IMPROVED PROCESS AND APPARATUS FOR AMALGAMATING THE PRECIOUS METALS
Year: 1863

page_text: LETTERS PATENT to William Edward Gedge, of the Firm of John Gedge
and Son, of No. 11, Wellington Street, Strand, in the County of
Middlesex, Patent Agent, for the Invention of "IMPROVED PROCESS AND
APPARATUS FOR AMALGAMATING THE PRECIOUS METALS."-A communication
from abroad by Jean Baptiste Baux, Merchant, and Alexis Guiod,
Joiner. both of No. 15, Passage des Petites Ecuries, Paris, France.
Sealed the 10th May 1864, and dated the 12th November 1863.
PROVISIONAL SPECIFICATION left by the said William Edward Gedge
at the Office of the Commissioners of Patents, with his Petition, on the
12th November 1868.
I, WILLIAM EDWARD GEDGE, of the Firm of John Gedge and Son, of
No. 11, Wellington Street, Strand, in the County of Middlesex, Patent
Agent, do hereby declare the nature of the said Invention for "IMPROVED
PROCESS AND APPARATUS POR AMALGAMATING THE PRECIOUS METALS," (a communi-.
cation to me from abroad by Jean Baptiste Baux, Merchant, and Alexis
Guiod, Joiner, both of No. 15, Passage des Petites Ecuries, Paris, France, to
be as follows:-
The object of this Invention is to obtain continuous amalgamation of the
precious metals, gold, silver, and others, contained in the ores or matters with
which they are mixed by putting them in constant and immediate contact with
an uninterrupted jet of mercury obtained by distillation and volatilization
and operating as herein-after described.

page_text: The ore, previously crushed, pulverized, and dry, is placed in a compartment
of the apparatus berein-after described, where it is heated to free it as much as
possible from moisture. In this compartment it is constantly moved about
and further pulverized by means of screw arms or blades. When the ore is
hot and dry and without clods or lumps it is made to fall gradually into a
second compartment immediately above a jet of distilled and volatilized
mercury, and the effect of the ore thus falling on a continuous jet of mercury
is that the latter instantly seizes all the particles of metal with which it has
affinity.
With the apparatus herein-after described precious metals may also be
amalgamated by submitting the heated ore to contact with heated but unvola-
tilized mercury, to effect which the ore and the mercury must be kept in
constant motion by means of the screw arms or blades and the hot mercury be
allowed to fall drop by drop and in larger quantity than if volatilized. Operating
according to this Invention may therefore be termed continuous amalgamation
or simply amalgamation by heat. The metal amalgamated with the mercury
may be constantly obtained without further cost, because the mercury containing
the amalgam is placed in the retort which serves to distil the mercury for the
amalgamation. When the retort contains no more mercury, the metal left in
the retort is withdrawn and is constantly replaced by mercury containing the
amalgam. By the same process, but with a small apparatus, ores may be
tested to ascertain what they contain, working as small a quantity as may be
desired, and at need, with one compartment only, a small one, as at Figure 5 of
the Drawing called "amalgamator;" after having hermetically closed this
compartment the ore kept in motion by screw arms or blades is submitted to
the jet of mercury.
I will now proceed to describe the apparatus used in the application of the
process of amalgamation above set forth, reference being had to the Sheets
of Drawing hereunto annexed and forming part of this my Provisional
Specification, the Figures 1 and 2 of Sheet 1 shewing the entire apparatus in
perspective (Fig. 1) and in vertical section (Fig. 2), and the Figures 3, 4, 5,
and 6 of Sheet 2 illustrating parts disconnected from the apparatus, Figures 1
and 2, Sheet 1, where they are indicated by the same numerals; Fig. 3 indicates
a cylindrical cast-iron vase which receives the already crushed ore, where it is
constantly moved about, heated, and pulverized, and from whence it is made
to fall by a hopper 2, which traverses the compartment, Fig. 4, and the
extremity of which, abuts in the compartment, Fig. 5, immediately above a
jet of distilled and volatilized mercury coming from the retort N by the
tube K, K. The compartment, Fig. 3, is termed the "dryer and pulverizer;"

page_text: Fig. 4 is a vase like the preceding (Fig. 3), and is termed the "heater," it
receives heat from the fire-place of the retort, and as it is placed in the centre
between the vases 3 and 5 it heats them both at once. The heat enters this
In the
placed on the side
vase by two openings b, b, (shewn Fig. 4, Sheet 2,)
towards the fire-place, and another opening a (Sheet 2) permits the heat and
also the smoke to escape by the chinney C. I would here observe that if the
heat from the fire-place of the retort should not be considered sufficiently active
to heat the compartment, Fig. 5, a fire-place may be constructed under this
compartment by making an opening on the side opposite the opening T, care
being taken to isolate the hopper i by a partition to preserve it from the heat
which it does not at all require; Fig. 5 is a vase like the preceding and is
termed the "amalgamator;" it receives the ore from the hopper Z immediately
over a jet of mercury from the tube K, K; the ore is then set in motion and
constantly brought back under the jet of mercury, so that all the particles of
metal may be submitted to contact with the mercury. In the compartments
3 and 5 arms or blades (set like those of an archimedean screw) move about
and further pulverize the ore in the compartment. Fig. 3, the screw arms
A, A, agitate the ore to cause it to dry and pulverize, and then fall in a
heated state into the hopper Z by the opening of a door V, (Sheet 2) which
hermetically closes the top of the hopper Z. To this door is fitted an iron
shaft c (Sheet 2) with a crank s.
centre of the compartments 8
and 4 is a hollow cast-iron tube X, in which passes the vertical shaft
which imparts motion to the screw arms or blades of the compartments 3.
and 5. The arms or blades of compartment 3 are placed and enter the
exterior of the tube X around which they turn (the letters J, J, indicate its
shape), they are set in motion by two curved branches B, B, fitted to the.
vertical shaft I; these arms or blades do not touch the vertical shaft. The
screw arms or blades of compartment 5 have the same shape as those of
compartment 8, and are set in motion by the shaft I, to which these arms,
marked Y, Y, are fitted by a key Q. P is a pivot in the centre of compart-
ment 5, it receives the blades or arms pierced to fit it. R indientes the
shape of the tube of the small arm which moves on the pivot. As in com-
partment 3, the blades or arms keep the ore with the mercury in motioni,
complete the pulverization, and further bring it constantly back beneath
the jet of mercury to complete its amalgamation. To this compartment is
fitted a hopper i having a door (like that above, Z) which is opened when
the amalgamation is completed. The ore and the amalgam fall from the
hopper into a case or vase from which they are withdrawn by the opening T.
I is the vertical shaft which gives motion to the screw arms or blades, A, A,
-

page_text: and Y, Y.
Above the shaft is fitted a bevelled wheel H gearing with
another G above it. The two branches B, B, are fixed by their centre to the
vertical shaft I, and it is these branches which impart motion to the arms
or blades of compartment Fig. 3. D is a cross piece held by two uprights
and pierced in the centre to hold the vertical shaft I, this cross piece also
supports the bearings E, E, which carry the horizontal shaft n to which
is fitted the bevelled wheel G gearing into the wheel H. F is a pulley fitted
on the shaft n, and which by means of a band gives motion to the two shafts
I and by the bevelled gear H, G. d, d, are two screws pressing on the
bearings E, E; Figures 6 and 7 represent the general arrangement of
the furnace containing the whole of the apparatus. This furnace is con-
structed of brickwork or other materials, and has two steps, seats, or planes,
as shewn in the Drawing; one, which may be termed the first plane,
receives the retort and encloses the fire-place which serves to heat it. This
first plane is covered by a sheet of cast iron pierced in the centre and
supporting the retort on the fire-place which heats it. The second plane
of this furnace is also covered with a cast-iron plate pierced in the centre
and which supports the vase, Fig. 3. The chimney C is also placed on the
second plane, This part of the furnace encloses the three vases, and an
interval of several inches should be left, firstly, that the heat in escaping
from vase 4 by the opening a may further heat the compartments 3 and 5
before leaving by the chimney C; and, secondly, in case anything should
get out of order, to permit the necessary alterations or repairs. The three
compartments are strongly bolted together, and a projection may be made
on the masonry to support compartment 5. The hoppers are solidly fixed
above the openings left in compartments 3 and 5 to give passage to the ore,
as indicated. On the first plane of the furnace is placed the retort N
containing the ore and the amalgam; this retort is closed by a lid, above
which is an iron bar or strap L keying tight on to the lid to close it
hermetically. This lid is pierced with two holes, one on one of the sides of
the lid for the introduction of the tube M furnished with tap F, and in the
other hole, pierced in the centre of the lid, is placed a bent tube K, K, also
with a tap; these taps are opened and shut as required, The tube K, K, is
in two parts, one of which corresponds with and is fitted to compartment 5,
where it permits the volatilized mercury to escape immediately beneath the
hopper Z. This tube is in two parts to permit the arched portion where
the tap is placed to be removed when it is desired to take out or open the
retort to withdraw the metal or re-introduce mercury, and in order not to
disarrange that part of the tube in connection with compartment 5. A

page_text: partition or inner masonry is left between the two openings b, b, and admits
that part of the tube K which is fixed to compartment 5. The object of this
partition is to preserve this tube in that part which enters compartment 5
from the action of the heat from the furnace which is fronting it, as too great
a heat might damage it. The tube M placed on the retort, and the extremity
of which comes outside the furnace, has for object to cause the evaporation
of the water the mercury may contain, it then serves to ascertain if the
mercury is distilling, the tap F must therefore be opened and that of the tube
K, K, be closed. When it is desired to commence the amalgamation, and
the mercury begins to distil, open the tap of the tube K, K, placed in the
middle of the retort and which has its issue in compartment 5, and then
close the tap of the tube M, so that all the distilled mercury passes into the
tube K, K, and spreads in the compartment 5, where it serves to effect the
amalgamation as above described. S' is a tube with a tap V which is fitted
to compartment 5; its function is to give air when open and to prevent
pressure in the amalgamation. If on the contrary it is desired to give some
pressure, the tap V is partially or entirely closed at the will of the operator.
This tube S' is in two parts, as indicated on the Drawing. S, S, are the two
keys the ends of which appear outside the furnace, they open and shut the
hoppers when required. When the ore is passed from compartment 3 to
compartment 5, and while the amalgamation is completing, more ore should
be at once introduced into compartment 8 to be heated and pulverized. As
soon as the ore has issued amalgamated from the compartment 5, and that
the door which has permitted its exit is reclosed, fresh ore is permitted to
fall into compartment 5" amalgamator," so as not to interrupt the operation
of amalgamation.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said William Edward Gedge in the Great Seal Patent Office
on the 10th May 1864.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
EDWARD GEDGE, of the Firm of John Gedge and Son, of No. 11, Wellington
Street, Strand, in the County of Middlesex, Patent Agent, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twelfth day of November, in the year of our Lord
One thousand eight bundred and sixty-three, in the twenty-seventh year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the

page_text: said William Edward Gedge, Her special licence that I, the said William
Edward Gedge, my executors, administrators, and assigns, or such others as
I, the said William Edward Gedge, my executors, administrators, and
assigns, should at any time agree with, and no others, from time to time and
at all times thereafter during the term therein expressed, should and lawfully
might make, use, exercise, and vend, within the United Kingdom of Great
Britain and Ireland, the Channel Islands, and Isle of Man, an Invention
for "IMPROVED PROCESS AND APPARATUS POR AMALGAMATING THE PRECIOUS
METALS," (a communication to me from abroad by Jean Baptiste Baux,
Merchant, and Alexis Guiod, Joiner, both of No. 15, Passage des Petites
Ecuries, Paris, France, upon the condition (amongst others) that I, the
said William Edward Gedge, my executors or administrators, by an instru-
ment in writing under my, or their, or one of their hands and seals,
should particularly describe and ascertain the nature of the said Invention,
and in what manner the same was to be performed, and cause the same to
be filed in the Great Seal Patent Office within six calendar months next and
immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said William Edward Gedge, do hereby
declare the nature of the said Invention, and in what manner the same is
to be performed, to be particularly described and ascertained in and by the
following statement :-
The object of this Invention is to obtain continuous, that is to say, unin-
terrupted amalgamation of the precious metals, gold, silver, and others,
contained in the ores or matters with which they are mixed, by putting them
in constant and immediate contact with an uninterrupted jet of mercury
obtained by distillation and volatilization operating as herein-after described,
and it is these several improvements, together with the apparatus by which
they are applied, that constitute this Invention.
The ore, previously crushed, pulverized, and dry, is placed in a compartment
of the apparatus where it is heated, as hereafter described, to free it as
much as possible from any moisture it may contain. In this compartment it
is constantly moved about, and further pulverized by means of screw blades.
The hot ore submitted in this state to pulverization pulverizes much better,
and claim is therefore made for the application of this method of crushing.
When the ore is hot, dry, and in a non-compact powder or dust without clods
or lumps, it is made to descend and fall gradually into a second compartment
immediately above a jet of distilled and volatilized mercury escaping from a
tube fitted to a retort, herein-after described, so that the ore falling thus on a
continuous jet of mercury this latter instantly siezes all the particles of precious

page_text: or other metal with which it has affinity. In this compartment, which may
be called the amalgamating chamber, there are, as in the upper compartment,
similar screw blades set in motion by the same motor. The object of these
blades is to further complete the pulverization of the ore and to bring it back
constantly, and as long as may be deemed necessary, under the jet of mercury,
so that all the particles of precious metal may be brought in contact with the
mercury, and as this amalgamation may be said to be instantaneous there is
a great saving of time, as compared with existing processes.
With the apparatus herein-after described, precious metals may be amal-
gamated by submitting the heated ore to contact with heated but unvolatilized
mercury, to effect which the ore and the mercury must be kept in constant
motion by means of the screw blades or arms, and the hot mercury be allowed
to fall drop by drop and in larger quantity than if volatilized. This method
of operating may therefore be termed continuous amalgamation or simply
amalgamation by heat. The advantages of the improvements above set forth
will be readily understood, as nothing interposes between the metal and the
mercury, neither water nor any foreign body, as by the known processes of wet
amalgamation.
Another advantage is worthy of mention; the precious metals are often in the
ore allied to matters opposing a good amalgamation, and hitherto it has been
necessary to submit the ore to a preliminary roasting or to chemical agents to
free it from these foreign bodies, or to neutralize them, whereas by using the
improvements the subject of this Invention, no roasting or the use of any
chemical agent is necessary, and the most difficult ores are amalgamated with
the greatest facility. The following advantages are not less important:-The
metal amalgamated with the mercury may be constantly obtained without
further cost, because the mercury containing the amalgam is placed in the
retort, which serves to distil the mercury for the amalgamation. When the
retort contains no more mercury the metal left in the retort is withdrawn, and
is constantly replaced by mercury containing the amalgam. Therefore the
operation of separating the metal from the mercury costs no more than by
the processes hitherto used. Further, the amalgamating apparatus is so con-
structed that the same fire placed between the two compartments, one of which
(the upper compartment, where the ore is heated and pulverized, as above
stated, is termed the "dryer, and the other the amalgamator,") serves also,
firstly, to distil and volatilize the mercury; and, secondly, to separate the
precious metal from the mercury itself. The application of this method of
amalgamating by means of distilled, or volatilized, or heated mercury, and
continuously, may be made by means of apparatus differing from that herein-

page_text: after described, and forming part of this Invention, the Inventors themselves
having two apparatuses of different form, therefore I specially set forth, as
novel, the means of continuous amalgamation by the use of distilled and
volatilized or heated mercury and dry amalgamation with heated ore by
simply submitting it to a current of distilled and volatilized mercury, and
claim is made for the amalgamation, as the heating of the ores to be sub-
mitted to amalgamation is not an absolute necessity, inasmuch as they have
been well amalgamated without previous heating. By the same process, but
with a smaller apparatus, ores may be tested to ascertain what they contain,
working as small a quantity as may be desired, and at need, with one com-
partment only, a small one, as at Figure 5 of the Drawing, termed
"amalgamator." After having hermetically closed this compartment, the ore
kept in motion by screw blades, as above stated, is submitted to the jet of
mercury.
I will now proceed to describe the apparatus used in the application of the
process of amalgamation above set forth, referring to the Sheet of Drawing
hereunto annexed, and forming part of this Specification, and to the figures
and letters of reference placed thereon, Figure 1 shewing the entire apparatus
in perspective, and Figure 2, vertical section thereof; Figure 3, cylindrical
cast-iron vase, which receives the previously crushed ore, where it is constantly
moved about, heated, and pulverized, and from whence it is made to fall by a
hopper Z, which traverses the compartment, Figure 4, and the extremity of
which abuts in the compartment, Figure 5, immediately above a jet of dis-
tilled and volatilized mercury coming from the retort N by the tube K, K.
The compartment Figure 8 is termed the "dryer and pulverizer;" Figure 4,
vase like the preceding, Figure 3, and termed the "heater;" it receives the
heat from the fire-place of the retort, and as it is placed in the centre between
the vases, Figures 3 and 5, it heats them both at once. The heat enters this
vase by two openings b, b, placed on the side towards the fire-place, and
another opening a permits the heat and also the smoke to escape by the
chimney C. I would here observe that if the heat from the fire-place of the
retort should not be considered sufficiently active to heat the compartment,
Figure 5, a fire-place may be constructed under this compartment by making
an opening in the furnace on the side opposite the opening T, care being
taken to isolate the hopper i by a partition to preserve it from the heat which
it does not at all require; Figure 5 is a vase like the preceding, and is
termed the "amalgamator." It receives the hot ore from the hopper Z imme-
diately over a jet of mercury from the tube K, K, the ore is then set in
motion, and constantly brought back under the jet of mercury, so that all the

page_text: particles of metal may be submitted to contact with the mercury.
In the
compartments 3 and 5, arms or blades like those of a screw propeller move
about and further pulverize the ore. In the compartment Figure 3 the
screw arms A, A, agitate the ore to cause it to dry and pulverize, and then
fall in a heated state into the hopper Z, through the opening g by the opening
of a door V, which hermetically closes the top of the hopper Z. To this door
is fitted an iron shaft C with a crank S, as shewn, Figures 3 and 4. In the
centre of the compartments 3 and 4 is a hollow cast-iron tube X, in
which passes the vertical shaft I, which imparts motion to the screw arms
or blades of the compartments 3 and 5. The arms or blades of compart-
ment 3 are placed and enter the exterior of the tube X, around which they
turn (the letters J, J, indicate its shape) they are set in motion by two curved
branches B, B, fitted to the vertical shaft I. These arms or blades do not
touch the vertical shaft. The screw arms or blades of the compartment,
Figure 5, have the same shape as at compartment 8, and are set in motion
by the shaft I, to which these arms, marked Y, Y, are fitted by a key Q; P is
a pivot in the centre of compartment 5, which receives the blades or arms
pierced with a hole to fit to this pivot; R, indicates the shape of the tube of
the small arm which moves on the pivot. As in compartment No. 3, the
blades or arms keep the ore with the mercury in motion, complete the pulve-
rization, and further bring it back constantly beneath the jet of mercury to
complete its amalgamation. To this compartment is fitted a hopper i, and by
means of a door Z (like that above described, which is opened when the
amalgamation is completed) the ore and the amalgam fall from the hopper
into a case or vase, from which they are withdrawn by the opening T; I is
the vertical shaft, which gives motion to the screw arms or blades A, A, and Y, Y.
As has been explained, above the shaft is fitted a bevilled cog H, gearing into
another cog G above it. The two branches B, B, are fixed by their centre to
the vertical shaft I, and it is these branches which impart motion to the arms
or blades of compartment No. 3; D is a cross piece held by two uprights, and
pierced in its centre to bold the vertical shaft I, this cross piece also supports
the bearings E, E, which carry the vertical shaft n, to which is fitted the
bevilled wheel G gearing into the wheel H; F is a pulley fitted on the shaft n,
and which by means of a band gives motion to the two shafts I and n, by the
beveled gear H and G; d, d, are two screws pressing on the bearings E, E.
Figure 6 represents the furnace. This furnace is constructed of brickwork or
other materials, and has two planes, one (which may be termed the first plane)
receives the retort, and encloses the fire-place which serves to heat it. This
first plane is covered by a sheet of cast iron pierced in the centre, and which

page_text: supports the retort on the fire-place which heats it. The second plane of the
furnace is also covered with a cast-iron plate pierced in the centre, and which
supports the vase, Figure 3. The chimney C is also placed on the second
plane. This part of the furnace encloses the three vases, and an interval of
several inches should be left, firstly, that the heat in escaping from vase 4 by
the opening a may further heat the interior of compartments 3 and 5 before
leaving by the chimney C; and, secondly, in case anything should get out of
order to permit the necessary alterations or repairs. The three compartments
are strongly bolted together, and a projection may be made in the masonry to
support compartment No. 5. The hoppers are solidly fixed above the openings
left in compartments 3 and 5, and to give passage to the ore as indicated. On
the first plane of the furnace is placed the retort N containing the ore and the
amalgam, this retort is closed by a lid, above which is an iron bridle or bent
bar L, tightened on to the lid by two keys or cottars to close it hermetically.
This lid is pierced with two holes, one on one of the sides of the lid, into which
is introduced a tube M furnished with a tap F, and in the other hole pierced
in the centre of the lid is placed a bent tube K, K, also with a tap; these taps
are opened and shut as required. This tube is in two parts, one of which
corresponds with and is fitted to compartment 5, where it permits the vola-
tilized mercury to escape immediately beneath the hopper Z, and to permit
the arched portion where the tap is placed to be removed when it is desired
to take out or open the retort to withdraw the metal or re-introduce mercury,
and in order not to disarrange that part of the tube in connection with the com-
partment 5. A partition or inner masonry is left between the two openings b, b,
and admits that part of the tube K which is fixed to compartment 5. The
object of this partition is to preserve this tube in that part which enters the
compartment 5 from the action of the heat from the furnace, which is exactly
fronting it, as too great a heat might damage it. The tube M placed on the
retort, and the extremity of which comes outside the furnace, has for object to
cause the evaporation of the water the mercury may contain, it then serves to
ascertain if the mercury is distilling, the tap F must therefore be opened, and
that of the tube K, K, be closed. When it is desired to commence the
amalgamation, and the mercury begins to volatilize, open the tap E¹ of the
tube K, K, placed in the middle of the retort, and which has its issue in
compartment 5, and then close the tap F of the tube M, so that all the
distilled mercury passes into the tube K, K, and spreads in the compart-
ment 5, where it serves to effect the amalgamation as above described. S¹ is a
tube with a tap V, which is fitted to compartment 5; its function is to give air
when open, and to prevent pressure in the amalgamation. If, on the contrary,

page_text: it is desired to give some pressure, the tap V is partially or entirely closed at
the will of the operator. This tube S' is in two parts, as indicated on the
Drawing. S, S, are the two keys, the ends of which appear outside the
furnace, they open and shut the hoppers when required. I would here
observe that when the ore is passed from the compartment 3 to the amal-
gamator 5, and while the amalgamation is completing, more ore should be at
once introduced into compartment 3 to be heated and pulverized. As soon as
the ore has issued amalgamated from the compartment 5, and that the door
which has permitted its exit is re-closed, fresh ore is permitted to fall into
compartment 5 ("amalgamator"), so as not to interrupt the operation of
amalgamation. The separation of the amalgamated mercury from the foreign
matters is effected by an ordinary washing, as in the other processes.
Having now described the nature of the said Invention, and the means by
which the same is to be performed, I desire it to be understood that I do not
confine myself to the precise details herein set forth and described, or illus-
trated on the annexed Sheet of Drawing, as variation may be made therein
without departure from this "Improved Process and Apparatus for Amal-
gamating the Precious Metals."
In witness whereof, I, the said William Edward Gedge, have hereunto
set my hand and seal, this Tenth day of May, in the year of our
Lord One thousand eight hundred and sixty-four.