Year: 1888

page_text: Date of Application, 7th July, 188
Complete Specification Left, 5th Apr.. 1089
Complete specification Accepte 1, 11th May. 1889
I CHARLES ANTHONY BURGHARDT of 35 Fountain Street, in the City of Manchester,
County of Lancaster, Analytical Chemist, do hereby declare the nature of this Inven-
tion to be as follows:-
My Invention relates to the production of metallic zinc from certain of its ores or
from oxides resulting from the treatment of zinc ores or other matters containing zinc.
For some purposes it is of great importance to obtain zinc in a state of purity that is
to say free from iron manganese or other matters with which ordinary zinc is
associated. I obtain the zine by electro deposition from an alkaline zincate solution
or from a bath in which the alkaline zincate is produced during the operation. I
prepare an alkaline zincate by dissolving the zinc oxide contained in roasted zinc or
by dissolving zinc oxide otherwise obtained in a caustic soda or potash solution
proceeding in the usual or in a suitable manner as for example I boil or heat the
solution until the oxide or a suitable proportion of it is dissolved. For the purpose of
my invention it is not necessary that the whole of the oxide shall be dissolved as I
work with the oxide in excess. This excess may be obtained by adding oxide to an,
alkaline zincate solution. I use the solution so prepared as a bath and obtain the pure.
zinc from such bath as an electro deposit upon a suitable cathode preferring to use a
cathode of pure zinc. The supply of oxide is replenished from time to time as may be
required to keep it in excess. As the zincate is decomposed the liberated alkaline
caustic combines with zinc oxide so that after the operation is started the production
of zincate continues it being only necessary to renew the bath when the accumulation
of foreign matters associated with the oxide interferes with the proper action. I
prefer to mount the cathode or cathodes in a compartment which is separated by a

page_text: porous partition from the compartment containing the anode or anodes the oxide or
substance containing the oxide being introduced only into the latter compartment. I
may agitate the solution in the anode compartment either continuously or at intervals.
I prefer to heat the contents of the said anode compartment by means of a steam coil
or by suitable means. In such a case I may employ a hollow steam heated anode or 5
otherwise constitute the steam coil an anode so that the heat is imparted at the best
place that is to say where it is most required.

page_text: I CHARLES ANTHONY BURGHARDT of 35 Fountain Street, in the City of Manchester,
County of Lancaster, Analytical Chemist, do hereby declare the nature of this Inven-
tion and in what manner the same is to be performed to be particularly described,
and ascertained in and by the following statement, that is to
say:
My Invention relates to the production of metallic zinc from certain of its ores or
from oxides resulting from the treatment of zinc ores or other matters 'containing
zinc. For some purposes it is of great importance to obtain zinc in a state of purity
that is to say free from iron manganese or other matters with which ordinary zinc is
associated. I obtain the zinc by electro deposition from an alkaline, zincate solution
or from a bath in which 'the alkalinė zincate is produced during the operation. 1
prepare an alkaline zincate by dissolving the' zinc oxide contained in roasted zinc ore.
or by dissolving zinc oxide otherwise obtained 'in' a caustic soda or potash' solution
proceeding in the usual or in a suitable manner as for example I hoil or heat the
mixture of zinc oxide and'caustic alkali solution until the oxide or a suitable propor-
tion of it is dissolved. I find it an advantage to grind or disintegrate the zinc, ore so
as to reduce it to a fine powder preparatory to the treatment with the caustic alkali
solution. For the purposes of my invention it is not necessary that the whole of the
oxide shall be dissolved as. I prefer to work with the oxide in excess. This excess
may be obtained by adding oxide to an alkaline zincate solution or by introducing
roasted zinc ore' into the anode compartments as hereinafter mentioned. I use the
solution so prepared as a bath and obtain the pure zinc from such bath as an electro
deposit upon suitable cathodes preferring to use cathodes of pure zinc. The supply of
As
oxide is replenished from time to time as may be required to keep it in excess.
the zincate is decomposed the liberated caustic alkali combines with zinc oxide so that
after the operation is started the production of zincate continues it being only neces-
sary to renew the bath when the accuinulation of foreign matters associated with the
oxide interferes with the proper action. I.prefer to mount the cathodes in compart-
ments which are separated by porous or permeable partitions or walls from the
compartments containing the anodes the oxide of zinc or substance containing such
oxide being introduced only into the latter compartments.
In an apparatus which I consider to be suitable for the purpose the anodes are
arranged to alternate with the cathodes within a tank or cistern containing a solution
prepared as aforesaid. The anodes are separated from the cathodes by means of
vertical pervious walls or partitions made of asbestos cloth or other suitable material
In each anode
so as to form separate compartments each containing an anode.
compartment I place a quantity of roasted zinc ore. To facilitate the charging and
replenishing of the anode compartments they may be made removable so that they can
be lifted out of their places and after being re-charged be lowered into position in the
tank. I have obtained good results in practice by the use of an electric current of a
power of four to five Ampéres for each square foot of cathode surface. After the bath

page_text: has been worked for some time there may be an accumulation of sodium or potassium
carbonate in the bath or solution. When this is the case I run the bath off into a pan
and evaporate the solution down until it has become concentrated to the crystalising
point of the alkali carbonate. I then allow the liquor to become cold and the crystals
of alkali carbonate to form. The clear liquor is then run off leaving the crystals of
sodium or potassium carbonate. The liquor so run off may be returned to the bath
and be again used or if necessary may be strengthened by boiling in company with
zinc oxide or powdered roasted zinc ore. As the metals usually associated with zinc
in its ores are not soluble in caustic soda or potash. such metals are precipitated as
oxides during the electro deposition of the zinc consequently the zinc is deposited in a
state of great purity. I may agitate the contents of the anode compartments or of the
tank either continuously or at intervals or I may employ suitable means to obtain a
constant circulation of the liquid. I may heat the contents of the said anode com-
partments by means of a steam coil or by suitable means. In such a case I may
employ a hollow steam heated anode or otherwise constitute the steam coil an
anode so that the heat is imparted at the best place-that is to say where it is most
required.
2
Having now particularly described and, ascertained, the nature of my said
invention and in what manner, 'the same is to be performed: I declare that, what I
claim is :-
H.
(1) In the obtainment of z
zinc by
y electro deposition the treatment of zinc oxide or
"
roasted zinc ore containing oxide of zinc with a solution of caustic alkali so as to
obtain an alkaline zincate solution for use as a bath substantially as set forth.
(2) In the obtainment of zinc by electro deposition; mounting the anodes in
compartments which are separated by means of porous or permeable walls or partitions
from other compartments containing the cathodes, or from the main body of liquid in
the tank, or cistern, charging the anode compartiments with roasted zinc ore or with
zinc oxide, and using a bath of alkaline zincate solution, the pure zinc being obtained
as an electro deposit upon the cathodes, substantially as set forth.
(3) In the apparatus for use in the manner and for the purpose set forth; the
hollow Anodes, into which steam may be introduced, in order to warm or heat the
solution in the Anode compartment.
Dated this 4th day of Anril 1889
DUTTON & FULTON,
1, St. James Square, Manchester,
Agents.