RU2392254C1 - Method for production of vermiculite heat-insulating composition - Google Patents

Abstract

FIELD: construction.

SUBSTANCE: method for preparation of vermiculite heat-insulating composition includes mixing binder - portland cement with additives with dry components of filler - blown-out vermiculite and ground mineral fibre, besides binder is previously mixed with mixing water, then mixed with 25-30% of mixture of dry filler components, and in 20-30 minutes it is mixed with remaining part of dry filler components mix previously heated up to 80-85°C in 5-10 minutes, and produced heat-insulating composition is maintained for 15-20 minutes before application onto protected surface.

EFFECT: increased adhesion of vermiculite heat-insulating coating with protected surface and provision of its integrity in process of operation at exposure to high temperature.

1 cl, 2 tbl

Description

The invention relates to the field of production of building materials and may find application for high-temperature thermal insulation of structures for various purposes.

A known method of preparing a vermiculite heat-insulating composition, selected by the applicant as a prototype, comprising mixing a binder — Portland cement with additives with dry aggregate components — expanded vermiculite and ground mineral fiber (fiberglass), clay (see patent RU No. 2073662 of 03/18/92). , publ. 02.20.97.).

This method does not ensure the uniformity of the vermiculite heat-insulating composition and, as a consequence, the sufficient adhesion of the vermiculite heat-insulating coating with the surface to be protected, and does not also ensure the integrity of the vermiculite heat-insulating coating when exposed to high temperature.

The technical task of the proposed solution is to increase the adhesion of a vermiculite thermal insulation coating with a protected surface and to ensure its integrity during operation under high temperature exposure.

The problem is solved by performing a known method of preparing a vermiculite heat-insulating composition, including mixing a binder - Portland cement with additives with dry aggregate components - expanded vermiculite and ground mineral fiber, in which according to the invention the binder is pre-mixed with mixing water, then mixed with 25-30% of the mixture dry components of the aggregate, and after 20-30 minutes, mix with pre-heated to a temperature of 80-85 ° C for 5-10 minutes sheysya part aggregate mixture of dry components and the resulting composition is heated insulating 15-20 minutes before application to the surface to be protected.

Mixing a part (25-30%) of the mixture of dry aggregate components with the closed binder ensures uniform wetting of the grains of the mixture of dry aggregate components, and subsequent mixing of the resulting suspension with the heated (up to 80-85 ° C) remaining part of the mixture of dry aggregate components facilitates the process of wetting the whole grains mass with the formation of thin films of a binder on the surface of the grains of the filler components. Exposure of the obtained heat-insulating composition for 15-20 minutes increases the uniformity of the resulting composition.

The preparation of the heat-insulating composition according to the proposed method provides an increase in the adhesion of the heat-insulating coating with the surface to be protected and its integrity during operation under high-temperature exposure, achieved by the totality of actions and conditions for their implementation in accordance with the distinguishing features of the claims.

The patent studies did not reveal similar technical solutions, which allows us to conclude about the novelty and inventive step of the claimed technical solution.

The domestic industry has all the tools (materials, equipment and technology) necessary for preparing a heat-insulating composition according to the proposed method and its widespread use in industry for high-temperature thermal insulation of structures for various purposes that are under high-temperature effects, for example, metal chimneys.

The essence of the proposed method for preparing a heat-insulating composition is confirmed by experiments.

In the method of preparing a vermiculite insulating composition was taken:

- as a binder - Portland cement (GOST 10178-85) with additives,

- as a filler - expanded vermiculite (GOST 12865-67) and ground mineral fiber (for example, glass wool).

A method of preparing a vermiculite insulating composition is as follows:

dry binder is placed in the mixer - Portland cement with additives and the required amount of mixing water and mixed,

then 25-30% of the mixture of dry components of the aggregate, expanded vermiculite and ground mineral fiber, is introduced and mixed;

after 20-30 minutes, the remainder of the mixture of dry aggregate dry components is preheated to a temperature of 80-85 ° C for 5-10 minutes in an additional heated mixer;

the obtained vermiculite heat-insulating composition is kept for 15-20 minutes (in a mixer or unloaded into a container) before application to the structure to be protected.

The preparation of a vermiculite heat-insulating composition includes conventional dosing and mixing operations of the starting components.

The authors conducted tests (see table 1) of the proposed method for the preparation of vermiculite thermal insulation composition.

Table 1 Method Operations / Experience Number one 2 3 four 5 one In a suspension obtained by mixing a binder (Portland cement and additives) with mixing water, 2 Part of the dry mixture of aggregate, expanded vermiculite of crushed mineral fiber, is introduced and mixed,% 25 thirty 27.5 thirty 25 3 After a certain time, min twenty thirty 25 27 thirty four The remainder of the dry mixture is introduced preheated to a temperature of 80-85 ° C for a time, min 10 5 fifteen 10 7.5 5 The mass is mixed 6 The exposure of the finished composition over a period of minutes fifteen twenty fifteen 17.5 17.5

The test results of vermiculite thermal insulation coatings obtained during the experiments (see table 1) experiments are presented in table 2.

table 2 Name of indicators / number of experience one 2 3 four 5 one Adhesion to the surface, MPa (adhesion) 1.70 1.71 1.72 1.70 1.73 2 Linear temperature shrinkage,% 0.12 0.21 0.19 0.24 0.16 3 Thermal resistance (number of cycles of air heat exchangers 25 ° C-800 ° C) 240 225 235 245 230 four Application temperature 900 900 900 900 900

The proposed method provides an increase in the adhesion of the heat-insulating coating with the surface to be protected and that cracks do not form on the coating during operation during high-temperature exposure and individual pieces do not crumble.

Claims (1)

A method of preparing a vermiculite heat-insulating composition, comprising mixing a binder - Portland cement with additives with dry aggregate components - expanded vermiculite and ground mineral fiber, characterized in that the binder is pre-mixed with mixing water and first mixed with 25-30% of a mixture of dry aggregate components, after 20 -30 min is mixed with pre-heated to a temperature of 80-85 ° C for 5-10 min the remaining part of the mixture of dry filler components and the resulting heat yatsionnuyu composition is heated for 15-20 minutes before application to the surface to be protected.