IMPROVEMENTS IN AND RELATING TO PROCESSES FOR EXTRACTING METALS FROM THEIR ORES, AND IN APPARATUS THEREFOR
Year: 1882

page_text: LETTERS PATENT to Henry Harris Lake, of the Firm of Haseltine, Lake,
& Co., Patent Agents, Southampton Buildings, London, for an Invention of
"IMPROVEMENTS IN AND RELATING TO PROCESSES FOR EXTRACTING METALS
FROM THEIR ORES, AND IN APPARATUS THEREFOR." A communication from
abroad by Nelson Frederick Evans, of Philadelphia, Pennsylvania, United
States of America.
PROVISIONAL SPECIFICATION left by the said Henry Harris Lake at the
Office of the Commissioners of Patents on the 4th March 1882.
HENRY HARRIS LAKE of the Firm of Haseltine Lake & Co. Patent Agents
Southampton Buildings, London. " IMPROVEMENTS IN AND RELATING TO
PROCESSES FOR EXTRACTING METALS FROM THEIR ORES AND IN APPARATUS
THEREFOR" [A communication from abroad by Nelson Frederick Evans of
Philadelphia Pennsylvania United States of America.]
This Invention relates to the extraction of metals from their ores and to apparatus
therefor.
It consists essentially in the use of chlorine gas under sufficient pressure to
accelerate its action in reducing the metals to the form of chlorides; and in
recovering the unused or uncombined gas from the ore undiluted and in the same
condition as when it entered the chlorinator. The said Invention comprises
apparatus for accomplishing the above objects.
In the ordinary or "Plattners" process of chlorination the chlorine gas is used
under a normal pressure or one just sufficient to cause it to flow into the chlorinator;
and the time required for the most perfect reduction is forty-eight hours, while by
this Invention I effect the same reduction in one hour or even less. Retaining the
gas for forty-eight hours in the presence of water couverts nearly or quite all of it
into chlorydric acid, and if any of it remains, it is so diluted with air that its
further use is impracticable. The short time and the low temperature at which the
gas and ore are brought into contact in my chlorinator prevent the formation of
chlorydric acid, and as the air is exhausted from the chlorinator before the
introduction of the chlorine it is recovered in an undiluted condition.

page_text: In carrying the said Invention into practice I provide a chlorine gas generator
which may be of any of the common forms, and a gasometer for storing gas from
the generator and that which has been recovered from the chlorinator, it being
connected to the generator, by pipes, and to the chlorinator by other pipes.
I employ a chlorinator which is in the form of a barrel which is arranged to
revolve and supported on trunnions and driven by a pulley and a goose neck is
passed through one of the trunnions into the open space above the charge; a pump
is connected to the gasometer by the pipes and to the chlorinator by other pipes
and the aforesaid goose-neck.
I provide a receiver for storing gas under pressure which is connected to the
pump by pipes and to the chlorinator by other pipes and the goose-neck.
An exhaust apparatus is used which may be a pump, water column, or any
suitable contrivance, it being connected to the chlorinator by a pipe and the goose-
neck, and to the receiver by other pipes. There are cocks or valves to connect or
disconnect the different parts of the apparatus.
The following modes of procedure have been found to be well adapted to the
successful practicing of my Invention viz.;-
The gasometer is put in order for holding the gas; the generator is then charged
with the necessary materials in the proper amounts for generating chlorine gas,
which, passing through the pipes, fills the gasometer. Connection is then made
between the exhaust and the receiver from which the air is exhausted, after which
the connection is closed and connection made between the receiver and the pump,
which is then connected with the gasometer and started, pumping the gas from the
gasometer into the receiver until a pressure of 50 or 60 pounds is obtained in the
receiver. The chlorinator is then charged nearly full of ore and water, leaving only
the point or opening in the goose neck not submerged, and it is made to revolve at
about the rate of about twenty revolutions per minute. Connection is now made
between the exhaust and the chlorinator through a pipe and goose-neck and all air
exhausted from the chlorinator; this connection is then closed and the one between
the chlorinator and the receiver opened when the gas from it passes into the
chlorinator subjecting the ore in it to a strong pressure. After the ore has been
under the gas for one hour or less according to its nature, connection between the
receiver and chlorinator is closed, and it is connected to the gasometer when the
greater portion of the gas passes into it. The chlorinator is now connected to the
pump and any gas remaining in the chlorinator is pumped into the receiver until
the chlorinator is exhausted. The ore and water are then discharged from the
chlorinator which is then ready for another charge. After chloridizing, the ore is
filtered and the gold precipitated and collected in the usual way.
In working this process another method may be employed viz: the chlorinator
is charged with ore and water as before. Into it is then put a proper proportion
of chloride of lime the whole being thoroughly incorporated by rotating the
chlorinator. The rotation is then discontinued and dilute sulphuric acid is now
added to the mixture and the tank is again rotated when there is produced a large
excess of chlorine under pressure by the chlorine gas being evolved from the
chloride of lime by the sulphuric acid, sulphate of lime being formed and chlorine
thrown off. The rotation continues from one half hour to three hours according to
the nature of the ore, when the chlorination is complete. Rotation during the
chlorination has the effect of expediting the chemical reaction involved.
The
chlorinator is now tapped and the excess of chlorine is drawn off into a gasometer,
or in the absence of the gasometer which (with the pump, generator, and receiver
may be dispensed with by this method) may be conducted by any suitable device
away into the air.
The free chlorine remaining in the chlorinator having been expelled in any usual
and suitable manner the chlorinator is now emptied into a proper vessel and the
metallic chlorides are afterwards collected in the usual manner.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Henry Harris Lake in the Great Seal Patent Office on the
22nd June 1882.
HENRY HARRIS LAKE, of the Firm of Haseltine, Lake, & Co, Patent Agents,
Southampton Buildings, London. "IMPROVEMENTS IN AND RELATING TO
PROCESSES FOR EXTRACTING METALS FROM THEIR ORES, AND IN APPARATUS
THEREFOR.' A communication from abroad by Nelson Frederick Evans, of
Philadelphia, Pennsylvania, United States of America.
"
This Invention relates to the extraction of metals from their ores, and to
apparatus therefor.
It consists essentially in the use of chlorine gas under sufficient pressure to
accelerate its action in reducing the metals to the form of chlorides; and in
recovering the unused or uncombined gas from the ore undiluted and in the same
condition as when it entered the chlorinator. The said Invention also comprises
apparatus for accomplishing the above objects.
"
In the ordinary or Plattner's" process of chlorination the chlorine gas is used
under a normal pressure or one just sufficient to cause it to flow into the chlori-
nator; and the time required for the most perfect reduction is forty-eight hours,
while by this Invention I effect the same reduction in one hour or even less.
Retaining the gas for forty-eight hours in the presence of water converts nearly or
quite all of it into chlorhydric acid, and if any of it remains, it is so diluted with
air that its further use is impracticable. The short time and the low temperature
at which the gas and ore are brought into contact in the chlorinator, according to
this Invention, prevent the formation of chlorhydric acid, and as the air is exhausted
from the chlorinator before the introduction of the chlorine, it is recovered in an
undiluted condition.
In the accompanying Drawing which represents a partial side elevation and
partial vertical section of apparatus embodying the said Invention A represents a
chlorine gas generator, which may be of any of the common forms, and d a gaso-
meter for storing gas from the generator, and that which has been recovered from
the chlorinator, the said gasometer being connected to the generator a by the pipes
b, c, and to the chlorinator E by the pipes d, h. E represents the chlorinator which is
in the form of a barrel which is supported and arranged to revolve on trunnions
e e¹ and driven by the pulley k; and f represents a goose neck which is passed
through one of the trunnions into the open space o above the charge; H represents
a pump connected to the gasometer d by the pipes d k and to the chlorinator E by
the pipesh and the goose-neck f.
F represents the receiver for storing gas under pressure, which is connected to the
pump H by the pipes i, k', and to the chlorinator E by the pipes i, h¹ and the goose
neck f. I represents an exhaust-apparatus which may be a pump, water column, or
any suitable contrivance, it being connected to the chlorinator by the pipe land
the goose-neck f, and to the receiver F by the pipes h¹ and i. The cocks or valves n
and care provided to connect or disconnect the different parts of the apparatus.
The following modes of procedure have been found to be well adapted to the
successful practicing of the said Invention, that is to say:-
:-The gasometer is first
put in order for holding the gas; the generator is then charged with the necessary
materials in the proper proportions for generating chlorine gas, which, passing
through the pipes bc, fills the gasometer D. Connection is then made between the
exhaust apparatus I and the receiver F from which the air is exhausted, after which
the connection is closed and connection made between the receiver and the pump H
which is then connected with the gasometer D and started pumping the gas from
the gasometer into the receiver until a pressure of from fifty or sixty pounds is
obtained in the receiver. The chlorinator is then charged nearly full of ore and

page_text: water, leaving only the point or opening in the goose-neck not submerged, and the
chlorinator is made to revolve at the rate of about twenty revolutions per minute.
Connection is now made between the exhaust apparatus and the chlorinator
through the pipe and goose-neck and all air exhausted from the chlorinator; this
connection is then closed and the one between the chlorinator and the receiver
opened, when the gas from the latter passes into the chlorinator, subjecting the ore
therein to a strong pressure. After the ore has been under the gas for one hour or
less, according to its nature, connection between the receiver and chlorinator is
closed, and the latter is connected to the gasometer into which the greater portion
of the gas passes. The chlorinator is now connected to the pump and any gas
remaining in the chlorinator is pumped into the receiver until the chlorinator is
exhausted. The ore and water are then discharged from the chlorinator which is
then ready for another charge. After chloridizing or chlorinating, the ore is filtered
and the gold precipitated and collected in the usual manner.
In carrying the said Invention into practice another method may be employed,
that is to say-The chlorinator E is charged with ore and water as before; into it
is then put a proper proportion of chloride of lime, the whole being thoroughly
incorporated by rotating the chlorinator; the rotation is then discontinued and
dilute sulphuric acid is added to the mixture, and the chlorinator is again rotated,
when there is produced a large excess of chlorine under pressure, the chlorine gas
being evolved from the chloride of lime by the sulphuric acid, sulphate of lime being
formed and chlorine thrown off. The rotation is continued from one half-hour to
three hours according to the nature of the ore, when the chlorination is complete.
Rotation during the chlorination has the effect of expediting the chemical reaction
involved. The chlorinator E is now tapped and the excess of chlorine is drawn off
into a gasometer D, or in the absence of the gasometer (which with the pump H,
generator A, and receiver F may be dispensed with by this method) may be con-
ducted by any suitable device away into the air.
The free chlorine remaining in the chlorinator having been expelled in any
usual and suitable manner, the contents of the chlorinator are now emptied into
a proper vessel and the metallic chlorides are afterwards collected in the usual
manner.
Having thus fully described the said Invention as communicated to me by my
foreign correspondent, and the manner of performing the same, I wish it understood
that I claim :-
First. The process of chlorinating ores, wherein the ore is charged with chlorine
under a pressure greater than that of the atmosphere, such pressure being produced
by the evolution of chlorine gas within a closed chamber containing the ore, or
otherwise produced, substantially as described and for the purpose specified.
Second. The process of chlorinating ores and recovering the unused or uncombined
chlorine gas, substantially as herein set forth.
Third. The goose-neck in combination with the chlorinator, and with or without
the exhaust apparatus, substantially as and for the purposes, set forth.
Fourth. The combination of the goose-neck with the chlorinator, the exhaust
apparatus, the pump H, the gasometer, and the connecting pipes with their valves
or cocks, substantially as described, and for the purposes set forth.
In witness whereof I the said Henry Harris Lake have hereunto set my
hand and seal this Tenth day of June in the year of our Lord, One
thousand eight hundred and eighty-two.