IMPROVEMENTS IN APPARATUS FOR EXTRACTING GOLD DUST FROM AURIFEROUS SANDS
Year: 1861

page_text: LETTERS PATENT to Eduard Claude Barbotte de Beaulieu, of Avallon,
in the Department of Yonne, in the Empire of France, for the Inven-
tion of "IMPROVEMENTS IN APPARATUS FOR EXTRACTING GOLD DUST FROM
AURIFEROUS SANDS."
Sealed the 2nd May 1862, and dated the 14th December 1861.
PROVISIONAL SPECIFICATION left by the said Eduard Claude Barbotte
de Beaulieu at the Office of the Commissioners of Patents, with his
Petition, on the 14th December 1861.
I, EDUARD CLAUDE BARBOTTE DE BEAULIEU, of Avallon, in the Department
of Yonne, in the Empire of France, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN APPARATUS FOR EXTRACTING GOLD DUST FROM
AURIFEROUS SANDS," to be as follows:-
My Invention has for its object the more complete separation of gold from
auriferous sands than bas hitherto been effected by machines in present use.
In my present Invention the sand is first washed in a trough filled with
water, in which a horizontal shaft with radial arms is made to revolve, so as
to stir up the sand and free it from particles of mud or clay so as to render it of
a perfectly loose nature. In order to remove from the sand the larger nodules
of gold before submitting it to the final operation, it is placed in a cylindrical
metal sieve, which is closed at the ends and is placed in an inclined position
in a trough containing water; to this sieve is imparted, firstly, a rapid vertical
vibratory motion by means of a small crank and connecting rod attached to

page_text: one end of the axle of the same; and, secondly, it at the same time receives a
vibratory motion round its axis by being attached to a short double-jointed side
lever fixed to the side of the trough. By means of this peculiar rapid vibra-
tory motion the fine auriferous sand is caused to pass through the meshes of
the sieve, whilst the coarser sand is retained inside the same together with the
small nodules of gold contained therein. The latter, by virtue of their greater
gravity, accumulate at the lowest point of the sieve, and can be removed thence
through a small trap door, whilst the coarse sand is removed through a central
opening in the end of the sieve. After these preliminary operations, the
auriferous sand containing gold in a very finely divided state is placed in an
apparatus constructed as follows:-A long shallow trough constructed of strong
sheet metal is suspended by a number of chains in a cistern full of water
heated to 212 degrees Fahrenheit, so as to be completely immersed. The
bottom of this trough is covered with a thin layer of mercury, which is capable
of being drawn off through a cock fixed close to the bottom of the trough.
The trough is attached at one end to the elastic end of a bell-crank lever, the
other end of which receives a vibratory motion by means of tappets on a
revolving shaft; thus rapid horizontal oscillating motion is imparted to the
trough, the effect of which is increased by the trough coming alternately in
contact with a block fixed a slight distance from each end of the same. The
same bell crank also imparts a tremulous motion to a hopper fixed over one
end of the trough, through which the auriferous sand is introduced into the
Jatter. At the farther end of the trough is a spout, through which the sand,
after being deprived of all its gold dust, passes into a box situated in a deeper
part of the cistern, which box is removed and emptied from time to time. The
auriferous sand being allowed to fall continually in small quantities from the
hopper into the vibrating trough, it gradually passes along the whole length of
the trough over the surface of the layer of mercury contained therein; and the
extremely rapid vibrations or shocks imparted to the trough causing the mer-
cury to undulate in an exceedingly rapid and mobile manner, the sand in its
progress over it is so thoroughly shaken, that every particle or nearly every
particle of gold dust contained therein is separated by virtue of its greater
gravity, and sinks into the mercury, with which it amalgamates; moreover,
by being immersed in water, the difference of gravity between the sand and
the gold is considerably increased, and their separation is thus greatly facili-
tated. From time to time the sides of the trough are raked by the attendant,
so as to bring adhering particles of sand which may gradually creep down
beneath the mercury to the surface again. When the mercury has absorbed

page_text: a sufficient quantity of gold, the trough is tilted towards the end in which the
cock is fixed, and the mercury flows through the latter into a channel formed
in the bed of the cistern, whence it passes through an exterior cock fixed in the
same. The sand is removed by the trough being tilted in the reverse direc-
tion, when it falls into the before-mentioned box. The tilting of the trough is
effected in the following manner :-The chains by which it is suspended are
attached to beams hinged at one end and supported at the other by a rope or
chain from the barrel of a crab or crane. By winding or unwinding this rope
or chain, the trough can therefore be tilted in one direction or the other.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Eduard Claude Barbotte de Beaulieu in the Great Scal
Patent Office on the 11th June 1862.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, EDUARD
CLAUDE BARBOTTE DE BEAULIEU, of Avallon, in the Department of Yonne, in
the Empire of France, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Fourteenth day of December in the year of our
Lord One thousand eight hundred and sixty-one, in the twenty-fifth year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto
me, the said Eduard Claude Barbotte de Beaulieu, Her special licence that
I, the said Eduard Claude Barbotte de Beaulieu, my executors, administrators,
and assigns, or such others as I, the said Eduard Claude Barbotte de Beau-
lieu, 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 "IMPROVEMENTS IN APPARATUS FOR
EXTRACTING GOLD DUST FROM AURIFEROUS SANDS," upon the condition (amongst
others) that I, the said Eduard Claude Barbotte de Beaulieu, my executors
or administrators, by an instrument 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.

page_text: NOW KNOW YE, that I, the said Eduard Claude Barbotte de Beaulieu,
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 thereof, reference being had to the accom-
.panying Drawing, and to the figures and letters marked thereon (that is to
say) :-
My Invention has for its object the more complete separation of gold from
auriferous sands than has hitherto been effected by machines in present
use. As a preliminary process, I prefer to wash the sand so as to free it
from particles of clay or other soluble substances, and render it of a perfectly
loose nature, for which purpose I prefer to place it in a trough containing
water, in which a horizontal shaft provided with radial arms is caused to
revolve, and thus to stir up the sand thoroughly with the water which is
allowed to flow off with the particles of clay or other soluble substance held
in suspension whilst the auriferous sand subsides. As a further preliminary
process, I prefer to separate the larger nodules of gold from the sand by the
process of sifting, for which purpose I employ an apparatus as shewn in
Figures 1, 2, and 3 on the accompanying Drawing.
Figure 1 shews a longitudinal section; Figure 2 shews a plan with the metal
gauze removed from the sieve; and Figure 3 shews an end view of the ap-
paratus. Similar letters of reference indicate similar parts in each of the
Figures.
A cylindrical sieve A, having fine wire meshes, is placed in a sloping position
in a trough B; it has a spindle C passing down its centre, to which it is
connected by means of the framework a, a. The upper end of the spindle
rests upon the trough B, while the lower end is carried by a bracket b. At
the lower end the cylinder A is closed, with the exception of a central opening
at c, to which is attached a spout d. The upper end of the sieve is open,
and serves to admit the sand to be sifted. The sieve is partially immersed
in water contained in the trough B to the height of the spout d. A con-
necting rod D is attached by its upper end to a collar E on the spindle C
by means of a hinged joint F, whilst the lower end is connected to a
small crank G upon a horizontal spindle H, which receives a rapid rotary
motion in any suitable manner. To the end of the spindle C is also fixed in
a rigid manner the end of the jointed lever I, I, the other end of which is
connected to a pin i fixed to the trough B. By this arrangement it will be
seen that from the rotary motion of the crank G a rapid vertical vibratory
motion will be imparted to the sieve, which by reason of its attachment to the

page_text: jointed lever I will at the same time receive a slight vibratory motion round
its axis. This combined motion will cause the fine auriferous sand to be
thoroughly sifted through the sieve into the bottom of the trough, as indicated at
J, whilst the coarser sand together with the larger nodules of gold will remain in
the sieve. These, by reason of their different specific gravities, (which difference
is increased by their immersion in water) will be separated by the vibratory
motion of the seive, the gold nodules collecting at the lowest point as indicated
at K, whilst the coarse sand at L which is freed from gold will pass away through
the opening at c as it accumulates. When a considerable quantity of gold as
thus accumulated at K, the whole of the sand L is carefully removed through a
sliding door at the lower end of the sieve, after which the gold is also removed.
The fine auriferous sand at J is then also removed from the trough, and is
subjected to the operation now to be described. In Figures 4 to 9 is
shewn the construction of my improved apparatus for separating to the
greatest possible extent the fine gold dust contained in auriferous sand.
Figure 4 shows a plan of the apparatus; Figure 5 shews a sectional plan
on line X, X; Figure 6 shews a longitudinal section; Figures 7 and 8 are end
views; and Figure 9 is an enlarged transverse section through the vibrating
trough. Similar letters of reference indicate similar parts in all these Figures.
A narrow long trough or tray of strong sheet metal A, the rim of which is
strengthened round three sides by a bar of metal a seen in transverse section,
Figure 9, is suspended from the beams B, B, by the chains C, C, C, on either
side of the trough, which chains are attached to the cross bars D, D, D,
running underneath and supporting the trough A. This trough is suspended
inside a cistern E, filled with water up to the dotted line b, which water is by
preference maintained at a temperature of about 212 degrees Fahrenheit by
any suitable means. The cistern is deepened at E' beyond the end of the
trough A, and in this part is placed a box F of sheet metal or other suitable
material. The end of the trough A just above this box is only closed to a part
of its height, and at the edge is formed a wide spout G projecting over the side
of the box F, at the other end the trough is provided externally close to its
bottom surface with a cock H, and immediately above this end is hung the
hopper I through which the auriferous sand is introduced into the trough. The
front of this hopper is provided with a sliding door C, to regulate the quantity
of sand passing into the trough; the hopper hangs upon pivots d, d, attached to
the beams B, B, and is supported at the back by resting with a shoulder e,
upon a fixed block J. When the apparatus is in operation a rapid vibrating
motion is imparted to this hopper as also to the trough A in the following

page_text: manner: A bell crank lever K, baving a fixed fulcrum at f, is attached by its
short arm k, (which is constructed so as to be elastic) to a forked rod L fixed
to the trough A whilst the long arm of the lever is acted upon by a series of
cams or tappets attached to a revolving shaft not shown on the Drawing. At
the point of the arm of the lever is also hinged a rod M, the other end
of which is attached to the shoulder e of the hopper. The end of the arm k¹
of the lever K being caused to rise and fall rapidly by the action of the before-
mentioned cam shaft, a rapid horizontal vibrating motion is imparted to the
end of the arm k, and consequently also to the trough A, whilst by the rod M
the hopper I receives a slight vertical vibrating motion, which facilitates the
passage of the sand from the same into the trough A. In order to render the
vibrating motion of the trough still more effective and to limit the extent of
the same, fixed stops T, T, T', T', are placed at such distances from each
end of the trough that at the end of each motion forward or backward, it
comes in contact with the stops with sufficient force to cause a certain
concussion.
In commencing operations with this apparatus such a quantity of mercury
is, in the first instance, poured into the trough as to form a thin layer over the
whole surface, as shown at N in Figures 6 and 9. The auriferous sand is
then admitted in small quantities from the hopper I, and the before-described
vibratory motion is imparted to the trough; by this motion the surface of the
mercury is broken up into small ripplets undulating with great rapidity. This
peculiar motion is imparted to the sand floating upon its surface, and to the
water situated over the sand, and as the sand passes slowly along the entire
length of the trough it is so thoroughly shaken by the motion of the mercury
and the water and brought into contact with the mercury that the whole of
the fine gold dust is, by reason of its gravity and affinity for the mercury, pre-
cipitated into and amalgamated with the same, and when a sufficient quantity
of sand has passed into the trough to fill it up to the top of the spout G, as
shewn at O, Fig. 6, then the sand which has been subjected to the above-
described operation, and has eventually arrived at the spout G deprived more
or less completely of the whole of the gold dust, will pass over the same into
the box F, where it will accumulate as the operation continues, and whence
it is removed at pleasure by means of a crane, or in any other suitable
manner. The separation of the gold dust from the sand will take place all
the more readily, inasmuch as the immersion in water increases the difference
between the specific gravities of the gold and sand from the proportion of
8 to 1 to that of 12 to 1, or by about one-third. When the mercury N has

page_text: absorbed a sufficient quantity of gold dust by the before-described operation,
the supply of fresh sand from the hoppers is stopped, and the mercury is
removed in the following manner:-The beams B, B, rest with one end on
the support P, and at the other end are suspended by chains Q, Q, from the
barrel of a crab or crane, not shewn on the Drawing. When it is desired to
remove the mercury the chains Q, Q, are lowered, by which the trough A is
made to tilt backwards towards the cock II, the mercury being thereby caused
to collect at this end. The cock H is then opened and the mercury passes
out to the bottom of the cistern E; this is formed with an incline at this end,
as shown, leading towards the channel R, through which the mercury passes
out of the cistern into any suitable receptacle. The sand contained in the
trough is then removed into the box F by raising the chains Q, Q, and tilting
the trough forward. During the before-described operation of extracting the
gold dust from the sand, it will be requisite from time to time to rake the
sides and bottom of the trough below the mercury in order bring to its
surface particles of sand that are apt to creep gradually down adhering to the
surface of the trough.
It will be evident that in my improved process the action upon the sand
may be continued at pleasure during any length of time, as its exit from the
trough A into the box F is entirely dependant on the quantity admitted from
the hopper. As the water in the cistern has no other motion beyond that
imparted to it by the vibrations of the trough, there is no liability of any of
the gold dust being washed away, as is the case in apparatus in present use
where a flow of water is employed to cause the sand to pass from the
surface of one bed of mercury in a quiescent state to that of another situated
below it.
Having now described the nature of my Invention, and in what manner
the same is to be performed, I wish it to be understood that I do not
limit myself to the exact form or proportions of the various details of my
improved apparatus as shown on the accompanying Drawing, as they may be
variously modified without departing from the nature of my Invention; nor
do I claim the preparatory processes of washing the sand and sifting the same
in cylindrical sieves, as herein-before described; but what I claim under the
before in part recited Letters Patent, is,-
Firstly, the arrangement by which the peculiar duplex vibrating motion is
imparted to cylindrical sieves, as herein-before described with reference to.
Figures 1, 2, and 3 on the accompanying Drawing.
Secondly, the construction of apparatus for separating the gold dust from

page_text: auriferous sands, in which the sand is caused to pass slowly along on the
surface of a bed of mercury to which a rapid vibrating or undulating motion
is imparted, which motion being communicated to the sand causes the gold
dust contained in the same to be separated from it by reason of its greater
specific gravity, and to be precipitated into the bed of mercury, substantially as
herein-before described with reference to Figures 4 to 9 on the accompanying
Drawing.
In witness whereof, I, the said Eduard Claude Barbotte de Beaulieu,
have hereunto set my hand and seal this Twenty-sixth day of May, in
the year of our Lord One thousand eight hundred and sixty-two.
E. C. BARBOTTE DE BEAULIEU. (L.S.)