Al2O3 intercalated expanded vermiculite heat-insulating material and preparation method thereof

Abstract

The invention relates to an Al2O3 intercalated expanded vermiculite heat-insulating material and a preparation method thereof. According to the technical scheme, the preparation method comprises the following steps: 1) preparing materials on the basis of a mass ratio of expanded vermiculite to aluminum nitrate nonahydrate to ethanol being 1:1:(2-3.5), dissolving the aluminum nitrate nonahydrate into the ethanol according to the mass ratio, and then adding the expanded vermiculite, stirring for 8-12 hours, and ageing for 1-2 hours at room temperature, thereby obtaining an expanded vermiculite aluminum gel compound; 2) soaking the expanded vermiculite aluminum gel compound into the ethanol solution, soaking for 18-30 hours at 55-65 DEG C and then soaking for 42-54 hours at 68-75 DEG C, taking out and drying, thereby obtaining an Al2O3 intercalated expanded vermiculite; and 3) taking 40-80wt% of Al2O3 intercalated expanded vermiculite and 20-60wt% of forsterite as raw materials, mixing the raw materials, additionally adding an aluminum dihydrogen phosphate solution which accounts for 10-20wt% of the raw materials, stirring, pressing and forming, and drying, thereby obtaining the Al2O3 intercalated expanded vermiculite heat-insulating material. The Al2O3 intercalated expanded vermiculite heat-insulating material has the characteristics of lower coefficient of heat conductivity, higher strength and wider application scope.

Description

technical field [0001] The invention belongs to the technical field of thermal insulation materials, in particular to an Al 2 o 3 Intercalated expanded vermiculite heat insulation material and its preparation method. Background technique [0002] It is an effective way to save energy by researching and developing high-quality heat-insulating refractory materials and using them reasonably in industrial kilns. It can not only increase the life of the kiln, but also improve the quality of products, reduce heat loss, improve heat energy utilization efficiency and reduce energy waste, so as to achieve the purpose of saving energy and reducing product costs. Therefore, the demand for effective high-temperature insulation materials is becoming more and more urgent. [0003] Vermiculite is a dioctahedral or trioctahedral aluminosilicate mineral with a 2:1 structural unit layer and exchangeable cations and water molecules between the layers. The interlayer charge is between 0.6 an...

AI Technical Summary

Problems solved by technology

[0004] When used as the filling of expanded vermiculite in the manufacture of high-temperature heat insulation materials, although the thermal conductivity of its products is low, the strength is also low, and the application is greatly limited.

When high-strength cementing materials are used to bond expanded vermiculite into finished products, although it has greater strength than expanded vermiculite, it also reduces the thermal insulation effect of vermiculite

In addition, due to the large high temperature expansion rate of expanded vermiculite, the interlayer spacing increases, and the through-holes between the layers lead to a decrease in the compressive strength of the heat insulation material. The strength decreases with the decrease of the bulk density, and as the temperature increases High thermal conductivity increases rapidly, so it is difficult to increase the use temperature of thermal insulation materials, especially the thermal conductivity is still high or vermiculite products occupy a large volume, which limits the scope of application