Low-thermal conductivity modified vermiculite composite thermal insulation material and preparation method thereof

Abstract

The invention relates to a low-thermal conductivity modified vermiculite composite thermal insulation material and a preparation method thereof. According to the technical scheme, 10 to 20 milliliters of an aluminum salt solution is prepared from expanded vermiculite per gram, wherein a ratio of urea to the amount of substance of Al3<+> in the aluminum salt solution is (8-15):1, and a volume ratio of concentrated sulfuric acid to the aluminum salt solution is 1:(400-500). The method comprises the following steps of: mixing the expanded vermiculite, the urea, the concentrated sulfuric acid andthe aluminum salt solution in a ratio of the raw materials, stirring at the temperature of between 80 and 100 DEG C for 18 to 32 hours, eluting, and drying to obtain modified vermiculite; and mixing 40 to 80 weight percent of modified vermiculite and 20 to 60 weight percent of forsterite which serve as the raw materials, adding an aluminum dihydrogen phosphate solution in an amount which is 10 to20 percent of the weight of the raw materials, stirring, pressing for forming, and keeping the temperature at the temperature of between 500 and 650 DEG C for 2 to 5 hours to obtain the low-thermal conductivity modified vermiculite composite thermal insulation material. Therefore, the low-thermal conductivity modified vermiculite composite thermal insulation material has the characteristics of low coefficients of heat conductivity, high strength and wide application range.

Description

Technical field [0001] The invention is the technology field of composite thermal insulation materials.Specifically involves a low thermal guidance modified vermiculite composite insulation material and its preparation methods. Background technique [0002] The development and development of high -quality thermal insulation and refractory materials, and reasonably supported in industrial kiln, is an effective energy -saving way.High -quality thermal insulation and refractory materials can not only improve the life of the kiln, but also improve the quality of the product, reduce thermal loss, improve the efficiency of thermal energy, and reduce energy waste, thereby achieving the purpose of saving energy and reducing product costs.Therefore, the more urgent the demand for effective high temperature insulation materials. [0003] Vermiculite is a 2: 1 layer of the structural unit, the inter -layer with exchanged cation and water molecules, or the three -eight -facial aluminum silic...

AI Technical Summary

Problems solved by technology

Due to the large high temperature expansion rate of the expanded vermiculite obtained by thermal modification, the interlayer spacing increases, and the through pores between the layers lead to a decrease in the compressive strength of the heat insulation material, and the strength decreases with the decrease of the bulk density, and As the temperature rises, its thermal conductivity increases rapidly, so that it is difficult to increase the use temperature of thermal insulation materials, especially if the thermal conductivity is still high or the vermiculite product occupies a large volume, which limits the application range.