IMPROVEMENTS IN. THE MANUFACTURE OF CHLORINE
Year: 1860

page_text: LETTERS PATENT to Andrew George Hunter, of 43, Dean Street, New-
castle-upon-Tyne, the younger, for the Invention of "IMPROVEMENTS IN.
THE MANUFACTURE OF CHLORINE."
Sealed the 6th November 1860, and dated the 1st June 1860.
PROVISIONAL SPECIFICATION left by the said Andrew George Hunter-
at the Office of the Commissioners of Patents, with his Petition,. on.
the 1st June 1860.
I, ANDREW GEORGE HUNTER, of 43, Dean Street, Newcastle-upon-Tyne, the-
younger, do hereby declare the nature of the Invention for "IMPROVEMENTS IN
THE MANUFACTURE OF CHLORINE," to be as follows:-
This Invention has for its object the production of oxide of manganese and
oxide of iron from and the utilization of the free acid in the residual or waste
liquors from stills used in the generation of chlorine..
I effect this, firstly, by acting on the said residual liquors, which usually
contain free acid and chlorine, by means of lime, carbonate of lime, sulphuret
of calcium, obtained from soda-maker's vat or tank waste, or from gasworks,
or slag obtained from blast furnaces, either alone or mixed with other matters..
These substances neutralize the free acid and precipitate the oxide of iron,
which can be separated from the solution. by filtration or subsidence and
decantation.
The clear liquor contains as chloride all, or nearly all, its original man-
ganese, and I precipitate this by means of lime, magnesia, or any caustic

page_text: alkali, and obtain a hydrated oxide of manganese, which after separation from
the liquor by filtration or subsidence and decantation, I dry and gently heat or
calcine in contact with air, by which means it is oxidized, and a substance
obtained containing a large percentage of peroxide of manganese.
This may be used as a substitute for native manganese ore for producing
chlorine in the usual manner, and for other purposes in which manganese ore
is used, and as afterwards described by me. The oxide of iron may be used
as a source of iron as a paint, and for other purposes in which oxide of iron is
usually employed.
Secondly, I effect the utilization of the free acid contained in the aforesaid
residual still liquors by causing it to act on artificially prepared peroxide of
manganese for the production of chlorine.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Andrew George Hunter, in the Great Seal Patent Office on
the 19th November 1860.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ANDREW
GEORGE HUNTER, of 43, Dean Street, Newcastle-upon-Tyne, the younger, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the First day of June, in the year of our Lord One
thousand eight hundred and sixty, in the twenty-third year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said
Andrew George Hunter, Her special licence that I, the said Andrew George
Hunter, my executors, administrators, and assigns, or such others as I, the
said Andrew George Hunter, my executors, administrators, and assigns,
should at any time agree with, and no others, from time to time and at
all times thereafter during the term therein expressed, should and lawfully
might make, use, exercise, and vend, within the United Kingdom of Great
Britain and Ireland, the Channel Islands, and Isle of Man, an Invention for
"IMPROVEMENTS IN THE MANUFACTURE OF CHLORINE," upon the condition
(amongst others) that I, the said Andrew George Hunter, my executors or
administrators, by an instrument in writing under my, or their, or one of their
hands and seals, should particularly describe.and ascertain the nature of the
said Invention, and in what manner the same was to be performed, and cause
the same to be filed in the Great Seal Patent Office within six calendar
months next and immediately after the date of the said Letters Patent.

page_text: NOW KNOW YE, that I, the said Andrew George Hunter 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 thereof, that is to say:
This Invention has for its object the production of oxide of manganese and
oxide of iron from and the utilization of the free acid in the residual or waste
liquors from the manufacture of chlorine.
In carrying out my Invention these liquors are first freed from excess of
acid and rendered neutral, which I prefer to do by carbonate or hydrate of
lime, though it may be done by the use of other preparations of lime or
alkalies, using by preference such as are waste products of other manu-
factures, such as sulphuret of calcium obtained from soda-maker's vat waste,
or from gasworks, or others suitable for neutralizing the excess of acid, as it
has been before performed by others. I then precipitate the oxides of iron by
means of hydrate or carbonate of lime, continuing to add the hydrate or car-
bonate of lime so long as the precipitate is reddish brown. This precipitated
oxide of iron I remove by means of filtration, or by subsidence and decan-
tation of the supernatant liquor, which contains as chloride all or nearly all
the manganese. I then precipitate this as oxide of manganese by means of
hydrate of lime or other caustic alkali, and remove this precipitate from the
remaining solution by means of filtration, or by subsidence and decantation.
The precipitated matters are then to be well washed with water to free the
oxide of manganese from chloride of calcium. The oxide of manganese thus
obtained may be employed for any of the purposes for which protoxide of
manganese is used, or it may be heated or calcined in contact with the
atmosphere, by which it will be oxidized and rendered suitable for being again
employed in the manufacture of chlorine in the usual manner, and as herein-
after described, and for other purposes to which oxides of manganese are
applied.
I utilize the free acid usually contained in waste liquors produced in the
manufacture of chlorine by the action of hydrochloric acid upon manganese
ores, by allowing the said waste liquors to act upon the artificially prepared
oxide of manganese in stills or other suitable vessels, and collecting the
chlorine thereby evolved, I having found that liquors containing free acid
which will no longer evolve chlorine from manganese ores, will do so from
artificially prepared oxide of manganese, and these liquors when thus further
charged with manganese in solution, are available for the production of oxides
of iron and manganese, as herein described.
The oxide of iron obtained as above, when freed by washing with water

page_text: from mechanically adhering impurities, is suitable for making into paint in
like manner to that in which oxide of iron has before been used for such
purpose, and for other purposes to which oxide of iron is applicable.
What I claim is the subjecting the residual waste liquors from the manu-
facture of chlorine to the processes herein explained, whereby the excess or
free acid is utilized and neutralized; the iron is separated, and manganese
obtained in the state of oxides, as herein described.
In witness whereof, I, the said Andrew George Hunter, have hereunto
set my hand and seal, this Second day of October, in the year of our
Lord One thousand eight hundred and sixty.
ANDREW GEORGE HUNTER. (L.S.)