IMPROVEMENTS IN OPERATING UPON METALLIFEROUS ORES AND OTHER MINERALS, AND UPON 'SLAGS' AND 'SWEEP," IN ORDER TO FACILITATE THE SEPERATION AND RECOVERY OF THE METALS AND OTHER PRODUCTS, ALSO IN MACHINERY OR APPARATUS FOR EFFECTING SUCH IMPROVEMENTS, WHICH IS IN PART APPLICABLE TO OTHER PURPOSES
Year: 1854

page_text: ETTERS PATENT to George Henry Bursill, of Offord Road, Barnsbury
Park, Islington, and of the Ranelagh Works, Pimlico, in the County of
Middlesex, Engineer and Assayer of Minerals, for the Invention of
"IMPROVEMENTS IN OPERATING UPON METALLIFEROUS ORES AND OTHER MINERALS,
AND UPON 'SLAGS' AND 'SWEEP," IN ORDER TO FACILITATE THE SEPERATION
AND RECOVERY OF THE METALS AND OTHER PRODUCTS, ALSO IN MACHINERY OR
APPARATUS FOR EFFECTING SUCH IMPROVEMENTS, WHICH IS IN PART APPLICABLE
TO OTHER PURPOSES."
Sealed the 30th May 1854, and dated the 19th January 1854.
PROVISIONAL SPECIFICATION left by the said George Henry Bursill
at the Office of the Commissioners of Patents, with his Petition, on the
19th January 1854.
I, GEORGE HENRY BURSILL, of Offord Road, & Pimlico, Middlesex, do
hereby declare the nature of the said Invention for "IMPROVEMENTS IN
OPERATING UPON METALLIFEROUS ORES & OTHER MINERALS, AND UPON SLAGS' AND
SWEEP, IN ORDER TO FACILITATE THE SEPERATION AND RECOVERY OF THE METALS
AND OTHER PRODUCTS, ALSO IN MACHINERY OR APPARATUS FOR EFFECTING SUCH
IMPROVEMENTS, WHICH IS IN PART APPLICABLE TO OTHER PURPOSES," to be as
follows:-
Firstly, my Invention relates to the pulverization of ores, and consists in
causing certain auriferous, argentiferous, and occasionally cupreous ores, in

page_text: which the metallic gold, silver, or copper exists in such extremely minute
particles as not to be visible to the eye, to be pulverized or ground, not with
metallic mercury alone or with metallic mercury and water only, as practised
heretofore, but along with a solution, or along with mercury and a solution
of some one or other of the salts of mercury that are soluble in water, the
advantage being that the ore so ground may be easily brought in contact and
moistened all over with such a solution and far more readily than with metallic
mercury, the specific gravity of which is so great as to give it a tendency to
keep to the bottom, while the minute portions of gold so moistened no sooner
come in contact with the machinery for grinding, or with the apparatus that
is purposely used in connection therewith, and which is of iron or other
material suitable for producing such effect, than they become coated with
running mercury that is precipitated from the solution by galvanic agency,
it being an established and elegant test for the presence of mercury, that if a
drop only of a strong solution of corrosive sublimate be placed upon a gold
coin or ring, the simple contact of the gold with iron, (that is through the
solution,) as with the point of a needle, for example, causes the mercury to
be thrown down in a bright silvery stain, and the minute specks of gold,
on becoming so coated, readily adhere to or amalgamate with any metallic
mercury to which they may be subsequently exposed.
Any material loss of mercury that may be retained in the solution can
equally and readily be avoided by galvanic and well known means.
Secondly, when I have reason to suspect the existence of any soluble salts
of gold or of silver, whether in the ore, mineral, or sweep, I do not simply
amalgamate, but I add to the ore whilst it is in the act of pulverization or of
grinding, as much water only, or as-much dilute acid or other medium, as shall
put it under favourable conditions for the galvanic influence, and I then
throw down the gold or silver in the metallic state while grinding, either by
the grinding machine itself or by appendages attached thereto, and which I
employ in the form of rotating plates, scrapers, or rakes, made of iron, copper,
or zinc. Or I cause the ore to be ground in solutions, (either with or without
the addition of mercury,) or with such re-agents as are calculated to precipitate.
the gold or silver as nearly as may be to the metallic state, or in a form as
favourable as possible to the action of metallic mercury when used for the
purposes of amalgamation, as in a solution of the proto-sulphate of iron,
or in a heated solution of carbonate of soda, or of oxalic acid, for example.
Or, having first caused the ore to be partially broken up by a dry process, I
evaporate to dryness, and then grind and amalgamate upon a hot plate at a
gentle heat, passing the tailings in every instance through the patent amal-

page_text: 16
gamator, or separator, a description of which will be found in the Specifi-
cation of a Patent granted to me by Her most Gracious Majesty Queen
Victoria, For Improvements in Operating upon Auriferous Quartz, Clays,
and other Minerals, preparatory to and in order to accomplish the Separation
of the Gold and other Metals; also in Machinery or Apparatus for Effecting
such Improvements," duly filed in the Great Seal Patent Office, and bearing
date the Twelfth day of February, in the year of our Lord One thousand
eight hundred and fifty-three.
Thirdly, my Invention relates to the treatment of sulphurets and certain
other in part volatile ores, in order to effect oxidation of the metal, and
facilitate the sublimation of the volatile parts.
For this purpose I make use of pumice, which, either in pieces or roughly
ground, and either alone or in combination with other ingredients, I find in
general to be a suitable medium for first mixing with the broken or pounded
ore.
After this I cause the mineral to be subjected, under suitable arrangements
as at a certain stage during the roasting, or as under pressure, when it is
advisable, to a blast or current of pure atmospheric air, previously heated up
to the temperature required by any suitable means.
On some occasions I make use of a current of hydrogen, which I cause to
be admitted to a chamber previously made hot, and in which are the sulphurets
and arseniats, mixed also with pumice, the object in this case being to volatalizo
the sulphur without producing oxidation of the metal, and I make use of
quicklime to absorb the moisture generated when an oxide is present.
When the mineral is exposed to the effects of heated air under pressure, it
is arranged that the chamber or cylinder in which the operation is to take
place may be converted at pleasure into a close vessel, and that the products
which get away through an outlet pipe to a tank or vessel filled with a fluid
or solution suitable for promoting the condensation, shall escape by means of
a valve affixed to such pipe, and which valve may be weighted if required.
An agitator working within the chamber or cylinder serves to bring the
mineral more intimately in contact with the heated air, and may sometimes
be used with advantage in addition to any agitator or rouser, working as is
usual within the vessel employed for condensation.
Fourthly, my Invention has reference to operations either during or imme-
diately subsequent to smelting, that is to say, I employ as far as may be con-
venient, and to assist in fluxing the ore, some minerals containing naturally,
as I find by analysis, so large a per centage cither of potash or soda as to give
to it a tendency to melt per se, and to which large proportion I occasionally

page_text: add either potash or soda in excess, that is to say, in much larger quantity
than is customary, (excepting perhaps only in the small way, the use of such
fluxes for the smelting of gold and silver ores having been hitherto precluded
in great measure on account of their expense,) my object being the formation
of a slag that is softer and soluble with less difficulty than that which is
commonly made; and this slag while still red hot, or as soon as it can be
separated from the metal after smelting, I cause to be precipitated into any
suitable fluid, whereby the soluble or other valuable products may be after-
wards readily recoverable for further use.
When a slag is formed only in the ordinary way, and contains a very large
proportion of silica, I precipitate into a caustic ley; my mode of operation in
this case, as well as for effecting the disintegration of slag already formed, (and
of which there is a great quantity in existence,) being agreeable to that which
I adopt for the disintegration of auriferous quartz, and which will be thoroughly
understood by consulting also the Specification of the former Letters Patent
granted to me by Her most Gracious Majesty Queen Victoria, and bearing
date the Twelfth day of February, One thousand eight hundred and fifty-three,
already referred to.
Fifthly, my Invention relates to machinery or apparatus for effecting pul-
verization, and differs according to the nature of the requirements, more
especially as I may be desirous of adopting either the cold and dry, or the hot
and dry, or the hot and wet process of grinding.
For the cold but dry process I prefer to use one or more pairs of horizontal
rollers, so constructed that one of the rollers in any given pair shall, by con-
sequence of its axis (or of the bearings in which it works) being made to rest
upon an inclined plain, be forced to lean upon and so be turned by the friction
of the other or working roller when set in motion, or by any medium passing
between them, as by the ore to be ground, or by endless chains, or bands of
any desired thickness placed at either end, and passing over a friction roller
above.
The working roller I prefer to be hollow and of at least equal diameter to
the other, whilst the loose roller is solid, the object being that the solid roller,
although it has a tendency to keep close to the other by reason of its sliding
down the inclined plane, has the power of getting away whenever a piece of
extremely obdurate material comes between them, and so to prevent any injury
to the rollers.
The arrangement described I use in combination with a rotary sieve whereby
the coarse particles are reserved for further operation, through a single
passage through a double set of the rollers described, the one pair being placed

page_text: beneath the other, will in most cases suffice for sulphurets and arsenical ores
previous to roasting.
Sixthly, I occasionally make use of an improved arastas. The improvement
consists in my causing the ball to bo urged forward by a friction roller, the
axis of which rests in bearings attached to or abutting against a spring or
springs, affixed either to an arm from the central rotating upright shaft itself,
or to a sleeve made to work upon a central shaft that is stationary, the whole
being so arranged as to enable me to work either with steam or water power,
and at a greater speed (though with less friction and less jerking of the ball)
than is usual in the common arastas.
The kind of ball I prefer to employ is a hollow ball, so cast as to be of
greatest thickness at one part, or weighted internally at one end, and which
gives to it when in action a peculiar motion which I deem of importance.
When more than one ball is employed, each ball is urged forward by its
separate friction roller, and the rollers are adjusted at an equal distance from
each other.
Lastly, I will proceed to describe the machine I employ for operating upon
the metalliferous ores, in order to facilitate the separation and recovery of the
contained metals during and subsequent to pulverization, and which machine
I consider the best adapted both for hot and wet, and hot and dry grinding,
especially when operating upon an extensive scale.
The machine consists of a particular arrangement of one or more edge
runners of a peculiar configuration, that combines the grinding properties
of the edge runner with others appertaining to the sphere, and which con-
figuration may be defined as consisting of a central cylinder, having convex or
partially convex ends or sides, while to each runner there is a central horizon-
tal spindle, which, whether keyed or not, projects only but to a short distance
from either side. The runners, of which I prefer to use three to each machine,
are placed at equal distances from each other upon a rimmed iron plate or
basin, substantially supported by masonry, and having a fire-grate and ash-pit
underneath, as is usual in the erection of a stationary hot plate, in the middle
of which plate, however, is a short upright stationary shaft, the upper part of
which is carefully rounded or turned for some distance from the top to a
projecting collar.
A wheel of somewhat larger diameter than that of the hot plate, and having
cogs or teeth near the periphery (but upon its under surface), also a central
socket to fit the upper end of the shaft, and to rest upon its collar, is so
adjusted that it can be made to rotate by any suitable means, (as by a toothed
wheel working beneath and keyed to a horizontal shaft, upon which is a drum

page_text: driven by a band from the steam engine;) and it is especially arranged that
the large horizontal wheel described shall drop half way over the runners (or
thereabouts), and in such a manner that certain gun metal appendages with
which it is supplied shall take the axles of the runners, and so press upon
them as to cause the runners to be driven when the wheel is set in motion,
though with liberty to rise or fall, as may be needed, in the event either of a
large piece of ore offering any material obstruction on the one hand, or of
their peripheries becoming gradually worn away on the other.
The machine is supplied, when requisite, with rotating plates, scrapers, or
rakes, travelling between the runners, and made of such metal as may be
necessary; the rakes, it may be observed, more especially when of iron, being
great service in the dry grinding of the ore upon the hot plates.
of
The ore to be ground should in most cases be previously reduced to a mode-
rate size by stampers, and which, as relates to the use of the horizontal rollers
more especially, should be so adjusted as to afford a continuous supply of
partially pounded ore, as by the simultaneous action of a screen or sieve.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said George Henry Bursill in the Great Seal Patent Office on the
19th July 1854.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, GEORGE
HENRY BURSILL, of Offord Road, Barnsbury Park, Islington, and of the
Ranelagh Works, Pimlico, in the County of Middlesex, Engineer, and Assayer
of Minerals, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Nineteenth day of January, in the year of our Lord
One thousand eight hundred and fifty-four, in the seventeenth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said George Henry Bursill. Her special licence that I, the said George
Henry Bursill, my executors, administrators, and assigns, or such others as
I, the said George Henry Bursill, 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 "IMPROVE-
MENTS IN OPERATING UPON METALLIFEROUS ORES AND OTHER MINERALS, AND UPON
SLAGS AND SWEEP,' IN ORDER TO FACILITATE THE SEPERATION AND RECOVERY
OF THE METALS AND OTHER PRODUCTS, ALSO IN MACHINERY OR APPARATUS FOR

page_text: EFFECTING SUCH IMPROVEMENTS, WHICH IS IN PART APPLICABLE TO OTHER PURPOSES,"
upon the condition (amongst others) that I, the said George Henry Bursill,
by an instrument in writing 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 Patent.
NOW KNOW YE, that I, the said George Henry Bursill, do hereby
declare the nature of my said Invention, and in what manner the same is
to be performed, to be particularly described and ascertained in and by the
following statement (that is to say) :-
My Invention of improvements in operating upon metalliferous and other
minerals, and upon slags and sweep in order to facilitate the separation and
recovery of the metals and other products; also in machinery or apparatus for
effecting such improvements, and which is in part applicable to other purposes,
is as follows:-Firstly, my Invention relates to pulverization, and consists in
causing certain auriferous and argentiferous ores and slags, sweep or tailings,
in which gold or silver exists in the metallic state, but in such minute particles
as not to be visible sometimes to the eye, to be pulverized, ground, or reground
to an impalpable powder, not with metallic mercury alone, or with metallic
mercury and water only as practised heretofore, but with a solution of
mercury or with a solution of some one or other of the salts of mercury that
are readily soluble in water, and either with or without the addition of metallic
mercury, the advantage being that the ore so ground may be readily brought
in contact with and thoroughly moistened by such a solution, and far more
casily than with metallic mercury, the specific gravity of which is so great as
to give it a tendency to remain at the bottom while the minute portions of
gold so wetted no sooner come in contact with the machinery for grinding or
with the apparatus used in connection therewith, such as rakes and scrapers
as are commonly employed, and which should be of iron or other material
suitable for producing such effect, than they become coated with running
mercury that is precipitated from the solution by galvanic agency, it being an
established and delicate test of the presence of mercury that if a drop only of
a strong solution of corrosive sublimate be placed upon a gold coin or ring, the
simple contact of the gold with iron (that is, through the solution) as with the
point of a pen-knife, for example, causes the mercury to be thrown down in a
bright silvery stain, and the minute specks of gold on becoming so coated
readily adhere to or amalgamate with any metallic mercury to which they may
be subsequently exposed.

page_text: When the corrosive sublimate of commerce is employed, it should first be
purified by crystallization, and then dissolved in about twelve parts of water
by weight. Any material loss of mercury that is retained by the solution may
also be readily avoided by galvanic means, as well understood. When I have
reason to suspect the existence of any soluble metallic salts, as of gold or of
silver, in the mineral under treatment, I proceed somewhat differently in that
case. I add to the mineral during the operation of grinding as much very
dilute acid only or other medium as shall put it under favourable condition for
the galvanic influence, and I then throw down the gold or silver in the metallic
state, either by the grinding machine itself or by appendages attached thereto,
in the form of rotating scrapers, rakes, or plates made of iron, copper, or zinc,
as may be required, or I cause the ore to be ground in a solution of the proto-
nitrate of mercury, or of the proto-sulphate of iron, or in a heated solution of
carbonate of soda or of oxalic acid, or with such re-agents as are best calculated
to precipitate the gold or silver as nearly as possible in the metallic state, and
therefore favourable to the subsequent action of the metallic mercury when
used for the purpose of amalgamation; or having first caused the ore to be
partially broken up by cold dry process effected by machinery herein-after
described, I evaporate to dryness, grind, and amalgamate upon a hot plate,
and at a gentle heat by other machinery also herein-after described, passing
the tailings in every instance through the patent amalgamator or separator, a
description of which will be found in the Specification of a Patent granted to
me by Her most Gracious Majesty Queen Victoria, "For Improvements in
Operating upon Auriferous Quartz, Clays, and other Minerals preparatory to
and in order to accomplish the Seperation of the Gold and other Metals, also
in Machinery or Apparatus for effecting such Improvements," bearing date
the Twelfth day of February, in the year of our Lord One thousand eight
hundred and fifty-three, the Specification being duly filed in Her Majesty's
High Court of Chancery on or about the Twelfth day of August of the same
year.
My Invention also relates to sulphurets, and to certain other in part volatile
ores when under treatment, in order to effect the oxidation of the contained
metal and sublimation of any volatile parts, to facilitate which processes I
employ pumice in pieces or roughly pulverized, and either alone or in com-
bination with other ingredients, which I find from its porosity and lightness
to be a suitable medium for first mixing with the pounded ore.. I also cause
the mineral under suitable arrangements, as under pressure (when advisable)
and at a certain stage during the roasting (as when the volatile products
cease to come over) to be subjected by suitable means to a blast or current

page_text: of atmospheric air, previously heated to the temperature required for effecting
volatilization. On some occasions I finish by the use of a current of hydrogen
which I cause to be admitted to the previously heated chamber in which are
the sulphurets mixed with pumice, the object being in this case to volatilize
any remaining sulphur, not merely without producing oxidation, but even to
assist in deoxidizing the metal. I expose the mineral to the effects of heated
atmospheric air under pressure, in order that the air may penetrate into every
pore and interstice, to effect which I conduct the operation of roasting in a
close vessel, conducting the volatile products through a pipe into a tank or
vessel filled with a fluid suitable for promoting condensation, the aperture of
escape from such pipe being fitted with a valve weighted when and according
as pressure is required to be maintained in the roasting chamber. An agitator
is employed within the roasting chamber in order to bring the mineral more
intimately in contact with the heated air, in addition to another agitator
working as is usual within the vessel employed in condensation.
My Invention also relates to operations during and immediately subsequent
to smelting, and consists in the employment of such minerals to assist in fluxing
the ore as contain naturally a large per centage of potash or soda as certain
varieties of felspar for example. For this purpose I select minerals contain-
ing the largest proportion of potash or soda, which I pound roughly, adding at
the same time potash and soda in excess, or so proportioned as to assist and
lead to the formation of a slag that is soluble with less difficulty than that
commonly made in the larger operations of smelting gold and silver, still less
of other metals (the use of potash and soda as fluxes having been hitherto in
a great measure precluded in consequence of their expense). This slag while
still red hot, or as soon as it can be seperated from the metal after smelting, I
cause to be precipitated into a very dilute ley, or into any suitable fluid from
which the potash or soda are recoverable by first throwing down any contained
silica, alumina, or other impurities by the aid of quick lime, then drawing off
the supernatant liquor and evaporating in the ordinary manner. By such
mode of proceeding the soda or potash introduced as a flux may be ultimately
recovered, in addition to that contained in the mineral used therewith, such
recovery of potash or soda rendering its use for the purpose of smelting com-
paratively inexpensive, which is the object I desire to attain. When a slag is
formed in the ordinary way, or contains a very large proportion of silica, I
precipitate red hot into a caustic ley that is of great strength; my mode of
operation in this case, as well as for effecting the disintegration of slags that
are already formed, being agreeable to that which I adopt for the disintegra-
tion of auriferous quartz, and will be thoroughly understood by consulting also

page_text: the Specification of the Letters Patent granted to me, and herein-before
referred to, but when the slag contains any metallic oxides that are easily
acted upon by a caustic ley, as the oxide of zinc for example, I either dilute
the ley or employ some other medium.
I will now procced to describe that part of my Invention that relates to
machinery for effecting pulverization and grinding, which differs according to
the requirements of the material, and more especially as I may be desirous of
adopting either the cold and dry, or the cold and wet, the hot and dry, or the
hot and wet processes of pulverization or of grinding.. For the cold and dry
process, I prefer to use one or more pairs of rollers so constructed that one of
the rollers in any given pair shall by reason of its axis (or of the bearings in
which it works) being made to rest upon an inclined plane be forced to lean
upon and so be turned by the friction of the other roller when set in motion,
or of any medium passing between them, as by the ore to be ground, or by
suitable collars fitted upon either end of one of the rollers.
The object of this arrangement is that the upper or crushing roller, although
it has a tendency to keep close to the under roller by reason of its sliding
down the incline, should have the power of getting away nevertheless when-
ever a piece of extremely obdurate material comes between them and so
prevent injury to the rollers. In combination with these rollers I use a sieve,
working below, whereby the coarser particles are reserved for further operation,
though a single passage through them will in most cases suffice for sulphurets
and arsenical ores, previous to roasting; or the rollers may be so arranged
that the upper or crushing roller has its axis in vertical slots made in the
framework, which permits of its rising and falling, and at the same time
maintains it in a central position immediately over the lower roller. A
perforated plate or grating is used in this case, which is placed between the
rollers; to this plate a reciprocating motion is given, and an alternating
rotatory motion is thereby imparted to the rollers. The ore to be crushed is
placed on this plate, and is by it carried backwards and forwards between the
rollers until it is sufficiently pulverized to pass through the perforations, which
thus completes the operation, and dispenses with the necessity of a sieve. In
conducting the cold and wet process of crushing by this machine, it is simply
necessary to substitute for the perforated plate before described a rimned
plate or tray to contain the fluid with the ore, and provide means for with-
drawing the fluid from the tray when required.
Lastly, my Invention refers to improvements in machinery or apparatus for
grinding, either by the hot and wet, or the hot and dry processes, and the machine
I use for these operations on an extensive scale consists of a particular arrange-

page_text: ment of edge runners of a peculiar configuration that combines the grinding
properties of the edge runner with others appertaining to the sphere, and which
configuration may be defined as consisting of a central cylinder with convex or
partially convex ends or sides. Each runner is furnished with a gudgeon
projecting on either side, which gudgeons are fitted to slotted bearings attached
to a horizontal plate or wheel, herein-after described. The runners, of which
there are three to each machine, are placed at equal distances from each other
upon a rimned iron plate or basin, substantially supported by masonry, and
having a fire-grate and ash-pit underneath, as is usual in the erection of a
stationary hot plate, or which may be otherwise heated by steam. In the
middle of this plate is a short stationary upright shaft, the upper part of which
is rounded and turned for some distance from the top down to a projecting
collar. A wheel of larger diameter than the hot plate, and having cogs or
teeth upon its under surface (near the periphery) has a central socket or boss
made to fit the upper end of the shaft described, and rest upon the collar
thereon, the wheel being so adjusted that it can be made to rotate by a smaller
toothed wheel or pinion working beneath and keyed to a horizontal shaft upon
which is a drum which is driven by a band from the steam engine. It is so
arranged that the large horizontal wheel shall drop about half way over the
runners in such position that the slotted bearings that are fitted thereto shall
receive the gudgeons of the runners and so cause them to be driven when such
large wheel is set in motion. The bearings are slotted in order that they may
not restrict the position of the rollers vertically, but permit the gudgeons to
rise and fall in the event of any irregularity in the size of the material under
operation, as well as to accommodate any variation in the size of the runners
resulting from wear. This machine is supplied when requisite with rotating
plates of iron, copper, or zine, affixed to the sides of the runners in any
convenient way, or with rotating scrapers or rakes travelling between the
runners, and made of such metal as may be necessary to induce galvanic
action. When employing a ball for grinding purposes, as with the common
or improved arasta, I form it hollow and cast it in such manner that one
hemisphere shall be much heavier than the other, which gives to it when
in action a greatly augmented gyratory motion which materially assists the
action of grinding.
Having described the nature of my Invention and the manner of carrying
the same into effect, I would have it understood that I do not confine myself
to the precise details herein laid down for carrying it into effect, as such may
be varied without departing from the nature of my Invention; but that what I

page_text: claim as my Invention, and desire to secure by the before in part recited
Letters Patent, is,―
First, the pulverization and grinding of metalliferous ores and minerals,
slags, and sweep, in or along with solutions of mercury, or of the salts of
mercury, or in or along with other solutions, or re-agents that effect either
amalgamation itself or precipitation in a state that facilitates amalgamation
and consequent recovery of the contained metals.
Secondly, I claim for the purposes of accelerating the oxidation of metals
and volatilization of mineral products, the use of pumice and of a current of
heated atmospheric air, and I also claim the employment of a current of
hydrogen, for deoxidation when pumice is used.
Thirdly, I claim the means described for disintegrating slag and for the
economical employment of potash or soda with minerals containing the same
to assist as fluxes in the operation of smelting.
And, lastly, I claim the machinery or apparatus as and for the purposes
herein-before described.
In witness whereof, I, the said George Henry Bursill, have hereunto set
my hand and seal, this Nineteenth day of July, in the year of our Lord
One thousand eight hundred and fifty-four.
Witness,
W. CLARK,
Patent Agent,
GEORGE HENRY BURSILL. (L.S.).
53, Chancery Lane,
London.