiments illustrated disclose a downflow tube and an
upflow slurry tube. These elements are illustrated as having a wide
angle of divergence. However, it is to be clearly understood that
this angle will vary with different terrain and in some instances
it may be found to be practical to include them in a single
conduit, bore or passage extending from the ground surface to the
underground reservoir.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings, wherein like reference characters
denote corresponding elements throughout the several views, and
first more particularly to FIG. 1, a mine site is indicated
generally at 10 and includes a ground formation 11 having a top
surface 12 and formed with a slightly inclined stope 13 at the
lower portion thereof in which the actual mining operation takes
place. The mine entrance for personnel is not shown.
Formed at ground surface 12 or immediately therebeneath is a lake
or pond forming a surface reservoir 14. This reservoir should be
extensive and much larger in relative size than indicated by the
diagrammatic representation thereof. It should have a capacity
sufficient to provide water for the operations now to be described,
with said volume of water being limited to that amount necessary to
enslurry a given volume of ore, to fill the operating system, and
to provide a minimum surplus as a safety factor. Extending
downwardly from surface reservoir 14 is a downflow tube 15 which as
illustrated is substantially vertical, although it well could be
inclined from the vertical. The lower end of tube 15 opens onto an
underground reservoir 16 which also would have a large capacity
comparable to that of surface reservoir 14. Included in downflow
tube 15, a short distance above underground reservoir 16, is a
turbine represented diagrammatically at 17. This turbine is driven
by the downflowing water in tube 15.
An upflow slurry tube is designated 18. The lower end of tube 18
communicates with a slurry mix tank 19 and its upper end with an
ore separator 20 which includes a pressure autoclave.
Ore, or essentially waste material, which is separated from the
slurry passes out one end of the separator 20 as indicated by arrow
21, leach solutions are stripped of metal values and processing
chemicals, and the resulting barren water is conveyed from
separator 20 by tube 22 which has preferably a slight downward
angle of inclination to surface reservoir 14. Thus, the water
conducted through tube 22 to surface reservoir 14 is spent, in that
it has performed the function required of it.
Included in slurry tube 18 immediately above slurry mix tank 19 is
a pump 23. Pump 23 is mechanically driven from turbine 17 by
driving connections represented at 24. It is believed unnecessary
to herein illustrate or describe details of the mechanical
connections 24, because such are generally well known. The
auxillary net power input system will be integrated with the
mechanical pump 23, with said details also being omitted since such
systems are well known. Such auxillary power input may take the
form of electric motor 6 which is mechanically connected to pump
23.
Water is delivered to slurry mix tank 19 by a pipe 25 which
includes a pump 26 that is driven by an electric motor 27 and the
lower end of which communicates with underground reservoir 16.
The ore formation which is being mined is represented at 28 and is
illustrated as being at one end of a slightly inclined stope 13. In
most instances this ore will contain a large quantity of rock which
in the embodiment now being described will be broken up by water
emanating from jet nozzles, one of which, representing the general
class of high pressure nozzles, is shown at 29. Jet nozzles 29 are
mounted on a mobile carrier 30 and water under pressure is supplied
by flexible and segmented tube 31 which is connected to downflow
tube 15 as indicated at 32. This connection 32 is located between
turbine 17 and underground reservoir 16. Another flexible and
segmented tube 33 has one end mounted on the carrier 30 immediately
adjacent to jet nozzles 29 and its other end to slurry mix tank 19
as indicated at 34. A pump 35 is included in tube 33 and is driven
by an electric motor 36. It will be understood that while pump 35
and motor 36 are illustrated diagrammatically, they would be
mounted on carrier 30.
Although the most sophisticated and advanced jet cannons
disintegrate the rock into fragments small enough to be carried
into a slurry acceptable for transport to the surface, an
alternative set of machinery would replace scoop at front of
carrier 30 if it were necessary to reduce particle size of
fragments even further. This machinery would include a rotating set
of scoops to drop material onto two counter-moving conveyors that
would move material to center of carrier 30. The material would
then be moved onto a third conveyor which is 90.degree. to the
other two. The material would be moved to the rear of the carrier
to be crushed in a wet ball mill 9, mobile like the carrier, or to
be moved to a stationary wet ball mill and thence moved to mixing
tank 19. The alternative equipment would be driven by electric
motors.
A drain tube 37 has an upper end at 38 which opens onto the floor
of stope 13 where it receives water resulting from the jets
provided by nozzles 29. Drain tube 37 has a slight downward angle
of inclination whereby water may flow therethrough to underground
reservoir 16. Included in drain tube 37 is a settling tank 39 in
which fine particles which may be suspended in water flowing
through drain tube 37 are collected. A transfer tube 40 has one end
connected to settling tank 39 as indicated at 41, and its other end
to slurry mix tank 19 as indicated at 42. Included in transfer tube
40 is a pump 43 which is driven by an electric motor 44.
A return tube 45 has a lower end communicating with underground
reservoir 16 as indicated at 46 and an upper end which communicates
with surface reservoir as indicated at 47. Included in return tube
45 is a pump 48 which is driven by an electric motor 49. Thus, the
water returned through tube 45 is spent, in that it has performed
its function of driving turbine 17.
OPERATION OF THE PREFERRED EMBODIMENT
While the manner in which the above described apparatus operates to
carry out the method of this invention is believed to be obvious
from the illustration of FIG. 1 and the description of parts as set
forth above, it is briefly outlined as follows:
Surface reservoir 14 contains an adequate amount of water to
provide the head and flow for the operations now to be described.
water flows downwardly through downflow tube 15 and drives turbine
17. It also supplies water under pressure to tube 31 which in turn
supplies the water to jet nozzles 29. Tube 31 pressure is developed
by free flow passage of water, downflowing from turbine 17, into
connection 32 in a manner that allows water to enter tube 31
without developing enough back pressure to reduce to any
significant degree the energy transfer at turbine 17, but whatever
energy loss results is made up in the net power input requirements.
An alternative for operating purposes and for emergencies is the
provision for a second pump at 7, with a bypass line 8 from
reservoir 16 to tube 31, said pump preferably being driven by an
electric motor which may be the motor 6 as illustrated. The high
pressure water jets break up the formation 28, whereupon the broken
pieces of ore and some water are sucked into the open end of tube
33 at mobile unit 30 by pump 35, or said material and water are
removed and transported as described above, and this mixture of
broken ore and water is conveyed to slurry mix tank 19 by tube 33.
In mix tank 19, the ore is further comminuted and additional water
supplied through pipe 25 from underground reservoir 16. Thus,
ore-containing slurry is drawn into the lower end of slurry tube 18
by pump 23 which is mechanically driven from turbine 17 by
connections 24, and by the auxillary net power input system. The
slurry under pressure is delivered to separator 20 in which waste
material and metal values are separated from the water. The
tailings pass out of the separator as indicated at 21 and the
stripped water is returned through tube 22 to surface reservoir
14.
Excess water from the mining operation is collected in a sump,
covered by grillwork similar to a cattleguard, provided by end 38
of drain tube 37 and flows through the latter to underground
reservoir 16. Fine particles are collected in the settling tank 39
and transferred by tube 40 to slurry mix tank 19 by pump 43.
Water from underground reservoir 16 is returned to surface
reservoir 17 through tube 45 under the influence of pump 48.
Pumps 26, 48, auxillary power input at pump 23 and bypass line 31
and pump 7 could be used to fight underground fires, if such an
emergency arose.
FIRST MODIFICATION
In this embodiment of the invention, the basic elements of the form
shown in FIG. 1 are included, with the basic difference residing in
the fact that the ore formation represented at 50 at the end of
stope 13 is adapted to be mined by conventional mining apparatus
represented graphically at 51. Mined ore is drawn into a crusher 52
and from the latter is dropped onto a conveyor 53 which delivers it
to slurry mix tank 19. It will be understood that mining apparatus
51, crusher 52 and conveyor 53 are preferably electrically driven,
although the electrical elements are not designated. In this
embodiment, the tubes 31, 33 and 40 and their associated devices of
FIG. 1 are omitted because they are unnecessary.
The operation of the embodiment of FIG. 2 is substantially the same
as that described above in connection with FIG. 1 with the notable
exception that mining apparatus 51 mines the ore from formation 30,
it is crushed in crusher 52 and transferred by conveyor 53 to
slurry mix tank 19. Slurry is mixed in the latter and conveyed
upwardly in slurry tube 18 by pump 23 in the manner above described
in connection with FIG. 1.
SECOND MODIFICATION
FIG. 3 discloses a modification which combines some of the features
of FIGS. 1 and 2, but which embraces the notable difference that
the slurry mix tank is hydraulically actuated.
In the method and apparatus of FIG. 3, the ore formation 28 is
broken into pieces by water emanating from jets 29 which is
supplied under pressure by flexible tube 31 which has an
alternative bypass line 31 with pump at reservoir 16. Jets 29 are
mounted on a mobile unit 54 which includes transfer mechanism 55
which delivers the mined ore to a conveyor 56. The latter delivers
the ore to slurry mix tank 19.
Pump 26 is driven by an hydraulic motor 57 which is connected by a
nipple 58 with downflow tube 15 immediately below turbine 17.
The operation of the apparatus of FIG. 3 comes quite close to being
completely hydraulically operated. The ore is mined hydraulically,
the slurry mix tank is operated hydraulically and the slurry is
raised by pump 23 which is driven by hydraulically energized
turbine 17. Thus, the only preferably electrically operated devices
are the transfer mechanism 55, conveyor 56 and pump 43 for settling
tank 39.
If the reservoirs 14 and 16 are of sufficient capacities to allow
net power input to be developed hydraulically, it will be entirely
practical and extremely desirable to conduct the mining operations
during the daytime when electric power is costly, but return the
water from underground reservoir 16 to surface reservoir 14 at
night, when electric power is much less expensive. Thus, great
savings in the mining operation may be achieved.
While preferred specific embodiments are herein disclosed, it is to
be clearly understood that the invention is not to be limited to
the exact steps, mechanisms and devices illustrated and described
because various modifications of these details may be provided in
putting the invention into practice.
* * * * *