Ix- PROVEMENTS IN TREATING ZINC ORES AND SOLUTIONS OP ZINC TO OBTAIN ZINC THEREFROM.
Year: 1862

page_text: LETTERS PATENT to James Dickson, of 66, Tollington Road, Holloway,
in the County of Middlesex, Gentleman, for the Invention of "Ix-
PROVEMENTS IN TREATING ZINC ORES AND SOLUTIONS OP ZINC TO OBTAIN ZINC
THEREFROM.
Sealed the 13th January 1868 and dated the 12th August 1862.
PROVISIONAL SPECIFICATION left by the said James Dickson, at the
Office of the Commissioners of Patents, with his Petition, on the
12th August 1862.
I, JAMES DICKSON, of 66, Tollington Road, Holloway, Middlesex, Gentle-
man, do hereby declare the nature of the said Invention for "IMPROVEMENTS
IN TREATING ZINC ORES AND SOLUTIONS OF ZINC TO OBTAIN ZINC THEREPROM," to
be as follows:-
The usual method of obtaining zinc from its ores is after the preliminary
sorting and roasting to expose the said ores mixed with carbonaceous matter
to a full white heat for many hours and during that time to slowly distil the
zinc from the said ores.
By my 1st method, I precipitate metallic zinc from aqueous acid, saline, or
alkaline solutions of zinc obtained from the said ores of zinc, either by roasting
the said ores and then adding them to water or to other suitable solvents, or

page_text: by treating the said ores at once with suitable acids, alkalies, or salts, and then
transmitting a current of voltaic electricity obtained from inexpensive sources of
that power through any of the said solutions of zinc by means of suitable anodes
and cathodes immersed therein, the metallic zinc in this case being precipitated
on the said cathode employed. Or the solution of zinc used is that which is
the product of voltaic batteries in which zinc has been used as a positive pole.
As an example of the decomposition alluded to any of the said solutions, if
neutral or alkaline, are poured into an iron decomposition cell, and into the
said decomposition cell a porous medium is immersed containing either
sulphuric acid, aqueous solution of sulphate of zinc, or of common salt, into any
of which a carbon anode is immersed; the said iron decomposition cell is then
used as a cathode on which the metallic zinc is precipitated by respectively
connecting the said anode and cathode with the negative and positive poles
of the voltaic battery employed, a heat of about 212° Fahrenheit being pre-
viously applied to the said decomposition cell. A porous cell may in some
-instances be dispensed with, and in using a porous cell as the positive compart-
'ment of the said decomposition cell I assist the said decomposition of the
said solutions of zinc by employing in the said porous cell a carbon or other
suitable anode immersed in various acid, saline, or alkaline solutions as positive
electrolytes also contained in the said porous cell, any of the said solutions of
zinc being contained in the negative compartment of the said decomposition
cell. The principal anodes which I employ are carbon, iron, lead, and other
metallic substances. The principal positive electrolytes are aqueous solutions
of the sulphides of the metals of the alkalies, or of the alkaline earths and
. similar solutions which contain any of the said sulphides combined with
sulphites or hyposulphites, aqueous solutions of the alkalies and alkaline
earths, aqueous solutions of sulphurous acid or of protochloride of iron, other
suitable acid, saline, or alkaline solutions.
By my 2nd method I obtain zinc from its ores or from chemical compounds
of zinc which are sufficiently rich in zinc by subjecting the said ores or com
pounds in a state of fusion to the action of a current of voltaic electricity by
immersing carbon or other suitable anodes and cathodes into the said fused
ores or compounds and then respectively connecting the said anodes and
cathodes with the negative and positive poles of a voltaic battery.