IMPROVEMENTS IN THE MANUFACTURE OF ZINC
Year: 1838

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, HARRISON
GRAY DYAR, of Mortimer Street, Cavendish Square, in the County of Middlesex,
Gentleman, send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Letters Patent under the Great Seal of Great Britain, bearing date at
Westminster, the Twentieth day of November, in the second year of Her
reign, did, for Herself, Her heirs, and successors, give and grant unto me, the
said Harrison Gray Dyar, Her especial license, full power, sole privilege and
authority, that I, the said Harrison Gray Dyar, my exors, adññors, and assigns,
or such others as I, the said Harrison Gray Dyar, my exors, adñors, or assigns,
should at any time agree with, and no others, from time to time and at all
times during the term of years therein expressed, should and lawfully might
make, use, exercise, and vend, within England, Wales, and the Town of
Berwick-upon-Tweed, and in all Her said Majesty's Colonies and Plantations
abroad, and also in the Islands of Jersey, Guernsey, Alderney, and Sark, my
Invention of "IMPROVEMENTS IN THE MANUFACTURE OF ZINC;" in which said
Letters Patent is contained a proviso that I, the said Harrison Gray Dyar,
shall cause a particular description of my said Invention, and in what manner
the same is to be performed, to be inrolled in Her said Majesty's High Court
of Chancery within six calendar months next and immediately after the date
of the said in part recited Letters Patent, as in and by the same, reference
being thereunto had, will more fully and at large appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
Harrison Gray Dyar, do hereby declare the nature of my Invention, and the
manner in which the same is to be performed, are fully described and ascer-

page_text: tained in and by the following statement thereof, reference being had to
the Drawing hereunto annexed, and to the-figures and letters marked thereon,
that is to say:-
According to the ordinary modes now pursued for manufacturing metallic
zinc, the oxide of zinc mixed with coal is submitted to a process of distillation
by enclosing oxide of zinc prepared for reduction in retorts, crucible pots, or
such like vessels, and by heat applied to the external surfaces of such retorts
or vessels, the metal is reduced from the oxide, and is driven off and condensed
in suitable receivers; this is necessary to protect the zinc from the action of the
air. Now, the object of my Invention is to accomplish the same end without
enclosing the zinc in such vessels, by depriving the air of those properties or
matters which would injuriously act on it, and the ore or oxide of zinc prepared
for reduction is exposed to the direct action of the fire; the burning fuel in
the furnace being so placed or arranged in relation to the ore placed in the
furnace, that the air after passing through the fuel shall, before it comes in
contact with the ore, be deprived of those properties or matters which would
otherwise be prejudicial to the process of obtaining metallic zinc; and in order
to give the best information in my power, I will describe the means and appa-
ratus resorted to by me for carrying out my Invention, and which I believe
to be the best arrangement for the purpose.
DESCRIPTION OF THE DRAWING.
The Drawing represents the section of a furnace suitably arranged for
carrying out the Invention, and I would in the first place remark, that in
arranging the furnace or apparatus properly for performing the Invention, that
its arrangement should be such (whatever may be its form) as to possess the
capabilities hereafter explained, whereby metallic zine may be advantageously
manufactured from the ore or oxide of zinc prepared for the purpose by
an exposure to or by means of what may be called a naked fire, in
contradistinction to the zinc being protected from the fire by being placed
in retorts, cruciblės, or such like vessels, as heretofore practised. The general
nature of the means whereby this modification of the process of smelting
is rendered practicable with zinc consists in so arranging the furnace or
burning fuel in relation to the ore of zinc or unreduced zinc, and the zinc after
reduction, as that when the hot or burnt air or gaseous products of the
combustion shall come in contact with the ore of zinc prepared and placed in
the furnace for reduction, there shall be in this hot or burnt air little or no
free oxygen, carbonic acid, or other gases or vapours capable of oxydizing
metallic zinc. By this method the necessity of enclosing the unreduced zinc

page_text: (in whatever substance or combination it may exist) in retorts, crucibles, or
other such vessels, is avoided, and instead thereof the hot or burnt air is
deprived of those matters which make the enclosing necessary. It should be
understood that the burnt air or products of combustion should only contain
carbonic oxide, nitrogen (or azote), hydrogen, carburetted hydrogen, or such
other gases or vapours as are incapable of having any prejudicial action upon
metallic zinc at the temperature which may be used in reducing zinc, and
that after the hot or burnt air has acted on the prepared zinc ore it shall be
so far cooled as that none of the zinc in the state of vapour or otherwise shall
A is
pass into the external air so as to be burnt, oxydized, or otherwise lost.
the fire chamber filled with coke; B, the chamber where the prepared ore is
placed to be reduced; C, a recipient for the condensed zinc, reduced and
distilled from the ore; D, a pipe from a blowing machine; E, a closed place
that can be opened to clear out the furnace; F, F, two covers of cast-iron
for getting at the chamber A and B. G, G, are cast-iron pieces with a groove
either circular or of such a shape as to receive the projecting sides or edges
of the covers, and being filled with sand to make a closed joint, as shown at H.
I is the upper part of the fire chamber; K, an iron pipe through which the
burnt air and vapourized zinc passes, and are cooled, to condense the metal
which falls into C; L, a pipe opposite to K, of sufficient length before opening
into the air to condense all the vapour of zinc, and so far cool the burnt air
as that it may pass into the atmosphere without carrying away any of the zinc.
N, a place for opening into the chamber B to clear out the refuse left from
the prepared ore, after the metal is separated. In this furnace the height of
the fire chamber A, below J, is intended to be sufficient to convert the oxygen
in the air feeding the fuel entirely into carbonic oxide by the time it passes
through the channel J to enter the chamber B. The channel J is made to
descend towards N, to prevent any zinc from at any time flowing towards the
fire chamber A. When the ore contains cadmium, arsenic, &c., I recommend
that a series of two, three, or more of the parts K, C, L, be added, connected
one after the other, so that the zinc which is most easily condensed may be
chiefly collected in the first recipient, whilst the more volatile cadmium, &c.,
will be received in the second or third. Thus, may be obtained the zinc in
the first recipient more pure than if all the metals had been condensed
together.
My Invention does not relate to any peculiar mode of preparing the ore
for reduction, but I prefer when the ore is naturally in the form of an oxide
of zinc, or is converted into an oxide previous to being operated on, to make
it up in balls of about two inches in diameter, with the usual quantity of fine

page_text: coal and a little clay or such other substance as may be calculated to keep
this prepared ore from falling into a powder in the chamber, whereby it
might prevent the free circulation of the hot air around and amongst the
prepared ore in the chamber B whilst being reduced. I would remark that
although I have described a mode of driving the air through a high column of
coke, in order to convert the oxygen of the air into carbonic oxide, yet, to
further ensure the entire conversion of all the oxygen into carbonic oxide, I
recommend the precaution of filling at each operation, or charging the furnace,
the upper part I of the furnace A, with bituminous coal, so that the heat
will distil off curburetted hydrogen to produce the effect upon the burnt air
of converting all the carbonic acid into carbonic oxide, by mixing therewith
in passing through the channel J, before it arrives at or amongst the ore in
the chamber B. It will be obvious to those who are acquainted with the
chemical principles upon which my Invention is founded, that the ores of zinc
inay be placed along with the fuel in the chamber A, .so as to produce ulti-
mately a result similar to that which I have explained; provided at the last
part of the operation or reduction the air that has passed through the fuel
has attained the condition herein-before mentioned, of being without those
properties or matters which would act upon metallic zinc; but I prefer keeping
the fuel and the unreduced zinc separate, in the manner I have above
described.
Having thus described the nature of my Invention, and the manner of
performing the same, I would have it understood that although I have been
particular in describing the construction of furnace or apparatus and fuel I
prefer, I do not confine myself thereto in respect of form, arrangement, or
fuel, so long as it is suitably arranged for carrying out my Invention; and I
would have it understood, that what I claim as my Invention is, the reducing
the ore or oxide of zinc as herein-before described and explained, by means
of a furnace so arranged or contrived that the hot or burnt air after passing
through the fuel shall, before or at the time it arrives amongst the ore or
zinc, be deprived of the properties or matters which render necessary the
enclosing of unreduced zinc and reduced zinc in the ordinary process as
described.
In witness whereof, I, the said Harrison Gray Dyar, have hereunto.set
my hand and seal, this Eighteenth day of May, in the year of our
Lord One thousand eight hundred and thirty-nine.
HARRISON GREY (L.s.) DYAR.

page_text: AND BE IT REMEMBERED, that on the Eighteenth day of May, in the
year of our Lord 1839, the aforesaid Harrison Gray Dyar came before our
said Lady the Queen in Her Chancery, and acknowledged the Specification
aforesaid, and all and every thing therein contained and specified, in form
5 above written. And also the Specification aforesaid was stamped according
to the tenor of the Statute made for that purpose.