IMPROVEMENTS IN THE TREATMENT OF ANIMAL CHARCOAL
Year: 1874

page_text: LETTERS PATENT to Charles James Crosfield and James Barrow, of
Liverpool, in the County of Lancaster, Sugar Refiners, and Edmund
Alleyne Cook, of the same Place, Analytical Chemist, for the
Invention of "IMPROVEMENTS IN THE TREATMENT OF ANIMAL CHARCOAL
"
PROVISIONAL SPECIFICATION left by the said Charles James Crosfield,
James Barrow, and Edmund Alleyne Cook at the Office of the
Commissioners of Patents, with their Petition, on the 10th June
1874.
We, CHARLES JAMES CROSFIELD and JAMES BARROW, of Liverpool,
in the County of Lancaster, Sugar Refiners, and EDMUND ALLEYNE
Cook, of the same Place, Analytical Chemist, do hereby declare the
nature of the said Invention for "IMPROVEMENTS IN THE TREATMENT OF
ANIMAL CHARCOAL USED IN THE DECOLORIZATION OF SUGAR SOLUTIONS," to be as

page_text: inert. The object of this Invention is to restore the decolorizing power
by treating the char with substances in solution and afterwards re-
burning, whereby pyrophosphate of lime, magnesia, or other insoluble
or slightly soluble base is produced in the char.
New char it is well known is produced by burning bones in closed
vessels, and consists of phosphates of lime and magnesia, carbon, car-
bonate of lime, and organic matter.
When the char has been repeatedly used and become "spent," its
composition varies with the kind of sugar for which it has been used.
It may contain much carbonate of lime, or that substance may be
almost absent. If much carbonate of lime is present we prefer to
remove it by any of the well-known methods, such as treatment with
dilute hydrochloric acid, or with hydrochloric acid gas, as patented by
Mr. Beanes.
To produce pyrophosphates in the spent or used char a dilute solution:
of phosphate of lime, containing only one equivalent of lime to one of
phosphoric acid, is poured over the washed char, preferably while still in
the cisterns, and afterwards it is reburned in the usual way.
We prefer that the solution of phosphate of lime should contain some
proportion of phosphate of ammonia; in fact it is not essential that the
solution should contain any lime. A dilute solution of phosphoric acid,
phosphate of ammonia, phosphate of alumina or magnesia, or any other
acid phosphate not containing iron or a poisonous metal will effect the
object in view.
The char after treatment and before burning turns blue litmus paper
red; after burning it is neutral in consequence of the phosphoric acid,
which was before apparent to litmus paper, having been converted into
pyrophosphoric acid and saturated with base.
When spent char is burnt until all the carbon is converted into car-
bonic acid it leaves a reddish ash. If this residue of impure phosphate a
of lime be treated with a phosphoric acid solution containing ammonia
and heated, it becomes more or less grey or brown according to the
proportion used. This is probably due to formation and decomposition
of phosphamate of lime, and to this we attribute the better effect pro-
duced when ammonia is present.

page_text: filed by the said Charles James Crosfield, James Barrow, and
Edmund Alleyne Cook in the Great Seal Patent Office on the
10th December 1874.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, CHARLES
JAMES CROSFIELD and JAMES BARROW, of Liverpool, in the County of
Lancaster, Sugar Refiners, and EDMUND ALLEYNE COOK, of the same
Place, Analytical Chemist, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Tenth day of June, in the year of
our Lord One thousand cight hundred and seventy-four, in the
thirty-seventh year of Her reign, did, for Herself, Her heirs and
successors, give and grant unto us, the said Charles James Crosfield,
James Barrow, and Edmund Alleyne Cook, Her special licence that
we, the said Charles James Crosfield, James Barrow, and Edmund
Alleyne Cook, our exccutors, administrators, and assigns, or such
others as we, the said Charles James Crosfield, James Barrow, and
Edmund Alleyne Cook, our 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 TREATMENT OF ANIMAL
CHARCOAL USED IN THE DECOLORIZATION OF SUGAR SOLUTIONS," upon the con-
dition (amongst others) that we, the said Charles James Crosfield,
James Barrow, and Edmund Alleyne Cook, our executors or adminis-
trators, by an instrument in writing under our, or their, or one of our or
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.
NOW KNOW YE, that we, the said Charles James Crosfield, James
Barrow, and Edmund Alleyne Cook, do hereby declare the nature of

page_text: De particularly described and ascertained
statement:-
111
anu by the following
When animal charcoal is used repeatedly for refining or decolorizing
sugar solutions it gradually loses its decolorizing power, and becomes
incrt. The object of this Invention is to restore the decolorizing power
by treating the char with certain solutions and afterwards reburning,
wliereby pyrophosphate of lime, magnesia, or other insoluble or slightly
soluble base is produced in the char.
New char it is well known is produced by burning bones in suitable
closed vessels, and consists of phosphates of lime and magnesia, carbon,
carbonate of lime, and organic matter.
When the char has been repeatedly used and become "spent" its
composition varies with the kind of sugar for which it has been used.
It may contain much carbonate of lime, or that substance may be
almost absent. If much carbonate of lime is present, we prefer to
remove it by any of the well-known methods, such as treatment with
dilute hydrochloric acid, or with hydrochloric acid gas, as patented by
Mr. Beanes.
To produce pyrophosphates in the spent or used char a dilute solution
of phosphoric acid, or of phosphate of lime, containing only one or less
than one equivalent of lime to one of phosphoric acid, is poured over the
washed char, preferably, while still in the cisterns, and afterwards it is
reburned in the usual way.
We prefer that the solution of phosphoric acid should contain some
proportion of phosphate of ammonia. A dilute solution of phosphate
of ammonia, phosphate of alumina or magnesia, or any other acid
phosphate not containing iron or a poisonous metal will effect the object
in view.
The char after treatment and before burning turns blue litmus paper
red; after burning it is neutral, in consequence of the phosphoric acid
which was before apparent to litmus having been converted into pyro-
phosphoric acid and saturated with base.
When spent char is burnt until all the carbon is converted into car-
bonic acid it leaves a reddish ash. If this residue of impure phosphate
of lime be treated with a phosphoric acid solution containing ammonia
and heated, it becomes more or less grey or brown, according to the

page_text: proportions used. That is probably due to formation and decomposition
of phosphamate of lime, and to this we attribute the better effect
produced when ammonia is present.
The proportions we find best suited to our treatment are 1 to 2 parts
of glacial phosphoric acid to 100 of dry char. This is diluted with
sufficient water to moisten the whole of the char. If the char be wet
the phosphoric acid solution requires less dilution than when it is dry.
When an acid phosphate is used, it is added in quantity proportionate to
the above to 2% of phosphoric acid. The amount of ammonia we
find it advantageous to have present is not more than sufficient to
neutralize of the phosphoric acid, but we do not bind ourselves to
the above quantities.
Having now described the nature of our said Invention and par-
ticularized the same, we claim treating charcoal by the solutions and
reburning, substantially in the manner and for the purposes set forth.
In witness whereof, I, the said Edmund Alleyne Cook, have here-
unto set my hand and seal, the Eighth day of December, in the
year of our Lord One thousand eight hundred and seventy-
four.
In the presence of
JAMES JOHNSON,
Patent Office,
Clayton Square,
Liverpool.
EDMUND A. COOK. (L.S.)