IMPROVEMENTS IN DECOLORIZING AND PURIFYING SACCHARINE JUICES AND SYRUPS
Year: 1876

page_text: LETTERS PATENT to Alexander Melville Clark, of 53, Chancery Lane, in the
County of Middlesex, Patent Agent, for the Invention of "IMPROVEMENTS
IN DECOLORIZING AND PURIFYING SACCHARINE JUICES AND SYRUPS," A
communication from abroad by Léon Auguste Geistodt and Jules Faron
Plicque, both of Paris, France.
Sealed the 15th May 1877, and dated the 16th November 1876.
PROVISIONAL SPECIFICATION left by the said Alexander Melville Clark at
the Office of the Commissioners of Patents on the 16th November 1876.
ALEXANDER MELville Clark, of 53, Chancery Lane, in the County of Middle-
sex, Patent Agent. IMPROVEMENTS IN DECOLORIZING AND PURIFYING SACCHARINE
65
JUICES AND SYRUPS."
This Invention relates to an improved process of decolorizing and purifying all
kinds of saccharine juices and syrups by means of aluminate of baryta or other
soluble alkaline earthy aluminate.
In the defecation of saccharine juices by lime, the proportion of foreign matters
eliminated and separated by this base are comparatively small, and the defecation
when thus operated, modifies the appearance of the juice and transforms the salts it
contains, but the lime by displacing the alkalies from their saline combinations
forms new salts which are partially soluble and may be found in the juices and
syrups even after carbonatation. On the other hand the combinations formed by
the lime with the azotised and gummy matters contained in the saccharine juices
are highly unstable, and the organic matters become again free during the several
stages of the manufacture.
The employment of aluminate of baryta, according to the present Invention, has
for its object the production in the juices and syrups of combinations which are
highly stable and perfectly insoluble.
Aluminate of baryta Al², 08, Ba, O, is soluble in ten times its weight of water.
By adding this concentrated solution to the saccharine juices, in proportion varying
according to the quality of the latter and the particular stage of the manufacture,
the composition is resolved as follows, viz.:-
1stly. Hydrated alumina, which as is well known forms a gelatinous precipitate

page_text: sulphates which in precipitating carry away a certain quantity of soluble salts of
potash and soda.
3rd. Malate of baryta, soluble when cold, but which precipitates in an anhydrous
condition during the boiling of the juices.
4th. Insoluble carbonate of baryta, due to the presence of the carbonic acid con-
tained in the juices.
5th. Insoluble oxalate of baryta.
6th. Insoluble phosphate of baryta.
7th. Insoluble pectate of baryta.
8th.. Soluble and insoluble organic salts of baryta..
The solution of aluminate of baryta in water is added to the juices as they come
from the rasp, or at any other suitable stage of the manufacture as before men-
tioned, after which the whole is raised to nearly a boiling temperature, and the
excess of baryta remaining in solution in the juices is precipitated. This result may
be obtained in various ways, for example,--
1stly. By the employment of sulphate of lime, which possesses the advantage of
forming insoluble sulphate of baryta and lime. The latter base combining with the
sugar and forming a soluble compound will maintain the alkalinity of the juices
which is an essential condition for preventing the alteration of the said juices.
2ndly. By means of sulphate of alumina which will precipitate the baryta in the
state of sulphate. The alumina precipitated in the state of hydrate will carry with
it a.certain quantity of foreign and coloring matters.
gas which
3rdly. By passing through the juices or syrups, a stream of carbonic acid
may be obtained in the ordinary manner either by calcining carbonate of lime or
by the combustion of coke or otherwise.
4thly. By means of sulphate of sesqui-oxide of iron which will form sulphate of
baryta and sesqui-oxide of iron, both of which are insoluble.
5thly. By the employment of phosphate of ammonia or other reagent which will
allow of completing the decomposition of the excess of aluminate of baryta
employed, and precipitating the baryta and alumina in the form. of insoluble
compounds.
The Invention is equally adapted for purifying refiners' syrups, except that as in
this case the impurities are less, a smaller quantity of the aluminate of baryta should
be employed. The chemical reactions effected are necessarily the same, the only
difference being in the proportion of insoluble compounds formed.
It should be remarked that the sulphate of baryta in precipitating carries with it
a certain quantity of sulphate of potash and soda, and further that the alumina
precipitated in the presence of saline combinations always retains a certain quantity
of these salts.
The aluminate of baryta may be manufactured in various ways, as for example,-
1st. By heating to redness a mixture of alumina and caustic baryta or carbonate
of baryta. On recovering. the mass in water the aluminate of baryta formed is
dissolved and separates from the insoluble foreign matters.
2nd. A more economical method consists in replacing the alumina. by bauxite,
which is a natural compound of alumina and sesqui-oxide of iron, found in
abundance in France and other countries. This mineral is mixed with natural car-
bonate of baryta or witherite, and the whole calcined on recovering by a sufficient
quantity of water, the aluminate of baryta formed becomes dissolved, leaving the
insoluble oxide of iron.
Aluminate of baryta may also be obtained in a crystallized form by the addition
of alcohol to the aqueous concentrated solution, but the crystals should be preserved
from contact with air.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Alexander Melville Clark in the Great Seal Patent Office on the
15th May 1877.
"
ALEXANDER MELVILLE CLARK, of 53, Chancery Lane, in the County of Middle-
sex, Patent Agent. IMPROVEMENTS IN DECOLORIZING AND PURIFYING SACCHARINE
JUICES AND SYRUPS." A communication from abroad by Léon Auguste Geistodt
and Jules Faron Plicque, both of Paris, France.
The present improvements relate to an improved mode of treating all kinds of
saccharine juices, syrups, glucose, molasses, &c., by means of aluminates of baryta
and strontia and other alkaline earthy aluminates or their elements employed either
separately, conjointly, or alternately, and whether alone or together with other
suitable compounds herein-after specified.
The substances hitherto employed for defecating and decolorizing saccharine juices
and syrups have the disadvantage of forming soluble compounds which are found
in the juices and syrups on concentration, while they also introduce injurious
elements such as sulphates into the juices.
In treating saccharine juices and syrups, it is essential to avoid the alteration of
the sugar, due to the organic matters contained in the liquids under treatment.
The use of lime is also avoided as much as possible, as it partially alters the sugar
under the action of heat.
It has been found by numerous experiments that by treating saccharine juices
and syrups by means of aluminate of baryta and other alkaline earthy aluminates
suitably prepared, a thorough defecation and decolorization may be obtained.
Aluminate of baryta (A, O³, Ba, 0,) is soluble in 10 times its weight of boiling
water; on adding this solution to the saccharine juices, the aluminate of baryta
gives rise to the following products and effects the defecation.
1st. Hydrated alumina which carries with it the organic matters forming
insoluble precipitates and a certain quantity of the salts carried down with it.
2nd. Insoluble sulphate of baryta.
3rd. Malate of baryta which precipitates during the boiling of the juices.
4th. Insoluble carbonate of baryta.
5th. Oxalate, phosphate, pectate, and other soluble and insoluble salts of baryta.
The processes forming the object of the present Invention (which may be called
processes of double defecation) admit of a much more advantageous treatment of
saccharine juices than the methods now in use, and enable the use of animal char-
coal, lime, and carbonic acid to be dispensed with. The operation may commence as
in ordinary by adding at the rasp or root-cutting machine either sulphite or hypo-
sulphite of soda, sulphite of alumina, or other antiseptic product, to prevent the
alteration of the juices in this preliminary stage of the treatment. The quantity of
aluminate of baryta to be added to the juices depends upon the mode of treatment
adopted by the manufacturer, and the condition of the beets or other matters to be
treated. The aluminate may be introduced in the rough state into the liquors to be
defecated, or if desired, in the form of a concentrated solution made with boiling
water by methodical levigation, and as much as possible out of contact with the air,
and even under pressure in order to quicken the effect. The process may be con-
ducted in two different ways, i.e., with or without heat.
Hot Process. In this method there is added to the juices coming from the rasp a
solution of aluminate of baryta in the proportion of from 3 to 18 oz. of real
aluminate to 22 gallons of juice, which is then raised to nearly a boiling temperature.
By this treatment the acids are saturated by the baryta, and the albumninoid and
organic matters are precipitated by the alumina; the defecation is in this manner
effected under excellent conditions. The juices are then treated again and the
baryta in excess in the juices is saturated, for which purpose either of the following
products, whose concomitant use with aluminate of baryta is entirely novel, are
employed, viz.-Phosphate of ammonia; acid phosphate of lime; sulphate of sesqui-

page_text: oxide of iron; sulphate of magnesia; sulphate of alumina alone or combined with
sulphate of ammonia, or with a simple addition of ammonia; carbonate of
ammonia.
The right is reserved to the simultaneous, alternate, and successive use of the
separate elements of the aluminates according to the method of procedure adopted.
The saturation being effected, and the alkalinity of the juices assured, the operation
is then continued in the ordinary way.
Cold Process. It is preferable to defecate the juices in a cold state, and only
heat them after treating with aluminate of baryta or its analogues, although in this
case it is necessary to employ a larger quantity of the product. The cold process
enables a small quantity of lime to be used at the beginning of the work in the
rasp, which lime is subsequently eliminated in the course of the operation, thus
allowing of a slight saving in the amount of alumina employed. The alumina in
solution is added to the juices coming from the presses, rasps, or diffusion apparatus
in the proportion of from about 1 lb. to 23 lbs. per 22 gallons of juice. If lime be
employed the proportion of alumina may be reduced one-half. The liquid.should
be thoroughly stirred to facilitate the action, which is slower by the cold process,
but it is otherwise more advantageous. The juices, after being thus deprived of the
greater part of their impurities, are recovered, and the baryta in excess is saturated
by the products above specified, but preferably by sulphate of alumina or ammonia
alum. In this manner the sucrates which may be formed are decomposed, insoluble
sulphate of baryta is produced, while the alumina precipitates the organic matters and
the glucic acids not eliminated by the first defection; the free ammonia maintains the
alkalinity of the juices. The juices may then be again decanted or filtered, although
this is not indispensable, and after being thus treated the juices may be kept for
some time without undergoing any alteration.
Another advantage of this process is that it considerably diminishes the quantity
of residue or scum in the proportion of 1 to 3 or even 4, the loss of sugar being
thus considerably reduced, and a correspondingly increased yield obtained. The
same process may also be applied for the treatment of molasses, which matters as
ordinarily obtained have a greenish tinge of repulsive appearance due to the
impurities contained, which also communicate a disagreeable flavor. The molasses,
after being treated with aluminate of baryta or other similar aluminate, entirely
loses its greenish tinge, and yields a product of very good quality, free from
the disagreeable flavour that it possessed previous to the treatment, which admits
of the whole of the sugar contained in the molasses being extracted, since all the
matters have been removed which hindered the crystallization. In order however
to render the treatment as efficacious as possible the molasses should be brought to
a density of from 10 to 15 degrees, in order that it may be passed through a filter,
after which the concentration is effected in the usual way.
The proportion of aluminate to be employed varies according to the degree of
impurity of the molasses, which is ascertained by a preliminary test, but it should
be sufficient to saturate all the sulphuric acid of the sulphates; a slight excess is
not injurious. In certain cases even more of the aluminate may be added in order
to decompose at least in part the carbonates. These processes apply equally well in
refining operations, and may therefore be employed with advantage in England and
the colonies, where th refining of sugar and the extraction from the cane is carried
on. Syrups may be operated on with equal advantage, either by the hot or cold
process; the quantity of aluminate employed being less, the purer are the sugars
under treatment. By the adoption of this process the use of blood is dispensed
with.
The aluminate of baryta may be manufactured in various ways,-
1st. By heating to redness a mixture of alumina and caustic baryta or carbonate
of baryta.
2nd. A more economical method consists in replacing the alumina by bauxite,
which is a natural compound of alumina and sesqui-oxide of iron found in
abundance. This mineral is mixed with natural carbonate of baryta or witherite,

page_text: and the whole calcined at a high temperature, after which it is recovered by water
if necessary.
3rd. Another mode of manufacturing aluminate of baryta consists in calcining at
a high temperature a mixture of natural sulphate of baryta, pulverised charcoal,
and bauxite in suitable furnaces, the mixture thus treated producing aluminate of
baryta. Owing to the high temperature at which the operation is effected the
sulphide which may form by the action of the charcoal upon the sulphate of baryta
is volatilised, and cannot thus contaminate the product. If, notwithstanding the
high temperature to which it has been subjected, the product still contains sulphides,
these may be eliminated by boiling with certain metallic oxides, specially oxide of
zinc, which forms sulphide of zinc, and sets free the baryta.
4th. The aluminate of baryta may be prepared by causing the aluminate of soda
to act upon nitrate of baryta, forming in this case aluminate of baryta and nitrate
of soda. The latter salt may be utilised in the manufacture of saltpetre or in other
ways, and the aluminate of baryta may be washed in cold water to remove any
remaining traces of the nitrate of soda.
Aluminate of baryta and its analogues may also be used in the rasping, pressing,
and diffusion operations, with the object of preventing as much as possible the
alteration of the saccharine juices. This process also has the further advantage of
effecting a large economy in material and motive power. The washing of scums to
extract the sugar therefrom is also rendered not only possible but very easy.
Immediately the saccharine juices come from the rasps, presses, or diffusion
apparatus, a concentrated solution of aluminate of baryta is mixed with them
whereby they are effectually defecated which enables them to be kept for a
considerably longer time before going to the sugar house.
In countries where cane sugar is chiefly made, as in England and the colonies, it
is advantageous to add directly at the outset of the operation the aluminate of
baryta or its analogues to the water used to extract the sugar from the cane by
diffusion.
Aluminate of baryta or its analogues may also be used with advantage to
saturate the sulphuric or other acid which has served to transform dextrine or other
analogous product into glucose. Hitherto immediately the transformation was
effected the sulphuric or other acid was saturated either with lime or carbonate of
lime, so as to produce sulphate of lime which was separated by concentrating the
liquor, but this method failed to remove the whole of the sulphate of lime, which
although but slightly soluble in water still remained in sufficient quantity to impart
a bitter flavour to the glucose obtained. Aluminate of baryta on the contrary
permits of the complete saturation of the acids employed for the production of
glucose, the sulphuric acid being precipitated in the form of sulphate of baryta,
which is entirely insoluble in water.
The aluminate of baryta or other alkaline earthy aluminates which have been
used in the defecation may be readily revivified by means of the alumina precipitated
with the organic matters and the baryta contained in the scum in state of sulphate,
malate, oxalate, and other salts of baryta or of other bases. This revivification is
effected by calcining the mixture, by preference in closed vessels, in order to collect
the ammonia which disengages from the organic matters during the calcination,
whereby an important saving is effected. This revivification may be repeated
several times until the scums contain such a quantity of salts of potash and soda,
that the aluminate is consequently no longer suitable for treating sugars: The
final residue containing potash, alumina, and ammonia furnishes an excellent
manure.
Having described the nature of the said Invention and the manner of performing
the same, I declare that what I claim as the Invention to be protected by the
herein-before in part recited Letters Patent is,-
1st. The processes of making aluminate of baryta herein described and consisting
chiefly, (a), in calcining at a high temperature an intimate mixture of hydrated
alumina and caustic or hydrated baryta; (b), in calcining at a high temperature a
.

page_text: mixture of bauxite, charcoal, and witherite; (c), in calcining a mixture of bauxite,
charcoal, and sulphate of baryta, and afterwards eliminating the sulphides by means
of metallic oxides; (d), in mixing aluminate of soda and nitrate baryta so as to
produce aluminate of baryta and nitrate of soda, which is utilisable for all the
purposes 'herein specified.
2nd. Treating all kinds of saccharine juices, syrups, molasses and glucose, especially
those obtained from beetroot, cane, and other sacchariferous or saccharine substances
as well in the manufacture as in the refining of sugar by the processes herein-before
described.
3rd. The employment of aluminate of baryta and its analogues for defecating and
decolorizing at the producers, the juice of the beetroot or cane as it leaves the
presses, levigating, or macerating apparatus, as herein specified.
4th. Saturating the acids which have been used in the production of glucose by
means of aluminate of baryta, as described.
5th. The process of revivifying the aluminate of baryta and other analogous
aluminates by treating the scums, the ammonia being collected as described.
In witness whereof, I, the said Alexander Melville Clark, have hereunto set
my hand and seal, this Fifteenth day of May, in the year of our Lord One
thousand eight hundred and seventy-seven.
A
AT ADDIZ
A. M. CLARE
R.K. (L.S.)