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

page_text: of Application, 26th July, 1889
Complete Specification Left. 28th Apr., 1890-Accepted. 14th June, 1890
PROVISIONAL SPECIFICATION.
Improvements in Extracting Precious Metals from their Ores and in
Means or Apparatus Employed therein.
I SIDNEY TRIVICK of 29 Gauden Road, Clapham Road, in the County of Surrey,
Analytical Chemist and Metallurgist, do hereby declare the nature of this invention
to be as follows:-
These improvements relate to the extraction of the precious metals from their pres
and means or apparatus to be employed therein.
The description of ores to which the present method of treatment is suitable and
designed to treat are those which do not contain a greater proportion of lead than
3 per cent.
These ores in a finely divided state are roasted in the first instance with from 6 to
10 per centum of chloride of sodium and intimately mixed with the ores.
The chloride of sodium employed contains to 1 per centum of sulphide of copper
obtained by precipitation as hereinafter described.
In the event of the ore to be treated containing arsenic, antimony, zine or other
readily volatilizable metals, then to eliminate these, the ores are treated by partly
first roasting, and the chloride of sodium is only added thereafter and roasting
operation continued to completion.
In order to attain the best results the roasted ores after removal should be finely
ground before leaching.
In effecting the roasting of the ores or sulphides of metals containing a sufficient
proportion of sulphur to support combustion I, according to my method, am able to
dispense with the use of special fuel for the purpose, except in starting the operation
using at such starting wool or charcoal to heat the ovens, the sulphur in the treated
matters supplying the combustible matter as the ores are successively worked from
hearth to hearth, combustion being supported and regulated by carefully regulated
currents of cold and heated air supplied by suitable inlets and passages, controlled by
doors or valves. The heated air being obtained by passage of the air through
passages arranged under, around and over heated surfaces of the oven, other surfaces
thereof also serving to heat a series of pipes through which liquid passes designed
for use in subsequent leaching of the treated ores. The resultant waste gases and
products are led off by suitable passage to the flue chamber and stack.
The roasting apparatus is arranged as follows. Upon a suitable bed or foundation
are built suitable hearths having chambers over, divided by floors of fire brick into
shallow roasting ovens each communicating one with the next above, by means of
openings left in each floor alternately one at back and the next at front whilst the
top floor is covered in, an opening from above being left, conveniently about central
thereof, for charging the ore through from the open drying floor above into the
furnace. The bottom floor is of iron and has closable openings and moreover can
be drawn away to deliver its charge to the hearth below. Each floor in turn is
supplied from the one above with sulphides to be roasted, the original charge being
received from the opening in the roof of the first floor from a receiving chamber
above. At the side of each chamber is an opening preferably towards the front
through which heated air enters supplied by passages passing alongside these roasting
chambers from above by passages each joining another vertical rearward passage
which again joins another passage below having access to the atmosphere at front
of the oven, the circuitous passages enabling the incoming air to be brought into
prolonged contact with the heated surfaces of the oven.
The products of the combustion of the sulphides pass through the series of
chambers and away from the uppermost by openings leading by passages to a middle

page_text: passage below a heating chamber to be described, and away to the stack. The said
heating chamber contains a series of coils of piping leading from and to a water
tank and passing through a tank containing leaching liquid, and this chamber is
filled with sand packed around the coils and serving to disseminate the heat.
Above the flue chamber is arranged an evaporating pan for evaporating the
solution containing chloride of sodium and other soluble chlorides previously
employed in the treatment of the ores and so to prepare it for re-use.
A pan is also
provided say over the flue of the furnace at the hottest part available in which
the precipitating mixture may be prepared and then conveyed to the reservoir
provided for it."
The finely ground ores are placed in one of a pair or other number of leaching
tanks and the leaching fluid is let on, by a suitable supply pipe communicating with
the tank, at a temperature of the fluid preferably about 15° Fah.
The leaching fluid is prepared by dissolving salt in water and preferably until the
specific gravity reaches 110 taking water at. 100. to this solution is added one
eighth per centum of neutral chloride of copper solution.
The leaching fluid having been drawn off or removed is then pumped into a mixer
or precipitating tank or tanks and the silver and gold precipitated by means of a
liquid made as follows:-
One hundred gallons of water are boiled with 35 pounds of oxide of calcium (lime)
and 18 pounds of sulphur, preferably until the specific gravity reaches 1050 (taking
water at 1000). Then chloride of sodium is added until the specific gravity reaches
preferably 1100. In precipitating gold and silver from the liquid care must be taken
not to add too much of the precipitating liquor, so as to avoid precipitating the copper
to any appreciable extent.
The leaching fluid may then be pumped back into the reserve leaching fluid reservoir
or tank.
Sulphide of copper being necessary for mixing with the chloride of sodium for roasting
further quantities of sulphides I precipitate the copper independently from the silver
and the gold by the precipitating liquor and then pumped back into the leaching fluid
reserve tank.
The excess of leaching liquor should be evaporated over the evaporating tank or
pans of the furnace or oven and the chlorides obtained utilized in the same way as the
chloride of sodium in the first roasting.
The precipitated product should be roasted and then smelted for the bullion.
A convenient arrangement of the plant is as follows: The whole is arranged on
three floors. The furnace as described supported on foundations on the ground, the
pipes for heating the fluid for the leaching tank passing up from over the furnace or
oven to the bottom of leaching fluid tank and being carried to and fro thercover so as
to heat the contents and thence to a supply water tank and back again to be
reheated.
This leaching liquor tank on the middle floor has a pipe leading to over the leaching
tanks and by a branch to each supply of liquor is effected onto the roasted sulphides
which are supported therein on a suitable wooden open flooring supported on cross
pieces the floor supports, basket work or other suitable reticulate supporting surface
on which is laid moss or other like or suitable material adapted to retain solid matters
and above this is laid cane and again above this is arranged other basket work to
prevent disturbance of the straining material and to perfectly filter the liquid.
Hot water can also be supplied from the hot water tank to these leaching tanks by
closing a valve below the leaching liquor and opening another in a pipe leading from
the hot water tank to the pipe delivering into the tanks.
The leached matters from the tanks pass into pipes leading to a pumping apparatus
by which they are forced up into a precipitating pan or mixer in which revolves a
central axis driven by means of a toothed pulley on another driven shaft engaging a
toothed pulley thereon. Upon the central shaft is carried an arm which swings
around the pan and has dependent arms which stir up the matters in the pan. These
arms are arranged with spaces between them which permit of their passing

page_text: perforated stem projecting upward from the floor of the pan and connected by pipes
with the precipitating liquor reservoir which may be arranged on the uppermost floor
and is filled as neede. The precipitated matters are drawn off by a pipe leading
from the bottom of this pan and are led to a filter or filters constructed substan-
tially in the same way as regards the straining materials and their arrangement as
already described in respect to the leaching tanks or vats. From the filter by means
of a force pump the separated clear liquor is pumped back into the reserve leaching
fluid tank for further use arranged on the uppermost floor from which it goes into
the supply leaching liquor reservoir.
Where the ores treated contain a sufficient percentage of copper it is not requisite
to provide this in the manufacture of the leaching liquor as the roasting of ores
and their subsequent treatment abstracts the necessary quantity.
The other
The piping employed for conveying the heating liquid for heating the leaching
liquid may be made of iron excepting the portions which pass through the leaching
fluid tank which portions must be of lead or metal not destroyed thereby.
piping must be of lead or lead and antimony for like reason and the valves or cocks
must also be of lead and antimony or wood or otherwise proof against corrosion.
Dated the 25th day of July 1889.
WM. BROOKES & SON,
55 & 56, Chancery Lane, London, Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in Extracting Precious Metals from their Ores and in
Means or Apparatus Employed therein.
I SIDNEY TRIVICK of 29 Gaulen Road, Clapham Road, in the County of Surrey,
Analytical Chemist and Metallurgist 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 statement :—
This invention relates to the treatment of roasted ground ores in order to obtain
precious metals by a method of leaching with a leaching liquid in vats or pans and
precipitating the leached precious metals therefrom and then filtering the precipitated
matters by suitable means for which purpose apparatus such as is shewn and described
in my application for Patent of concurrent date (No. 11882) with the present is
designed and fitted to be used.
The finely ground ores are intimately mixed with chloride of sodium and sulphide
of copper and roasted by the combustion of their associated sulphur aided by carefully
adjusted currents of air as set forth in my said specification of application or in other
suitable or usual manner.
In cases where the ores do not contain any appreciable quantity of volatilizable
metal a partial preliminary roasting is not needed.
These roasted and finely ground ores containing precious metals are placed in a
tank which may be one of a pair or other number of such receptacles so that whilst
one is being filled another may ha in use, or being emptied, and into this tank upon
the ores, whilst they are supported on a suitable strainer or filter hed to be described,
is poured a leaching fluid, said fluid being let on by a suitable pipe communicating for
supply with a reservoir of leaching fluid maintained at about a temperature of
150° Fah.
This leaching fluid is prepared by dissolving chloride of sodium in water in the
proportion of salt to water, by preference, indicated by the specific gravity of the
solution reaching 1150 taking water at 1000 and to the said solution adding one
eighth per centum of neutral chloride of copper in solution.
This leaching fluid having been forced through the ores in the tank is drawn off or
removed and pumped or expelled by means of air pressure into a mixer or precipitating
tank or tanks and the silver and gold taken up by the leaching solution is precipitated
by means of a liquid prepared by boiling one hundred gallons of water with preferably

page_text: thirty five pounds of oxide of calcium (lime) and 18 pounds of sulphur until preferably
the specific gravity of the solution reaches 1050 (taking the spec. grav. of water as
1000). Then chloride of sodium is added until the specific gravity reaches
(preferably) 1100. In effecting the addition of this precipitating liquid to separate
the gold and silver from the liquid which contains it care must be taken not to add too
large a proportion of the said precipitating liquid to avoid throwing down the copper
to any appreciable extent.
The leaching fluid so treated may then be pumped back into a reserve tank or
reservoir provided for the purpose ready for reuse. Sulphide of copper being
necessary for mixing with the chloride of sodium for roasting further quantities of fores
I precipitate the copper independently from the silver and gold by the precipitating
liquor and then the liquid is pumped back into the reserve tank for leaching liquor.
When I have excess of leaching liquor it is evaporated over the evaporating tank
provided over and heated by the roasting oven and the chlorides obtained utilized for
admixture with ores rich in sulphur for the purpose of roasting with such ores in the
roasting furnace.
The gold and silver products precipitated from the leaching liquid are dried in a
dessicator, roasted, and then smelted for the bullion.
The leaching liquid supplied to the ground ores is heated in its tank by means of
coils of lead pipe laid therein and communicating with a chamber over the furnace
Alue in rear of each furnace already referred to, the pipes outside the tank being of
iron.
The filter bottom floors of the leaching vessel are composed of an open framing with
cross supports, on which is laid a reticulate surface for which basket work may be
conveniently used and on this is laid a fibrous retaining matter for which purpose moss
is useful, this material retains solid matters. Either above under or above and under
this moss is laid canvas and again above this is arranged other basket work to prevent
disturbance of the straining material and to aid in the perfect filtration of the liquid
from solid matter.
In the precipitating vessel the leached liquid is stirred by stirrers whilst the
precipitating liquor is being distributed therein and thence the resultant mixture is led
away to a filter vessel constructed as regards the straining bottom thereto, substantially
as already described for the bottom of the leaching vessel.
This invention also relates to improvements in apparatus forming a plant for
treating roasted ground ores to obtain precious metals therefrom adapted for use in
treating roasted ground ores of precious metals that have been roasted by any known
or suitable method, or such method as is hereinafter described.
The apparatus consists essentially of a vessel (preferably employing a pair at least
of such vessels so as to change from one to the other of the pair in working) having a
porous bottom on which the ground roasted ores rest, means of supply of leaching
liquid controlled by valve, means of drawing off leached liquid, conveyance thereof to
and means of stirring said liquid in a mixing chamber, a filter vessel having a porous
floor and means of pumping the filtered liquid to a reservoir, means of evaporating
the leaching liquid to recover the contained salts also recovering the copper salts for
reuse and means of heating the leaching liquid also means of dessicating the
product.
The invention also consists in a furnace for roasting ores of precious metals of any
suitable known description having a chamber in which are contained coils of piping,
packed in sand, said piping serving to convey and heat water supplied by a suitable
tank and to which said water returns, the piping conveying same passing in its
passage through the sides of a leaching liquor reservoir and therein to and fro over
the floor thereof to beat contained leaching liquor. Also in a tank located over the
Hue chamber of an ore roasting furnace for evaporating leaching liquor supplied
thereto; in order to recover the salts dissolved therein and a pan for preparing
precipitating liquor in, also located over a part of the flue chamber of said furnace
from which the precipitating liquid is transported to a reservoir conveniently situate
and having a pipe controlled by valve leading to a precipitating chamber or vessel also

page_text: communicating by pipe with a filter chamber having a filtering floor therein of peculiar
construction to be described, said precipitating chamber being also connected by a
pipe with a force pump which again has a pipe communicating with a leaching vat
into which are introduced the roasted and ground ores to be leached and the leaching
liquid therefor is supplied by a pipe leading from the leaching liquor reservoir, also
means of cutting off flow of leaching liquor to the leaching vat and letting on water
from the water heating system and reservoir thereto for cleansing or otherwise.
Also in a system of heating pipes and reservoir of water, or reservoir for leaching
liquid heated by said water pipes a reserve reservoir for leaching liquor and a system
of pipes for distributing the leaching liquor to a tank or tanks wherein the ground
roasted ores are leached, having a porous floor to support said ores as set forth.
Also in a reservoir of leaching liquid a system of pipes for distributing said liquid
and a set of tanks wherein is provided an open or porous floor for supporting the
ground roasted ores to be leached supplied by said pipes and means for drawing off
the leaching liquid with its contained precious metals and for delivering them to a
mixer, and a mixer wherein they are mixed with a precipitating liquid, and a filter
wherein the solid precipitates are separated from the liquid as set forth.
Also in a mixing vessel, having series of stirrers rotated therein, interspacing in
their rotation with fixed vertical distributing pipes, having perforations through which
flows into said vessel the precipitating liquid supplied to said distributors, a system of
piping for effecting said supply, a reservoir of precipitating liquid and mechanism for
effecting rotation of said stirrers in the mixing vessel as set forth.
DESCRIPTION OF THE DRAWINGS.
Fig. 1 is a vertical sectional elevation of the apparatus forming a plant for the
treatment of roasted ground ores to obtain precious metals.
Fig. 2 is a ground floor plan of such plant.
Fig. 3 is a separate view of a detail being the mixer tank and mixing arms with
the distributing pipes of the precipitating liquid and means of rotating said mixer
arms.
Fig. 4 shews in p'an view the mixer tank with a portion of the mechanism removed,
both figs. 3 and 4 being drawn to a larger scale than the preceding Figures.
a indi-
cates a furnace for roasting ores of precious metals. a is the flue chamber thereof,
a is a chamber over, and heated by the flue chamber a packed with sand around a
circuit of piping said piping passing up and into and in a circuit to and fro over the
bottom of the leaching reservoir c thence up to and so as to deliver into the reservoir 61
containing hot water and thence the piping completes the circuit.
13 (Fig. 2) is a mill to which the ore is removed after roasting and cooling, by
means, say, of a trolley running on the rails 14 from whence it is removed to the
tanks d, d by means of the trolley 15 running on the running rails 16, such trolley 15
having a rope or line attached to it at 19 which rope is coiled round the winding
drum 20 for the purpose of drawing the trolley up the inclined rails 16.
The reservoir containing leaching liquid has a pipe e which communicates with a
pan located behind the semi circular pan for preparation of precipitating solution
as described and both pans are located over and so as to be heated by the flue a¹ so
that as leaching liquor in excess of requirement in a liquid form is let in by the
valves e to the pan c the salts (of chloride of sodium and other soluble chlorides)
contained are retained in the pan for reuse in roasting the ores whilst the water is
evaporated. is a pipe having a valvo e leading from the reservoir c to the two
branch pipes c, c which are controlled as to supply by the valves c, and these pipes
deliver leaching liquid into the vats d, d'..e is a separate outlet for drawing off
leaching liquor when required and is fitted with a valve 2. c* is a pipe controlled by
a valve c through which when the valve c is closed and valves c**, cs and c³ or
either, or any of them is or are open water may be supplied instead of leaching liquid
to the leaching vats d, d'. The leaching vats d, d' have removable plates d² covering
holes in their sides useful in removing solid matters to the trolley 17 running on the
rails 18 for removal from the building.

page_text: •
The floors of these vats are constructed of cross rafters ³ supporting a floor of per-
forated wood (best shewn by detail view Fig. 5) on which floor is laid basket
work d³ and again on this basket work is laid porous straining material dª for which
purpose moss is cheap and good.
Above this layer of moss is laid more wicker work. The upper layer of basket
work I under lay, or over lay, or both under and overlay with canvas as thereby
disturbance of the filter, is prevented, by inflowing liquid. The bottom of each leach-
ing vat is sloped to and connected with an exit pipe e controlled by a tap el of ordinary
construction and this pipe e and its counterpart both lead by a pipe e² to a pump e
which may be of any usual, or suitable construction by which the leached liquid in the
pipe is forced up through pipe g into the mixing vat wherein it is mixed with pre-
cipitating liquid, supplied thereto by means of upright perforated tubes f¹ (shewn
separately to an enlarged scale by figures 3 and 4).
Rotating arms 2 downwardly projecting from a cross head f³ pass around in this
vat and mix its contents, being driven around as the supporting vertical axis j' is
rotated in its bearings by the toothed wheel being driven by another tooth
wheel mounted on an axis f" at right angles to the axis. On this axis is also
mounted another wheel driven by band /¹º from a wheel driven by a band z from
any suitable motor such as by means of the wheel from the steam engine ³.
Band 13 (Figure 2) drives an air pump by means of a pulley is situate upon
the same shaft as 12, such air pump being employed for the purpose of producing
pressure upon the surface of the leaching liquid for the purpose of effecting filtration
when desirable in the ore leaching tank or d and in the precipitating filter h. The
vats may be arranged for superposed pressure to take the place of the force pump
and also for the purpose of forcing air into a dessicating chamber 5 (see Fig. 2) through
the pipe 6 so that when the tap 7 is closed and the tap S is open the air being pumped
through the pipe 9 from a dry air chamber, as 10, situate above the flue a¹ of furnace a
may be forced into the dessicating chamber 5 in which I arrange in a suitable manner
trays containing the precipitated precious metals obtained froin the filter h. When
the air is required for the purposes of producing pressure in the tank the tap 11 in
the inlet pipe may be closed and the tap 12 opened so that cold air may be obtained
or I
may employ hot air.
9
In Figs. 6, 7 and 8 is indicated the mode of securing the lid of tank which is
raised and lowered by means of chains o' connected to the lid and passing through the
pulley blocks o². o' is a knucklo jointed bolt attached as to its jointed end to the body
of the tank d¹ and of which I fit as many as may be necessary to the body of each
tank. is one of a series of cast iron plates secured to the lid of the tank so that
when such lid is in its position on the tank it may rest at right angles to the axis
of the bolt o and the slotted piece of may project sufficiently for the bolt of to be
introduced by turning it on its hinge towards the slot of when it may be tightened
down with the other of such bolts by its butterfly nut o7, and 8 represents suitable
packing which is compressed between the body of the tank and its lid on tightening
the nuts and thus makes an air tight joint. The mixed precipitated matters and
leaching liquor are discharged from the vat into the filtering vessel h, by means of
the pipe h, wherein the precipitated matters containing the precious metals are
strained from the clear leaching liquor by means of a filter bed constructed substan-
tially identically as that to vessel d and shewn in part to a larger scale at Fig. 5.
This vessel is supported on trunnions 2 carried in the framing 3 bedded on the
floor A on which rests the building B* B* carrying and enclosing the plant.
By means of the pump 3 shewn in Fig. 2 connected by the pipe 4 with the filter
bottom in the vessel the clear leaching liquid may be withdrawn therefrom and forced
up into the reserve reservoir of leaching liquid by another pipe is a pipe con-
trolled by a valve leading from the reservoir i to the reservoir e and for refilling of
the reservoir c from the reservoir with liquid as occasion may require.
is a bath over the furnace flue for preparing precipitating liquid in, for trans-
ference to the precipitating liquid reservoir : whence its supply to the mixer is
regulated by the valvo k².

page_text: Having now particularly described and ascertained the nature of iny said inven-
tion, and in what manner the same is to be performed, I declare that what
I claim is
1. The herein described method of treating roasted ground ores by leaching the
ores in vessels having a porous bottom with a leaching liquid heated to about 150°
Fahrenheit composed of chloride of sodium in water in which has been dissolved
neutral chloride of copper and then precipitating the gold and silver from the leaching
liquid by admixture and precipitation in a mixer tank by a precipitating liquid com-
posed of water in which is dissolved oxide of calcium and sulphur and chloride of
sodium added in suitable proportions afterwards filtering the solid matters from the
liquid, roasting dessicating and smelting the precipitates to extract the bullion and
utilizing the effluent liquor by evaporation and precipitation, all substantially as and
for the purpose set forth.
2. The method of leaching roasted ground ores of precious metals in porous
bottomed vessels with a heated leaching liquor composed of chloride of sodium
dissolved in water to which is added one eighth per centum of neutral chloride of
copper in solution and then mixing with the liquid resultant from such leaching a
precipitating solution composed of oxide of calcium (lime) and sulphur with chloride
of sodium added and then filtering off the solid matters containing the gold and
silver substantially as set forth.
3. The described method of leaching roasted and ground ores containing precious
metals in vessels having porous bottoms with a liquor composed of chloride of sodium
dissolved in water to a specific gravity of 1150 approximately and taking the specific
gravity of water at 1000, to which is added one eighth per centum of neutral chloride
of copper in solution as set forth.
4. A leaching liquor for ores of precious metals composed of chloride of sodium
dissolved in water until the liquor with water of specific gravity of 10 10 attains a
sp cific gravity of about 1150 and adding about one eighth per centum of neutral
chloride of copper in solution as set forth.
5. The described method of precipitating the precious metals from the leached
liquors from ground roasted orcs of such metals by admixture with such leached
liquors of a precipitating fluid composed of oxide of calcium (lime) boiled with
sulphur in water and to which is added chloride of sodium substantially as set forth.
6. A precipitating liquid for the resultant liquor from the leaching of ground and
roasted ores of the precious metals composed of water oxide of calcium (lime) and
sulphur to which is added chloride of sodium in the proportions approximately of one
hundred gallons of water at a specific gravity say of 1000 boiled with preferably
thirty five pounds of oxide of calcium (lime) and eighteen pounds of sulphur until
the specific gravity of the liquor reaches 1050 then adding chloride of sodium until
the specific gravity reaches 1100 as set forth.
7. In a plant for treating roasted ground ores of precious metals to extract those
metals a leach vat having a porous floor to support ore as described with means of
conveying the leaching liquid onto such ores, a reservoir for leaching liquid, a hot
water reservoir and circuit of pipes and heating furnace for same, for heating the
leaching liquid in said leaching liquid reservoir in combination with a mixing
chamber in connection by piping and force pump with said leaching vat, and
containing mixing arms driven as set forth, supplied with precipitating liquid by
pipes having perforations therein and fed by piping from a reservoir and a filter
vessel fed by piping from said mixing vessel and means of distributing the leaching
and precipitating liquid substantially as and for the purpose sot forth.
8. In a plant for treating roasted and ground ores a furnace having a chamber for
heating packed with sand, a coil of piping therein connected at one end with piping
leading to another coil located in the leaching liquid reservoir, and at the other end
connected with piping leading to a hot water reservoir and thence to the coil in the
leaching liquid reservoir, said leaching liquid tank and piping for distributing same
in combination with a leaching vat wherein ores are leached and piping for carrying

page_text: off leached metals in solution, pump for conveying same to a precipitation mixer, said
mixer and a filter all substantially as set forth.
9. In a plant for extracting gold and silver from ores a furnace for roasting ores,
a hot water tank and circuits, one over the flue of the furnace and the other in the
leaching liquor tank connected by piping, a leaching liquor tank and distributing
pipes therefor, by-pass between hot water cistern and leaching liquor distribution
pipe, valves for same in combination with a leaching vat and conduit for liquor there-
from as set forth.
10. The apparatus for leaching ores of their contained gold and silver comprising
a leaching liquor reservoir, conduits from same, a leaching vat having a porous floor
constructed substantially as set forth, conduits and force pump in combination with a
precipitation mixer as set forth and a filter vessel all substantially as described and
illustrated by the drawings.
11. An ore leaching vat, a floor to samo of porous materials as set forth, a conduit
therefrom, a force pump interposed in said conduit, a precipitation mixer having
rotatory stirrers and liquor distributors, in combination with a filter vessel and
conduits thereto.
12. A leaching vat having a porous straining floor for ores a conduit therefrom and
valve thereto in combination with a precipitation vessel provided with a rotating
stirrer and means for rotating same, distribution branches for liquor and conduit for
liquid therefrom as set forth.
13. A precipitation vat for leached liquid containing gold and silver having a set
of rotating arms revolving interspaced with distribution branches perforated to
distribute precipitating liquid amongst such leached liquid, piping for supply and
draw off and means of rotating said stirrer.
14. An ore leaching vat having a floor to same of porous material as set forth, a
conduit therefrom, a force pump interposed in said conduit, a precipitation tank and a
filter vessel and conduits thereto, all substantially as set forth.
15. A furnace flue chamber a², hot water coil b, tank 6, leaching liquid reservoir c,
conduits therefrom, reserve reservoir i, conduits thereto and from, leaching vat d,
force pump and conduits cooperating therewith, mixer, filter h and system of piping
for distributing the filtered liquid, all substantially as set forth.
16. The system of reservoirs c, b' and i in combination with the various pipes for
distribution of liquid to and from same as set forth.
Dated the 24th day of April 1890.
WM. BROOKES & SON,
55 & 56, Chancery Lane, London, Agents for the Applicant.