AN IMPROVED PROCESS OF REGENERATING THE FLUIDS OF GALVANIC-BATTERIES IN WHICH CAUSTIC ALKALIS ARE EMPLOYED, AND OF RECOVERING TILE ZINC HYDRATE FROM SOLUTION
Year: 1880

page_text: LETTERS PATENT to Alexander Melville Clark, of 53, Chancery Lane, in the
County of Middlesex, Patent Agent, for an Invention of "AN IMPROVED
PROCESS OF REGENERATING THE FLUIDS OF GALVANIC-BATTERIES IN WHICH
CAUSTIC ALKALIS ARE EMPLOYED, AND OF RECOVERING TILE ZINC HYDRATE
FROM SOLUTION." A communication from abroad by Emile Reynier, of
Paris, Franco.
PROVISIONAL SPECIFICATION left by the said Alexander Melville Clark
at the Office of the Commissioners of Patents on the 9th September 1880.
ALEXANDER MELVILLE CLARK, of 53, Chancery Lane, in the County of Middlesex,
Patent Agent. "AN IMPROVED PROCESS OF REGENERATING THE FLUIDS OF
GALVANIC BATTERIES IN WHICH CAUSTIC ALKALIS ARE EMPLOYED, AND OF
RECOVERING THE ZINC HYDRATE FROM SOLUTION." [A communication from
abroad by Emile Reynier, of Paris, France.]
This Invention consists in a process of regenerating the electrolytic fluids of
galvanic batteries in which caustic soda or potash are employed, and of recovering
the zinc hydrate which has become dissolved therein, by utilising the property of
this oxide, of being abundantly soluble in a concentrated caustic soda or potash
lye, only slightly soluble in a weak lye, and insoluble in plain water.
The process of treating the electrolyte of a battery in which caustic soda or
potash are employed, and which has become charged with zinc hydrate by the
working of the battery, consists essentially in precipitating the oxide of zinc by
the addition of water, reconcentrating and decarbonating the liquid.
I proceed as follows:-
1st. I separate by decantation the insoluble carbonate of zinc which may have
been formed by the carbonic acid of the air, or by any carbonates that may
accidentally be present with the caustic alkalis.
2nd. To the liquid freed from the insoluble carbonate of zinc I add four to eight

page_text: volumes of water, which precipitates the zinc hydrate, this precipitation being
more complete the more dilute the solution.
3rd. I decant, collect the zinc hydrate, wash thoroughly, and drain and dry it.
4th. I then evaporate the dilute lye which has been drawn off, concentrating it
till it attains its original density.
5th. I eliminate any carbonic acid the liquid may still contain by caustification
with lime.
The process is applicable to all liquids containing caustic alkalis, solvents of zinc
employed in galvanic batteries, and particularly to the exciting liquids described
in the Specification of a former Patent, dated 22nd March 1880, No. 1234.
The presence of salts added to these liquids increase their conductivity, usually
presents no obstacle to the application of the new process of regeneration herein
described, since these salts are not precipitated by the addition of water.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Alexander Melville Clark in the Great Seal Patent Office on the
8th March 1881.
ALEXANDER MELVILLE CLARK, of 53, Chancery Lane, in the County of Middlesex,
Patent Agent.
"AN IMPROVED PROCESS OF REGENERATING THE FLUIDS OF
GALVANIC BATTERIES IN WHICH CAUSTIC ALKALIS ARE EMPLOYED, AND OF
RECOVERING THE ZINC HYDRATE FROM SOLUTION." A communication from
abroad by Emile Reynier, of Paris, France.
This Invention consists in a process of regenerating the electrolytic fluids of
galvanic batteries in which caustic soda or potash is employed, and of recovering
the zinc hydrato which has become dissolved theroin by utilising the property of
this oxide, of being abundantly soluble in a concentrated caustic soda or potash
lyc, only slightly soluble in a weak lye, and insoluble in plain water.
The process of treating the electrolyte of a battery in which caustic soda or
potash is employed, and which has become charged with zinc hydrate by the
working of the battery, consists essentially in precipitating the oxide of zinc by the
addition of water, reconcentrating and decarbonating the liquid.
I proceed as follows:-(1,) I separate by decantation the insoluble carbonate of
zinc which may have been formed by the carbonic acid of the air, or by any
carbonates that may accidentally be present with the caustic alkalies; (2) to the
liquid freed from the insoluble carbonate of zinc I add 4 to 8 volumes of water,
which precipitates the zinc hydrate, this precipitation being more complete the
more the solution is diluted; (3,) I decant, collect the zinc hydrate, wash thoroughly,
and drain and dry it; (4,) 1 then evaporate the dilute lye which has been drawn
off, concentrating it till it attains its original density; (5,) I eliminate any carbonic
acid the liquid may still contain by caustification with lime.
The process is applicable to all liquids containing caustic alkalis, solvents of zinc
employed in galvanic batteries, and particularly to the exciting liquids described
in the Specification of a former Patent, dated 22nd March 1880, No. 1234. The
presence of sults added to these liquids to increase their conductivity usually
presents no obstacle to the application of the new process of regeneration herein
described, since these salts are not precipitated by the addition of water.
Having described the nature of the said Invention, and the manner of performing
the same, I declare that what I claim as the Invention to be protected by the
hereinbefore in part recited Letters Patent is,-
The improved process of regenerating the electrolytic fluids of galvanic batteries
in which caustic soda or potash is employed, and of recovering the zinc hydrate
from solution, the process consisting essentially in precipitating the oxide of zinc
by the addition of water, reconcentrating the liquor or lye by heat, and decarbonating
by means of lime, substantially as specified.
In witness whereof, I, the said Alexander Melville Clark, have hereunto set
my hand and seal, this Eighth day of March, A.D. 1881.