Improvements in Obtaining Precious Metals from their Ores and in Means or Apparatus Employed therein
Year: 1889

page_text: Date of Application, 24th July, 1889
Complete Specification Left, 12th Feb., 1890-4Accepted, 29th Mar., 1890
PROVISIONAL SPECIFICATION.
Improvements in Obtaining Precious Metals from their Ores and in
Means or Apparatus Employed therein,
I DONALD DENNES of Denver in the State of Colorado, one of the United States
of America at present residing at Pevensey in the County of Sussex Engineer
(partly communicated to me froni abroad by Tom Kirke Rose of Denver aforesaid
Assayer and is partly the result of invention and discovery made by myself) do
hereby declare the nature of this invention to be as follows :-
This invention relates to improvements in obtaining precious metals from their
ores by what is known commonly as wet processes and is especially designed for use
in connection with the wet chlorination or bromination processes for extracting
precious metals
According to the invention the leaching vat is constructed with the sides closed
and the top thereof also closed, except that there is provided a valve or valves for the
admission of the charge when required from the hopper or part above, and this valve
is counterweighted to cause it to he held up to its seat except when depre-sed for
entrance of a charge; so that when air pressure is applied the valve automatically
closes: but this access of material to be strained may be attained by a manhole with
closable lid or otherwise. The pipe, or pipes, for admission of air under pressure
also passes through the top of this vat. The matters to be treated in their mixed
state, as they come from the mixing vessel, may be charged into the hopper or entrance
to this leaching vat in any convenient manner.
The vat is also connected to lugs, or parts, connected by ties to similar lugs. or
parts, below connected to the cylinder of a hydraulic rain, or other forcing machine
adapted to raise and lower a ram piston, or lifter, which in rising raises a bottom for
tho vat to and so as to press its edges tightly to the lower edges of the vat, elastic
packing being interposed between the abutting parts to ensure tight fitting. This
bottom is provided with wheels which when the raising means is lowered come onto
rails, or vice versa, and serve for the bottom to be run away on.
This bottom is formed recessed and in the recess aro laid cross supports or like
means and on these a perforated flooring. say of wood, lead or any suitable support,
not liable to induce inconvenient precipitation, and on this loose floor is laid graded
sand coarser grades below and fine above, and over the sand is laid a shield of
sacking or canvas or similar protecting porous material to prevent displacement of
the sand during charging of the matters into the vat. This canvas is applied by
preference by straming over an annular projection on fin around the filter bottom
retaining its edges in place by elastic band or tie.
The expelled liquid resulting from the pressure of air forced into the vat passes
away by a pipe provided with a valve to control flow, applied to the bottom and is
led away to another vat, or vessel, constructed substantially as is that just described,
except that the straining material should be of sufficiently fine nature and the bottom
may be fixed or formed with the sides, and the top be removable and clamped or
locked to the sides.
In place of sand, other suitable filtering material may be used.
From the latter vessel the liquid holding the precious metals in solution is led away
for precipitation by known methods.

page_text: COMPLETE SPECIFICATION
Improvements in Obtaining Precious Metals from their Ores and in
Means or Apparatus Employed therein.
-I DONALD DENNES of-Denver in the State of Colorado one of the United States
of America at present residing at Pevensey in the County of Sussex Engineer do
hereby declare the nature of this invention (which has been partly communicated to
me from abroad by Tom Kirke Rose of Denver aforesaid Assayer and is partly the
result of invention and -discovery-made-by-myself)-and-in what manner the=samo**
is to be performed to be particularly described and ascertained in and by the
following statement :-
'This Invention has for its object to provide improved means for obtaining precious
metals from their ores by what is commonly known as a wet process and is especially
designed for use in connection with the wet chlorination or bromination processes for
extracting precious metals.
According to this invention the leaching vat in which the liquid matter is soparated
from the solid refuse matter consists of a vessel provided with a removable bottom
(constructed as hereinafter described). This vessel is closed, at the sides and top
except that there is provided in the top a valve or valves for the admission of the
material to be treated, this valve being counterweighted to cause it to be held up to
its seat except whon depressod to admit of the introduction of a charge; so that when
air or other fluid pressure is applied the valve is automatically closed. If desired a
man hole and cover may be provided in place of the valve for the introduction of the
material to be treated. The pipe or pipes for admission of air or the like under
pressure may also pass through the top of this vat. The matters to be treated in their
mixed state as they come from the mixing vessel may be charged into the hopper or
entrance to this leaching vat in any convenient manner.
This vat is connected by lugs and tie rods or bolts and nuts to the frame of a raising
and lowering device below such for example as a hydraulic ram or a screw forcing
device adapted to raise and lower the bottom of the vat into and out of contact with
the lower edges of the vat. Elastic packing is interposed between the abutting parts
of the apparatus to insure tight joints. The removeable bottom is provided with
wheels which when the bottom is lowered come onto rails on which the bottom may
then be run from beneath the vat.
This removeable bottom carries a filtering bed which may consist of wood with
grooves in the surface and having perforations through which liquids can pass into a
chamber below. The surface of the wood is preferably covered with canvas to prevent
the passages or perforations being clogged with the gritty matter. On this floor of
wood, graded sand may be laid coarser grades being below and fine above and over
the whole may be laid sacking or canvas or similar protecting porous material to
prevent displacement of the sand.
The liquid portion of the material is forced through the filter bed by the fluid
pressure admitted into the vat the liquid passing thence by a pipe (provided with a
valve to control the flow) into another vessel, preferably formed in the removeable
bottom of the vat, and provided with a removable bottom containing a filter bed similar
to that last described.
From the latter vessel the liquid holding the precious metals in solution is led away,
for precipitation by known methods.
And in order that my said invention may be fully understood I shall now proceed
more particularly to describe the same and for that purpose shall refer to the several
figures on the annexed sheet of drawings the same letters of reference indicating
corresponding parts in all the figures.
Figure 1 is a side elevation and Figure 2 a vertical section of a leaching vat
or separating vessel constructed according to this invention and Figure 3 is a plan
of the same.
The body of this vat or vessel consists of a cylinder A of cast iron or other

page_text: uitable metal preferably lined with lead and mounted on beams or other suitable
upport so as to leave space below to admit of the discharge of the refuse material
hrough the bottom of the vessel as hereinafter described.
The top of this cylinder is closed by means of a cover B having an opening C
herein through which the material after having been treated in a mixing vessel is fed
n any convenient manner. The opening is closed by an inwardly opening valve D
connected to a lever E carrying at its outer end a counterweight tending to maintain
the valve D against its seat In the cover Bare passages G and H one of which G is
in communication with a pipe I through which compressed air or other fluid may be
forced into the vessel. The other passage H is connected with pipes K and L through
which slime is discharged from the vessel. The vessel is provided with a hollow
removeable bottom constituting a vessel or chamber B into which the solution from
the vessel A is conducted to be further treated as hereinafter described.
The
In the upper surface of this removable bottom a recess is provided for the reception
of a filter bed N which may consist of graded sand but is preferably made of wood
with grooves or channels a in the upper surface and perforated with a number of
holes through which the more fluid portion of the solution in the vessel A passes
into a passage or pipe c by which it may be conducted into the chamber or vessel B
or into other suitable receptacles placed in position to receive it. The vessel B is
also provided with a removeable bottom O containing a filter bed P through which
the solution in the vessel B is forced and thence through a passage Rinto precipitating
vessels on prossers to obtain the precious metals therefrom by known means.
mixed material from a mixing vessel is fed into the hopper S and is conducted there-
from onto the valve D which by the weight of the material thereon is caused to
descend and discharge the material into the vessel A the valve being then immediately
raised by the counter-weighted lever I so as to again close the opening C. When
sufficient material has been fed into the vessel A time is allowed to admit of the
gritty or solid portion of the mixture to settle after which the cock or valve d in the
pipe I is opened to admit air or other fluid under pressure into the vessel A the cock
or valve e and cock f in the pipe L being also opened so that the pressure of air
acting on the mixture, the top stratum or slimy portion thereof is forced through the
flexible pipe K and past tho valve e into tho pipe L whence it passes by the cock f
and pipe g into the vessel D to be further treated.
When the charge contained in the vessel A is sufficiently cleared of its top stratum
of slime the valve e and the cock are closed and the cock h in the branch pipe i
leading from the pipe I into the vessel B 13 opened so as to admit through the said
branch fluid pressure into the vessel B.
The fluid pressure then acting on the surface of the mass in both vessels A and B
will force the liquid portion through the filter beds P' and N whence it flows through
the pipes and R into suitable receivers or direct to the precipitating presses to
To the mouth or entrance to the flexible
precipitate the precious metals therefrom
pipe K is attached a float T which floats on the surface of the material in the vessel A
and so maintains the mouth of the pipe in contact thero with and ensures the slimy
matter entering therein when acted upon by the fluid pressure. If the solution which
5 has passed through the filter bed N is not sufficiently clear it may be conducted by
cocks and fand the pipe g into the vessel or chamber B to be again filtered.
The solution having been subjected to the fluid pressure in the vessel B the desired
length of time the cock h in the pipe is closed and the pipes cg and i are disconnected
at cg from the vessel B after which the said vessel comprising the bottom to the
0 vessel A may be lowered and withdrawn so as to allow the refuse material to discharge
therefrom. In like manner the underneath portion or bottom O of the vessel B may
also be lowered and withdrawn from the part B so as to permit of the removal
therefrom of any slime that may have accumulated therein.
Any suitable mechanism may be employed for effecting the lowering and raising
5 of the removeable bottom such for example as a hydraulic ram arranged beneath the
vessel. In the drawing we have illustrated a convenient arrangement consisting of a
screw U working in a nut V in a crosshead V' and having fast thereon a worm

page_text: wheel W with which gears a worm ✗ operated by hand or power as inost convenient.
By turning the worm in one direction rotation will be given to the screw so as to
cause it to descend in the nut, the vessel or chamber B descending therewith until the
wheels Y and half nut Z carried by the said vessel rest upon the rods or spindles m m
_ after which by continuing the motion of the screw in the samo.direction-the-bottom-O
of the vessel or chamber B will descend until the wheels p and half nuts thereon (not
shown in the drawing but similar to that marked Z) rest upon the rods or spindles 7.
The half nuts engage screw threads on the spindles m' and ' so that upon rotating
those spindles in one direction by means of the hand wheels & the vessel B may
*be withdrawn from beneath the cylinder A and the bottom O together with the
crosshead V may be withdrawn from beneath the vessel or chamber-Band admit
of the free discharge of the refuse material from the said vessols. The refuse material
having been discharged from the vessels and from the surface of the filter beds, the
rods or spindles mare tuined in the reverse direction so as to return the bottom o
together with the crosshead V2 and the vessel or chamber B to beneath the cylinder A
and then by turning the screw U in the reverse direction to that in which it was
turned for lowering the bottoms, the bottom O will be first raised into contact with
the vessel or chamber B and then by the continued rotation of the screw in the same
-direction the chamber B will be elevated into position against the lower edgo of the
cylinder A. A packing of india rubber or other suitable yielding material as shown
at is interposed between the chamber B and the cylinder A and also between
the chamber B, and its removeable bottom 0 to make fluid tight Joints at these
parts.
The removeable bottoms of the vessels A and B having beon replaced and the
pipes eg and i again connected to the vessel B a fresh charge of mixed material is
fed into the vessel A and the operations herein before described are repeated.
wo is a pipe connected to the space between the filter bed N and the bottom of
the recess in which it rests, though which pipe water may ho torced into the space
and through the filter bed when desired for the purpose of cleaning the filter and for
washing and disturbing or agitating the ore in the vessel A.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
1st. The general combination and arrangement of parts constituting an apparatus
for leaching ores in a wet chlorination or bromination process for obtaining precious
metals from their ores substantially as hereinbefore described and illustrated by the
accompanying drawings.
2nd. In a wet chlorination or bromination process for obtaining precious metals
from their ores a closed leaching vat or separating vessel having a removeable bottom'
carrying a filter bed through which the solution of the precious metal is forced by
fluid pressure into another vessel or chamber formed in the removeable bottom the
said chamber being also provided with a removeable bottom and a filter bed sub-
stantially as and for the purpose herein before described with reference to the
accompanying drawings.
Dated this 12th day of February 1890
J. H. JOHNSON & Co.,
Agents.