SU1229240A1 - Method of preparing sorbent for making electric insulating paper - Google Patents

Description

one

The invention relates to the field of preparation of materials, in particular the preparation of a sorbent used in the pulp and paper industry for the production of capacitor and cable paper with active filler, as well as at power condenser building enterprises for cleaning impregnating masses,

The aim of the invention is to simplify the method of preparing the sorbent while maintaining the quality of the electrically insulating paper.

Example, Prepare a 4% suspension of palygorskite, which is preliminarily cleaned from mechanical impurities (sand, contaminants of plant origin) by upholding the prepared suspension with its subsequent decantation. 2.0 ml of a 25% aqueous ammonia solution () is added to a 1 l suspension of palygorskite prepared in this way, then 1% polyacrylamide solution is added at slow stirring until complete precipitation of palygorskite, the pH of the suspension is 8.0 palygorskite washed as follows. Dissociated palygorskite was diluted with deionized water to a concentration of 4%, followed by vigorous stirring for 10–15 min and settling the resulting suspension until the palygorskite was completely precipitated. After the palygorskite precipitates, the water into which the monovalent ions have passed is drained.

The consumption of polyacrylamide is 40 ml or 1% by weight of abs. dry matter in suspension. After suspension and precipitation twice, the amount of polyacrylamide in the sorbent does not exceed 0.4%, the content of NHi is not detected,

In the precipitated sorbent, in addition to the content of polyacrylamide, the content of sodium cations in mg / l, the electrical conductivity and the pH of the aqueous extract are monitored. If the quality indicators of the precipitated natural aluminosilicate do not meet the established requirements, the washing with deionized water is repeated five times.

Test data are summarized in the table.

29240. 2

Example 2. To a purified 4% suspension of palygorskite prepared according to example I, add 4.0 ml of a 25% aqueous solution of ammonia (NH40H), then add 1% polyacrylamide solution at stirring slowly until the palygorskite is completely precipitated, the pH of the suspension is 9.0.

The flow rate of PAA is 35 ml or

0.9% by weight of abs. dry matter in suspension.

The precipitate of palygorskite is washed analogously to example 1,

5After two suspension

and the amount of PAA in the sorbent does not exceed 0.4%. Contents lnd - not detected.

Test data are summarized in the table.

Example 3, K1l of a 4% suspension of palygorskite prepared according to an example, is added 8.0 ml of a 25% aqueous solution of ammonia theft, then an I% solution of PAA is added with slow stirring until complete precipitation of the palygorskite, pH suspensions 12.0,

The consumption of PAA in this case is

0 30 ml or 0.8% of. Abs mass, dry matter in suspension.

After this treatment, the amount of PAA in the sorbent does not exceed 0.3%, the NH4 content is not detectable

The proposed method of preparing sorbents from natural aluminosilicate-t5v, in particular bentonite clays from ionic impurities, makes it possible to obtain a sorbent from natural aluminosilicates (palygorskite and its natural mixture with montmorillonite) for use in the electrical industry and to organize the production of the sorbent in the form of powder in one specialized enterprises for use in pulp and paper industry.

This will reduce the cost of transporting natural clay material, capital costs for installations and their maintenance.

The invention also allows refusing the use of expensive synthetic synthetic (and silica gel) sorbents used in capacitor engineering for cleaning impregnating masses.

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45

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Original paper without papygorskite

With palygorskit, cleaned with PAA after double washing, according to examples

Compiled by I. Koltsova Editor P. Kossey Tekhred M.Hodanich Proofreader T. Kolb

Order 2422/23 Circulation 355 Subscription

VNIIPI USSR State Committee

for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab, 4/5

Production and printing company, Uzhgorod, st. Project, 4

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Claims (1)

METHOD FOR PREPARING THE SORBENT FOR PRODUCING ELECTRIC INSULATION PAPER, comprising preparing a suspension of natural aluminosilicate and purifying it from impurities of monovalent ions, characterized in that, in order to simplify the method while maintaining the quality of electrical insulation paper, the purification of natural aluminosilicate from its impurities is carried out by alumina deposition flocculant-polyacrylamide at a pH of 8-12 and a flow rate of polyacrylamide of 0.8-1.0% by weight of the sorbent, followed by washing the obtained precipitate of deionized aluminosilicate Anna water. 1 1229240