SU58206A1 - The method of extraction of tannin from aqueous solutions - Google Patents

Description

Tannic is usually obtained by extracting water with TanBine-containing materials, evaporating the aqueous extracts and extracting the product from them with any organic solvent.

The author of the present invention proposes to treat aqueous extracts of tannin without prior evaporation with cooking ool and extract tannin with a mixture of butyl acetate and normal butyl alcohol. Instead of the latter mixture, amylacetate can be used in a mixture with isoamyl alcohol.

At meer. 3 kg of crushed

- leaves sumach insist on cold

with 10 water. 5 liters of juice is obtained,

-Containing about 3, tannin and

1, gallic acid.

Further, in a 1Nnu glass jar with a capacity of Q l, equipped with a mechanical sinter, 5 l of juice are poured, and 400 g of salt is poured. Stir the mixer for a few minutes until the salt has dissolved. The mixer is then stopped and a mixture of FROM 1.2 L of butyl acetate and 0.3 L of normal butanol is added. The mixer is again allowed to stir for one hour. The number of revolutions of the stirrer is 150-200 per minute.

After one hour, the agitator is stopped and the contents of the can are transferred to a separatory funnel. Two LAYERS are obtained: above - ethereal, below - aqueous. The ethereal LAYER is contaminated with a small amount of sticky substance and contains about 20 gadflies. The ether LAYER is filtered off by suction from impurities; the filtrate immediately stratified into the water and clean

EFFICIENT LAYER.

The butyl acetate is distilled off from the ether LAYER under vacuum. Before the end of the distillation, some water is added to the flask in order to finally remove the last traces of ether from the aqueous solution of tannin.

A half-concentrated concentrated aqueous solution of tannin is dried in a vacuum sushi.tei at 35-50 °. Dried tannin is ground to a fine powder.

The subject matter of the invention.

Claims (2)

1. A method for extracting tannin from aqueous solutions obtained by extraction, without heating, the leaves of sumac or skumpii, by treating the solutions with an alcohol-ether mixture, followed by distilling off the solvents and adding small amounts of water to obtain a concentrated aqueous solution of tannish, characterized in that the aqueous extract of tannin, without prior evaporation, is treated with sodium chloride and a mixture of butyl acetate and normal butyl alcohol, after which tannin is extracted from The alcohol-ether layer in the usual way. 2. Modification of the method according to claim 1 ,. characterized in that instead of butyl acetate and normal butyl alcohol, amylacetate and isoamyl alcohol are used.