IMPROVEMENTS IN SEPARATING MATTERS OF DIFFERENT DENSITIES, AND ESPECIALLY IN SEPARATING THE METALS FROM AURIFEROUS AND ARGENTIFEROUS MATTERS, AND IN APPARATUS FOR EFFECTING SUCH SEPARATION
Year: 1879

page_text: LETTERS PATENT to Ernest Bazin, of Paris, in the Republic of France, Civil
Engineer, for the Invention of "IMPROVEMENTS IN SEPARATING MATTERS OF
DIFFERENT DENSITIES, AND ESPECIALLY IN SEPARATING THE METALS FROM
AURIFEROUS AND ARGENTIFEROUS MATTERS, AND IN APPARATUS FOR EFFECTING
SUCH SEPARATION."
Sealed the 18th April 1879, and dated the 11th January 1879.
PROVISIONAL SPECIFICATION left by the said Ernest Bazin at the Office of
the Commissioners of Patents on the 11th January 1879.
ERNEST BAZIN, of Paris, in the Republic of France, Civil Engineer. " IMPROVE-
MENTS IN SEPARATING MATTERS OF DIFFERENT DENSITIES, AND ESPECIALLY IN
SEPARATING THE METALS FROM AURIFEROUS AND ARGENTIFEROUS MATTERS, AND
IN APPARATUS FOR EFFECTING SUCH SEPARATION."
"
This Invention has for its object improvements in separating matters of different
densities, and especially in separating the metals from auriferous and argentiferous
matters, and in apparatus for effecting such separation.
I separate matters of different densities by a "filtration" through mercury, such
filtration" being obtained by the aid of an hydraulic column and of a small current
of water. After this "filtration" the sterile matters are expelled or thrown off by
centrifugal force, brought to act upon them whilst they are beneath water, these
two operations, the filtration" and the expulsion, taking place simultaneously.
The Drawings represent apparatus for the application of my system of
separation.
"
In a water vat a, a, there is supported upon a footstep ba rotating self discharging
vessel or "projector "c; or for the footstep ban axis may be substituted, passing
by a stuffing box through the bottom of the vat a. The vessel c is submerged to
the extent of 5 or 6 centimetres in the water contained in the vat a, and the
cylindrical part d is filled with mercury d¹. This vessel c is suitably rotated either
by hand or by mechanism; the rotary movement is obtained by means of two
bevilled wheels placed above the water level; the pinion or smaller wheel is fixed
upon the spiral shaft 2. A sluice e serves for the escape, that is to say, for the exit
of the sterile matters. The opening of this sluice is regulated in such manner that
the escape of water and sterile matter deposited at the bottom of the vat may be
proportional to the admission of water and matters to be treated.

page_text: An overflow cock e¹, fixed upon the side of the vat a, serves to regulate the height
of the column of water, and to maintain the level of the water in the interior of
the vat.
A vertical tube f, furnished with an inlet cock f¹, and terminating at its upper
end in a funnel g, is intended to contain a column of water of a height to balance
that of the coluinn of mercury, and to serve at the same time as a conduit pipe for
the matters which, mixed with water, are to be introduced. The lower end of this
conduit tube should be somewhat narrowed in order to obtain a sufficient speed of
injection, and thus to facilitate the penetration of the water and of the matters
through the mercury.
The opening at (to which a cover is fitted) permits of the mercury being readily
removed; it gives the operator access to the emptying cock y. For this cock a
screw plug may be substituted.
The tightness of the connection of the pipes forming the admission conduit is
obtained by compressing a ring of caoutchouc v between two collars fixed upon the
pipes.
'
The operation of the apparatus is very simple; the equilibrium of the mercury
intended for the "filtration" of the matters having been obtained by a column of
water of suitable height, there is then poured continuously into the funnel g the
quantity of water necessary to maintain a very gentle flow, and with it the matters to
be treated; these latter evidently increase the speed of the current in consequence of
their density. The mixture issues at the base of the mercury column in the
cylindrical part of the centrifugal vessel c. From this point the earths, the sand,
the quartz; in a word, the sterile matters of which the density is very much less
than that of mercury, effect their escape upwards through the mercurial bath, and
arrive at the surface of the mercury; the current of water makes them to pass over
the edge of the cylindrical part, and to fall back into the centrifugal projector c,
which, having a suitable rotary movement, projects them along the curves h, and
expels them, in a word, by centrifugal force beneath water, throwing them out into
the vat a, a.
As a measure of precaution the bottom of the so-called "projector" contains also
a small quantity of mercury, which is obviously subject to the centrifugal action ;
but that contained in the cylindrical part will experience much less of this centrifugal
action, which would have the inconvenience of depressing the centre of the mercury.
This depression would be felt on the equilibrating column of water, and would
occasion constant changes of level.
The gold will, if in nuggets, remain principally at the bottom of the mercurial
bath in consequence of its density, and in the case of gold in powder, scales or
impalpable dust being carried upwards with the sterile matters, it will not be able
to completely traverse the mercurial bath without being amalgamated.
Silver, which is of a less density than that of mercury, will equally, especially
when very finely divided, bo susceptible of amalgamation in traversing the mercurial
bath.
Besides, after the filtration through mercury for rich minerals which may ex-
ceptionally have. been able to traverse the mercurial bath and yet to escape the
amalgamating action, thero still remains another operation, namely, the separation
of the matters of different densities beneath water by centrifugal force, which takes
place simultaneously with the "filtration" through mercury.
The gold or silver which has been able to traverse the mercurial bath without
becoming amalgamated acquires, so to speak when in water, a much greater weight
than it had whilst in the mercury, and will not be expelled from the rotary vessel c
with the sterile matters which have a much less density. It will remain in the
mercury bath contained in the discharging vessel, and ultimately will become
amalgamated.
For the purpose of retarding and diminishing the rapidity of the rise of the
matters, and to cause them to remain longer in the mercurial bath, I make them
traverse when in this material a longer path than that vertically upwards, and this

page_text: I do by placing in the cylindrical part of the vessel c (Figure 1) a shaft p surrounded
by three spirals q, q', q, and through the centre of which the conducting pipe ƒ for
he mixture of water and matter to be treated passes.
It will be easily understood that the rich matters, that is to say, matters having
a density superior to the earths, sand, or quartz, and which might be carried over
by too strong an upward current of water, will have frictions to overcome in
ascending the spirals q, q', q", which frictions will oppose the rise of the said rich
matters, and the circular course which they are compelled to take occasioning a
longer contact with the mercury will thus greatly facilitate the operation of
amalgamation.
Another arrangement to bring about the retardation of the matters during their
rise and at the same time their sub-division is shown in the Drawings in detail at
Figure 1".
The inclination of the spirals q may be variod to retard the rise of the matters to
a greater or less extent, and by the rotation of the vessel c and the spirals iu one
direction or the other I can increase or diminish the rate at which the matters
risc.
I can also increase the power of the apparatus by increasing the diameters
without increasing the height of the parts. I can also increase the depth of the
mercurial bath, the height of the water column being increased in a liko degree, so
as to obtain a very long travel for the matters beneath the mercury.
Thus it will be seen that in the type of separator which I have described there are
several chances for the amalgamation of gold or silver by "filtration 'through
mercury-
1. For gold in nuggets, especially that is to say in masses on which the upward
current will have little effect, the density will suffice to retain it at the bottom of
the mercurial bath, where after a time it will become amalgamated.
2. For very finely divided matter if it rises the amalgamation will take place
during the rise through the mercury.
"
3. Then again in the case of matters which are more dense than the sterile
matters when they escape from the amalgamating action of the "filtration
through the mercury whilst they are ascending the cylindrical part of the vessel c
there is still a chance of separating these inatters from the sterile matters by the
centrifugal action below water in which the earths, the quartz, and the sand are
thrown out, whilst the gold and the silver are retained, and in time become amal-
gamated in consequence of their contact with the mercuial bath contained in the
rotating self discharging vessel or projector.
Figure 1 represents a type of separater, in which the rotary discharging vessel
has a cylindrical bottom of a height suited to receive spirals and the mecurial bath,
this type applicable to the treatinent of quartz, earths, and sands, but especially to
quartz which has been stamped fine.
Figure 1 represents in detail to a larger scale the rotary vessel and shaft carrying
spirals of Figure 1.
Figure 1 represents to a larger scale the rotary vessel provided with a shaft
armed with radial bars.
Figure 2 represents a type of separater, applicable especially to earths and
auriferous sands.
The driving gear, by which the rotating vessel is actuated, is in this type of
apparatus placed beneath the water, so that in case of an accidental deficiency of
mercury the apparatus may be employed to treat the matters with water alone, for
which purpose it is only necessary to remove the conducting tube f.
A disc marked in dots protects the gearing from the falling sand.
The centrifugal action will here evidently make itself felt, even to the bottom of
the rotating vessel, but the projecting curves are steeper than those of the vessel or
projector represented in Figure 1. It is without spirals, and the conducting tube
is furnished at its lower end with a wooden bulb x to avoid by its displacement the
necessity for the employment of too large a quantity of mercury.

page_text: Around this bulb several rows of iron points are arranged tolerably close together;
they are intended to retard the rise of the matters under treatment, and to soparate
the particles.
The cylindrical part which holds the column of mercury may in some cases be
made independent of the rotary discharging vessel, so that in that case the said
cylindrical part would not partake of the rotary motion imparted to the discharging
vessel; it would remain fixed. This makes no alteration in the method of action;
it is only a difference in the construction of the apparatus.
Figure 3 represents in outline a separating apparatus on my system, placed at the
bottom of the hold of a dredging barge. The extractor adapted to treat auriferous
sands and earths is arranged in such manner that the dredging apparatus bringing
from the bottom of the river the sands and the aueriferous earths pours them directly
into the funnel of the conducting tube, and these matters are then treated precisely
according to my system of separation described above.
The operation of my apparatus effects, as will be seen, not only an excellent
primary separation, but also causes the rich matters which have escaped the mercurial
bath to be retained to submit them to amalgamation by their continued contact
and dwell with the mercury in the rotating vessel.
I sometimes work with hot water, and in certain cases this hot water may be
acidulated, and if need be it may contain a certain quantity of salt, especially for
the treatment of sulphuretted argentiferous quartz.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Ernest Bazin in the Great Seal Patent Office on the 11th July
1879.
ERNEST BAZIN, of Paris, in the Republic of France, Civil Engineer. " IMPROVE-
MENTS IN SEPARATING MATTERS OF DIFFERENT DENSITIES, AND ESPECIALLY IN
SEPARATING THE METALS FROM AURIFEROUS AND ARGENTIFEROUS MATTERS, AND
APPARATUS FOR EFFECTING SUCH SEPARATION."
This Invention has for its object improvements in separating matters of different
densities, and especially in separating the metals from auriferous and argentiferous
matters, and in apparatus for effecting such separation.
28
I separate matters of different densities by a filtration" through mercury, such
"filtration" being obtained by the aid of an hydraulic column, and of a small
current of water. After this "filtration" the sterile matters are expelled or
thrown off by centrifugal force brought to act upon them whilst they are beneath
water, these two operations, the "filtration" and the expulsion, taking place
simultaneously.
The Drawings represent apparatus for the application of my system of
separation.
"
In a water vat a, a, sec Figure 1, there is supported upon a footstep ba rotating
self discharging vessel or projector" c. Or for the footstep b an axis may be
substituted, passing by a stuffing box through the bottom of the vat a.
The vessel
c is submerged to the extent of 5 or 6 centimetres in the water contained in the
vat a, and the cylindrical part & is filled with mercury d¹. This vessel c is suitably
rotated either by hand or by mechanism; the rotary movement is obtained by
means of two bevilled wheels placed above the water level; the pinion or smaller
wheel is fixed upon the spiral shaft p. A sluice e serves for the escape, that is to
say, for the exit of the sterile matters. The opening of this sluice is regulated in
such manner that the escape of water and sterile matter deposited at the bottom
of the vat may be proportional to the admission of water and matters to be
treated.
An overflow cock e¹, fixed upon the side of the vat a, serves to regulate the
height of the column of water, and to maintain the level of the water in the interior
of the vat.
A vertical tube f, furnished with an inlet cock f¹, and terminating at its upper
end in a funnel g, is intended to contain a column of water of a height to balance
that of the column of mercury, and to serve at the same time as a conduit pipe for
the matters which, mixed with water, are to be introduced. The lower end of this
conduit tube should be somewhat narrowed, in order to obtain a sufficient speed of
injection, and thus to facilitate the penetration of the water and of the inatters
through the mercury.
The opening at (to which a cover is fitted), permits of the mercury being readily
removed; it gives the operator access to the emptying cock y. For this cock a
screw plug may be substituted.
The tightness of the connection of the pipes forming the admission conduit is
obtained by compressing a ring of caoutchouc v between two collars fixed upon the
pipes.
The operation of the apparatus is very simple; the equilibrium of the mercury
intended for the "filtration" of the matters having been obtained by a column of
water of suitable height, there is then poured continuously into the funnel g the
quantity of water necessary to maintain a very gentle flow, and with it the matters
to be treated; these latter evidently increase the speed of the current in consequence
of their density. The mixture issues at the base of the mercury column in the
cylindrical part of the centrifugal vessel c. From this point the earths, the sand,
the quartz, in a word, the sterile matters of which the density is very much less

page_text: than that of mercury, effect their escape upwards through the mercurial bath, and
arrive at the surface of the mercury. The current of water makes them to pass
over the edge of the cylindrical part, and to fall back into the centrifugal projector
c, which having a suitable rotary movement, projects them along the curves h, and
expels them in a word by centrifugal force beneath water throwing them out into
tho vat a, a.
As a measure of precaution the bottom of the so called "projector" contains also
a small quantity of mercury, which is obviously subject to the contrifugal action,
but that contained in the cylindrical part will experience much less of this centri-
fugal action, which would have the inconvenience of depressing the centre of the
mercury. This depression would be felt on the equilibrating column of water, and
would occasion constant changes of level.
The gold will if in nuggets remain principally at the bottom of the mercurial
bath in consequence of its density, and in the case of gold in powder scales or
impalpable dust being carried upwards with the sterile matters, it will not be able
to completely traverse the mercurial bath without becoming amalgamated.
Silver, which is of a less density than that of mercury, will equally, especially
when very finely divided, be susceptible of amalgamation in traversing the mercurial
bath.
Besides, after the "filtration" through mercury for rich minerals which may
exceptionally have been able to traverse the inercurial bath, and yet to escape the
amalgamating action, there still remains another operation, namely, the separation
of the matters of different densities beneath water by centrifugal force, which takes
place simultaneously with the "filtration" through mercury.
The gold or silver which has been able to traverse the inercurial bath without
becoming amalgamated, acquires, so to speak, when in water, a much greater weight
than it had whilst in the mercury, and will not be expelled from the rotary vessel c
with tho sterile matters, which have a much less density. It will remain in the
mercury bath contained in the discharging vessel, and ultimately will become
amalgamated.
For the purpose of retarding and diminishing the rapidity of the rise of the
matters, and to cause them to romain longer in the mercurial bath, I make them
traverse when in this material a longer path than that vertically upwards, and this
I do by placing in the cylindrical part of the vessel c (Figure 1) a shaft 2, sur-
rounded by three spirals 7, 9', q", and through the centre of which the conducting
pipe for the mixture of water and matter to be treated passes.
Three projections at the lower end of the shaft 2 enter recesses in the bottom of
the rotary vessel c, which thus has motion communicated to it.
It will be easily understood that the rich matters, that is to say, matters having
a density superior to the earths, sand, or quartz, and which might be carried over
by too strong an upward current of water, will have frictions to overcome in
ascending the spirals q, q', q", which frictions will oppose the rise of the said rich
matters, and the circular course which they are compelled to take, occasioning a
longer contact with the mercury d', will thus greatly facilitate the operation of
amalgamation.
Another arrangement to bring about the retardation of the matters during their
rise, and at the same time their subdivision, is shown in the Drawings in detail at
Figure 3.
The inclination of the spirals q may be varied to retard the rise of the matters
to a greater or less extent; and by the rotation of the vessel c and the spirals in
one direction or the other, I can increase or diminish the rate at which the matters
rise.
I can also increase the power of the apparatus by increasing the diameters without
increasing the height of the parts. I can also increase the depth of the mercurial
bath, the height of the water column being increased in a like degree, so as to
obtain a very long travel for the matters beneath the mercury.
Thus it will be seen that in the type of separater which I have described there

page_text: are several chances for the amalgamation of gold or silver by “filtration” through
mercury.
1. For gold in nuggets especially, that is to say, in masses on which the upward
current will have little effect, the density will suffice to retain it at the bottom of
the mercurial bath, where after a time it will become amalgamated.
2. For very finely divided matter if it rises, the amalgamation will take place
during the rise through the mercury.
3. Then, again, in the case of matters which are more dense than the sterile
matters R when they escape from the amalgamating action of the "filtration "
through the mercury whilst they are ascending the cylindrical part of the vessel c,
there is still a chance of separating these matters from the sterile matters by the
centrifugal action below water, in which the earths, the quartz, and the sand are
thrown out whilst the gold and the silver are retained, and in time become amalga-
mated in consequence of their contact with the mercurial bath contained in the
rotating self-discharging vessel or projector.
Figure 1 represents a type of separater in which the rotary discharging vessel has
a cylindrical bottom of a height suited to receive spirals and the mercurial bath;
this typo is applicable to the treatment of quarts, carths, and sands, but especially
to quartz which has been stamped fine.
Figure 2 represents in detail to a larger scale the rotary vessel and shaft carrying
spirals of Figure 1.
Figure 3 represents to a larger scale the rotary vessel provided with a shaft armed
with radial bars.
Figure 4 shows a type of separater in which the mercury bath is stationary, and
is surrounded near its upper end by a rotating self-discharging vessel or projector,
consisting of a double pan c¹. Mercury is placed in the projector to about the samo
level as that in the stationary bath; it prevents the matters penetrating to the
joint, and so lessens friction. The spiral in this arrangement is fixed upon the lower
end of the conducting tube f. The projector c' is connected by radial bars with a
collar on the tube f, and the driving pinion is fixed to the collar.
Figure 5 shows a very simple form of the apparatus, in which the projector turns
upon the cylindrical mercury receiver, which remains stationary.
As the Drawing shows, there is a bronze collar which may be returned when it
becomes worn, and a bevilled ring serves to exclude the matters from the joint. The
projector is supplied with a small quantity of mercury, and is driven in the manner
described in respect to Figure 4.
In this type of separater the projector can be readily changed, and others of a
different curvature substituted when desired.
Figure 6 represents a type of separater applicable ospecially to earths and aurife-
rous sands.
The driving gear by which the rotating vessel is actuated is in this type of appa-
ratus placed beneath the water, so that in case of an accidental deficiency of mercury
the apparatus may be employed to treat the matters with water alone, for which
purpose it is only necessary to remove the conducting tube f.
A disc marked in dots protects the gearing from the falling sand.
The centrifugal action will here evidently make itself felt, even to the bottom of
the rotating vessel, but the projecting curves are steeper than those of the vessel or
projector represented in Figure 1. It is without spirals, and the conducting tube is
furnished at its lower end with a wooden bulb x, to avoid by its displacement the
necessity for the employment of too large a quantity of mercury.
Around this bulb several rows of iron points are arranged tolerably close together;
they are intended to retard the rise of the matters under treatment, and to separate
the particles.
Figure 7 represents in outline a separating apparatus on my system placed at the
bottom of the hold of a dredging barge. The extractor adapted to treat auriferous
sands and earths is arranged in such manner that the dredging apparatus bringing
from the bottom of the river the sands and the auriferous earths, pours them directly

page_text: into the funnel of the conducting tube, and these matters are then treated precisely
according to my system of separation described above.
The operation of my apparatus effect, as will be seen, not only an excellent primary
separation, but also causes the rich matters which have escaped the mercurial bath
to be retained, to submit them to amalgamation by their continued contact, and
dwell with the mercury in the rotating vessel.
I sometimes work with hot water, and in certain cases this hot water may be
acidulated, and if need be it may contain a certain quantity of salt, especially for
the treatment of sulphuretted argentiferous quartz.
It is essential that the mercury bath should be completely covered by the water
to diminish their density, and aid in their expulsion by the projector, or even with-
out its aid.
Figure 8 shows an apparatus very similar to Figure 5, and specially applicable to
the treatment of quartz, earths, and auriferous and argentiferous sands, by causing
them by means of an hydraulic column to traverse a submerged mercurial bath.
There are spirals to retard the ascent, and a rotary projector.
Having thus described the nature of my said Invention, and the manner of
performing the same, I would have it understood that I claim,―
First. The separation of auriferous and argentiferous matters by the aid of an
hydraulic column, balancing a column of mercury and carrying forward the matters
to be treated, the sterile matters being thus made to pass through the mercury and
into a submerged vessel, whence by reason of centrifugal force applied under
water they are expelled, whilst the rich matters remain and become amalgamated
in the mercury.
Second. The apparatus, substantially as described, intended especially for the
treatment of auriferous and argentiferous matters based upon the application of an
hydraulic column, causing the "filtration" of the matters through a mercurial bath
from the bottom upwards, and upon the simultaneous expulsion of the sterile matters
by the employment of centrifugal force beneath water. This apparatus constitutes
a separater, which operates by mercury and by water, thus having two functions
although forming one whole.
Third. The application in such apparatus of immersed spirals in the mercury
bath, forming an obstacle to the too rapid rise of the matters, and compelling them
to make a longer trave! beneath the mercury.
Fourth. The application in such apparatus of a hollow shaft, or axis, or tube,
conducting the matters immersed in the mercurial bath, and furnished with small
bars, act diagonally in suitable manner to divide and retard the rise of the matters,
and retain them longer in contact with the mercury.
Fifth. The arrangements herein described, in which the mercury bath is
stationary.
In witness whereof, I, the said Ernest Bazin, have hereunto set my hand and
scal, this Eighth day of July, in the year of our Lord One thousand eight
E. BAZIN. (L.S.)