SU1609744A1 - Electrolyte for producing swollen graphite - Google Patents

Abstract

This invention relates to electrochemical methods for producing expanded graphite by anodic treatment of graphite powder in electrolytes. Extruded graphite extruded products are used in mechanical engineering, electrical and radio engineering, and the chemical industry. In order to reduce the bulk density of the expanded graphite and increase the tensile strength of its products, oxidation is carried out in an electrolyte of the following composition, g / l: ammonium nitrate 60-120

urea 30-75

ammonium oxalate 2-10. The oxidized graphite is washed, dried at 100-105 ° C and heat treated at 630 ° C. The bulk density of graphite treated with an electrolyte of the indicated composition is 4-6 g / dm ³ , the maximum tensile strength of the pressed tape is 8.0-9.1 n / mm ² . 1 tab.

Description

The present invention relates to the process of luchuseni of expanded graphite by the anodic treatment of graphite powders in electrolytes, in particular in electrolytes based on ammonium nitrate. Products made of extruded expanded graphite, having a high. electrical conductivity and high anti-friction properties, are used in mechanical engineering, electrical engineering, radio engineering and chemical industries.

The purpose of the invention is to reduce the density of graphite and increase, "the tensile strength of products from its"

Example: 1.90 g of ammonium nitrate () is dissolved in 850 cl of distilled water and introduced into a solution of 55 g of urea (CO {NH g)) After dissolving the urine, 6 g of ammonium oxalate ((NH4)) is added distilled water, the volume of the solution is up to 1 l and stirred until complete: dissolving ammonium oxalate,

20.0 g of graphite of the Zaval brand, Evsky place are placed in a vinyl chloride cover with a graphite rod as an anode and immersed in 200 ml of electrolyte. Second grafittot

OS About About vj 4

As follows from the data in the table, electrolyte treatment of the proposed composition makes it possible to obtain exfoliated graphite with a lower bulk density. The tensile strength for breaking the pressed ribbon from it increases at the same time.

31609744

four

YOU rod serves as a cathode. Anodic

processing of graphite powders provo

dt at voltage on bath UE

and the strength of the current I A during

bots are removed from the cover,

filtered, washed distilled

water and dried at a

After drying, the powder is placed in a porcelain porcelain of the invention.

crucible crucible and heat

The electrolyte for producing expanded graphite on ammonium nitrate otHOBe, characterized by the fact that, in order to reduce the bulk density of graphite and increase the tensile strength of products from it, ok also contains urea and ammonium oxaloxane in the following 20 ratio of components, g / l ;

Coy processing in a muffle furnace at.

The expanded graphite powder is placed in a mold and precompressed under a pressure of 1 kgf / mm. Next, the pressed powders are pulled through rollers to make graphite tape 30x2 mm with a rolling pressure of 1.1 1.2 kgf / mm,

Bulk density of the expanded graphite and tensile strength of the pressed tapes from it, depending on the electrolyte composition according to the proposed method and the prototype, are presented in the table.

25

Nitrate

ammonium

Urea

Oxalate

ammonium

As follows from the data in the table, electrolyte treatment of the proposed composition makes it possible to obtain exfoliated graphite with a lower bulk density. The tensile strength for breaking the pressed ribbon from it increases at the same time.

Nitrate

ammonium

Urea

Oxalate

ammonium

6

2 10

6

one

6 S2

,

 An increase in the urea concentration above 75 g / l does not lead to an increase in the tensile strength of the pusyem to the products, therefore it is economically disadvantageous. An increase in the concentration of ammonium oxalate over 10 g / l does not lead to a further increase in the tensile strength of the compressible products, except In the process of anodic treatment in solution, the precipitation of oxalates precipitates.

Editor H, Kistulinec

Compiled by M, Gruzdeva

Tehred m. Didyk Proofreader .I, Erdeyi

Order 3703

Circulation 416

 ZNIIPI State Committee on Arts and Discovery at the State Committee on Science and Technology of the USSR 113035, Moscow, Zh-35, 4/5 Raushsk nab.

20-25

3.4-4.3

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Claims (2)

Claim The electrolyte for producing expanded graphite on the basis of ammonium nitrate, characterized in that, in order to reduce the bulk density of graphite and increase the tensile strength of products from it, it additionally contains urea and oxalate ammonium in the following ratio of components, g / l: Ammonium nitrate Urea Oxalate 60-120 30-75 are presented in the table. ammonium 2-10 Composition Content, g / l nh ₄ no ₉ corresponding (No. ₄ ) _g C _g H ₄ Bulk • density of expanded graphite, g / dm ^e The tensile strength of the pressed tape, N / mm ² 1 90 55 6 4-6 8.0-9.1 2 60 thirty 2 10-12 5.2-6.2 3 120 75 10 4-6 8.0-9.1 4 90 25 6 45-50 2.2-3.2 5 90 55 1 25-30 3.0-4.0 6 90 80 * 6 4-6 8.0-9.1 7 90 55 12** 4-6 8.0-9 ,! Proto- type 8 from 5% to saturated ha 20-25 3.4-4.3 niya * An increase in the concentration of urea in excess of 75 r / l does not lead to an increase in the tensile strength of the pressed products, therefore, it is economically disadvantageous. Increased Concentration: Oxalic 'Ammonium Svep 10 g / l does not lead to a further increase in the tensile strength of the pressed products, except that during the anodic treatment in the solution precipitation of oxalates is observed.