A NEW OR IMPROVED MANUFACTURE OF SUGAR AND LIME FROM MOLASSES AND SOLUTIONS OF CANE SUGAR
Year: 1880

page_text: PROVISIONAL SPECIFICATION left by Charles Denton Abel at the Office
A com-
of the Commissioners of Patents on the 30th November 1880.
munication from abroad by Josef Drucker, of Brünn, and Louise Steffen, of
Vienna, in the Austrian Empire.
"
CHARLES DENTON ABEL, of No. 28, Southampton Buildings, Chancery Lane,
in the County of Middlesex. A NEW OR IMPROVED MANUFACTURE OF
SUGAR AND LIME FROM MOLASSES AND SOLUTIONS OF CANE SUGAR." [A com-
munication from abroad by Josef Drucker, of Brünn, and Louise Steffen, of
Vienna, in the Austrian Empire.]
According to the present Invention molasses or solutions of cane sugar are brought
together with lime, either in the form of calcium, oxide, or hydrated, and water in
such manner and such proportions that an intimate and rapid mixture and
combination of the particles of sugar and lime is effected resulting in the formation
of a solid precipitate consisting of saccharate of lime, which can then be readily
separated from the mother liquor. For this purpose the lime employed is not less
in quantity than the sugar present in the liquid, and so much in excess of such
minimum is added as may be requisite to effect the more or less complete
combination of the sugar present.
Whether it be necessary to employ more than the minimum of 100 parts by
weight of lime to 100 parts by weight of sugar, will depend upon the nature of the
molasses or saccharine solution, as also upon that of the lime used, and the
necessity for a greater or less excess will be shewn by the circumstances and
indications to be presently referred to.
This
By bringing sugar rapidly and intimately together with a sufficient quantity of
free lime in finely divided condition, a chemical relation will be brought about
between the soluble compound of sugar and lime thus produced and the free lime,
which is shewn by the fact that the sugar and lime are precipitated in the liquid
as an insoluble mass, from which the adhereing liquid may be removed by any
known processes for separating precipitates from their mother liquors.
separation of the liquid from the precipitate must be effected quickly after
precipitation, as this combination of the saccharate of lime and free lime only
exists for a short time, so that if allowed to stand it decomposes again into a
soluble saccharate of lime and free hydrate of lime. This last named property of
the compound is made use of to separate the considerable excess of lime from the
saccharate after removal from the mother liquor, for which purpose the compound is

page_text: treated with water in any suitable known lixiviating apparatus, yielding &
sufficiently concentrated saccharate solution and hydrate of lime separate from
each other.
The saccharate of lime solution thus produced can then be decomposed by carbonic
acid, or by any other known process for separating lime, and the sugar solution be
evaporated for crystallization, or otherwise treated, Or the saccharate of lime
solution can be added to green beet syrup as a separating agent, and the whole be
then treated for the manufacture of sugar.
In producing solid saccharate of lime from watery solutions of cane sugar or
molasses by employing certain proportions of lime as above described, the separated
liquid which I will term mother liquor, and to which may also be added the water
used for entirely freeing the precipitate from such liquor, is either run off, if the
sugar has been sufficiently extracted therefrom, or the liquors or washing water or
both may be used for diluting fresh qualities of sugar solution or molasses in carrying
on the above described operation for the production of saccharate of lime. Or again
the mother liquor and washing water or either of them may be further deprived of
sugar by adding thereto lime in the proportion above described so as to combine
with the sugar to form saccharate of lime.
In practically carrying out the above described process, the lime is by preference
employed in the form of burnt or quick lime, ground to a fine powder in a mill, or
otherwise; if hydrated or slaked lime be used, this must also be in a finely divided
form, and must be taken in such quantity that the percentage of lime therein gives
the above described proportion of equal parts of lime and sugar as the minimum.
On mixing the lime with the solution of sugar or molasses in a vessel and stirring
rapidly, a viscous precipitate will be quickly formed, consisting of lime and sugar,
which can be readily separated from the mother liquor in filter presses. centrifugal
machines, or the like, and can then be treated with water for the separation of the
excess of lime.
If the aqueous solution of molasses or cane sugar should, on account of the
prescence of impurities, not form the above described compound with lime when
equal parts are combined as described, more lime must be added until the precipitate
is formed. The dilution of the molasses or sugar solution should be such that it
can be rapidly and easily stirred up with the lime, and it has been found
advantageous to carry the dilution to such a degree that there are less than 30 per
cent of solid matter present in the liquor, but I do not bind myself to this
proportion. Or a portion of the lime might be mixed with the saccharine solution
or molasses at any degree of concentration, and the remainder be added after dilution;
or again, the diluting water and the lime might be added simultaneously. After
removing the greater part of the mother liquor from the precipitate by means either
of filter presses or centrifugal machines, as above stated, water is added in the same
presses or machines for removing the remaining liquor, or the precipitate may for
this purpose be treated with water in washing apparatus of known construction,
and be then again placed in the filter presses. If the cleansing is effected in the
centrifugal machine the screening face thereof is covered with a cloth.
If it be desired, before utilizing the precipitate thus produced, to remove some of
the excess of lime therefrom, the solid mass is broken up into pieces, or it is ground
fine together with water or a saccharate of lime solution, and it is then brought
together with water in a lixiviating apparatus or battery of known construction,
whereby a soluble saccharate of lime with small precentage of lime will be obtained
separate from the free hydrate of lime which may then either be used directly for
the production of fresh saccharate of line, or it may be previously brnt to produce
caustic lime for this purpose.