IMPROVEMENTS IN THE TREATMENT OF ZINC ORES
Year: 1879

page_text: LETTERS PATENT to Friedrich Carl Glaser, of 92, Linden Strasse, Berlin, in the
Kingdom of Prussia and Empire of Germany, Engineer and Patent Agent,
for the Invention of "IMPROVEMENTS IN THE TREATMENT OF ZINC ORES."
A communication from Rudolf Wiester, of Kattowitz, in the Kingdom of
Prussia and Empire of Germany.
Sealed the 20th April 1880, and dated the 25th October 1879.
PROVISIONAL SPECIFICATION left by the said Friedrich Carl Glaser at the
Office of the Commissioners of Patents on the 25th October 1879.
FRIEDRICH CARL GLASER, of 92, Lindenstrasse, Berlin, in the Kingdom of
Prussia and Empire of Germany, Engineer and Patent Agent. "IMPROVEMENTS
IN THE TREATMENT OF ZINC ORES" A communication from Rudolf Wiester, of
Kattowitz, in the Kingdom of Prussia and Empire of Germany.
The present method of treating zinc ores in muffle furnaces necessitates so large
a consumption of fuel and of refractory products for the distilling vessels that it
appears to be no longer remunerative to operate in such wise upon poor zinc ores.
The process the subject of this Invention requires less fuel, and the decrease in the
consumption of fire clay distilling vessels renders the treatment more advantageous
generally, and particularly in a better extraction of the quantity of zinc contained
in the ore. Thus poor ores may be used, the treatment of which by the methods
hitherto in use is not remunerative.
This improved method is described substantially as follows:-
The zinc ores (oxydized ores, such as calamine, bydrosilicate of zinc, franklinite,
or roasted blende) are mixed with the requisite quantity of reducing coal or coke.
The mixture is spread upon the sole or hearth of an English reverberatory furnace,
slightly lengthened, and submitted to the action of a high temperature pushed to a
white red heat, until the charge nearly ceases to disengage zinc vapours, and that
the residue is entirely freed from zinc, or at least only retains a relatively very
small quantity. The zinc vapours which are disengaged in the furnace burn
immediately as they become disengaged from the ore by contact with atmospheric
air, becoming retransformed into oxyde, and the zinc flame with its characteristic
Price G/1

page_text: coloration which appears during the operation serves to mark its progress, and par-
ticularly to indicate the moment of its completion. The oxyde of zinc which is
formed issues with the flame by the inclined flue, and is led by the flue or channel
joined to the incline into condensation chambers of sufficient capacity to lessen the
speed of the gases which are disengaging, so that the oxyde of zinc has the time
and the opportunity to deposit upon the bottom of the chambers and to collect
there. For the better emptying of the chambers it is well to form their bottom
of an arrangement of hoppers, by the opening of which the collected oxyde may be
removed. The oxyde thus obtained is transformed with metallic zinc by the known
method in crucible furnaces.
This process may be put into operation by the aid of well known apparatuses.
The arrangement shown on the accompanying Drawing may serve as an example
of a suitable plant for this purpose.
Upon this Drawing A represents the reverberatory furnace, which is slightly
lengthened for this purpose, and also in order to better utilize the flame, and which
is fed by means of a current of air forced beneath the grate.
The oxyde of zinc which forms as above set forth issues from this furnace inixed
with the other products of combustion by the inclined flue B and goes into a
chamber C, which serves as a refrigerator. In the arrangement which I have chosen
for example this chamber is a wooden box or chest, the inlet side of which is con-
structed of masonry because of the high temperature of the gases which enter it.
The cover or lid of this chest is formed of an iron bowl or basin with perforated
bottom, into which the water is conducted, to run from thence like rain through
the holes in the bottom and cool the gases which pass through the chest.
The water which issues from the chest may when it carrics with it a rather large
quantity of oxyde of zinc be again collected in a clarifying vessel, and the zinciferous
mud or matter deposited in this latter may be collected to be submitted to further
treatment.
The gases mixed with oxyde of zinc issue from this refrigerator and go to a
chamber D, which I term the condensing chamber, and which is formed of suspended
cloth. The bottom of this chamber is composed of cloth sacks or bags in the form
of hoppers, in which the oxyde of zinc which deposits is collected. To empty the
chamber it is only necessary to open these sacks or bags.
The capacity of this condensing chamber is, as aforesaid, calculated so that the
speed of the gases which pass through it is sufficiently reduced to give the oxyde
of zinc time to precipitate. The construction of this chamber is in fact identical
with that of the condensing chambers now in use in the manufacture of zinc white.
The further treatment and the reduction of the oxyde of zinc obtained take place
in the ordinary well known manner.
It will be evident that the arrangement here chosen as example and shown on
the accompanying Drawing does not constitute the only way in which the
apparatus required for the operation may be constructed. The furnace as well as
the refrigerator and the condensing chamber may all be otherwise constructed to
answer the purpose to be attained, my Invention being for the conduct of the
operation as a whole.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by the
said Friedrich Carl Glaser in the Great Seal Patent Office on the 22nd April
1880.
66
:
FRIEDRICH CARL GLASER, of 92, Linden Strasse, Berlin, in the Kingdom of
Prussia and Empire of Germany, Engineer and Patent Agent. IMPROVEMENTS
IN THE TREATMENT OF ZINC ORES." A communication from Rudolf Wiester; of
Katowitz, in the Kingdom of Prussia and Empire of Germany.
The present method of treating zinc ores in muffle furnaces necessitates so large
a consumption of fuel and of refractory products for the distilling vessels. that it
appears to be no longer remunerative to operate in such wise upon poor zinc ores:
The process the subject of this Invention requires less fuel, and the decrease in the
consumption of fire-clay distilling vessels renders the treatment more advantageous
generally, and particularly in a better extraction of the quantity of zinc contained
in the ore. Thus poor ores may be used, the treatment of which by the methods
hitherto in use is not remunerative.
This improved method is described substantially as follows:
The zinc ores (oxydized ores, such as calamine, hydrosilicate of zinc, franklinite,
or roasted blende) are mixed with the requisite quantity of reducing coal or coke.
The mixture is spread upon the sole or hearth of an English reverbatory furnace
slightly lengthened, and submitted to the action of a high temperature pushed to a
white red heat until the charge nearly ceases to disengage zinc vapours, and that
the residue is entirely freed from zinc, or at least only retains a relatively very
small quantity. The zinc vapours which are disengaged in the furnace burn
immediately as they become disengaged from the ore by contact with atmospheric
air, becoming retransformed into oxide, and the zinc flame with its characteristic
coloration which appears during the operation serves to mark its progress, and
particularly to indicate the moment of its completion. The oxide of zinc which is
formed issues with the flame by the inclined flue, and is led by the flue or channel
joined to the incline into condensation chambers of sufficient capacity to lessen the
speed of the gases which are disengaging, so that the oxide of zinc has the time and
the opportunity to deposit upon the bottom of the chambers and to collect there.
For the better emptying of the chambers it is well to form their bottom of an
arrangement of hoppers, by the opening of which the collected oxide may be
removed. The oxide thus obtained is transformed into metallic zinc by the known
methods in crucible furnaces.
This process may be put into operation by the aid of well known apparatuses.
The arrangement shown on the accompanying Drawing may serve as an example
of a suitable plant for this purpose.
Upon the Drawing A represents the reverbatory furnace, which is slightly
lengthened for this purpose, and also in order to better utilize the flame, and which
is fed by a current of air forced beneath the grate. The oxide of zinc which forms
as above set forth issues from this furnace mixed with the other products of com-
bustion by the inclined flue B and goes into a chamber C, which serves as a
refrigerator. In the arrangement which I have chosen for example this chamber is
a wooden box or chest, the inlet side of which is constructed of masonry because of
the high temperature of the gases which enter it.
The cover or lid of this chest is formed of an iron bowl or basin with perforated
bottom, into which water is conducted, to run from thence like rain through the
holes in the bottom and cool the gases which pass through the chest.
The water which issues from the chest may when it carries with it a rather large
quantity of oxide of zinc be again collected in a clarifying vessel and the zinciferous
mud or matter deposited in this latter may be collected to be submitted to further
treatment.

page_text: The gases mixed with oxide of zinc issue from this refrigerator and go to a
chamber D, which I term the condensing chamber, and which is formed of suspended
cloth. The bottom of this chamber is composed of cloth sacks or bags in the form
of hoppers, in which the oxide of zinc which deposits is collected. To empty the
chamber it is only necessary to open these sacks or bags.
The capacity of this condensing chamber is, as aforesaid, calculated so that the
speed of the gases which pass through it is sufficiently reduced to give the oxide of
zinc time to precipitate. The construction of this chamber is in fact indentical
with that of the condensing chambers now in use in the manufacture of zinc
white.
The further treatment and the reduction of the oxide of zinc. obtained takes place
in the ordinary well known manner.
•
It will be evident that the arrangement here chosen as example and shown on
the accompanying Sheet of Drawing does not constitute the only way in which the
apparatuses required for the operation may be constructed. The furnace as well as
the refrigerator and the condensing chamber may all be otherwise constructed
to answer the purpose to be attained, this Invention being for the conduct of the
operation as a whole.
Having now described and ascertained the nature of the Invention communicated
to me as aforesaid, and in what manner the same is or may be performed,
What I claim as novel and as secured to me by the herein before in part recited
Letters Patent is,―
The herein before described process, consisting in reducing zinc ores to the state
of metallic zinc, and particularly calamine, hydrosilicate of zinc, franklinite, and
roasted blende upon the sole or hearth of a reverbatory furnace, mixing them with
reducing agents (coal or coke) by the action of direct flame, and then collecting or
gathering in suitable chambers the oxide of zinc, which is immediately formed by
the contact of the disengaged vapours of zinc with atmospheric air, substantially
as hereinbefore described.
The further treatment and the reduction of the oxide of zinc taking place by
known methods.
In witness whereof, I, the said Friedrich Carl Glaser, have hereunto set my
hand and seal, this Eighth day of April, in the year of our Lord One
thousand eight hundred and eighty.
F. C. GLASER. (L.S.)