SU937432A1 - Composition for making heat insulating material - Google Patents

Description

(5) COMPOSITION FOR MAKING HEAT-INSULATING

MATERIAL

one

The invention relates to the production of heat insulating materials on mineral fibrous fillers that have high heat resistance, for example, based on basalt fiber, which can be used for thermal insulation of furnaces, turbines and other thermal units with a hot surface temperature of 300 ° C and higher.

A heat insulating mass is known, including a basalt superfine fiber with a diameter of 1.5 µm, taken in an amount of 88-98, and a clay binder, taken in an amount of 212% 1.

The disadvantage of this mass is that the material produced from it has low mechanical strength and high water absorption.

Closest to the invention in its technical essence and the achieved result is a thermal insulating mass 2, comprising basalt fiber, an aluminum-chromophosphate binder and fine ground serpentinite in the following ratio of components,% by weight:

Basalt fiber 8t-90

Agvomohromfo sfatnoe

binder 7-10

It is ground serpen tinit3-6

Claims (2)

The disadvantages of the known mass are rather high thermal conductivity and large deviations of the geometrical dimensions of the material produced from it, caused by shrinkage effects that occur during the heat treatment of the molded raw material. The latter circumstance results in the formation of significant gaps in the joints between the pans of the drying chamber and the material being dried, leading to large heat leaks and over-assured. the duration of the heat treatment. 393 The purpose of the invention is to improve the physicomechanical properties of the insulating material. This goal is achieved by the fact that the composition for the manufacture of heat insulating material, including basalt fiber, aluminum-chromophosphate binder, and finely ground serpentinite, additionally contains straw in the following ratio of components, wt. The use of straw in the composition for making the heat insulating material results in its chemical interaction with the aluminum-chromophosphate binder, which has an acidic reaction, as a result of which A weakening of the chemical bonds and the destruction of thick stalks of straw into a multitude of fine fibers occur, accompanied by the release into solution of some of its high molecular weight compounds (hemicellulose, lignin, etc.). Thin fibers during the mass mixing process evenly They are built in its volume, forming a reinforcing cage preventing linear linear shrinkage of the raw material during heat treatment. Under the conditions of exploitation of the material at 300-800 ° C, straw fibers burn out, due to which porosity increases, i.e. air content of the material, which, respectively, leads to a decrease in its coefficient of thermal conductivity. Reducing the straw content below 6 wt.% Does not allow for sufficient reinforcement of the material, and also impairs its thermal insulation properties. An increase in the solo content above 10% leads to the extraction of an increased amount of highly viscous components from its composition in an acidic environment, which makes it difficult to vacuum molding the raw material, increases the moisture content of the latter and requires a large flow rate of the heat carrier during the heat treatment process. In this case, in addition, the components of the straw, when interacting with the aluminum-chromophosphate binder, substantially neutralize its chemical activity, making it insufficient for effective reaction with finely ground serpentinite. Example 1.K10 weight. aluminum bromide phosphate binder added 6 wt. finely ground serpentinite and 8 wt.% of straw, the mixture is closed with water to a density of 1.11 g / cm and thoroughly mixed in a reactor equipped with a stirrer. 76 wt. Are gradually introduced into the reactor. basalt fiber and continue mixing until a stable aqueous fiber suspension is obtained. The finished suspension is poured into a vacuum form, where at a vacuum of 500 mm Hg. - molding takes place. Molded raw cooks at 200 for 3.5 hours. Example 2. Q8 wt.% Of the aluminum chromophosphate binder is added. A weight. fine ground serpentinite and 7 wt. straw, mix the mixture with water to a density of 1.11 g / cm and mix thoroughly in a reactor equipped with a stirrer. Next, 81% by weight of basalt fiber are gradually introduced into the reactor and continue to be stirred until a stable water-fiber suspension is obtained. The finished suspension is poured into a vacuum form, where at a vacuum of 500 mm Hg. raw molding takes place. The molded raw is heat treated for 3.0 hours. Example 3. “7% by weight of an aluminum-chromophosphate binder is added 3% by weight of finely ground serpentinite and 6% by weight of straw, the mixture is sealed with water to a density of 1.11 g / cm and thoroughly mixed in a reactor equipped with a stirrer. Next, 8 wt.% Of basalt fiber is gradually introduced into the reactor and continues to be stirred until a stable aqueous fiber suspension is obtained. The finished suspension is poured into a vacuum form, where at a vacuum of 500 mm Hg. raw molding takes place. The molded raw is subjected to heat treatment for 2.5 hours. The table shows the properties of the compositions according to the examples. m. 3.3 Formula of the Invention The composition for the manufacture of heat insulating material, including basalt fiber, aluminum-chromophosphate binder and finely ground serpentinite, is characterized in that, in order to improve the physical and mechanical properties of the heat insulating material, it additionally contains straw at the following ratio of components, masd: basalt fiber 76-84 2.02.30 2.30 2.55 0.8 1.2 3.0 0.059 0.058 0.072 0.059 0.089 0.089 0.087 0.101 3.0 2.8 , 0 Alumochromophosphate binder Fine-grained serpentinite Straw Sources of information taken into account during the examination 1. Author's certificate of the USSR №, cl. C 0 R, 1973. 2. USSR author's certificate N 773035, cl. From 04. In 43/02, 1980 (prototype).