AN IMPROVED PROCESS AND APPARATUS FOR CONCENTRATING ORES OR TAILINGS, OR SEPARATING PULVERIZED MINERAL SUBSTANCES OF DIFFERENT KINDS OR QUALITIES FROM EACH OTHER
Year: 1861

page_text: of "AN IMPROVED PROCESS AND APPARATUS FOR CONCENTRATING ORES OR
TAILINGS, OR SEPARATING PULVERIZED MINERAL SUBSTANCES OF DIFFERENT
KINDS OR QUALITIES FROM EACH OTHER."-A communication from abroad
by Henry Eberhard Roeder, of No. 363, Broadway, New York, in the
United States of America.
PROVISIONAL SPECIFICATION left by the said Benjamin Browne at the
Office of the Commissioners of Patents, with his Petition, on the 28th
August 1861.
I, BENJAMIN BROWNE, of No. 52, King William Street, in the City of
London, Civil Engineer and Patent Agent, do hereby declare the nature of
the said Invention for "AN IMPROVED PROCESS AND APPARATUS FOR CONCENTRATING
ORES OR TAILINGS, OR SEPARATING PULVERIZED MINERAL SUBSTANCES OF DIFFERENT
KINDS OF QUALITIES FROM EACH OTHER," (a communication) to be as follows:-
This Invention consists in first agitating pulverized ore or minerals in a
quantity of water or fluid, and then allowing the same to fall while in this
state of agitation into a lower vessel, or a lower apartment of the vessel by
its relative specific gravity, whereby a separation of the different particles is

page_text: obtained. For this purpose I employ a deep vessel or vessels filled with water
or any other suitable fluid, in the upper part of which the pulverized minerals
are first agitated, until all the particles are mechanically suspended in the fluid,
when by the sudden opening of suitable doors or valves the agitated minerals
are allowed to subside into the water or fluid in the lower part of said
vessel, whereby the law of gravity and in exact proportion to the specific
gravity of each substance, the soveral particles of the pulverized minerals will
arrive at the bottom in regular layers. Those particles containing precious
metals, and consequently the most valuable, having a greater specific gravity,
will form the lowest layer, while those of less value and less specific gravity,
such as earthy particles, form the upper layer.
The apparatus above mentioned consists of a vessel filled with water, or any
other suitable liquid. This vessel is made of such a beight as may be required
to give sufficient time and velocity for the different particles to arrive in
regular order at the bottom. About eight feet from the top end doors are
arranged, hinged in the middle to a bar, said doors are perforated and covered
with very fine wire cloth, and have chains or cords attached fastened to a
roller, whereby said doors may be opened or shut as may be desired. The top
part of the aforesaid vessel is provided with a piston connected to one end of a
lever, the other end of which is provided with a weight to counterbalance the
piston. The aforesaid lever is attached to a shaft turning in suitable bearings
in a frame, another lever is attached to said shaft to give a vibrating motion
to the first-mentioned lever, and, consequently, a corresponding up-and-down
motion to the piston. This piston is provided with one or more valves opening
outwards. A pipe is connected with the aforesaid vessel some distance below
the perforated doors, said pipe being provided with a self-acting valve opening
inwards, or towards the inside of the aforesaid vessel, and near the bottom of
the said vessel, a large door is arranged, for the purpose of taking out a
receiving vessel with a perforated bottom, for the purpose of facilitating the
operation, and to save time between each operation. A perforated bottom
may likewise be placed into the lower part of the vessel some distance above
the solid bottom, upon which the minerals may be precipitated. The per-
forated bottom in the vessel, or in the receiving vessel, as well as the perforated
doors, must be covered with fine wire cloth, so as to prevent the minerals
falling through the same, but at the same time to allow air to pass through
Between the perforated bottom of the aforesaid receiving vessel, or of the first-
mentioned vessel and the solid bottom of this vessel, a pipe is made to enter
and provided with a self-acting valve opening towards the inside of this said
vessel. Above the door before mentioned a valve or slide is arranged for

page_text: shutting off the column of water above said valve or slide, while the pre-
cipitated minerals in this bottom of this said vessel or of the receiving vessel
containing the same are removed. The manner of operating is as follows:-
The pulverized ore or minerals before they are to be operated on must first be
passed through several sieves of different textures, or separated by some other
known process, so as to obtain all the particles of the pulverized minerals for
one operation as nearly as possible of the same size. The first-mentioned
vessel is then filled with water, or any other suitable fluid some distance above
the doors thereof, which are then shut. The pulverized and sieved ore or
minerals are then thrown upon the said doors, either through the valve in the
piston, or through any other opening, which must afterwards be tightly closed.
The piston is then put in motion, by which a vacuum will be produced during
the upward motion of the piston above the body of water, and the minerals
situated upon the doors aforesaid. The production of this vacuum above the
water or fluid and minerals will cause air to enter through certain pipes,
and after passing through the water will force itself upwards through the
minerals upon the doors aforesaid, at the same time forcing the same upwards.
By the return stroke or downward motion of the piston the valve in the piston
will open, so as to allow the air to escape, while at the same time the valves
in the aforesaid pipes will be closed by the pressure of the water against the
same, and prevent any further introduction of air. The ore or minerals being
therefore during this downward motion of the piston relieved from the agitating
action of the air, will sink down again upon the doors aforesaid.
This
agitation of the minerals, or forcing the same upwards by a current or jets of
air, will be repeated by each upward stroke of the piston, while the precipitation
of the same will happen by each downward motion of said piston. By this
repeated agitation of the ore or minerals the different particles thereof will be
separated and thoroughly mixed with the water or fluid, so as to produce as
much as possible a mechanical mixture of every particle of the ore or minerals
separately with the water, whilst by the repeated precipitations the lightest
particles and those of the least specific gravity will soon come uppermost.
When this operation has been continued for some time, and while the ore or
minerals are still being agitated, the doors aforesaid are suddenly opened, by
which the ore or minerals will sink into the body of water or fluid in the lower
part of the vessel aforesaid. The pipe is then closed, so as to prevent any
further introduction of air. The separate particles, which, as above stated,
have been sieved, and are, consequently, as near as possible all of the same
size, and which by the above-mentioned operation have been separately mixed
with the water or fluid, begin to sink into this lower body of fluid at a velocity

page_text: proportionate to their respective different specific gravities. To retard this
precipitation a little, and at the same time to ensure a perfect separation of
the different particles from each other, the motion of the piston is continued
for some time after the doors have been opened, whereby air is still caused to
enter through the pipe, thereby meeting the different particles of minerals,
and retarding particularly the lighter particles in their precipitation, thereby
ensuring a more distinct separation of the particles. The motion of the piston
is then stopped, whereby the current of air through the pipe ceases, and the
minerals are allowed quietly to settle and collect in the bottom of the vessel
or in the receiving vessel; when the precipitation is completed the valve is
closed, whereby the column or body of water or fluid above said valve is shut
off from the lower part, and the door aforesaid is then opened to take out the
ore or minerals, or to withdraw the vessel containing the same, and replace it
by an empty one. The door is then again closed, the valve or slide opened,
the vessel replenished with water or fluid ready to repeat the above-described
operation. As above mentioned, the minerals are for each operation, on
account of their being sieved or otherwise separated, all of exactly the same
size or magnitude, in consequence of which during their precipitation, those
which contain any quantity of precious metals will, in consequence of their
greater specific gravity, arrive sooner at the bottom than those which contain
a less quantity, or different metals, and which are lighter. The lowest layer
will, therefore, consist of those particles containing gold, silver, lead, while the
layer above will consist of particles containing iron, copper, zinc, and the
earthy particles will form the top layer; or, in other words, the valuable
minerals will be concentrated into the lowest layer by this mode of operation,
and can easily be separated from the less valuable minerals and earthy
substances.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Benjamin Browne in the Great Seal Patent Office on the
28th February 1862.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, BENJAMIN
BROWNE, of No. 52, King William Street, in the City of London, Civil
Engineer and Patent Agent, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-eighth day of August, in the year of our Lord
One thousand eight hundred and sixty-one, in the twenty-fifth year of Iler

page_text: reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said Benjamin Browne, Her special licence that I, the said Benjamin
Browne, executors, administrators, and assigns, or such others as I, the said
Benjamin Browne, my executors, administrators, and assigns, should at any
time agree with, and no others, from time to time and at all times there-
after 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 "AN
IMPROVED PROCESS AND APPARATUS FOR CONCENTRATING ORES OR TAILINGS, OR SEPA-
RATING PULVERIZED MINERAL SUBSTANCES OF DIFFERENT KINDS OR QUALITIES FROM
EACH OTHER," (a communication to me from abroad by Henry Eberhard Roeder,
of No. 363, Broadway, New York, in the United States of America, Engineer,)
upon the condition (amongst others) that I, the said Benjamin Browne,
my executors or administrators, by an instrument in writing under my, or
their, or one of their hands and seals, should particularly describe and ascer-
tain 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 Benjamin Browne, do hereby declare
the nature of my said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement, that is to say :-
This Invention consists in first agitating pulverized ore or minerals in a
quantity of water or fluid, and then allowing the same to fall while in this
state of agitation into a lower vessel or a lower apartment of the vessel by its
relative specific gravity, whereby a separation of the different particles is
obtained. For this purpose I employ a deep vessel or vessels fitted with water
or any other suitable fluid, in the upper part of which the pulverized minerals
are first agitated until all the particles are mechanically suspended in the fluid,
when by the sudden opening of suitable doors or valves the agitated minerals
are allowed to subside into the water or fluid in the lower part of said
vessel, whereby the law of gravity, and in exact proportion to the specific
gravity of each substance, the several particles of the pulverized minerals will
arrive at the bottom in regular layers. These particles containing precious
metals, and consequently the most valuable, having a greater specific gravity,
will form the lowest layer, while those of less value and less specific gravity,
such as earthy particles, form the upper layer.
The apparatus above mentioned consists of a vessel filled with water or any.

page_text: other suitable liquid. This vessel is made of such a height as may be required
to give sufficient time and velocity for the different particles to arrive in
regular order at the bottom. About eight feet from the top end doors are arranged
hinged in the middle to a bar, said doors are perforated and covered with very
fine wire cloth, and have chains or cords attached fastened to a roller, whereby
said doors may be opened or shut, as may be desired. The top part of the
aforesaid vessel is provided with a piston connected to one end of a lever, the
other end of which is provided with a weight to counterbalance the piston.
The aforesaid lever is attached to a shaft turning in suitable bearings in a
frame; another lever is attached to said shaft to give a vibrating motion to
the first-mentioned lever, and consequently a corresponding up-and-down
motion to the piston. This piston is provided with one or more valves opening
outwards; a pipe is connected with the aforesaid vessel some distance below
the perforated doors, said pipe being provided with a self-acting valve opening
inwards or towards the inside of the aforesaid vessel; and near the bottom of
the said vessel a large door is arranged for the purpose of taking out a
receiving vessel with a perforated bottom for the purpose of facilitating the
operation, and to save time between each operation. A perforated bottom may
likewise be placed into the lower part of the vessel some distance above the
solid bottom upon which the minerals may be precipitated. The perforated
bottom in the vessel or in the receiving vessel, as well as the perforated doors,
must be covered with fine wire cloth, so as to prevent the minerals falling
through the same, but at the same time to allow air to pass through. Between
the perforated bottom of the aforesaid receiving vessel, or of the first mentioned
vessel and the solid bottom of this vessel, a pipe is made to entor, and provided
with a self-acting valve opening towards the inside of this said vessel. Above
the door, before mentioned, a valve or slide is arranged for shutting off the
column of water above said valve or slide while the precipitated minerals in
the bottom of this said vessel, or of the receiving vessel containing the same,
are removed. The manner of operating is as follows:-The pulverized ore or
minerals before they are to be operated on, must first be passed through
several sieves of different textures, or separated by some other known process,
so as to obtain all the particles of the pulverized minerals for one operation as
nearly as possible of the same size. The first-mentioned vessel is then filled
with water or any other suitable fluid some distance above the doors thereof,
which are then shut. The pulverized and sieved ore or minerals are then
thrown upon the said doors, either through the valve in the piston or through
any other opening, which must afterwards be tightly closed. The piston is
then put in motion, by which a vacuum will be produced during the upward

page_text: motion of the piston above the body of water and the minerals situated upon
the doors aforesaid. The production of this vacuum above the water or fluid
and minerals will cause air to enter through certain pipes, and after passing
through the water will force itself upwards through the minerals upon the
doors aforesaid, at the same time forcing the same upwards by the return
stroke or downward motion of the piston, the valve in the piston will open so
as to allow the air to escape, while at the same time the valves in the afore-
said pipes will be closed by the pressure of the water against the same, and
prevent any further introduction of air. The ore or minerals being therefore
during this downward motion of the piston relieved from the agitating action
of the air will sink down again upon the doors aforesaid. This agitation of the
minerals, or forcing the same upwards by a current or jets of air, will be
repeated by each upward stroke of the piston, while the precipitation of the
same will happen by each downward motion of said piston. By this repeated
agitation of the ore or minerals the different particles thereof will be sepa-
rated and thoroughly mixed with the water or fluid, so as to produce as much
as possible a mechanical mixture of every particle of the ore or minerals
separately with the water, whilst by the repeated precipitations the lightest
particles, and those of the least specific gravity, will soon come uppermost.
When this operation has been continued for some time, and while the ore or
minerals are still being agitated, the doors aforesaid are suddenly opened, by
which the ore or minerals will sink into the body of water or fluid in the lower
part of the vessel aforesaid; the pipe is then closed, so as to prevent any
further introduction of air. The separate particles which, as above stated,
have been sieved, and are consequently as near as possible all of the same
size, and which by the above-mentioned operation have been separately mixed
with the water or fluid, begin to sink into this lower body of fluid at a velocity
proportionate to their respective different specific gravities. To retard this
precipitation a little, and at the same time to ensure a perfect separation of
the different particles from each other, the motion of the piston is continued
for some time after the doors have been opened, whereby air is still caused to
enter through the pipe, thereby meeting the different particles of minerals, and
retarding particularly the lighter particles in their precipitation, thereby ensur-
ing a more distinct separation of the particles. The motion of the piston is
then stopped, whereby the current of air through the pipe ceases, and the
minerals are allowed quietly to settle and collect in the bottom of the vessel
or in the receiving vessel. When the precipitation is completed the valve is
closed, whereby the column or body of water or fluid above said valve is shut
off from the lower part, and the door aforesaid is then opened to take out the

page_text: ore or minerals, or to withdraw the vessel containing the same, and replace it
by an empty one. The door is then again closed, the valve or slide opened,
the vessel replenished with water or fluid ready to repeat the above-described
operation. above mentioned, the minerals are for each operation, on
account of their being sieved or otherwise separated, all of exactly the same
size or magnitude, in consequence of which during their precipitation those
which contain any quantity of precious metal will, in consequence of their greater
specific gravity, arrive sooner at the bottom than those which contain a less
quantity or different metals, and which are lighter. The lowest layer will
therefore consist of those particles containing gold, silver, lead, while the
layer above will consist of particles containing iron, copper, zinc, and the
earthy particles will form the top layer, or in other words, the valuable
minerals will be concentrated into the lowest layer by this mode of operation,
and can easily be separated from the less valuable minerals and earthy
substances.
In order to explain this Invention as completely as possible, I now proceed
to describe the best means I am acquainted with for carrying the same into
practical effect, reference being had to the illustrative Sheet of Drawings
hereunto annexed, and to the numeral figures and lotters of reference marked
thereon respectively, as follows:-
DESCRIPTION OF THE DRAWING.
In Figure 1, A represents, in section, a vessel filled with water or any other
suitable liquid; this vessel is made from fifteen to twenty feet or more in
height, or of such a height as may be required to give sufficient time and
velocity for the different particles to arrive in regular order at the bottom.
About eight feet from the top end, doors B are arranged, hinged in the middle
to a bar S; these doors are perforated and covered with very fine wire cloth,
and have chains or cords n attached, fastened to a roller C, whereby said doors
may be opened or shut as may be desired. The top part of the vessel A is
provided with a piston D, connected through the rod E to one end of a lever F;
the other end of this lever F is provided with a weight G to counterbalance said
piston D. This lever F is attached to a shaft H turning in suitable bearings in
the frame J. A lever K is attached to said shaft II to give a vibrating motion
to the levor F, and consequently a corresponding up-and-down motion to the
piston D; this piston is provided with one or more valves P opening out-
wards. L is a pipe connected with the vessel A some distance below the
perforated doors B, and provided with a self-acting valve m opening inwards
or towards the inside of the vessel A; near the bottom of the vessel A, a large

page_text: door M is arranged for the purpose of taking out the receiving vessel N.
This receiving vessel N is made with a perforated bottom covered over with
very fine wire cloth, and is for the purpose of facilitating the operation, and to
save time between each operation. A perforated bottom may likewise be
placed into the lower part of the vessel A, some distance above the solid
bottom x, upon which the minerals may be precipitated. The perforated
bottom in the vessel A, or in the receiving vessel N, as well as the perforated
doors B, must be covered with fine wire cloth, so as to prevent the minerals
falling through the same, but at the same time to allow air to pass through.
Between the perforated bottom of the receiving vessel N or of the vessel A
and the solid bottom of the vessel A, a pipe O is made to enter, constructed
similar to the pipe L, and provided with a self-acting valve w opening towards
the inside of the vessel A. Above the door M a valve or slide R is
arranged in such a manner, that by the same the column of water above said
valve or slide can be shut off, while the precipitated minerals in the bottom of
the vessel A, or the receiving vessel N containing the same, are removed,
saving thereby the necessity of refilling the vessel A after each operation. By
the introduction of the receiving vessel N, considerable time will be saved by
each operation, as after each precipitation this box or vessel N can easily and
in a very short time be removed and replaced by an empty box. The
manner of operating is as follows:-The pulverized ore or minerals, before
they are to be operated on, must first be passed through several sieves of
different textures, or separated by some other known proces, so as to obtain
all particles of the pulverized minerals for one operation as much alike in
size and magnitude as possible. The vessel A is then filled with water or any
other suitable fluid same distance above the doors B, which latter are then
shut by means of the shaft C operating the chains n attached to the said
doors. The pulverized and sieved ore or minerals are then thrown upon the
doors B either through the valve P in the piston D, or through any other
opening, which latter must then be closed up tight. The piston D is then put
in motion, by which means a vacuum will be produced during the upwards
motion of the piston above the body of water and the minerals situated upon
the doors B. The production of this vacuum above the water or fluid and
minerals will cause air to enter through the pipes L and O, which, after
passing through the water, will force itself upwards through the minerals upon
the door B, at the same time forcing the same upwards. By the return stroke
or downward motion of the piston, the valve P in the piston D will open so
as to allow the air to escape, while at the same time the valvesim and w in
the pipes L and O will be closed by the pressure of the water against the

page_text: most.
The ore or minerals being
piston, relieved from the
same, and prevent any further introduction of air.
therefore, during this downward motion of the
agitating action of the air, will sink down again upon the doors B. This
agitation of the minerals, or forcing the same upwards by a current or jets of
air, will be repeated by each upward stroke of the piston, while the precipi-
tation of the same will happen by each downward motion of said piston. By
this repeated agitation of the ore or minerals, the different particles of the
same are separated and thoroughly mixed with the water or fluid so as to
produce as much as possible a mechanical mixture of every particle of the ore
or minerals separately with the water, while by the repeated precipitations the
lightest particles and those of the least specific gravity will soon come upper-
When this operation has been continued some time, but while the ore
or minerals are still being agitated, the doors B are suddenly opened, whereby
the ore or minerals will sink into the body of water or fluid in the lower part
of the vessel A. The pipe L is then closed so as to prevent any further
introduction of air through the same. The separato particles which, as above
stated, have been sieved, and are consequently as near as possible all of the
same size or magnitude, and which, by the above-mentioned operation, have
been separately mixed with the water or fluid, begin to sink into this lower
body of fluid at a velocity exactly in proportion to their respective different
specific gravity. To retard this precipitation a little, and at the same time to
ensure a perfect separation of the different particles from each other, the
motion of the piston is continued for some time after the doors have been
opened, whereby air is still caused to enter through the pipe O, meeting the
different particles of minerals, and retarding particularly the lighter particles
in their precipitation, ensuring thereby a more distinct separation. The motion
of the piston is then stopped, whereby the current of air through the pipe O
censes, and the minerals are allowed quietly to settle and collect in the bottom
of the vessel A, or in the receiving vessel N. When the precipitation is
completed the valve R is closed, whereby the column or body of water or fluid
above said valve is shut off from the lower part, and the door M is then opened
to take out the ore or minerals, or to withdraw the vessel N containing the
same, and replace an empty box. The door M is then again closed, the valvo
or slide R opened, the vessel A replenished with water or fluid, when the
abovo described operation can be repented. As above mentioued, the minerals
are for each operation on account of their being sioved or otherwise separated
all of exactly the same size or magnitude, in consequence of which, during their
precipitation, those which contain any quantity of precious metal will, in
consequence of their greater specific gravity, arrive sooner at the bottom than

page_text: those which contain a less quantity or different metals, and which are lighter.
The lowest layer will therefore consist of those particles containing gold,
silver, and lead, while the layer above will consist of particles containing iron,
copper, and zinc, and the earthy particles will form the top layer, or, in other
words, the valuable minerals will be concentrated into the lowest layer by this
mode of operation, and can easily be separated from the less valuable minerals
and earthy substances. Instead of making a piston to work in the upper part
of the vessel A to produce a vacuum in the manner and for the purpose above
described, a cylinder or box Q may be fitted into the upper end of the vessel A,
Figure 2, the bottom of which consists of perforated doors B', hinged in the
middle, and supported and operated by chains n¹, as above described. This
inner cylinder or box is provided with suitable packing to make the same
work air-tight in the vessel A, and is connected to a beam F', through which
the same is moved upwards and downwards in the vessel A, similar to a piston.
The vessel A is filled with water or fluid until the same stands some distance
above the doors B¹, when the pulverized ore or minerals are thrown upon said
doors B'. The minerals being very finely pulverized, will form a solid body
upon the doors, preventing the water above the same passing through when
the cylinder Q is moved upwards, forming thereby the equivalent of a solid
piston, which produces thereby by each upward motion of said cylinder Q, a
vacuum below the minerals situated in the bottom of the cylinder Q upon
the doors B. This vacuum thus formed will cause the air to flow in through
the pipe L', filling up the vacuum space between the top of the fluid and the
under side of the doors B¹ or cylinder Q. When the cylinder moves down-
wards, the valve m³ in the pipe L' closes, and the air situated then between
the bottom of said cylinder and the body of water or fluid will be forced
through the perforated doors B', and the ore or minerals forcing the same
upwards, and producing thereby the same result as above mentioned; when
the cylinder moves upwards again the minerals will fall back upon the doors,
forming again the equivalent of a solid piston necessary for the production of
the required vacuum. By the repeated up-and-down motion of this cylinder,
a current of air will be made to pass through the minerals by each downward
motion of the cylinder, agitating and mixing thereby the ore or minerals
thoroughly with the water or fluid, after which the thus agitated minerals are
allowed to subside into the body of water or fluid by the opening of the
doors B¹ according to their specific gravity, and by which the heavier and
more valuable particles are separated from the lighter particles or those of less
value, and fall in different layers upon the bottom. Instead of producing a
vacuum above the ore, as represented in Figure 1, or below the ore, as shewn

page_text: same.
by the plan represented in Figure 2, for the purpose of causing thereby a
current or jets of air through the minerals, so as to agitate the same with the
water or fluid, an air pump may be attached below the doors B, and air forced
into the vessel below said doors at short intervals, which, while forcing itself
through the ore or minerals, will agitate the same in a manner similar as
above described. Instead of operating the ore as above mentioned, by causing
a current of air to pass through the same, the vessel A may be arranged with
solid doors V (see Figure 3) in the upper part of said vessel, hinged on the
centre, and operated by chains for the purpose of opening or shutting the
Above these solid doors V an upright shaft is then arranged, provided
with arms, wings, or a spiral screw W, and made to revolve by means of
gearing X or any other suitable contrivance. The vessel A being filled with
fluid or water up to a certain height above the doors V and above the screw W,
the doors V are then closed, and the pulverized oro or minerals are thrown upon
the same when the shaft with its arms, wings, or screw is set in motion. The
inotion of the arms, wings, or screws will produce a continual agitation of the
body of the water or fluid above the doors V and of the minerals, mixing the same
thoroughly together, so as to produce as much as possible a mechanical sus-
pension of every particle of the minerals separately in the water. The doors V
are then opened, and the minerals allowed to sink into the body of water
bolow, according to their specific gravity, as above described and mentioned.
In the above-described operation the precipitated ore or minerals are after each
operation or precipitation removed from the machine. With some description
of minerals tho earthy substances which, as above mentioned, form the upper
layer, will, after the precipitation is complete, be found sufficiently strong and
compact to allow of two or more precipitations to be made upon the already
precipitated minerals without danger that the lower and most valuable layer of
the next precipitation will, on account of its weight, sink into or mix with the
upper layer of the before precipitated minerals. In this case the valve or
slide R, and the receiving vessel N, are dispensed with, as well as the pipe O
and doors U, U, and other parts are provided, one above the other, for nearly
the whole height of the lower part of the vessel A (see Figure 2), for the
purpose of taking out the thus precipitated ore or minerals. If several
precipitations are made in this manner one upon the other, the ore which is
the coarsest should first be operated with, then with the next finer ore, and last
with the finest, as the coarser the ore is the greater height will be required for
the different particles to fall, so as to obtain a distinct separation of the heavier
from the lighter, and consequently of the valuable from the valueless particles
of the minerals.

page_text: What I claim as of this Invention, and desire to secure by Letters
Patent, is,
-
First, the process of separating pulverized mineral substances from one
another by agitating them in a body of water or other fluid, and while in such
agitated state deliver the mixture into a lower body of water or fluid, through
which the particles of minerals sink with a velocity according to their specific
gravity, and by which the heavier are separated from the lighter, and fall
accordingly in different layers upon the bottom, substantially as described and
specified.
Second, I claim producing such agitation by passing currents or jets of air
through the minerals and the body of water or other fluid containing the
minerals substantially as above described.
Third, I claim retarding the descent of the particles of minerals by passing
jets or currents of air in an opposite direction through the fluid through which
the minerals sink, substantially as described, the lighter particles being more
retarded thereby than the heavier particles.
In witness whereof, I, the said Benjamin Browne, have hereunto set my
hand and seal, this Twenty-eighth day of February, in the year of our
Lord One thousand eight hundred and sixty-two.
BENJ. BROWNE. (L.S.)