IMPROVEMENTS IN SEPARATING SUBSTANCES OF DIFFERENT SPECIFIC GRAVITIES
Year: 1855

page_text: LETTERS PATENT to Alfred Vincent Newton, of the Office for Patents,
1:
66, Chancery Lane, in, the County of Middlesex, Mechanical Draughts-
man, for the Invention of "IMPROVEMENTS IN SEPARATING SUBSTANCES OF
DIFFERENT SPECIFIC GRAVITIES."-A Communication.
**
Sealed the 26th October 1855, and dated, the 27th August 1855.
PROVISIONAL SPECIFICATION left by the said Alfred Vincent Newton at
the Office of the Commissioners of Patents, with his Petition,, on the
27th August 1855.
I; ALFRED VINCENT NEWTON, of the Office for Patents,-66, Chancery Lane,
in the County of Middlesex, Mechanical Draughtsman, do hereby declare the
nature of the said Invention, for "IMPROVEMENTS IN SEPARATING SUBSTANCES OF
DIFFERENT SPECIFIC GRAVITIES" to be as follows:-
This Invention relates to the employment of what may be termed a grain
separator, for separating the grains of gold and other precious metal from the
earthy substances or crushed gangue, preparatory to and in combination with
a crushing mill, the separator acting as a hopper to the crushing mill. The
substances to be crushed are conducted by a feeding tube below the surface of

page_text: a column of water in the crushing mill, the object being to run off the fine
particles of the substance under operation into an amalgamator.
The crushing mill consists of one or more heavy wheels, running vertically
on their own axis, and revolving about a vertical shaft within a vessel, which
receives a column of water of sufficient depth to cover the wheels. This vessel
is provided with a discharge above the wheels, and at a higher level than that
at which the feeder supplies the vessel with the substances to be crushed.
Connected with the mill is an amalgamator, coutaining mercury at the
bottom (presenting an unbroken surface), and a column of water above the
mercury.
The substances containing the metallic particles are supplied below the
surface of the water, which is continually agitated, that the lighter substances
may be carried upward by the current or currents induced by the agitators
and discharged at top, whilst the metallic particles are permitted to subside,
and to be carried by gravity to the mercury below, where the amalgamation
takes place.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Alfred Vincent Newton in the Great Seal Patent Office on
the 27th February 1856.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ALFRED
VINCENT NEWTON, of the Office for Patents, 66, Chancery Lane, in the County
of Middlesex, Mechanical Draughtsman, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-seventh day of August, in the year of our
Lord One thousand eight hundred and fifty-five, in the nineteenth year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto
me, the said Alfred Vincent Newton, Her special licence that I, the said
Alfred Vincent Newton, my executors, administrators, and assigns, or such
others as I, the said Alfred Vincent Newton, 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 SEPARATING SUBSTANCES OF DIFFERENT SPECIFIC
GRAVITIES," being a communication from abroad, upon the condition (amongst
others) that I, the said Alfred Vincent Newton, by an instrument in writing

page_text: under my hand and seal, 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.
NOW KNOW YE, that I, the said Alfred Vincent Newton, 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, reference being had to the Drawing hereunto annexed,
and to the letters and figures marked thereon (that is to say):-
This Invention relates to the employment of a novel construction of
apparatus for separating gold and other precious metals from foreign
substances.
In the accompanying Drawing, Fig. 1 represents, in longitudinal section, the
improved apparatus for separating gold, silver, &c. as arranged for use, and
consisting of a "grain separator," for separating gold, silver, &c. from the
previously crushed ores or earthy matters; a wet mill (shewn in sectional plan
at Fig. 2) for grinding the latter under water after the grains of gold or other
precious metals have been separated; and an amalgamator, for extracting the
fine dust of the precious metals thus liberated; these parts being combined
together, and each essential to the others.
.
A is a strong iron vessel with a flat bottom, and capable of holding a
large body of water and the heavy wheels used for grinding. It is sup-
ported at a convenient height by four legs, and surmounted by two pillars,
which support the cross head a, and the machinery suitable for giving
motion to the shafts band k. B, B, Figures 2, are two solid cast-iron
wheels, running vertically under water, and which revolve on their own
axis and around the shaft 6 upon a thick plate of chilled iron c resting
upon the bottom of the vessel A. For the convenience of removing or
cleaning this iron plate, and to prevent waste of iron, it is made to corre-
spond in size to the circle formed by the rotation of the wheels around
the shaft b, and the intermediate spaces are filled with wood or cement
to the height of the iron plate, so as to form a surface level with the
cock d. The axle of these wheels B, B, is made to fit loosely on the shaft
and key, so as to rise up when necessary, and is made to turn with the
shaft by means of the key or feather which is firmly attached to the shaft.
C is an iron pan or hopper to the mill A, and serves to separate the metallic
grain from the previously crushed ore or earthy matters which are supplied to
the apparatus. This hopper or grain separator is supported by arms e, which

page_text: rest upon the upper rim of the vessel A, and keep the hopper stationary by its
own weight. At the bottom of this hopper is a large tube r, through which
the shaft b passes, leaving a space between the tube and shaft for conduct-
ing the earthy matters into and under the surface of the water. This tube
extends above the bottom of the pan, which is inclined upward for a short
distance to form the connection with the upper edge of the tube thus
elevated above the bottom of the pan. D is a round iron plate within the
hopper C, with a socket and thumb screw at the top, by which it is attached
to and revolves with the shaft b, and is supplied with a number of teeth
on the lower side, nearly touching .the bottom of the stationary pan C.
G is a flat scraper, of wood or iron, with bevilled edges, and keyed to the
bottom of the shaft b, its object being to keep the centre of the mill clear,
and conduct the earthy matters which fall to the bottom' under the wheels
B, B; it is also used for cleaning the mill, the cock d being then open
and the shaft kept in motion. E is a semicircular iron vessel, capable of
holding a large body of water, and supported by the framework f,f, at a
convenient height to receive the overflow from the mill A, which passes
through the pipe m into the pan H, which is in the centre of the vessel E.
F, F, are two paddle or water wheels, with solid sides; hollow axles, and
furnished each with wooden or iron paddles h. Fig. 3 shows the position of
these paddles as inserted into the solid sides of the wheels F. These wheels
revolve vertically under water on their own axes and around the shaft k, to
which they are firmly keyed, and which is put in motion by the belt and
pulleys v, v, the upper, edges bearing with friction against the bottom of the
pan H, and the lower edges just skimming over the surface of the mercury g,
which is contained in the bottom of the vessel E, and is entirely unobstructed
by any projection from the bottom, which would cause the 'earth or sand to
remain, the shaft k and wheels F, F, being supported by the collar s and
bracket t, t, which is bolted to one of the pillars of the mill A. The cock i is
for drawing off the mercury preparatory to straining and distillation to obtain
the gold or silver contained therein. H, Fig. 1, is a heavy iron pan,
resting upon and with sufficient friction to turn the paddle wheels F, F,
upon their own axis. This pan is confined to the centre of the vessel E
by arms bolted to the sides of the latter. In the centre of this pan is a
short tube j, through which the shaft k passes, and outside of this centre tube
are several smaller tubes 1, 1, level with the upper surface of the bottom of
the pan, but projecting below it nearly to the axle of the wheels F, F.
I is a tube, connected with two arms, supplied with teeth and a thumb

page_text: screw, by which it is attached to. and revolves with the shaft k, the teeth.
nearly touching the bottom of the stationary pan H, and serving to keep the
latter free from deposits of earth; or sand. J is an iron pipe, connected
with the upper part of the vessel E,- for discharging the overflow. into the
trap boxes K, K, the use of which will be presently described. P, P, are
pails or tubs with overflow pipes for conducting water into. the trap boxes
K, K, through: the, trough. g, when the mill A or amalgamator. E are to be.
cleaned or repaired.
necessary,
. !
"
The apparatus herein described may be used with, steam, water, or horse
power, which should be applied in such a manner as to give the shaft b from
twenty-five to thirty revolutions per minute to perform the work to the best
advantage. In putting it up for use, the apparatus should be firmly supported
and bolted on solid masonry or timbers, imbedded in the earth, so that when.
the power is applied it may rest firmly on its foundation. The earth or other
substance to be washed for gold, silver, or other precious metal should, if
-be previously prepared,, so as to render it suitable to enter the
hopper or grain separator, described above. The mode of preparation necessary
to this object varies, according to the nature of the substance from which the
precious metal is to be separated. Quartz, ores, and other hard substances,
such as old crucibles and refiners, sweep, should first be ground, or stamped by
powerful machinery, and thus rendered as fine as possible, so as to liberate
the larger metallic grains before entering the, grain separator, by which the
largest and most valuable portion of the precious metal is speedily separated,
and saved from further abrasion and loss. Earth, clay, sand, or river mud do
not require to be previously ground or stamped; but if necessary, these sub-
stances should be passed through a coarse sieve, to remove pebbles or other
substances, which are of no value, and the earthy portion may then be passed
through the grain separator, as above.
..On commencing the operation of separating gold or other precious metals
from the substances prepared as above, the apparatus.described herein is to be
set in motion; and a stream of water to be allowed to pass into it through the
hopper C, filling the mill A, thence through the pipe n into the pan H, and
through the pipes;l, 1, filling- the vessel E, and finally through the pipe J into
the boxes K, K, from which it may be allowed to escape, or if necessary used
over again after the earthy matters have settled. The course of the current
of water is shewn by the arrows. The earthy matters which have been pre-
viously prepared are then to be supplied gradually to the apparatus through
the hopper C, in which the grains of gold or silver (if any be present) will be

page_text: retained, and cleaned, by the action of the teeth on the under side of the plate
D, from the sand, which would otherwise remain. If the motion of this plate
be very slow, much sand will remain with the gold or other precious metals;
and if too fast, some of the latter will be carried over in the current of water
to the mill below, where it will be retained, however. But to perform its duty
to the best advantage, this plate should revolve about twenty-five times a
minute, by which the metallic grains are left clean and bright, and almost
entirely free from sand, if the current of water is allowed to pass through the
apparatus in motion for about two hours after the supply of earth has ceased.
After the grains have been thus separated by passing through the hopper, the
earthy portion is carried by the current of water through the tube r into and
under the surface of the large body of water in the mill A, the finer portions
passing off with the current of water into the pan H of the amalgamator, and
the coarser portion, which is too heavy to be thus carried off, falls to the bottom
of the mill, where it is ground and mixed up with the water, until this also
passes off into the amalgamator, leaving a small residue very rich in gold at
the bottom of the mill if the current of water is allowed to pass through the
apparatus in motion for about two hours after the supply of earth has ceased.
The earthy matters from which the greater portion of the gold or silver has
been now extracted pass from the mill into the pan H, and are stirred up and
suspended in the water by the teeth attached to the tube and arms I, and are
carried thence by the current of water through the small tubes 1, 1, into the
centre of the second large body of water contained in the vessel E, and directly
in contact with the mercury on the bottom, the surface of which is kept con-
stantly clean by the revolving action of the paddle wheels around the shaft k,
which also causes an outer current in the space between the wheels and the
sides of the vessel, into which the earthy matters are thrown by the revolution
of the paddle wheels upon their own axis, thus allowing the heaviest metallic
portions to fall by virtue of their greater specific gravity, and remain in con-
tact with the mercury until amalgamated, while the light and refuse earth
is rapidly washed away. After leaving the amalgamator, the refuse earth or
tailings pass into the trap boxes K, K, where it is deposited, and may be sub-
sequently examined, and its value (if any) ascertained. This, however, is
necessary only in case of rich washings, such as refiners' sweep, which contains
some metal, combined with the borax and other fluxes used, and which can
only be obtained by subsequent smeltings. For quartz, earth, or other
natural deposits containing gold or silver, these boxes may be dispensed with
without loss after these substances have passed through the apparatus in the

page_text: manner above described; but in localities where water is scarce a number of
such boxes can be used to great advantage, because the earthy matters will
settle in them, and leave the water in the last box clear, and suitable for sup-
plying the apparatus constantly and repeatedly with the same.
At the close of the operations for the day the supply of water should be
stopped, and the cock d should be opened for a few minutes while the shaft b
is still in motion, so as to draw off the small rich residue which remains at the
bottom of the mill into the pail P, while the water passes off through the
overflow pipe into the trough q, and is conducted thence into the traps K.
The rich residue thus obtained from the wet mill in some cases contains
sulphur and generally iron, both of which may be oxidized by roasting or
burning the residue, and by passing the ashes through the grain separator at
the next operation, either alone or with a fresh supply of earthy matters, the
ashes and oxide of iron are removed, and the gold or other precious metal
contained therein will be separated and cleaned.
After the above-mentioned residue has been drawn off from the mill, the
machinery should be stopped, and the ironplate D raised up from the hopper,
by sliding on the shaft b, to the upper part of which it is to be temporarily
fastened by the thumb screw, while the gold, silver, or other metal which has
accumulated in the pan G is removed through the tap o at the bottom into a
small pail, which for this purpose is to be hung upon the hook n, and in which
the valuable grains are dried, and are now ready to be melted with soda ash
and nitre, and cast into ingots. The tap o in the bottom of the grain
separator is then to be closed by a screwed plug which is fitted to it, the plate
D is to be returned to its place, and the apparatus is again ready for operation
the next day. The niercury in the amalgamator requires to be removed only
once a week, or once a month, according to the quantity of material which
has been passed through the apparatus. When sufficiently charged, the
amalgam is to be drawn off through the cock i into the pail P, which retains
it, and permits the water to pass off into the traps. The amalgam is then to
be strained, the solid portion distilled off to obtain the gold or silver, and the
fluid mercury is to be returned to the amalgamator, and if any has become
lost by handling, a little more should be added, so as to cause the surface of
the whole to touch the paddle wheels, as before.
The principles involved in the above-described Invention are based on the
following mechanical facts: grains of gold, silver, or other ductile metals, when
ground or crushed with quartz or other hard substances, flatten under the
mill, and thus the crushing surfaces are prevented from coming close enough.

page_text: to crush the strong matrix or admixture to a very fine powder; but if, when
thus crushed as fine as possible, the grains of gold or other metal thus
liberated are separated, the remaining stoney matter can then be crushed to an
impalpable powder, so that the finest particles, and even such as are invisible
to the naked eye, may be liberated, and with proper apparatus be saved. To
accomplish this great disideratum effectually, the mill A and the amalgamator
E are, so constructed as to hold a large column of water, in each of which the
earthy matters are kept constantly suspended by the agitation of the wheels,
while the light and heavy substances are separated from each other by virtue
of their respective specific gravities, the heavy metallic portions falling to the
bottom of the columns of water, while the light and refuse earth is washed
away in the current which constantly passes through the apparatus, as above
described.
I am aware that gold and other precious metals have been separated from
the gangue by crushing or grinding, and that this operation has been per-
formed by what is known as the Chilian mill, consisting of two heavy wheels,
revolving about a common axis, and rolling, on the ore deposited on the
bottom of an annular basin. And I am also aware that water has been
used in connection with such machinery, sufficient in quantity simply to
cover the solid matter to be crushed, but I am not aware that such mills
have been used with the crushing wheels entirely or nearly submerged,
and in combination with a feeding tube, to supply the substances to be
crushed below the surface of the water within which the crushers operate,
for the purpose and operating in the manner substantially as described above.
And I am also aware that separators have been used, consisting of a pan
supplied with the substances to be separated, mixed in water, and agitated
within the pan by agitators, for the purpose of discharging the lighter sub-
stances over the edge of the pan, and causing the heavier particles of metal to
settle by gravity at the bottom; but I am not aware that such a separating
apparatus has been employed as a hopper to and in combination with a
crushing mill by means of a feeding tube, or equivalent therefor, for the pur-
pose of separating the lumps of metal, which have been previously liberated
from the gangue by crushing or otherwise, that the stoney or earthy substances
may be re-crushed or ground to liberate the smaller and often invisible particles
of metal without impediment from the lumps of metal, substantially as above
specified. And I am also aware that the finer particles of metal have been
separated from the foreign substances with which they are mixed by amal-
gamation with mercury, by causing the substances containing precious metals

page_text: to pass in contact with mercury contained in a vessel; but I am not aware that
this has been applied by supplying the substances containing the metallic par-
ticles below the surface of a considerable column of water resting on the surface
of the mercury, and. continuously agitated at and above the surface of the
mercury, that the lighter substances may be carried upward by the current or
currents induced. by the agitators, and discharged at top, whilst the metallic
particles are permitted to subside, and to be carried by gravity to the mercury
below, where the amalgamation takes place; nor am I aware that this has
been combined with a crusher, working under a column of water, and dis-
charging the substances to be separated into and, below the surface of the
column of water resting on the mercury, substantially as herein-above specified.
And whilst it is my purpose to avoid claiming anything before known, I do not
wish to be understood as limiting myself to the special construction and
arrangement which has been practised by my correspondent-with success, and
which I have minutely specified, as the said Invention may be variously modified
whilst essentially the same mode of operation is preserved, and therefore I wish
to be understood as claiming the said mode of operation, however the mode of
application may be varied by the mere substitution of equivalent means.
.
13
What I claim as the Invention secured to me by the herein-before in part
recited Letters Patent is, the employment of what I term a grain separator, for
separating the grains of metal from the earthy substances or crushed gangue,
substantially as described, preparatory to and in combination with the crusher,
or equivalent therefor, when the separator is employed as a hopper to the
crusher, and combined therewith by a feeding tube, or equivalent therefor, for
conducting the substances to be crushed below the surface of the column of
water in the crusher, substantially as and for the purpose specified.
And I also claim working the crusher, consisting of one or more heavy
wheels running vertically on their own axis, and revolving about a vertical shaft
within a vessel containing a column of water of sufficient depth to enable the
wheels to work under water, and with a discharge above the wheels, and a
feeder to supply the substances to be crushed below the level of the discharge,
substantially as and for the purpose specified.
I also claim working the amalgamator with mercury at the bottom, pre-
senting an unbroken surface, and a column of water above the mercury, in
combination with the agitating wheels above the surface of the mercury, and
within the water, and the supply or feeding tubes, or equivalents, for supplying
the substances to be separated below the surface of the water, substantially as
specified.

page_text: And, finally, I claim the combination of the separator, the "wet mill" or
crusher working under water, and the amalgamator, operating in connection
with each other, substantially as and for the purpose specified.
year
In witness whereof, I, the said Alfred Vincent Newton, have hereunto
hand and seal, the Twenty-seventh day of February, in the
of our Lord One thousand eight hundred and fifty-six.
set my
Witness,
J. W. MOFFATT,
66, Chancery Lane.
A. V. NEWTON. (L.S.)