SU1516464A1 - Method of producing modified calcium carbonate - Google Patents

Abstract

The invention relates to the production of a hydrophobic chalk, which can be used for heat insulation of heating mains, as a filler for products based on polyvinyl chloride, in rubber, cable and other industries. In order to simplify the process and increase the degree of hydrophobicity of calcium carbonate, an aqueous dispersion with C ₁₆ -C ₂₄ fatty acids is created in a ratio, wt.%: Water 53.7-75.4

calcium carbonate 24.3-46.1

fatty acids 0.2–1.2 and are treated with electropulse discharges at a voltage of 15–25 kV, a capacitance of 1.0–1.5 µ0, and a discharge heating temperature of up to 50–55 ° C. The method allows to increase the degree of hydrophobicity of calcium carbonate by 14-15%, as well as to simplify the process by combining two stages (crushing and modification) into one. 3 tab.

Description

The invention relates to the production of hydrophobic chalk, which can be used for thermal insulation of heating mains, as a filler for products based on polyvinyl chloride, in the rubber, cable and other industries.

The aim of the invention is to simplify the process and increase the degree of hydrophobicity of calcium carbonate.

Example 1. Preparing a dispersion of calcium carbonate in water together with fatty acids with a fraction of the following quantitative ratio (Table 1).

The resulting dispersions are pulsed with a voltage of 20 kV, a capacitance of 1.0 µF to a temperature of 52 C. As a result of processing and subsequent drying at 105 C, samples of hydrophobic calcium carbonate with a wetting angle of 160 (140 - by a known method).

When the content of water, calcium carbonate, fatty acids is less respectively 53.7; 24.3; 0.20 wt.% Wetting angle is reduced to 140, i.e. no better than by a known method. With increasing dosages of calcium carbonate and fatty acids more than А6.1 and 1.2 may. Z, respectively, there is a difficulty in drying the final material.

Example 2. Preparing a calcium carbonate dispersion in water together with Cs-C fatty acids in amounts: l

one

The ratio of water, calcium carbonate, fatty acids is 69.8; 29.9; 0.3 wt.% Respectively. The dispersion is processed by pulsed discharges at a voltage of 20 kV, a capacitance of 1.0 µF according to the temperature regime: temperature of modification 48; 50; 52; 55 and.

After the electrohydropulse treatment of the dispersion, the calcium carbonate was dried at 105 ° C. It turned out that when the dispersion temperature was below 50 ° C, calcium carbonate was not hydrophobized — the wetting angle was 50. At temperatures of 50–55 ° C, the wetting angle was. When the heating temperature rises above 55 ° C, the angle does not change. At the same time, heating the suspension above 55 s requires additional energy consumption and therefore is inefficient.

Example 3. A calcium carbonate dispersion in water is prepared together with Cif, -Czt fatty acids in a ratio of water, calcium carbonate, fatty acids 69.8; 29.9; 0.3 wt.% Respectively. The dispersion is processed by pulsed discharges at a voltage of 20 kV, heating temperature up to 52 ° C. As a controlled factor, the capacity of pulse discharges is used: 0.5; 1.0; 1.25; 1.5 and 2.0 μF.

After the electrohydropulse treatment, the calcium carbonate is dried at 105 s. The hydrophobicity of the target product is evaluated. At a capacity of less than 1.0 µF, hydrophobization is insufficient (wetting angle 50 ° C). When exposed to a discharge energy of 1.0-1.5 microfarads, the wetting angle remains unchanged at 160.

Example 4 A calcium carbonate dispersion was prepared together with fatty acids in a water ratio.

calcium carbonate, fatty acids: 69.8; 29.9; 0.3 May. 7, respectively. Disperse discharge processing with a capacity of 1.0 µF to 52 ° C. The difference is used as a controlled factor. voltage impulse discharges: 10; 15; 20; 25 and 30 kV.

After electrohydropulse obra-. Calcium carbonate is dried at 105 s. The hydrophobicity of the target product is evaluated. At a voltage of less than 10 kV, the hydrophobization is

f does not appear, with a voltage of 10 15 kV it is insufficient (wetting angle 50), with a voltage of 15-25 kV the wetting angle remains unchanged and is equal to 160, and

Q at a voltage greater than 25 kV, hydrophobization does not occur.

The advantage of the described method over the known one is that it allows combining the crushing stages.

5 and modifications, as well as increase the degree of hydrophobicity by 14-15%.

Formula

and 3

gaining

0

0

five

The method of obtaining modified calcium carbonate, which includes the mixing of calcium carbonate with fatty acids of the Cff fraction, —C, is about the same, in order to simplify the process and increase the hydrophobicity of calcium carbonate, by mixing calcium carbonate with fatty acids, water is supplied in the following ratio of components, May. %: Water53.7-75.4

Calcium carbonate 24.3-46.1 Fatty acids 0.2-1.2 and the resulting aqueous dispersion is subjected to an electric pulse discharge treatment with a voltage of 15-25 kV, with a capacity of 1-1.5 microfarads, to a dispersion heating temperature of 50-55 C followed by drying of the product.

Component

one

dip version

151646A

Justification table Ratio of components, May.

LXixiTiiiiiztiniiiztz

Water

Carbonate

Kaj biftiH

Fatty

acids

560 69.9 560 69.8 560 69.6 560 69.2 560 69.0 240 30.0 240 30.0 240 29.8 240 29.6 240 29.5

0.6 0.1 1.2 0.2 4.8 0.6 9.61.2 12.0 1.5

Editor N. Rogulich

Compiled by M. Naumov

Tehred A. KravchukKorrektor O. Kravtsova

Order 6348/23

Circulation 35

VNIIPI State Committee for Inventions and Discoveries at the USSR GKKT 113035, Moscow, Zh-35, 4/5, Raushsk nab.

Production and publishing plant Patent, Uzhgorod, st. Gagarin, 101

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Claims (1)

Claim A method of producing a modified calcium carbonate, comprising mixing calcium carbonate with fatty acids of the C _{/ b} ~ C ^ fraction, characterized in that, in order to simplify the process and increase the degree of hydrophobicity of calcium carbonate, water is fed to the mixture of calcium carbonate with fatty acids next component ratio, may. %: Water 53.7-75.4 Calcium Carbonate 24.3-46.1 Fatty acids 0.2-1.2 and the resulting aqueous dispersion are subjected to electric pulse treatment with a voltage of 15-25 kV, a capacitance of 1, 0-1.5 μF to a heating temperature of the dispersion of 50-55 C, followed by drying of the product. Component of water dispersion h eleven eleven eleven eleven Ι ^τ Ratio components May. —I I! 1 S4 1 eleven 1 eleven 1 5 * 1 eleven eleven eleven eleven 1 84 1 eleven eleven ί --------------- 1 eleven eleven 1 · I 1 S '1 eleven 1__________________1 I I 1 84 1 eleven 1 * _h Water 560 82.0 560 75,4 560 69.8 560 53.7 560 36.7 Calcium carbonate 120 17.6 180 24.3 240 29.9 480 46.1 960 63.1 Fatty acids ^C ", - ^C 14 2,4 0.4 2,4 oh s 2,4 oh s 2,4 0.2 2,4 0.2 Table continuation Component of water dispersion The ratio of components, May. h ί ’ I - h h X hours | % I ’· R Water 560 69.9 560 69.8 560 69.6 560 69.2 560 69.0 Carbonate kadtsya 240 30,0 240 30,0 240 29.8 240 29.6 240 29.5 Greasy acid ^C ng ^C 14 0.6 0.1 1,2 0.2 4.8 0.6 9.6 1.2 12.0 1,5