Process and Apparatus for the Extraction of Zinc.
Year: 1893

page_text: COMPLETE SPECIFICATION.
Process and Apparatus for the Extraction of Zinc.
I, LEO VICTOR JOAN LYNEN of Nos. 18 and 19 Fenchurch Street in the City
of London, Engineer do hereby declare the nature of this invention and in what
manner the same is to be performed to be particularly described and ascertained
in and by the following statement :-
The extraction of zinc is carried out at the present time in different ways, for
instance, either by the Silescian process or by the Liege process or by the combined
Silesian-Liege process in such manner, that the vapourous zinc produced in the
muffle or in the tube enter into a smaller and cooler receiver organically in one
with the same, and condense there; connected to the receiver is an extension
("allonge") or crucible ("Tüte") in order to catch in addition a part of the
uncondensed zinc vapours going through the receiver which take the form of zinc
dust. In this manner each system consists of:-
Retorts, receiver and crucibles forming an enclosed single apparatus with all the
deficiencies of small and intricate apparatus.
The quantity of zinc extracted is therefore essentially dependent on the
temperature necessary for the condensation of the zinc vapours being kept up in the
receiver. The limits are tolerably narrow between which the reduction into a fluid
state of the zinc is effected from vapour form, say between 420° C. and 555° C. If
the temperature in the receiver be below 420° C., the zinc vapours instantly go
over to the solid condition, that is to say, they solidify. If the temperature be
above 550° C., they go through the receiver without condensing and are partly burnt
in the furnace.
The mistake in the present system is that it is impossible to regulate the
temperature of every single receiver in either one or the other direction, whereby
also a great loss of time is unpreventible.
The new process has for object to meet this inconvenience in such manner that
the retorts are all connected to one or more condensation chambers common to all,
which by their proportions and arrangements permit of a determined influence
being exercised on the temperature of the interior and the retaining of the same
within the desired limits. If necessary the chambers may be warmed, and they
may also be cooled by conducting cold air or water through them. In like manner,
the temperature may be so automatically regulated that a part of the liquefied zinc
is always left in the condenser and is not run off. This liquefied zinc besides this
would act favourably by surface attraction on the condensation of the vapourous
zinc. Simultaneously a complete liquation of the lead takes place. By dispensing
with the receiver and extension piece the charging of the muffle is facilitated
and made to be carried out mechanically by, for instance, charging the material
in envelopes, whereby are prevented on emptying and charging again great loss
of time and heat as well as the contamination of the sides of the muffle by the
slag.
As the furnace is entirely closed the poisoning of the air with zinc vapours
is finally prevented and the furnace is consequently preferable also on hygienic
grounds.
The accompanying drawings represent an apparatus for carrying out this
invention of which

page_text: The zinc vapours given off from the charged retorts a enter the condensing
chamber where they are precipitated-in case of need the condensing chamber
can be cooled by conducting air or cold water through the cooling pipes c.
The retorts are simply interiorly luted on to the tubular connection d. The
condensed zinc reaches the inclined trough e from whence it may easily be drawn
off. The uncondensed zine dust goes out of the condensing chambers 6 through
the channel or shaft finto the serpentine coils of the dust chamber g. In order
to permit of carrying away the final residue of the zinc vapours, to which the
pressure in the retorts does not suffice, the dust chamber is connected to the
chimney shaft or other suitable exhausting apparatus.
The charging of the retorts is carried out in such manner that the charge is
first of all put into an envelope of the cross section of the retort, which, envelope
is made of paste board or other suitable material which is prepared before use
with water glass or in any other suitable manner.
This envelope or several of same are simultaneously introduced from a charging
table into the retorts. They carbonize during the heating of the retort, thus
serving as a protection for the walls and facilitate the removal of the slag.
By the
mechanical charging of the finished charged envelope the hitherto unavoidable
loss of time and the therewith allied cooling of the furnace are prevented.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :
1. A zinc distilling furnace characterized by the removal of receivers and
crucibles and the employment in lieu thereof of one or more common condenser
chambers in which the zinc vapours are condensed substantially as described and
shewn.
2. In a furnace as firstly claimed the arrangement of one
or more dust
chambers g for the reception of the zinc dust substantially as described and
shewn.
3. In a furnace as firstly claimed the arrangement of cooling or heating
pipes c in the condensing chamber for the purpose of conveniently regulating the
temperature.
4. In a furnace as firstly claimed the combination with the chimney shaft or
other suitable exhausting apparatus of the condensing chamber or of the dust
chamber for the purpose of permitting of drawing off of the last residue of the
zinc vapours out of the retorts into the condensing chamber substantially as
described and shewn.
5. The process for mechanically charging the furnace as firstly claimed, con-
sisting in introducing the charge into envelopes and putting same into the retorts
for the purpose of preventing loss of time and of heat as well as the contamination
of the sides of the retort by the slag substantially as described and shewn.
6. The construction of zinc distilling furnace as shewn on the drawings.
Dated th
JENSEN & SON,
77, Chancery Lane, London, W.C., Patent Agents.