EFFECT OF ADDING PORCELAIN ON PROPERTIES OF POROUS CERAMIC
BASED ON ELECTROMELTED CORUNDUM
A. V. Belyakov,
Zaw Ye Maw Oo,
N. A. Popova,
and Ye Aung Min
Translated from Novye Ogneupory, No. 11, pp. 43 – 47, November, 2016.
Original article submitted July 14, 2016.
Porous permeable ceramic is prepared from electromelted corundum (EMC) with fineness of about 0.5 mm
with added porcelain. Compositions are prepared with different ratios of EMC/porcelain: 99/1, 97/3, 95/5,
93/7, and 90/10. Specimens in the form of bars with a size of 40 ´ 7 ´ 6.5 mm are prepared by uniaxial
semidry compaction under a pressure of 25 and 50 MPa and fired at 1350 and 1450°C. Specimen open poros
ity varies from 22 to 30%, and ultimate strength in bending from 1.1 to 9.3 MPa. Porous ceramic is promising
for filters and ceramic membrane substrates.
Keywords: porous ceramic, electromelted corundum (EMC), porcelain, filter elements.
Porous ceramic is used throughout the world for filter-
ing, heat insulation, and heat protection. During filtering im-
portant parameters are a porous structure and properties con-
nected with it, i.e., pore size, pore size distribution, average
capillary diameter, permeability, and specific surface. There
is increasing interest in porous ceramic materials due their
capacity to operate at high temperature in corrosive and abra
sive media. These materials may be used for filtering various
liquids (liquid solutions in various solvents, with almost any
medium pH, and melts, including metals, polymers, salts),
and also gases [1 – 4].
In an article 
the effect is studied of the ratio of two
fractions (2 – 3 and 0.5 mm) of electromelted corundum
(EMC) with a constant content of porcelain binder of mix
) on porous ceramic properties. Specimens were
compacted under a pressure of 25, 50 and 100 MPa and then
fired at 1350 and 1450°C. The aim of the work was prepara
tion of porous permeable ceramic based on EMC with a
binder of porcelain and a study of ceramic properties in rela
tion to binder content. Porous ceramic is particularly suitable
for use as a filter element with a narrow pore size distribution
and average pore size of 6 mm .
The filler used was EMC F20 (~0.5 mm), and the binder
used was porcelain powder mix (gel porcelain mix grade
PFL-1 (PFL is cast semi-porcelain ). PFL chemical com
position, %: SiO
CaO 0.45, MgO 0.3, K
O 1.7, Na
O 0.9; loss on calcination
6.8%. Compared with EMC the particle size in the mix is
much smaller, the residue on a screen with a cell size of
63 mm is not more than 2.0%. Overall shrinkage after drying
and firing is not more than 13.0%. A firing temperature of
1200 – 1220°C is recommended.
Dried porcelain mix (subsequently porcelain) was mixed
with EMC by a dry method in a corundum drum with corun
dum milling bodies for 3 h, and the ratio of milling
balls : material was 1 : 1. Compositions were prepared with
additions of porcelain to EMC powder in amounts of 1, 3, 5,
and 10%. After mixing and adding a temporary process
binder a powder molding mix was obtained. The temporary
process binder used was 5% aqueous solution of polyvinyl
alcohol (PVA); binder was added in an amount of 7% of
charge weight. The PVA solution was added in small por
tions to a dry mix of components with continuous stirring.
The moistened carefully stirred mix was additionally homog
Refractories and Industrial Ceramics Vol. 57, No. 6, March, 2017
1083-4877/17/05706-0609 © 2017 Springer Science+Business Media New York
D. I. Mendeleev Russian Chemical Technology University, Mos
There are misprints in the article. The porcelain mix is not LT, but
PFL-1. Values of strength in bending are given in kg/m
, but writ
ten MPa, i.e., ten times greater.
Here and subsequently wt.% shown.