Improved Methods of Preparing Solution Compounds for Galvanic Batteries.
Year: 1889

page_text: Date of Application 8th Jan., 1889
Specification Accepted, 12th Feb., 1889
COMPLETE SPECIFICATION.
Improved Methods of Preparing Solution Compounds for
Galvanic Batteries.
WILLIAM PRESCOTT KOOKOGEY, of the City of Brooklyn, in the County of
Kings and State of New York, United States of America, do hereby declare the
nature of the said invention and in what manner the same is to be performed, to be
particularly described and ascertained in and by the following statement:-
My invention relates especially to the preparation of that class of battery compounds,
composed of bichromate of soda, sulphate of soda, and sulphuric acid, which are
designed to be kept and transported in the dry state, and converted into solutions for
use by merely dissolving them in water. Heretofore the compound has been prepared
by mixing the ingredients all at once. The character of the ingredients is such that
at first the mass is in a liquid or semi-liquid state, but gradually changes into a coarse
powder upon stirring, and the difficulty has been, to form a homogeneous mass i.e. to
make the mixing complete before this change takes place. Small lumps of one or
other of the ingredients are likely to form in the mass, and make its strength
irregular so that it is impossible to know how much to use to produce a given
strength in a cell.
But I have discovered that this difficulty may be avoided and a much more efficient
compound may be produced by adopting the method of this invention, which is, in
general, to first dissolve the whole of the sulphate and bichromate in about one-half
of the quantity of acid to be used, and then add the remaining half of the acid as
quickly as possible, stirring vigorously. By some peculiar property of the ingredients,
the chemical combinations which cause the change from the liquid to the solid form,
go on more evenly in this way, and result in a much more homogeneous mass.
proportion of the acid to be used in the first place should be, all that can be added
without causing the change from liquid to solid to begin at any point. The entire
mass is then ready for the change all at once. Another advantage is that by this
process a given quantity of the compound may be made in about half the time that it
would otherwise take.
The
To describe more in detail the best method of applying this process: take eight
parts of sulphate of soda, seven parts of bichromate of soda, and sixteen parts of

page_text: .
sulphuric acid; the parts to be by weight, and the acid to be about 66° Beaumé
heat about half of the acid to about 150° Fahrenheit, and dissolve the sulphate of
soda in it; add the bichromate of soda and dissolve add the remainder of the acid
all at once, and as quickly as possible, and stir vigorously until the mass solidifies. It
becomes a nearly solid mass of chromium-trioxide and acid-sulphate of soda. The
degree of heat to which the first half of the acid is to be brought, if between about
100° and 212° Fahrenheit, is unimportant, 150° is the most convenient. The second
half of the acid is preferably added not heated.
Another and additional feature of my invention is as follows: instead of adding
the bichromate of soda to the sulphuric acid in its dry state, first dissolve it in a small
quantity of boiling water (say 8 parts of the bichromate and 2 parts of water); and
in such case take fourteen parts of the sulphuric acid instead of sixteen; to this super-
saturated solution of the bichromate, add about one-half (say 7 parts) of the quantity
of acid to be used, which is preferably to be added not heated heat the mixture to
about 150° Fahrenheit; dissolve therein the sulphate of soda; add the remainder of
the acid all at once and as quickly as possible, and stir vigorously until the mass
solidifies. The compound produced by this variation of the process is substantially
the same compound, though in a much more deliquescent state. Its advantage lies in
the comparative case and quickness of manufacture. It takes but a few minutes to
manufacture a given quantity, while without the use of the water to dissolve the
bichromate in the first instance, it would take a much longer time. The amount of
water used should be just enough to hold the quantity of bichromate in solution for.
the time required to perform the operation. After the mixing of all the ingredients.
and during the stirring, the compound may be kept heated, in order to drive off as
much as possible of the water.
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 1
claim is,
1. The process of making a battery dry compound whose ingredients are sulphate
of soda, bichromate of soda, and sulphuric acid, consisting of the following steps;
viz. first, dissolving the sulphate and the bichromate in about one-half of the quantity
of acid to be used, the same being heated; and then adding quickly the remainder of.
the acid substantially as described.
2. The process of making a battery dry compound whose ingredients are sulphate
of soda, bichromate of soda, and sulphuric acid, consisting of the following steps ;
viz. first, dissolving the bichromate in just enough hot water to hold it in super-
saturated solution; and then mixing therewith the sulphuric acid and sulphate of
soda to be used; substantially as described.
3. The process of making a battery dry compound whose ingredients are sulphate.
of soda, bichromate of soda, and sulphuric acid, consisting of the following steps:
viz. first, dissolving the bichromate in just enough hot water to hold it in super-
saturated solution; second, mixing with this bichromate solution about one-half of
the quantity of acid to be used, and also dissolving the sulphate therein; and, third,
adding quickly the remainder of the acid; substantially as described.
Dated the 31st day of October 1888.