IMPROVEMENTS IN TREATING ORES CONTAINING ZINC, AND THE PRODUCTS OBTAINED. THEREFROM
Year: 1852

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JAMES
GRAHAM, of Camden Grove, Peckham, in the County of Surrey, send
greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Royal Letters Patent, under the Great Seal of the United Kingdom of Great
Britain and Ireland, bearing date at Westminster, the Eighth day of March
(One thousand eight hundred and fifty-two), in the fifteenth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto
me the said James Graham, my exors, adñors, and assigns, Her especial
license, full power, sole privilege, and authority, that I, the said James
Graham, my exors, admors, and assigns, or such others as I, the said James
Graham, my exors, admors, 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 and Wales and the Town of Berwick-upon-Tweed, my Invention of
"IMPROVEMENTS IN TREATING ORES CONTAINING ZINC, AND THE PRODUCTS OBTAINED.
THEREFROM;" in which said Letters Patent is contained a proviso, that I, the
said James Graham, shall cause a particular description of the nature of my
said Invention, and in what manner the same is to be performed, by an
instrument in writing under my hand and seal, to be inrolled in Her
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

page_text: 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
James Graham, do hereby declare the nature of my said Invention and the
manner in which the same is to be performed, are fully described and ascer-
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:-
My Invention relates, firstly, to a method in calcining or roasting the ores
of zinc as to obtain sulphuric acid and carbonic acid in the process of roasting
or calcining the ores in the manufacture of oxide of zinc. Figures 1 and 2
a furnace for roasting blende or calamine, heated by a coke oven, Figures 3
and 4. A, is a furnace for the manufacture of the oxides of zinc; B are
retorts or pots, the number shewn in the furnace are five, but those numbers
can be increased by altering the arch on the top of the furnace; C are pipes
for conveying away, first, the gases, &c, and subsequently the white oxide into
the receiving chambers; H* is a pipe made of galvanized sheet iron, air-tight,
or any suitable material placed immediately over the pipe C, for receiving and
conveying the oxides into the receiving chambers; I is an opening closed
with a lid or door in the iron pipes H*, which serves the double purpose of a
means to keep the pipe clear and an escape of the gases, &c., before the
metallic vapours are given off; J is a valve or small iron door for shutting
off the communication to the receiving chamber until the metallic vapours
appear, the gases, &c. escaping at I, the valve J being closed, and so soon as
the metallic vapours come over they are oxidized in chamber N, the lid I
is closed, and valve J opened, the oxide then passes into the receiving
chamber, a slight draft into which is kept up by an opening into a shaft, or
other suitable means; so soon as the charge is finished, or coming over in a
very small quantity, the valve J is to be shut, and the lid I opened, the door
or mouthpiece of the retort taken out, the charge withdrawn, and a fresh
one replaced, and so on as each retort requires. K are round holes or pipes
built in N the oxidizing chamber, exactly opposite to the pipe C, which answers
the double purpose for the facility of admitting an iron chisel bar to keep the
pipe clear during the operation of the charge, and also to admit sufficient air
to gorge the gases, preventing explosion. N is the oxidizing chamber; D, fire-
place; E, feeding holes; F, flues; G, ash-pits; H, tiles upon which the pots
stand; M, adjusting screw to keep the cover or mouthpiece tight when
claying; O are valves in case of an accidental explosion. If found necessary,
a small iron pipe may be let into the pipe C, within an inch of its opening

page_text: into the oxidizing chamber, for conveying a current of air to oxidize the
metallic vapours, if they are inclined to reduce in the pipe C, or a hole may be
left of about three-eighths of an inch in the mouthpiece or front of the retort
above the level of the charge, but, I have found the charge work very regu-
larly without either of the contrivances.
I will now describe the first part of my Invention. I burn or roast the
blende ground finish in close vessels, pots, or retorts, having a small hole for
the access of air, and pass the sulphurous gas into a chamber, where it is con-
verted into sulphuric acid, the process of forming which, when sulphurous gas
is obtained from other sources, is so generally known as to render it unnecessary
to explain in this my Specification, this part of my Invention consisting of
combining the process of making sulphuric acid with the roasting of blende,
and this process of roasting or burning may be conducted in furnaces similar
to those which iron pyrites are burned for the same purpose; but I prefer a
furnace, as shewn at Figures 1 and 2, heated by a coke oven, the coke from
which may serve as fuel for working the furnace, as shewn in Figure 3. In
furnaces 1 and 2 the blende is to be laid on shelves of the furnace to the
thickness of about two inches, and stirred by passing the handle of a rake or
hoe through the holes in the door for the air to pass to supply combustion,
such stirring being performed every half hour at the least, and I have found
that the ore should, after the first two hours, be raised to a bright red, and
kept at it for fifteen hours, and if properly attended to, about four-fifths of its
sulphur will have passed off; the ore is then to be drawn out, or may be shut
off from communication with the chamber for making sulphuric acid, and the
remaining sulphurous acid allowed to pass off by a flue. If the ore be drawn
out, it will be necessary to transfer it to a reverberatory or calcining furnace,
to drive off the remaining sulphur. In working calamine I employ a similar
furnace to that used and described for the blende, as by such means the
carbonic acid gas can be passed into a chamber, and thus obtained, may be
used for some of the numerous purposes for which carbonic acid is applied.
Secondly, my Invention consists in the manufacture of oxide of zinc.
Figure 3 shews the furnace with references. After the ore is roasted or
calcined, I mix it with one-third its weight of charcoal or anthracite coal, and
proceed as described under Figure 3. I treat calamine the same.
Having thus described the nature of my Invention, and the best means
I am acquainted with for performing the same, I would wish it to be under-
stood that I do not confine myself to the precise details so long as the
peculiar character of either part of my Invention be retained; but what I
claim is,-

page_text: Firstly, the roasting or calcining that zinc ore which is called blende in
close vessels or furnaces, so as to obtain sulphuric acid during the process of
such treatment in the manufacture of oxide of zinc.
Secondly, I claim the mode of arranging the pots or retorts, the oxydizing
chamber, and the holes for keeping the pipes clear, and the mode of pre-
venting explosion of the gases in the manufacture of oxide of zinc from blende
and calamine; and I also claim the roasting or calcining that zinc ore which
is called calamine in close vessels or furnaces, so as to obtain carbonic
acid during the process of such treatment in the manufacture of the oxide
of zinc.
In witness whereof, I, the said James Graham, have hereunto set my
hand and seal, this Fifth day of August, One thousand eight hundred