Improvements in Purifying and Clarifying Tannic Liquids.
Year: 1892

page_text: Date of Application, 16th Dec., 1892
Complete Specification Left, 14th Sept., 1893-Accepted, 14th Oct., 1893
PROVISIONAL SPECIFICATION.
Improvements in Purifying and Clarifying Tannic Liquids.
We JEAN MARIE EMILE FONTENILLES and HENRI GABRIEL JULIEN RENÉ
BAGUENIER-DESORMEAUXx both of 21 Boulevard Poissonniere Paris in the
Republic of France Chemists do hereby declare the nature of this invention to be
as follows:-
Our invention relates to a process for purifying and decolourising or clarifying
tannic liquids. Taking for example a tannic liquid obtained by the decoction or
infusion of wood in water we add oxalic acid to the said liquid. On mixing a
precipitate is formed and after this precipitate has been deposited the liquid is
subjected to a species of clearing or sizing operation performed on the liquid in a
cold condition by introducing albuminous matter and stirring. A precipitate is
deposited leaving the tannic liquid perfectly limpid and of a light clear yellow
colour which is most advantageous for tanning hides and mordanting fabrics.
The proportion of oxalic acid to be employed varies according to the nature of
the liquid and may amount to as much as from about 15 to 20 per cent. for example
of the tannin in the liquid. The amount of albuminous matter varies according
to the albumen which it contains and may be as much as 20 per cent. of the tannin
for example.
The clarifying may be accelerated by placing the liquid in a centrifugal apparatus
and subjecting it to the action of centrifugal force.
Dated 16th day of December 1892.
J. H. JOHNSON & Co.,
47, Lincoln's Inn Fields, London, W.C., Agents.
COMPLETE SPECIFICATION.
Improvements in Purifying and Clarifying Tannic Liquids.
We, JEAN MARIE EMILE FONTENILLES, and HENRI GABRIEL JULIEN RENÉ
BAGUENIER-DESORMEAUX both of 21 Boulevard Poissonniere, Paris, in the
Republic of France, Chemists do hereby declare the nature of this invention and
in what manner the same is to be performed to be particularly described and
ascertained in and by the following statement:-
Our invention relates to a process for purifying and clarifying or decolouring
tannic liquids. Taking for example a tannic liquid obtained by the decoction or
infusion of wood in water we add oxalic acid to the said liquid and mix it there-
with. After mixing a precipitate is formed and after this precipitate has been
deposited, the liquid when in a cold condition is subjected to a clarifying clearing
or sizing operation by introducing thereinto albuminous matter and stirring. A
precipitate is deposited leaving the taunic liquid perfectly limpid and of a light
clear yellow colour which is most advantageous for tanning hides and mordanting
fabrics.
•
The proportion of oxalic acid to be employed varies according to the nature of
the tannic liquid or of the plant from which it has been obtained and may amount
for example to as much as from about 15 to 20 per cent. of the chemically pure
tannin contained in the liquid. The amount of albuminous matter employed for
the clarifying operation varies according to the albumen which the said matter
contains and may for example be as much as 20 per cent. of the chemically pure
tannin contained in the liquid.

page_text: The clarifying may be accelerated by placing the liquid in a centrifugal apparatus
and submitting it to the action of centrifugal force when the heavy particles
suspended in the liquid will be forced against the inner periphery of the centrifugal
apparatus leaving the liquid perfectly limpid.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed we declare that what
we claim is :-
Purifying and clarifying tannic liquids by treatment with oxalic acid and
afterwards with albuminous matter substantially as hereinbefore described; whether
the clarifying be accelerated by the action of centrifugal force, or not.
Dated this 14th day of September 1893.
J. H. JOHNSON & Co.,
Agents.