Improvements in or relating to the Mining of Placer Deposits or similar Deposits of a Sedimentary Nature, and Extraction of the Gold or other Valuable Material therefrom.
Year: 1897

page_text: Date of Application, 14th Dec., 1897- Accepted, 14th Dec., 1898
Improvements in or relating to the Mining of Placer Deposits or
similar Deposits of a Sedimentary Nature, and Extraction of the
Gold or other Valuable Material therefrom.
I, WILLIAM FRANCIS LAY, of No. 1, Broadway, New York, in the County and
State of New York, United States of America, Mining Engineer, do hereby declare
the nature of this invention and in what manner the same is to be performed,
to be particularly described and ascertained in and by the following state-
ment:-
i
The object I have in view is the mining of placer deposits or similar deposits
of a sedimentary nature, containing gold or other valuable mineral, and the
extraction of the gold or other valuable mineral therefrom in a rapid and econo-
mical manner, and especially in locations where a sufficient head and quantity
of water are not available for hydraulic mining as ordinarily conducted.
In carrying out my invention, I employ a power plant operated by a steam
engine or other source of power, and the power thus obtained drives one or more
hydraulic pumps for supplying "giant" nozzles which disintegrate the placer, and
also drives one or more centrifugal pumps which by their powerful suction, draw
the mixture of water and placer material from near the point where the placer
is disintegrated by the nozzles to the mill. At the mill the material is delivered
to revolving separating and washing screens, which separate the small percentage
of valuable mineral-bearing material from the large percentage of worthless
debris, the latter of which is conveyed to the dump. The valuable mineral-bear-
ing material is then further treated by suitable processes to recover the mineral
therefrom. In the case of gold-bearing placers, to which the invention is especi-
ally applicable, the small percentage of gold-bearing sand and gravel which is
separated from the large percentage of worthless debris by the revolving separat-
ing and washing screens is preferably carried to other separating and wash-
ing screens, where the sand and gravel are separated from each other,
the sand being run into a settling tank, from which it may be taken at intervals
and smelted, while the gold-bearing gravel is delivered to an amalgamating table
for the collection of the gold by the amalgamating process, or is treated by any
of the well known processes suitable for the purpose. If the valuable gold-
bearing residuum, after the removal of the worthless debris, is all suitable either
for smelting or for amalgamating or similar process of recovering the gold, the
second separation by the screens will not be performed but the residuum will be
conveyed directly from the first set of screens to the settling tank or the amal-
gamating table, as the case may be. The water which is delivered with the
placer material to the screens, and the additional water taken direct from the
source of supply, which is required in the separating and recovering processes,
is not allowed to run to waste, but is conveyed, after it has performed its duty
in the separating and recovering processes, to a reservoir from which the hydraulic
pumps (one or more) for supplying the disintegrating nozzles take their supply,

page_text: and it is in this way that a circular system is established, the water being used
over and over again.
I prefer also, to convey part of the water by gravity or power back to the
sump from which the centrifugal pumps draw the placer material independently
of the disintegrating nozzles. The water required to make good the loss from
evaporation and other unavoidable causes is supplied from a primary source,
such as a stream or artesian well, by power or by gravity.
The mining is performed as follows;-A pit is excavated with the nozzles or
otherwise, in the placer until the bed rock or a hard clay is reached; and then
a sump is blasted out of the bed rock or formed in the clay. Into this sump
is placed a suction pipe of the centrifugal pumps. The side walls of the pit are
then disintegrated by the nozzles, and the placer material is washed along the
bed rock into the sump, from whence it is elevated and delivered to the revolv-
ing separating and washing screens at the mill by the centrifugal pumps. Care
should be taken not to wash into the sump boulders which cannot readily pass
through the pipe and pump. This can be avoided by removing such boulders by
hand or by placing a sceening plate over the sump and around the suction pipe.
As the placer is washed away, new sumps will be blasted out of the bed rock
and the suction pipe will be extended to them. The material being washed
along the surface of the bed rock or surface of the clay into the sump, the bed
rock or clay will itself be washed clean, and all the gold-bearing sand and gravel,
which are formed principally at or near the surface of the bed rock or clay will
be secured; and a like effective result will be attained in the case of other valu-
able minerals.
Where it is necessary to break the gold-bearing material, such as gravel, etc.,
the said material after being separated from the fine material, is passed between
crushing rollers or other suitable device and the material is thereby broken up
into fine particles. It is then delivered on a suitable amalgamating table, or
other separating device, together with a fine material and the gold is recovered
from the debris.
The invention consists in the method and apparatus for the mining of placers
and the recovery of the valuable mineral therefrom, -as more fully hereinafter
described.
In 'the accompanying drawings:
--
Fig. 1 is a landscape showing the apparatus in operation.
Fig. 2 is a schematic illustration of the apparatus.
Fig. 3 is a schematic illustration of a modified form of the apparatus.
Fig. 4 is a longitudinal sectional view of the revolving separating and washing
screen used in the apparatus.
Fig. 5 is a transverse sectional view of a revolving separating and washing
screen.
The placer deposit is indicated by A, and the bed rock or clay by B. The
pit C, is excavated in the placer A, until the surface of the bed rock or clay B,
is exposed. The sump D is blasted or formed in the bed rock or clay B. The
inlet of the suction pipe E, is located in the sump D. The "giant "nozzles F
and are connected with the pressure pipe G. To the right of these features
is shown in Figs. 2 and 3 the mill apparatus. The centrifugal pump H, which
receives the placer material mixed with water, forces it through the pipe 'E'
into the hopper a. From the hopper a, the water and material passes by means
of the sluice b, into the revolving separating and washing screen I. "This screen
is of such mesh that it will allow to pass through its sides all particles bearing
gold or other valuable material, while the large percentage of worthless material
is discharged from the lower end of the screen into the hopper c.
'In some
instances the hopper c, is substituted by the sump C formed in the surface of
the ground as shown in Fig. 1. The material deposited in the hopper c, is carried
'away by any suitable means to the 'dump. 'In Fig. 2 the means for conveying
such material to the dump is in the form of a belt J, while in Figs. 1 and 3,

page_text: a centrifugal pump K, is employed, said pump forcing the material through the
pipe K, back into the pit C.
The mesh of the screen I, will vary with different deposits, proper sizes of
mesh being determined in each case. This screen, it will be understood, is
illustrative of any number of screens (one or more) each may be required to
effect this preliminary separation of the worthless debris from the valuable
residuum. In case the valuable residuum is gold-bearing gravel, this material,
which passes with water through the sides of the screen I, is received by an
inclined trough or other conveyor d, (see Fig. 2) and delivered through a hopper e
and sluice f, to a revolving separating and washing screen K¹, which, like the
screen I, is illustrative of any number of screens (one or more) which may be
required to do this work. The screen K¹ is of such mesh that it permits the
gold-bearing sand to pass through its sides to the trough or other suitable con-
veyor g, by which it is led with the water to the settling tank L. In the form
of the invention, as shown in Fig. 2, the gold-bearing gravel is discharged from
the end of the screen K¹ into the hopper h, from which it passes to the amal-
gamating table M. The revolving separating and washing screens I and K¹ are
preferably steel cylinders, supported by suitable trunnions at their ends, which
trunnions are carried in movable brackets, allowing the said cylinder to be
inclined from the horizontal at either end, and supported at one or more inter-
mediate points if required, and having rectangular or other shaped openings in
their sides, which are covered by suitable perforated screen plates bolted thereto
so that they may be readily removed when worn out.
The screen is stiffened by longitudinal bars or I-beams i connecting the heads
with the cylinder which bars or I-beams i, also act as stirrers or buckets, carrying
a portion of the material from the bottom of the screen upwardly on one side
and showering it down upon the material in the bottom of the screen. The
screen is supported on its ends by hollow trunnions, through which passes a
stationary central water pipe K provided with a series of nipples on its under
side, which deliver jets of water under pressure to the surface of the material in
the screen.
Another similar pipe 1, may be located above and outside of the
screen and extend longitudinally thereof, delivering jets of water to the outside
of the screen and serving to clear the screen perforations.
Within the screens are attached to the longitudinal stirring bars or I-beams i,
and to the steel cylinder, inclined conveying plates m, which serve by the revo-
lution of the screen to drive the material lengthwise of the screen from the point
of its reception and to discharge the material at the opposite end. These con-
veyors are required because the screens are set in a horizontal position, or only
slightly inclined therefrom, the object being to have the material traverse the
screen at the proper speed and to be thoroughly washed and screened before reach-
ing the discharge end.
In the form of the invention as shown in Fig. 2, it will be observed that the
second screen K₁ and its attachments are dispensed with. In many instances
it is found that but one screen may be used to advantage. As shown in Fig. 3,
the course material passes through the end of the screen I upon the skid N.
If the skid N is in the position as shown in the heavy lines in the said fig., the
material passes under the crushing rollers n, and is deposited upon the skid n',
and is conveyed by gravity into the receptacle or settling tank L. If it is found
desirable to crush the coarse material as it passes from the end of the screen I,
the skid N, is placed in a position as shown in the dotted lines and the coarse
material passes between the crushing rollers n. The skid n¹ is removed and the
material falls from the crushing rollers n, upon the amalgamating table M, and
the gold is recovered.
The debris is carried from the receptacle or settling tank L, by means of a
centrifugal pump K, through the pipe k, and is deposited at any suitable place.
N¹ is a water reservoir which supplies water from the primary source, such as
a stream, or artesian well, by power of gravity through the pipe O. The over-

page_text: flow from the settling tank L, as shown in Fig. 2, is received by the reservoir N
as well as the water from the amalgamating table M. A pipe P¹ leads from the
reservoir N to the inlet of the hydraulic pressure pump Q, from the outlet of
which pressure supply pipe G, extends to the "giant" nozzles F and F. Another
and similar pressure pipe R, also takes water from the reservoir N¹ and supplies
through branches n¹o, p, q, and r, water to the hopper h, for the amalgamating
table, to the central pipes of the screens and to the exterior pipes 7, of the
screens. A pipe S, also leads from the reservoir N back to the pit C, con-
veying any amount of water to the sump D, independent of the nozzles so as to
give such additional water for the suction of the centrifugal pumps as may be
required over that furnished by the nozzles.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what
I claim is:-
IM
1. The method of mining gold-bearing placers or similar sedimentary deposits,
consisting in evacuating a pit in the deposit, forming a sump in the said pit
or deposit, washing the placer material along the surface of the pit to said sump
by water pressure, and removing the water and placer material from the sump
by power.
2. In the hydraulic mining of gold-bearing placers or similar sedimentary
deposits and the recovery of the valuable mineral therefrom the circulatory
system for using the same water over and over again.
3. The method of mining gold-bearing placers or similar sedimentary deposits,
consisting in evacuating a pit in the deposit, forming a sump in such pit or
deposit, or bed rock, washing the placer material along the surface of the pit
or deposit or bed rock, to such sump by water pressure, removing the water and
placer material from the sump by power, separating the water from the placer
material, and returning the water to the pit.
4. The method of mining gold-bearing placers or similar sedimentary deposits,
consisting in evacuating a pit in the deposit, forming sump in such pit or
deposit or bed rock, washing the placer material along the surface of the pit or
deposit or bed rock to such sump by water pressure, removing the water and
placer material from the sump by power, separating the water from the placer
material and returning the water to the pit partly through disintegrating nozzles
and partly independent of such nozzles.
5. The method of mining gold-bearing placers or similar sedimentary deposits
and recovering the gold or other valuable mineral therefrom, consisting in wash-
ing the placer material by water pressure along the surface of the pit or deposit
or bed rock into a sump formed in the pit or deposit or bed rock removing the
water and placer material by power, and separating the gold or other valuable
mineral from the debris.
6. A method of mining gold-bearing placers or similar sedimentary deposits
and removing the gold therefrom consisting in washing the placer material by
water pressure along the surface of the pit or deposit or bed rock into a sump
formed in the pit or deposit or bed rock, removing the water and placer mate-
rial by power and separating the gold and gold bearing material from the
debris.
7. The method of mining gold-bearing placers or similar sedimentary deposits
recovering the gold therefrom, consisting in washing the placer material by
means of water pressure along the surface of the pit or deposit or bed rock into
a sump formed in the pit or deposit or bed rock, removing the water and placer
material from such sump by power, separating the gold-bearing sand and gravel
from the debris, and then separating the gold from the said sand and gravel.
8. The combination with the suction and force pumps and the disintegrating
nozzles and the suction pipe at the pit, of separating apparatus and the reservoir
receiving the water from the separating apparatus and supplying the force pumps.

page_text: 9. The combination with the suction and force pumps and the disintegrating
nozzles and the suction pipe at the pit, of revolving separating and washing
screens, means for amalgamating the gold and the reservoir receiving the water
from the amalgamating apparatus and supplying the force pumps.
10. The combination with the suction and force pumps and the disintegrating
nozzles and the suction pipe at the pit of revolving separating and washing
screens for cleaning and separating the valuable gold-bearing sand and gravel,
means for separating the gold, and means for removing the debris at any point.
11. The combination with the suction and force pumps and the disintegrating
nozzles and the suction pipe at the pit of revolving separating and washing
screens for cleaning and separating the valuable gold-bearing sand and gravel,
means for crushing the gold-bearing material, means for separating the gold and
means for removing the debris to any level point.
12. In a system of mining gold-bearing placers or similar sedimentary deposits,
the combination of a pit excavated in the placer or bed rock and a sump therein
formed in the bed rock, with one or more disintegrating nozzles for disintegrat-
ing the placer material and washing it along the surface of the deposit or bed
rock into the sump, a force pump or pumps for supplying water under pressure
to the said nozzle or nozzles, a suction pipe opening in said sump, a centrifugal
pump connected with said suction pipe for elevating the mixed water and placer
material from the sump, and means for supplying water to the said pit indepen-
dently of the disintegrating nozzles.
13. In a system of mining gold-bearing placers, or other sedimentary deposits,
the combination of a pit excavated in the placer to the bed rock and a sump
therein formed in the bed rock with one or more disintegrating nozzles for disin-
tegrating the placer material and washing the same along the surface of the
deposit or bed rock into the sump, a force pump or pumps for supplying water
under pressure to said nozzle or nozzles, a suction pipe opening in said sump, a
centrifugal pump connected with said suction pipe for elevating the mixed water
and placer material from said sump, a revolving screen I, to which the mixed
water and placer material are delivered and by which the heavy debris is
separated, a discharge from said screen for receiving the water and separated gold-
bearing materials, a second revolving screen to which such water and gold-
bearing materials are delivered and by which the water is separated from the
gold-bearing materials, and means for subsequently extracting the gold from said
materials.
14. In a system for mining gold-bearing placers, or similar sedimentary
deposits, the combination of a pit excavated in the placer to the bed rock and a
sump therein formed in the bed rock or deposit with one or more disintegrating
nozzles for disintegrating the placer material and washing the same along the
surface of the deposit or bed rock into the sump, a force pump or pumps for
supplying water under pressure to said nozzle or nozzles, a suction pipe opening
in said sump, a centrifugal pump connected with said suction pipe for elevating
the mixed water and placer material from the sump, a revolving screen I, to
which the mixed water and placer material are delivered and by which the heavy
debris is separated, a discharge from said screen for receiving the water and
separated gold-bearing material, a second revolving screen to which the water
and gold-bearing materials are delivered and by which the gold-bearing materials
are separated from the water, an amalgamating table for extracting the gold from
the gold-bearing materials and a regulated independent water supply for washing
the gold-bearing material on said amalgamating table.
°
15. In a system of mining gold-bearing placers or other similar sedimentary
leposits, the combination of a pit excavated in the deposit or bed rock, and a
ump therein formed in the deposit or bed rock, with one or more disintegrating
ozzles for disintegrating the placer material and washing the same along the
urface of the deposit or hed rock into the sump, a force pump or pumps for
upplying water under pressure to said nozzle or nozzles, a water reservoir N, for

page_text: supplying said force pump or pumps, a suction pipe opening in said sump, a
centrifugal pump connected with said suction pipe for elevating the mixed water
and placer material from said sump, a revolving screen I, above said reservoir
to which the mixed water and placer material are delivered, and by which the
debris is separated, a discharge from said screen for receiving the water and
separated gold-bearing material, a second revolving screen K, to which such water
and gold-bearing materials are delivered and by which the water is separated
from the material, a discharge for the water separated by the second screen, a
settling tank L, connected with the said discharge and having an overflow to the
reservoir, a second discharge from said screen K, receiving the gold-bearing
material therefrom, an amalgamating table M, connected to the latter discharge,
an independent water supply for washing the material on said table, and a
pump R, for supplying said water supply and connected to said reservoir.
16. In a system of mining gold-bearing placers or similar sedimentary deposits,
the combination of a pit excavated in the placer to the bed rock, a sump formed
in the bed rock, one or more disintegrating nozzles for disintegrating the placer
material and washing it along the surface of the deposit or bed rock to the sump;
a suction opening in said sump at the pit for elevating the mixed water and placer
material from the pit, one or more force pumps for supplying the said nozzles, a.
water reservoir from which the said pumps take their supply, a centrifugal pump
connected with the said suction pipe, separating apparatus to which the centri-
fugal pump delivers the mixed water and placer material for separating the large
percentage of worthless material from the small percentage of gold-bearing mate-
rial, means for supplying, to the separating apparatus from said reservoir water in
addition to that which is supplied with the placer material by the centrifugal
pump, means for collecting the water from the separating apparatus in said
reservoir, and means for delivering water to said pit independently of the said
disintegrating nozzle or nozzles.
17. In a system of mining gold-bearing placers or similar sedimentary deposits,
the combination of a pit excavated in the placer to the bed rock and sump therein
formed in the deposit or bed rock, a storage reservoir adjacent to the pit and
above the level of the sump, a force pump or pumps connected with said reser-
voir, one or more disintegrating nozzles for the disintegrating of the placer
material and washing the same along the surface of the bed rock or deposit into
the sump, said nozzles receiving water under pressure from said force pump, a
suction pipe opening into said sump, a centrifugal pump connected with said
suction pipe for elevating the mixture of water and placer material from said
sump, separating apparatus above the reservoir and to which the mixed water
and placer material are delivered by said contrifugal pump, and a discharge from
said separating apparatus for conveying the water therefrom back to said
reservoir.
18. In a system of mining gold-bearing placers or similar sedimentary deposits.
the combination of a pit excavated in the placer to the bed rock and a sump
therein formed in the bed rock, a storage reservoir adjacent to the pit and above
the level of the sump, a force pump or pumps connected with said reservoir, one
or more disintegrating nozzles for disintegrating the placer material and washing
the same along the surface of the bed rock or deposit into the sump, said nozzles
receiving water under pressure from said force pump, a suction pipe opening into
said sump, a centrifugal pump connected with said suction pipe for elevating the
mixture of water and placer materials from said sump, separating apparatus
above the reservoir and to which mixed water and placer material are delivered
by said centrifugal pump, a discharge from said separating apparatus, a settling
tank connected with said discharge for receiving the same and for allowing
solid materials to separate from water therein, and an overflow for conveying the
water from said settling tank back to the reservoir.
19. In a system of mining gold-bearing placers or similar sedimentary deposits
the combination of a pit excavated in the placer to the bed rock, and a sump

page_text: therein formed in the bed rock, a storage reservoir adjacent to the pit and above
the level of the sump, a force pump connected with said reservoir, one or more
disintegrating nozzles for disintegrating the placer material and washing the
same along the surface of the bed rock or deposit into the sump, said nozzles
receiving water under pressure from said force pump or pumps, a suction pipe
opening in said sump, a centrifugal pump connected with the suction pipe for
elevating the mixed water and placer material from said sump, separating appa-
ratus above the reservoir and to which the mixed water and placer material are
delivered by said centrifugal pump, a discharge from said separating apparatus
for conveying the water therefrom back to the reservoir, an amalgamating table
adjacent to said reservoir for receiving the gold-bearing material from the
separating apparatus, and an independent water supply for said amalgamating
table whereby water may be pumped upon said amalgamating table and from
thence will flow to the reservoir.
20. In a system mining gold-bearing placers or similar sedimentary deposits,
the combination of a pit excavated in the placer and a sump formed in said pit,
with one or more disintegrating nozzles for disintegrating the placer material
and washing the same along the bottom of said pit into the sump, a force pump
or pumps for supplying water under pressure to the said nozzle or nozzles, a
suction pipe opening in said sump, a centrifugal pump connected with said
suction pipe for elevating the mixed water and placer material from said sump,
the separating apparatus to which the mixed water and placer material are
delivered by said centrifugal pump, comprising means for separating the débris
from the gold bearing material and means for subsequently extracting the gold
from said material.
ated this 13th day of December 1897.
WM. P. THOMPSON & Co.,
Of 6, Lord Street, Liverpool, Agents for the Applicant.