Porous corundum-mullite ceramics with nano-pore size and preparation method thereof

Abstract

The invention relates to a porous corundum-mullite ceramic with the nano pore diameter and a preparation method thereof. The technical scheme is as follows: fine aluminum hydroxide powder is sequentially heated to 280-450 DEG C and 800-1,200 DEG C and kept at the constant temperature, and aluminum oxide powder with high porosity is obtained. 70wt%-90wt% of the aluminum oxide powder with high porosity, 9wt%-29wt% of silica sol and 1wt%-10wt% of fume silica are matched, the aluminum oxide powder with high porosity is placed in a vacuum mixer, vacuum is pumped to be 2.0 kPa or below, then silica sol and fume silica are added to the vacuum mixer and stirred, and a mixture is obtained. The mixture is kept at the constant temperature of 110-220 DEG C, cooled, mechanically pressed, dried, then sequentially heated to 800-1,100 DEG C and 1,400-1,600 DEG C and kept at the constant temperature, and the porous corundum-mullite ceramic with the nano pore diameter is obtained. The produced product has nanoscale pore diameter and has the characteristics of low air permeability, low heat conductivity and coefficient, good volume stability and high strength.

Description

technical field [0001] The invention belongs to the technical field of porous corundum-mullite ceramics. In particular, it relates to a nano-pore porous corundum-mullite ceramic and a preparation method thereof. Background technique [0002] Corundum-mullite material has the advantages of high load softening temperature, good thermal shock resistance and low high temperature creep rate, and is widely used as the lining material of industrial furnaces such as blast furnace hot blast stoves and heating furnaces. Due to the low porosity and high thermal conductivity of the corundum-mullite material, it will cause a certain heat dissipation loss of the furnace lining. Thermal conductivity, the development of porous corundum-mullite ceramics as thermal insulation materials for working kilns is imminent. [0003] At present, the research on the preparation of porous corundum-mullite ceramics includes: such as literature technology (Cao Hehui, Wang Gang, Yuan Bo, etc. Preparation...

AI Technical Summary

Problems solved by technology

[0003] At present, the research on the preparation of porous corundum-mullite ceramics includes: such as literature technology (Cao Hehui, Wang Gang, Yuan Bo, etc. Preparation of corundum-mullite porous ceramics by foam injection method [J]. Refractories, 2013, 47( 5):334-337.) Using plate-like corundum powder, alumina micropowder and silica sol as raw materials, corundum-mullite porous ceramics were prepared by foam casting method. The material prepared by this method not only has low strength and pores The pore size is large, and the pore size and volume stability of the pores are poor; another example is the literature technique (Yan W, Chen Q, Lin X, et al. Pore characteristics and phase compositions of porous corundum-mullite ceramics prepared from kaolinite gangue and Al(OH) 3 with different amount of CaCO 3 addition[J]. Journal of the Ceramic Society of Japan, 2015, 123(1441):897-902.) Using in-situ decomposition technology to form pores, Al(OH) 3 and coal gangue as raw materials to prepare porous corundum-mullite ceramics, but its pore diameter is large, the air permeability is large and the strength is low