Method for preparing alumina porous ceramic using gelatin wrapping-freeze drying process

Abstract

The invention discloses a preparing method of porous alumina ceramic through sol-gel freezing drying technique, which comprises the following steps: adopting aluminium isopropoxide as former; hydrolyzing under high temperature to obtain alumina sol; controlling the solid content of sol; adding moulding agent; blending evenly; casting; moulding; removing air to form vacuum; freezing at low temperature; drying and moulding the frozen sample; detackifying moulded sample under low temperature; placing in the high-temperature furnace; sintering; obtaining the porous alumina ceramic with bending-proof strength reaching 65Mpa and bulk density at 0.14-2.4g / cm3. The adjustable aperture is 1-100um, which can be filter, catalyst carrier and heat insulating material.

Description

technical field [0001] The invention relates to a method for preparing alumina porous ceramics by a sol-gel-freeze-drying process, and more specifically to a method for preparing high-porosity and low-density alumina by combining a sol-gel powder synthesis method with a freeze-drying sample molding process A method for porous ceramics belongs to the field of porous ceramics. Background technique [0002] Alumina porous ceramics are widely used in the fields of filters, catalyst carriers, thermal insulation materials and refractory materials due to their advantages of chemical corrosion resistance, wear resistance, light weight, high permeability, low expansion coefficient and good high temperature stability. Broad application prospects. In order to meet the application in different fields, there are many reports about the preparation method of alumina porous ceramics, for example, Cheng Changrui et al. The salt solution is used as the basic raw material, and the pH value i...

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Problems solved by technology

[0005] At present, there are few reports on the direct molding of ceramic powder by freeze-drying method. Freeze-drying molding can reduce the shrinkage caused by ordinary drying molding. sample

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