CERTAIN IMPROVEMENTS IN TREATING ZINC ORES, AND IN. MANUFACTURING. OXIDE OF ZINC
Year: 1847

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, CHARLES
ANDRE FELIX ROCHAZ, of Paris, in the Kingdom of France, Merchant, send
greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Royal Letters Patent under, the Great Seal of Great Britain, bearing date at
Westminster, the Twenty-second day of December, in the eleventh year of
Her reign, did, for Herself, Her heirs and successors, "give and grant unto me,
the said Charles André Felix Rochaz, Her' especial licence, full power, sole
privilege and authority, that I, the said Charles André Felix Rochaz, my
executors, administrators, and assigns, and such others as I, the said Charles
André Felix Rochaz, my executors, administrators, 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 mentioned, should and lawfully might make, use,
exercise, and vend, within England, Wales, and the Town of Berwick-upon-
Tweed, my Invention of "CERTAIN IMPROVEMENTS IN TREATING ZINC ORES, AND
IN. MANUFACTURING. OXIDE OF ZINC ;" in which said Letters Patent is con-
tained a proviso obliging me, the said Charles André Felix Rochaz, by an
instrument in writing under my hand and seal, particularly to describe and
ascertain the nature of my said Invention, and in what manner the same is
to be performed, and to cause the same 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 and by. the same,
reference being thereunto had, will more fully and at large appear...

page_text: NOW KNOW YE, that in compliance with the said proviso, I, the said
Charles Andre Felix Rochaz, do hereby declare that the nature of my said
Invention, and the manner in which the same is to be performed, is particu-
larly described and ascertained in and by the. following description thereof,
reference being had to the Drawings hereunto annexed, and to the letters and
figures marked thereon (that is to say) :-
This Invention consists, firstly, in improvements in the treatment of zinc
ores; and, secondly, in improvements in manufacturing oxide of zinc.
.
First, as regards the treatment of the ores of zinc.-This process has
usually been effected by first converting them into the state of oxide by
roasting or calcination, and afterwards reducing and distilling these oxides by
mixing them with coal, and submitting them to great heat in close vessels or
retorts. This mode of operation is attended with great disadvantages, for
besides occasioning great consumption of fuel and retorts, the product obtained
is by no means in proportion to the richness of the ore. By my improved
process the employment of retorts is entirely dispensed with, and the fuel and
labor are greatly economized; the operation is also completely independent of
the skill of the workman or attendant; and lastly the, loss of metal incidental
to the ordinary method is prevented. Besides these advantages, I would
observe that ores of lead and zinc may both be operated upon at once by my
improved method. The principal features of my, Invention consists in the
reduction of roasted blend-ore, (native sulphuret of zinc) and of the carbonates,
oxides, or, silicates, of zinc, and also, of the sulphurets and oxides of lead, by the
action of the reducing, gases of a blast furnace, by which the scoria, or slag is:
fused, the reduced zinc volatilized, and, the, vapours, condensed; and conducted
into a receiver.of a peculiar form, situated over the mouth of the, furnace, and
heated by the gases therefrom.
.
In Sheet. 1. of the accompanying Drawings, Fig. 1 is, a vertical section of
the furnace taken in a line, with the tuyere holes.; Fig. 2. is an elevation, of the
same on that side, where the aperture, for, charging is, situated, the.condensers
being shewn in section; Fig. 3. is an elevation of the furnace on. the side where.
the tuyere, pipes, are situated. The same letters, are, marked upon correspond-
ing parts, in all these Figures, a is, the aperture. or, channel for charging;
a, sliding partition; b, outer door or cover for closing, the charger channel;
c, c, c, are apertures through which the,scoria are run; d; opening between the
body, of the, furnace and, the receiver, e, the lower part of which is formed: by.the
cover, or partition at the top of the, furnace, and, the upper part by another
cover, larger than, the lower,one, forming, a kind of channel in which the zinc.
is condensed, 9 (Fig. 2) openings for the escape. of the gases; h, hydraulic

page_text: main; ke; k; openings for extracting the zinc and any extraneous matters; these
openings are luted every time the metal; &c. is run off; B is the tüyere ör
blast pipe.
Mode of Operation.The furnace having been heated to the required tein
perature by the combustion of fuel alone; a charge of zinc ore, either in the
state of oxide; carbonate, or silicate, mixed with any suitable flux, according to
the nature of the ore; is introduced into the charging aperture a between the
sliding plate a* and the door b, so that by drawing out the slide a*; the charge
will descend by its own gravity into the body of the furnace without allowing
the gases to escape through the charging aperture b. The charge thus falls upön
a layer of incandescent fuel; rising to a certain height above the tuyere B; à
layer of fuel is then poured upon the ore, then another charge of ore; and so on
alternately until the furnace is full; and it is to be replenished in the samê
manner when the charge sinks below a certain depth, which can be easily ascer-
tained by experience. The zinc is volatilized by the heat, and the scoria fall
into the lower part of the furnace, and are run out at the apertures c; c; c.
The volatilized zinc is carried off with the gases arising from combustion, and
passes through the opening d into the receiver e above. The gases from the
fireplace escape through the openings g, and as these latter might carry off
particles of zinc with them, they are passed through an hydraulic main h
before being allowed to escape into the atmosphere. By this means all sölið
matters are retained, and the zinc, together with any dust or extraneous parti
cles, is extracted through the openings . When the ore to be operated upon
is in a comminuted state, it is advisable to make it up into a paste, together with
the flux, by the addition of water, so that it may be charged in pieces of such
size as not to pass through the fuel. Zinc ore is often mixed with sulphurėt
of lead, and by this mode of operation the zinc is obtained by volatilization,
and the lead by fusion: (this latter running to the bottom of the furnace below
the scorià), if by previous roasting a portion of the sulphur has been driven off
from the ore:
The second part of my Invention consists in a novel construction of appa-
ratus for the manufacture of oxide of zinc; which is représented in Sheet II.
of the accompanying Drawings; Fig. 1 being a vertical section of the furnace
taken in the line' a, b, of Fig. 4, and of the chamber for the reception of the
oxide of zinc: Fig. 2 is a vertical section taken in the line c; d; of the samė
Figure. Fig. 3 is an elevation of the furnace taken at the side where the
door C is situated. Fig. 4 is a horizontal section of the furnace taken in the
line e, f, of Fig. 1. Fig. 5 ista plan view of the collecting chamber. The
same letters are marked upon corresponding parts in all those Figures. A, A,

page_text: retorts or subliming pots, of which there may be any convenient number placed
in the sole of the furnace; B, B, covers of the retorts, which are perforated;
C, door of the oxidizing chamber; F, upper flue through which the gases and
other products of. combustion pass from the fireplace to the chimney; K, K,
vessels for receiving the zinc in case of rupture of the retorts.or pots, in:
which case the liquid metal. would run down on the floor a, a, and from thence
into these vessels. L, flue or chimney of the furnace. m, m, (Fig. 4) vertical
flues in the wall for the passage of the waste gases of combustion; N; top:
partition dividing the oxidizing chamber E from the horizontal flue F; M, M;
chamber for receiving the oxide of zine; O, chimney for creating a draft, and
thus drawing the oxide of zinc, together with air and gases, through the
chamber M in the direction shewn by the arrows, alternately over and under
the upper and lower partitions P and Q. There may be any number of these
partitions, according to the size of the apparatus and the quantity of oxide to
be manufactured, or other circumstances, which will be easily determined by
practice. is a wire cloth or other suitable sifting partition at the end of the
chamber M, for retaining the oxide of zinc, and at the same time allowing
the air and gases to pass through the chimney O. It will be seen that the
furnace is divided into three separate chambers or compartments. The lower
onc, which may properly be called the furnace or heating flue, contains the
retorts A, which are charged with the zinc to be operated upon. The vola-
tilized zinc escapes through the orifices in the covers B of the retorts, and
enters the middle or oxidizing chamber E. The zinc vapor is oxidized and
forced through the chamber M either by means of a blower or by the draft
created by the chimney O at the end of the chamber M. The upper compart
ment F is nothing more than a narrow channel or flue for the passage of the
smoke and gases from the fireplace to the chimney L. These gases heat
the dome N, and thus keep the oxidizing chamber at a sufficiently high
temperature to burn the zinc vapors with facility and rapidity. The par
titions P and Q in the chamber M. are for the purpose of checking the
power of the current and facilitating the deposit of the oxide in the chamber
M, from whence it is withdrawn by means of openings at the sides.
Z
Having now described my Invention, and the means of carrying the same
into effect, I would observe, in conclusion, that I am aware that oxide of zinc
has been heretofore obtained by distillation and bringing the volatilized metal
into contact with atmospheric oxygen in an oxydizing chamber; I do not
therefore intend to claim generally producing oxide of zinc in this 'manner;
nor do. I intend to confine myself rigidly to to the precise arrangement or
construction of parts herein shewn and described, as they may perhaps be

page_text: varied without departing from the nature and object of my Invention; but that
which I consider to be new, and therefore wish to claim as the Invention
secured to me by the herein-before in part recited Letters Patent is,-.
First, obtaining metallic zinc in the manner and by means of the apparatus
above set forth and described, or any mere modification thereof.
Second, producing oxide of zinc by distilling the metal or matters containing
the metal in subliming pots or vessels furnished with perforated covers, through
which the volatilized metal may issue into an oxidizing chamber, where it is
met or brought into contact with the oxygen of the atmosphere, and becomes
converted into oxide of zinc.
In witness whereof, I, the said Charles André Felix Rochaz, have here-
unto set my hand and seal, this Ninth day of June, in the year of our
Lord One thousand eight hundred and forty-eight.
Taken and acknowledged by. Charles
André Felix Rochaz (party hereto),
at Paris, in the Kingdom of France,
the Ninth day of June, One thou-
sand eight hundred and forty-eight,
C. A. F. (Ls.) ROCHAZ.