Process for obtaining Tartaric Acid and Tartrates.
Year: 1896

page_text: PROVISIONAL SPECIFICATION.
Process for obtaining Tartaric Acid and Tartrates.
We, ALEXANDER SCHMITZ, of Düsseldorf the Rhine Province, Kingdom of
Prussia, German Empire, Doctor of Philosophy, and ERNST CHRISTIAN WILHELM
TOENGES, of the same place, Manufacturer, do hereby declare the nature of this
invention to be as follows:-
This invention relates to a process for obtaining tartaric acid either as such
or in the form of tartrate of lime or cream of tartar, from raw materials, bye
products, partially manufactured substances and refuse containing tartaric acid.
The process consists essentially in subjecting the crude lye, obtained by
lixiviating the raw material with solution of alkaline carbonate, and which
lye contains the acid in the form of alkaline tartrate, to the action of a solution
of a hypochlorite, preferably an alkaline solution of a hypochlorite, before treat-
ing it with chloride of calcium, by doing which those component parts of the
crude lye, such as colourizing matter, tannic, and other organic combinations
which are detrimental to the obtaining of a pure product, are destroyed.
We are aware that attempts have already been made to purify crude lye con-
taining tartaric acid by treating it with chlorine in the form of cold gas. This
process has, however, been abandoned, on account of its many disadvantages. It
has been found that the gaseous chlorine attacks the tartaric acid itself, forming
muriatic acid; on the other hand, the chlorine combines with part of the basis
of the acid salt present, and thereby causes a dark coloured bitartrate to separate
out, which reaction causes a great loss and is most troublesome. Furthermore,
the bleaching effect is only very slight. If, however, a hypochlorite be applied
in alkaline solution, not only is a complete decolorisation effected, but the effect
is accomplished quietly and smoothly without any secondary reaction, and without
separating any acid salts or decomposing any tartaric acid, so that the tartaric
acid contents can be obtained in the form of a perfectly white nearly chemically
pure calcium tartrate.
The following may be used as raw materials:-
Any kind of wine lees, either dry or wet, whether containing much or little
tartaric acid;
Crude tartars, dregs of tartar, ordinary cask dregs, Spanish argols, &c;
Crude tartrates of lime, bye-products of commerce, of wine-cultivation and the
manufacture of grape oil, as well as all kinds of manufacturing residues and
refuse containing tartaric acid from dye and printing works.
This process is best worked in the following manner :-
1. The more or less finely ground or otherwise reduced material consisting,
for example, of wine lees of little value is introduced by portions in a boiling
solution of sodium carbonate and the whole boiled up with, or without, applica-
tion of pressure. The treatment is to be so regulated that, when the boiling is
completed, a slight excess of alkali will be perceptible by means of litmus paper.
By this treatment, the tartaric acid and tartrates contained in the material

page_text: treated will be converted into alkaline tartrates which will be present in solution
in the liquid.
2. The whole is then filtered in a suitable manner, and the residue thoroughly
lixiviated; the washings being added to the filtrate.
3. The weak alkaline dark brown coloured liquid is then treated with an
alkaline solution of a hypochlorite, as for instance hypochlorite of sodium
(obtained by decomposing chloride of lime with a solution of soda), so much of
said solution being added to the deeply coloured liquid that the dark brown
colour becomes converted to a light vinous yellow, through the destructive effect
of the hypochlorite on the colouring matter, tannic, and other organic im-
purities. It is preferable to assist the reaction by careful warming.
4. The vinous yellow-coloured alkaline liquid is fully neutralised with mineral
or organic acid, as for example, diluted muriatic or acetic acid, so that is is perfectly
neutral to litmus paper.
5. The neutral, pure, tartaric acid salt solution, thus obtained, is then mixed
with a chloride of calcium solution in slight excess, whereby all the tartaric acid
is separated out in the form of white tartrate of lime, which is then removed
by filtration and washed.
6. To obtain pure tartaric acid from this deposit, the latter is once more boiled
for some hours, as above described, with sodium carbonate in slight excess, then
once more treated with some hypochlorite of sodium and neutralised with acid.
The neutral almost water clear solution thus obtained is treated with chloride
of calcium, whereby a dazzling white, pure tartrate of calcium is precipitated.
From the calcium salt thus prepared pure tartaric acid is obtained by the
decomposition of the former by means of a mineral acid in well known manner.
7. To obtain cream of tartar, the deposit produced as described in No. 5 is
boiled for several hours with a solution of potassium carbonate in an open vessel,
or under pressure, an excess of potasium carbonate being employed. By filtering
off the carbonate of lime formed and thoroughly washing all the tartaric acid is
obtained in the form of a solution of neutral tartrate of potash. This solution
is once more treated with a small amount of hypochlorite, as before described,
when the cream of tartar is thrown down, in the form of a dazzling white preci-
pitate, from the pure light solution, which is sufficiently diluted with water,
by means of an organic or inorganic acid, as for example muriatic, sulphuric,
or acetic acid. The precipitate is then filtered, washed, and dried, and generally;
if carefully dealt with, contains from 99 to 100 per cent. of cream of tartar.
In a similar manner, any tartrates can be obtained in pure state from the crude
Ive after treatment with hypochlorites.
Daed this 94th day of 1004
fr
COMPLETE SPECIFICATION:
. Process for obtaining Tartaric Acid and Tartrates.
We, ALEXANDER SCHMITZ, of Düsseldorf in the Rhine-Province, Kingdom' of
Prussia, German Empire, Doctor of Philosophy, and ERNST CHRISTIAN WILHELM
TOENGES, of the same place, Manufacturer, do hereby declare the nature of said
invention to be as follows:-
This invention relates to a. process for obtaining tartaric acid. either as such
or. in the form of tartrate of lime or cream of tartar,. from raw materials,, bye

page_text: 'products, partially manufactured substances, and refuse containing tartaric
acid.
The process consists essentially in subjecting the crude lye, obtained by
lixiviating the raw material with a solution of alkaline carbonate, and which
5 lye contains the acid in the form of alkaline tartrate, to the action of a solution
of a hypochlorite, preferably an alkaline solution of a hypochlorite, before treat-
ing it with chloride of calcium, by doing which those component parts of the
crude lye such as colouring matter, tannic acid and other organic combination's
which are detrimental to the obtaining of a pure product, are destroyed.
We are aware that attempts have already been made to purify crude lye con-
taining tartaric acid by treating it with chlorine in the form of cold gas. This
process has, however, been abandoned, on account of it's many disadvantages. It
has been found that the gaseous chlorine attacks the tartaric acid itself, forming
muriatic acid; on the other hand, the chlorine combines with part of the base
of the acid salt present, and thereby causes a dark coloured bitartrate to separate
out, which reaction causes a great loss and is most troublesome. Furthermore,
the bleaching effect is only very slight. If, however, a hypochlorite be applied
in alkaline solution not only is a complete decolorisation effected, but..the effect
is accomplished quietly and smoothly, without any secondary reaction, and without
separating any acid salts or decomposing any tartaric acid, so that the tartario
acid contained in the material can be obtained in the form of a perfectly white
nearly chemically pure calcium tartrate.
The following may be used as raw materials:-
4:
..
Any kind of wine lees, either dry or wet, whether containing much or little
tartaric acid;
..
. Crude tartars, dregs of tartar, ordinary cask dregs, Spanish argols, &c.;
Crude tartrates of lime, bye-products of commerce, of wine-cultivation and the
manufacture of grape oil, as well as all kinds of manufacuring residues and
refuse containing tartaric acid from dye and printing works.
This process is best worked in the following manner:-
1. The more or less finely ground or otherwise reduced material consisting,
for example, of wine lees of little value is introduced by portions in a boiling
solution of sodium carbonate and the whole boiled up with, or without, applica-
tion of pressure. The treatment is to be so regulated that, when the boiling is
completed a slight excess of alkali will be perceptible by means of litmus paper.
By this treatment, the tartaric acid and tartrates contained in: the material
treated will be converted into alkaline tartrates which will be present in solution
in the liquid.
2. The whole is then filtered in a suitable manner, and the residue thoroughly
lixiviated; the washings being added to the filtrate.
3. The weak alkaline därk brown coloured liquid is then treated with an
alkaline solution of a hypochlorite, as for instance hypochlorite of sodium
(obtained by decomposing chloride of lime with a solution of soda), so much of
the said solution being added to the deeply coloured liquid that the dark brown
colour becomes converted to a light vinous yellow, through the destructive effect
of the hypochlorite on the colouring matter, tannic acid, and other organic im-
purities. It is preferable to assist the reaction by careful warming.
4. The vinous yellow coloured alkaline liquid is fully neutralised with mineral
or organic acid, as for example, diluted muriatic or acetic acid, so that it is perfectly
neutral to litmus paper.
5. The neutral, purified, tartaric acid salt solution, thus obtained, is then mixed
with a chloride of calcium solutiion in slight excess, whereby all the tartaric acid
is separated out in the form of white tartrate of calcium, which is then removed
by filtration, and washed.
6. To obtain pure tartaric acid from this deposit, the latter is once more boiled
for some hours, as above described, with sodium carbonate in slight excess, then
once more treated with some hypochlorite of sodium and neutralised with acid.

page_text: The neutral almost water clear solution thus obtained is treated with chloride
of calcium, whereby a dazzling white pure tartrate of calcium is precipitated.
From the calcium salt thus prepared pure tartaric acid is obtained by the
decomposition of the former by means of a mineral acid in well known manner.
7. To obtain cream of tartar, the deposit produced as described in No. 5, is
boiled for several hours with a solution of potassium carbonate in an open vessel,
or under pressure, an excess of potassium carbonate being employed. By filtering
off the carbonate of lime formed and thoroughly washing all the tartaric acid is
obtained in the form of a solution of neutral tartrate of potash. This solution
is once more treated with a small amount of hypochlorite, as before described,
when it is sufficiently diluted with water and the cream of tartar is thrown down,
in the form of a dazzling white precipitate, by means of an organic or inorganic
acid, as for example muriatic, sulphuric, or acetic acid. The precipitate is then
filtered, washed, and dried, and generally, if carefully dealt with, contains from 99
to 100 per cent. of cream of tartar.
In a similar manner, any tartrates can be obtained in pure state from the crude
lye after treatment with hypochlorites.
Having now particularly described and ascertained the nature of said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is:
1. The process for obtaining tartrate of lime from raw products, partly manu-
factured substances, bye products and refuse containing tartaric acid or tartrates,
consisting in lixiviating the said material with a solution of alkaline carbonate,
treating the lye thus obtained with an alkaline solution of a hypochlorite, and
precipitating with chloride of calcium after neutralisation, substantially as
described.
2. The process for obtaining tartaric acid from the tartrate of
calcium produced as above claimed, which consists in boiling the said calcium
tartrate with alkali in slight excess, then treating the solution with hypochlorite,
neutralizing, precipitating with chloride of calcium, and decomposing the pre-
cipitate by means of a mineral acid, substantially as described.
3. The process for obtaining cream of tartar from the tartrate of calcium pro-
duced according to Claim 1, which consists in boiling the said tartrate with an
excess of potassium carbonate, filtering, treating the filtrate with hypochlorite,
and precipitating cream of tartar by the addition of an acid, substantially as
described.
1000
ERNEST DE PASS,
Chartered Patent Agent,
78, Fleet Street, London, and 5A Market Street, Nottingham,
Agent for the Applicants.