An Improved Method and Means of Treating Ores.
Year: 1891

page_text: Date of Application, 21st Nov., 1891
Complete Specification Left, 22nd Aug., 1892-Accepted. 12th Nov., 1892
PROVISIONAL SPECIFICATION.
An Improved Method and Means of Treating Ores.
I. DAVID ALEXANDER LOUIS of 77 Shirland Gardens, in the County of
Middlesex, Mining Engineer, do hereby declare the nature of this invention to be
as follows:
This invention relates to an improved method and means of extracting metals
from ores. The ore, and any suitable solvent, are either mixed, agitated and
digested together in the usual manner in barrels, vats, or other suitable vessels, or
they are mixed, agitated and digested in a vat with a perforated false bottom and
provided with an agitator fitted thereto.
Where the special vat described cannot be obtained the first leaching or washing
is performed by suspending and supporting in the mixed mass a perforated hollow
cylinder or sphere which is covered externally with filtering cloth or other suitable
material and is connected internally with the suction system herein described.
Rubbers or scrapers are arranged so as to keep the mass in motion and to prevent
its fouling and also to keep the surface of the filter clean and free from accumulation
of ore.
These rubbers also aid and assist thorough and rapid washing.
When retreatment is not required the leaching is performed in a vessel provided
with a perforated false bottom covered with a filtering cloth or the like, the space
beneath which is in connection with a suction apparatus.
The said suction apparatus consists of a number of air-tight collecting vessels,
each provided with suitable gauges, pipes, and connections, which are connected to
the pump or other exhausting apparatus on one side and to the filtering vessels on
the other.
The liquors in the collecting vessels are caused to pass into precipitation vats, or
other appliances for separating the valuable material.
In the cyanide process for gold I cause such liquor to pass through revolving
cylinders containing any of the well-known precipitants, scraps of zinc for instance.
The motion prevents the gold from precipitating on the zinc and so the latter
remains clean and retains its activity, accelerating, facilitating and perfecting the
separation of the metal.
To collect the finely divided metal obtained by this process I pass the liquors
holding them in suspension into revolving centrifugals, where the suspended matter
collects at the periphery which may or may not be perforated and furnished with a
filtering cloth or the like. Or, I effect the collection of the gold etc. on a filtering
arrangement connected with a suction system as hereinbefore described.
This system permits of a rapid and effectual filtration proceeding in many vats
simultaneously and continuously without interruption, inasmuch as when one
collecting vessel is full it can be shut out from the system and the filtering vat can
be immediately attached to another collecting vessel without in any way interfering
with the progress of the operation.
Dated this 21st day of November 1891.
CASTLE SMITH,
Invention" Office, 54, Fleet Street, London, E.C.,
Agent for the Applicant.

page_text: COMPLETE SPECIFICATION.
An Improved Method and Means of Treating Ores.
I, DAVID ALEXANDER LOUIS, of 77 Shirland Gardens, in the County of
Middlesex, 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 statement :-
This invention relates to an improved method and means of extracting metals
from ores.
The ore and any suitabe solvent are either mixed, agitated, and digested
together in the usual manner in barrels, vats, or other suitable vessels, or they are
mixed, agitated, and digested in a vat with a perforated false bottom and provided
with an agitator fitted thereto.
Where the special vat cannot be obtained the first leaching or washing is
performed by suspending and supporting in the mixed mass a perforated hollow,
shallow cylinder or sphere which is covered externally with filtering cloth or other
suitable material, and is connected internally with a suction system. Rubbers.
brushes, or scrapers, are arranged to revolve so as to keep the mass in motion and
to prevent its fouling and also to keep the surface of the filter clean and free from
accumulations of ore. These rubbers also aid and assist thorough and rapid
washing.
When re-treatment is not required, the leaching is performed in a vessel provided
with a perforated false bottom covered with a filtering cloth or the like and
revolving brushes, scrapers, or rubbers are arranged to travel over and sweep the
filtering surface and so keep it free from accumulations of mud. In a cylindrical
vessel it is preferable to have the revolving cleaners attached to arms fixed to a
revolving vertical shaft working in a foot step which also supports the false bottom
at its centre. In a rectangular vessel, as shewn in the accompanying drawings, it
is preferable to employ for keeping the filtering surface clean an endless band or
chains to which are attached blades carrying the cleaning appliances. The endless
band or chains work longitudinally through the vessel over drums or pulleys
supported transversely in the vessel which are revolved when required by pulley
or band or other gearing in the ordinary way.
For suction system it is preferable to employ a series of air-tight collecting
vessels of convenient capacity furnished with gauges and pipes connecting with the
space beneath the false bottom of the leaching vessel and other pipes connecting
with a suction main, such pipes being provided with stop-cocks or valves so that
any one collecting vessel can be isolated at any moment from the system.
To sustain a steady suction an intervening air-tight vessel is preferably placed
between the suction main and the suction pump or apparatus.
The liquors in the collecting vessels may be caused to pass into precipitation
vats, or other appliances for separating the valuable material.
When however it is desired to precipitate the valuable metal directly the liquors
are caused to pass from the collecting vessels through revolving cylinders mounted
on hollow trunnions and containing the precipitating material. This is found to
be very advantageous inasmuch as the valuable metal only adheres slightly to
the precipitating material and so does not impede its activity.
To collect the finely divided metal obtained by this process I
pass the liquors
holding them in suspension into revolving centrifugals, where the suspended matter
collects at the periphery which may, or may not, be perforated and furnished with
a filtering cloth or the like. Or I effect the collection of the gold etc. on a filtering
arrangement connected with a suction system as hereinbefore described. Both
these arrangements can be enclosed in a suitable casing which may be secured by
a lock or other suitable device to protect the valuable contents from theft without
impeding the action of the apparatus.

page_text: The liquid flowing from these filters can be if desired collected in a tank and
re-used.
This system permits of a rapid and effectual filtration proceeding in many vats
simultaneously and continuously without interruption, inasmuch as when one
collecting vessel is full it can be shut out from the system and the filtering vat
can be immediately attached to another collecting vessel without in any way
interfering with the progress of the operation.
As will be evident the apparatus according to my invention can be constructed
in various forms.
In the accompanying drawings, wherein the same letters of reference, so far
as they are used in different views, are there applied to the same parts in each case-
Figure 1. is a plan shewing the general arrangement of my invention, when
employing a rectangular vat, and a mode of its application; Figure 2 is a part
elevation of the plant shewn in Figure 1, and Figure 3 is a section of the plant
shewn in Figure 1.
The material for treatment being fed into the vat A is kept in motion by the
stirring apparatus as shewn which scouring the filter cloth covering the false
bottom B allows the liquid to percolate and be discharged through the pipe C
into one of the vats D in which reduced pressure is maintained through the
connections E, as shewn with the vacuum reservoir F.
When the valuable metal is to be directly precipitated, the liquors are caused to
pass by taps and tubes G through the revolving cylinder H carried on hollow
trunnions and containing the precipitating material into the filtering apparatus I
which is connected with tank J when liquors are to be saved, which in its turn is
connected by pipe and stop cock to vacuum reservoir F.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what ]
claim is :-
(1) In an apparatus for treating ores as herein before described, the rubbing,
scraping, or brushing arrangements for keeping the surface of the filter free from
accumulations of ore, substantially as and for the purpose herein set forth and
described.
(2) In an apparatus for treating ores as hereinbefore described, the combination
of the cleaning devices referred to in the preceding claim with a system of collecting
vessels substantially as and for the purpose herein set forth and described.
(3) In an apparatus for treating ores as hereinbefore described, the employment
of a vessel revolving on hollow trunnions for precipitating the valuable metal from
the solution substantially as and for the purpose herein set forth and described.
(4) A combination of parts forming an apparatus for treating ores substantially
as and for the purpose herein set forth and described.
Dated this 22nd day of August 1892.
CASTLE SMITH,
"Invention " Office, 54, Fleet Street, London, E.C.,
Agent for the Applicant.