Method for preparing porous ceramic heat-insulating material by sol-gel method

Abstract

The invention discloses a method for preparing a porous ceramic heat-insulating material by a sol-gel method and belongs to the technical field of heat insulating materials. The method comprises the following steps: calcining Al2O3 so as to obtain powder, in which the content of Al2O3 is 99wt%, putting 100g of Al2O3 powder, 80g of ammonium citrate, 100ml of deionized water and Al2O3 milling balls into a stirring mill together, carrying out ball milling for 1 hour, and filtering out the Al2O3 milling balls, so as to obtain Al2O3 slurry with the mass percent of 75%; adding 20ml of silica sol and 25ml of triethanolamine lauryl sulfate into the Al2O3 slurry, adding 10g of ammonium chloride into the Al2O3 slurry until volume expansion is achieved, and carrying out stirring for 30 seconds; after a gel reaction, injecting the reaction product into a mold rapidly, and carrying out demolding after a blank is cured; and transferring the blank to a thermo-hygrostat and an air-blast drying oven for curing and drying, and carrying out sintering on the dried blank in a sintering furnace at the temperature of 1,500 DEG C to 2,000 DEG C while carrying out heat preservation for 2 to 4 hours. The heat-insulating material prepared by the method has the advantages of high strength, low density and low thermal conductivity.

Description

technical field [0001] The invention belongs to the technical field of heat insulating materials, and in particular relates to a preparation method of a porous ceramic heat insulating material. Background technique [0002] In the prior art, the heat insulation material used in high temperature industry is mainly Al 2 o 3 Hollow sphere products and Al 2 o 3 fiber products. The former itself consumes a lot of energy in the preparation process. Although the market price is relatively low, it has high density, high thermal conductivity, and general heat insulation effect; the latter has low density and low thermal conductivity, but has low strength and is easy to powder. Chemical, not resistant to erosion, greater harm to the human body and other shortcomings. Therefore, in response to the energy-saving and consumption-reducing requirements of high-temperature industrial development, there is an urgent need for a new type of thermal insulation material with high strength, ...

AI Technical Summary

Problems solved by technology

The former itself consumes a lot of energy in the preparation process. Although the market price is relatively low, it has high density, high thermal conductivity, and general heat insulation effect; the latter has low density and low thermal conductivity, but has low strength and is easy to powder. Chemical, not resistant to erosion, greater harm to human body and other disadvantages