POROUS PERMEABLE CORUNDUM CERAMIC
BASED ON ALUMINUM POWDER.
PART 1. STUDY OF DIFFERENT GRADES OF ALUMINUM
HYDROXIDE POWDER PROPERTIES
B. L. Krasnyi,
V. P. Tarasovskii,
Yu. M. Mosin,
A. B. Krasnyi,
and A. Yu. Omarov
Translated from Novye Ogneupory, No. 1, pp. 35 – 41, January 2014.
Original article submitted February 4, 2013.
Results are provided for preparation and properties of porous permeable ceramic with high values of open po-
rosity and strength based on different grades of aluminum hydroxide powder. Part 1 of this article is devoted to
studying properties of these powders.
Keywords: porous corundum ceramic, aluminum hydroxide powder, gibbsite, bayerite, boehmite.
Objects of porous permeable ceramic exhibit a number
of advantages compared with the same objects made from
porous metals, glass, and plastics. They have higher values
of strength, stability in acid and alkali, molten ferrous and
nonferrous metals, corrosive slags, and they may operate for
a long time at high temperature. Therefore, currently objects
of this ceramic are of considerable interest for users.
With respect to areas of application of porous permeable
ceramic objects it is possible to separate several groups:
group 1 is objects whose operating process is characterized
by presence of excess gas or liquid pressure, which proceeds
through pore channels, clean, homogenize, separate, and
mix. These objects concern filtering elements for air cleaning
from dust, water and oil mist, and also air and hot corrosive
gases, for example blast and open-hearth furnaces, with tem-
peratures up to 1000°C ; filtering elements for cleaning
aerosols from gases, including radioactive materials ; fil-
ter elements for cleaning drinking water and effluent from in-
dustrial enterprises, electrolyte solutions, pulp, salt solutions,
wine milk, acid, alkali, molten ferrous and nonferrous metals
[3 – 5]; dispersers for finely-dispersed atomizing of gases in
liquid media or melts, and also gaseous reagents in chemical
reactors with the aim of increasing surface contact ; group
2 is objects of capillary-porous ceramic materials, whose op-
eration is based on use of capillary pressure, arising at a liq-
uid-gas interface. These objects concern evaporators, con-
densers, heating pipe wicks, capillary pumps, hydraulic
valves, etc. ; groups 3 is objects of porous ceramic materi-
als with special properties. for which during operation there
is typically reaction of a pore surface with a phase previously
introduced or passed through pore channels, which intensi-
fies physical and chemical processes. The objects concern
membranes for reference electrodes, bone tissue replace-
ments, etc. .
Traditional methods for preparing porous permeable co-
rundum ceramic, such as partial sintering (solid-phase) of
narrow fraction alumina powders, liquid-phase sintering of
narrow-fraction powders (using readily melting processing
binders), with use of powders from materials with a non-cu-
bic structure and with differing LTEC in the direction of the
main crystallographic axes, using different pore formers, do
not make it possible to obtain porous permeable materials
with high (greater than 40%) values of open porosity . It
has been shown [10, 11] that introduction into the composi-
tion of aluminum oxide powder of an aluminum hydroxide
additive makes it possible to obtain porous ceramic material
with porosity values up to 50%, although the strength of
these materials is quite low.
Refractories and Industrial Ceramics Vol. 55, No. 1, May, 2014
1083-4877/14/05501-0030 © 2014 Springer Science+Business Media New York
ZAO NTK Bakor, Shcherbinka, Moscow Region, Russia.
FGBOU VPO D. I. Mendeleev Russian Chemical Technology
University, Moscow, Russia.
FGBOU VPO Moscow, State Industrial University, Moscow,