IMPROVEMENTS IN THE MANUFACTURE OF CERTAIN CHEMICA AND T PRO
Year: 1882

page_text: LETTERS PATENT to Josiah Wyckliffe Kynaston of Liverpool in the county
of Lancaster Manufacturing Chemist for an Invention of "IMPROVEMENTS
IN THE MANUFACTURE OF CERTAIN CHEMICA
AND
T
PROVISIONAL SPECIFICATION left by the said Josiah Wyckliffe Kynaston at
the Office of the Commissioners of Patents on the 10th August 1882.
"
JOSIAH WYCKLIFFE KYNASTON of Liverpool in the County of Lancaster
Manufacturing Chemist. IMPROVEMENTS IN THE MANUFACTURE OF
CHEMICALS AND IN THEIR PURIFICATION FROM IRON."
CERTAIN
The object of this invention is the manufacture more especially of sulphate of
alumina free from iron but it also relates to the extraction of ferruginous matters
from other salts that will not suffer decomposition by the addition of per oxide of
mangonese.
In making sulphate of alumina solution from bauxsite and sulphuric acid
sulphate of iron remains dissolved in the liquor. This if allowed to remain would
be very prejudicial to the application of the sulphate of alumina in Calico printing
and other arts.
To extract the iron I add freshly precipitated hydrated per oxide of manganese
or Weldon mud preferably after washing with acid. This in some way combines
with the iron and causes it to precipitate.
If however monoxide of manganese or a ferrous salt be present sulphate of
manganese is formed and passes into solution.
This however can be eliminated by adding a little bleaching powder.
The solution before adding the manganese should be as neutral as possible
otherwise some manganese will pass into solution.
The precipitated iron and manganese material after being separated from the
solution is treated with an acid preferably sulphuric and the iron extracted when.
the manganese mud is ready for use afresh.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, and of
an Order of the Lord Chancellor, filed by the said Josiah Wyckliffe Kynaston
in the Great Seal Patent Office on the 12th September 1883.
JOSIAH WYCKLIFFE KYNASTON of Liverpool in the County of Lancaster,
Manufacturing Chemist " IMPROVEMENTS IN THE MANUFACTURE OF
CHEMICALS AND IN THEIR PURIFICATION FROM IRON "
CERTAIN
The object of my Invention is the removal of iron from certain solutions
contaminated therewith, and the process is especially applicable to the production
of pure or almost pure Sulphate of Alumina from ferruginous Aluminous minerals,
but it may also be used for the removal of iron from alkaline earthy and
metallic salt solutions, which do not decompose the agent used.
Several methods are in use for the extraction of iron from such solutions, as for
instance, the very old process of crystallization of the salt, when the iron remains
in the mother liquors; the use of white arsenic and chalk in conjunction, when the
iron is precipitated in combination with Arsenious Acid; the precipitation of iron
by means of ferro- and ferri-cyanides, or by long agitation of the solution with a
large excess of hydrate of peroxide of lead by which the iron is removed. Lastly
it has been proposed to effect the removal of iron from such solutions by heavy
pressure of the crystalline magma obtained by concentration and subsequent
cooling of the impure solution.
In my new process, now to be described, the agent used is the hydrato of
peroxide of manganese or more correctly speaking the manganite of hydrogen or
other manganite as precipitated from solutions of manganese by any of the well
known means, such as by the addition of solution of bleaching powder or other
hypochlorite, or of a solution of a permanganate, or, and this is the form I prefer,
I use the recovered manganese known as Weldon mud and so extensively used in
the manufacture of Chlorine.
By whichever mode the manganite of hydrogen be produced, if it be con-
taminated with foreign matters, or if a manganite of other bases such as that of
lime and protoxide of manganese as it exists in Weldon mud, I prefer to freo it
from such matters or bases by washing it with dilute nitric or other acid which
will not decompose the manganous acid. But this is not essential to the success of
the process.
I will now describe my invention as applied to the production of pure or nearly
pure Sulphate of Alumina from aluminous minerals containing iron.
Finely powdered Bauxite or other aluminous mineral is added to hot sulphuric
Acid of sp. gr. 1.45 to 1.50 in sufficient quantity to produce a neutral or almost
neutral salt. When the violent reaction has abated, there is added to the mass a
sufficient quantity of hot water to prevent solidification and then sufficient cold
water to reduce the mixture to sp. gr. about 1.20 whilst hot.
Whilst the reaction is proceeding as above it is desirable, but not absolutely
necessary, to add to the seething mixture nitrate of soda or other suitable oxidizing
agent in sufficient quantity to convert the protoxide of iron present into peroxide.
The quantity of Nitrate of Soda required varies from 4 to 8 or 10 pounds per ton
of hydrated Sulphate of Alumina contained in the batch, according to the quality
of the Bauxite used.
Or, if it be preferred, the iron present may be peroxidised by adding to the
mixture after dilution with water, a solution of bleaching powder or other hypo-
chlorite, with brisk agitation of the mixture, the complete peroxidation of the
Iron being ascertained by failure to produce a blue colouration when a drop of

page_text: the alumina solution is brought into contact with a drop of solution of ferricyanide
of potassium.
The aluminous solution is now allowed to stand at rest until the undissolved
matters have completely subsided, and the clear solution is then drawn off. To
extract the iron from this solution I now add thereto the precipitated manganite
in the state of wet mud, and continuously agitate the mixture, adding from time
to time fresh portions of the manganite, until, by testing a filtered sample of the
mixture, it is ascertained that the iron is completely or almost completely removed.
The agitation is then discontinued and the precipitate allowed to subside. The
clear yellowish or brownish coloured supernatant liquor is then drawn off and may
be at once concentrated till of sufficient strength to set on cooling. The cake thus
obtained is white or slightly yellowish and is very pure.
If before the addition of the manganite of hydrogen to the solution to be
purified from iron, the iron be not perfectly peroxidized, or if the solution contain
free acid, or if the manganite mud be not purified as above mentioned, then
a proportionate quantity of manganese will pass into solution in the state of
protoxide or sesquioxide, and this must be removed before the solution is boiled
down.
This I accomplish by the addition of a sufficient quantity of solution of
bleaching powder or other hypochlorite. If the quantity of manganese contained
in the Aluminous Solution be considerable, a brown or even black precipitate
of manganite of hydrogen is at once produced on the addition of the hypochlorite,
otherwise there is no immediate alteration in the appearance of the solution, but
on standing for 24 hours, a more or less deep brown colouration develops. In
either case, the solution is after standing 24 hours heated to boiling, when the
manganese becomes insoluble, and is allowed to subside. The supernatant liquor
is then concentrated so as to yield a solid cake of Sulphate of Alumina on
cooling.
The separation of dissolved manganese from the Aluminous solution may also
be effected by the addition of solution of a permanganate so long as the pink
colour of the permanganate is destroyed, when on the application of heat, the
manganese originally present and that added as permanganate, mutually react
and separate as insoluble manganite of hydrogen.
The separation of dissolved manganese by either process is very perfect, but on
economical grounds I prefer the mode of separation by hypochlorite.
To recover the manganite of hydrogen used in this process for the separation of
iron from aluminous solutions for repeated use, the compound of manganese and
iron deposited from the solution together with that subsequently separated by
means of hypochlorite or permanganate, is first well washed with water (the
washing waters being used in the production of a fresh batch of aluminous
solution), and then thoroughly agitated with a sufficient quantity of dilute
Sulphuric Acid, which completely dissolves out the iron from the compound. The
ferric solution is separated from the manganite of hydrogen in any convenient way,
either by the use of a filter press or otherwise, and the last traces of acid removed
by repeated washing with water. The inanganite of hydrogen mud is then ready
for use for the purification from iron of a fresh batch of Aluminous solution.
When it is not desired to recover the manganese mud for repeated use, the
purifying agent may be added to the aluminous solution in its first stage of
preparation, that is whilst still containing the undissolved bauxite and insoluble
matters suspended in it.
After the dilution of the mixture and the perfect peroxidation of the iron as
before described, the manganese mud is added and the mixture thoroughly agitated
until the iron is completely or almost completely removed from solution. The
mixture is then allowed to stand at rest when the compound of manganese and
iron subsides together with the other insoluble matters, and the clear supernatant
solution is concentrated till it yields a solid cake on cooling. The separation of
iron by this mode of operation is as completo as by the method first described.

page_text: This invention is applicable for the removal of iron from aluminous solutions
obtained by other processes than those herein described, and also from solutions of
other salts which do not decompose the manganous acid of the manganite, and the
process is substantially as described for the removal of iron from aluminous solutions
obtained from Bauxite.
Having now described my invention, and the best mode known to me of
carrying it into effect, I wish it to be understood that I have read Semper's
Specification as amended N° 4440 of 1882 and do not claim any portion of the
same as my invention, and further I make no claim for precipitating iron from
aluminous solutions by means of any oxide of manganese as I know of no oxide of
manganese that is adaptable for this purpose, and it is only manganite of hydrogen
(the hydrate of the peroxide of manganese) or other manganite that is effectual,
peroxide of manganese itself having no appreciable effect no matter how finely
pulverized, but that what I claim as my invention under the Letters Patent is :-
First-The separation of iron from solution of Sulphate of Alumina or other
salts not having a decomposing action on the manganous acid of the manganite,
by means of precipitated manganite of hydrogen ("hydrate of peroxide of
manganese") or other manganite such as described, whether in the form of
Weldon mud (purified or not), or other artificial precipitate prepared previously
or formed at the time in the solution by means of a chemical or chemicals added
thereto, substantially as herein described.
Second-In the process of separating iron from solutions by means of a
manganite, the recovery of manganite of hydrogen in a state for re-use by
removing the iron with dilute sulphuric or other acid which will dissolve the iron
without decomposing the manganite of hydrogen simultaneously produced.
Third-In the separation of Iron from Aluminous solutions by means of a
compound of manganese, the preliminary peroxidizing of the protosalts of iron
in the solution by means of an oxidizing agent, and also the subsequent separa-
tion of any dissolved manganese by means of an oxidizing medium, substantially
as specified.
In witness whereof I the said Josiah Wyckliffe Kynaston have hereunto set
my hand and seal this fifth day of September in the year of our Lord One
thousand eight hundred and eighty three
("ST) NOISWAIN CLINTIM HYISOL