Improvements in the Manufacture of Permanganates and Chlorates.
Year: 1888

page_text: Date of Application, 13th July, 1888
Complete Specification Left, 15th Apr., 1889
Complete Specification Accepted, 1st June,
1889
PROVISIONAL SPECIFICATION.
Improvements in the Manufacture of Permanganates and
Chlorates.
We, GEORGE HARRISON BOLTON, JOSIAH RIGBY WYLDE and HENRY AUER,
all of Widnes in the County of Lancaster, Manufacturing Chemists, do hereby
declare the nature of this invention to be as follows:-
A process of making a mixture of permanganate of soda and chlorate of soda is
set forth in patent No. 8217 of 1887. This mixture is contaminated with chloride of
sodium.
The present invention is for a method of separating these three salts from each
other by means of their different solubilities in hot and cold water.
Our experimental method of carrying out this invention is as follows:
-
To eliminate the chloride of sodium, we boil down the liquor and fish out the
chloride until the other salts begin to fall out. To the hot solution we add chloride of
potash in quantity required and then cool, when the permanganate of potash separates
out in a crystalline form.
On
The mother liquor still contains some chloride of sodium and permanganate of
potash. These two are eliminated by boiling down and fishing the salts out.
subsequently cooling the mixture, chlorate of soda crystallises out.
In case, however, chlorate of potash is wanted, the mother liquor aforesaid is boiled
with a corresponding amount of chloride of potash and allowed to cool. The chlorate
of potash being less soluble in cold water than the chlorides, it crystallises out, and
the remaining mother liquor, consisting chiefly of chloride of soda is put into a new
batch or otherwise.
C T 1
1000
WM. P. THOMPSON & Co.,
Of 6, Lord Street, Liverpool,
Patent Agents for the Applicants.

page_text: COMPLETE SPECIFICATION.
Improvements in the Manufacture of Permanganates and
Chlorates.
We, GEORGE HARRISON BOLTON, JOSIAH RIGBY WYLDE and HENRY AUER
all of Widnes, in the County of Lancaster, Manufacturing Chemists, do hereby
declare the nature of this invention and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement :-
Manganate of soda, as obtained by igniting a mixture of a higher oxide of
manganese and caustic alkali, always contains a quantity of these ingredients still
uncombined. We accordingly treat with chlorine, the aqueous solution of all that is
soluble in the ignited mass. By this means, the manganate of soda is converted into
permanganate and chloride of sodium, and the caustic soda finally into chlorate and
chloride of sodium, as described in Patent No. 8217 of 1887. We propose now to
utilise the resulting solution for the manufacture of permanganate of potash and
chlorate of soda, or of permanganate of potash and chlorate of potash, by means of
fractional precipitation with chloride of potassium.
In carrying out the process, the chlorinated solution is evaporated to about
90 degrees Twaddle specific gravity, and the chloride of sodium which separates out
in boiling down, is occasionally fished out; the solution contains now only about
one third of the chloride of sodium originally present, besides almost the whole of the
permanganate and chlorate. In adding now less chloride of potassium than is
theoretically required for converting the permanganate of soda into the corre-
sponding potash salt and allowing the solution, measuring about 80 degrees Twaddle
specific gravity to cool, the bulk of the permanganate of potash crystallizes out,
whilst the chlorate of soda remains entirely in solution. An additional quantity of
permanganate of potash is obtained by further concentrating to about 130 degrees
Twaddle specific gravity, fishing the chloride of sodium occasionally out of the liquor
and allowing to cool. The crystals which fall out furnish on recrystallising,-same
as the first crop, a pure permanganate of potash.
The fished out salts are deprived of the adhering mother liquor, dried, and contain
up to six per cent. of permanganate of potash; they can be used as a disinfectant
and brought to any required medium strength by mixing with the first crystals of
permanganate.
The mother liquor from the fished out salts and those resulting from recrystallising
the crude permanganate return to the process.
The strong mother liquor contains now chiefly chlorate of soda, chloride of sodium
and a small quantity of permanganate of potash, the latter of which has to be com-
pletely eliminated before working up the liquor for chlorates. This can be done by
means of sulphuretted hydrogen, alkaline sulphides, etcetera, or sulph-hydrates of
the alkaline earthy metals (soda lye, strontia mother liquor, etcetera), which are mixed
with the above heated solution until the dark red colour of the latter turns faint pink.

page_text: The permanganate is precipitated thereby in form of a mud, consisting of dioxide of
manganese in combination with alkali; this has to be filtered off and the clear liquor
contains now only chlorate of soda and chloride of sodium, in the proportion of
about 1 equivalent of each.
Some manganese ores contain a considerable quantity of carbonate of lime which is
carried forward in the course of the process. According to its quantity, it is partly
or entirely precipitated by the soluble sulphates formed through the action of per-
manganate on the sulphides, etcetera should any lime remain in solution, it is
advisable to precipitate it at this juncture, by means of sulphate or carbonate of soda
or with the vat liquor of the Le Blanc alkali process. The sulphate or carbonate of
lime is filtered off and the purified liquor boiled down.
In boiling down to 100 to 120 degrees Twaddle specific gravity, a further small
quantity of chloride of sodium can be fished out; the settled liquor deposits, on
cooling, chlorate of soda of great purity. The remaining mother liquor is preferably
added to a new batch of purified chlorate liquor and boiled down along with it.
Should chlorate of potash be wanted, the chlorate of soda liquor is boiled down to
about 80 degrees Twaddle with the theoretically required quantity of chloride of
potassium, in order to convert the soda-salt into the corresponding potash-salt, the
chloride of sodium fished out, the liquor slightly diluted and allowed to crystallize.
The mother liquor returns in the process.
Having now particularly described and ascertained the nature of our said inven-
tion, and in what manner the same is to be performed, we wish it to be understood
that we make no claim in this specification for anything set forth in
specification No. 8217 of 1887, but that what we claim is
:-
our
The improvements in and additions to the process set forth in our previous patent
substantially as herein set forth, by which we are enabled to separate the perman-
ganate and the chlorate from each other and from the alkaline chloride and to obtain
pure chlorate whether of potash or of soda, and also permanganate in a pure and
isolated form.
n11 1011 1
CA 1000