SLAG RESISTANCE OF PERICLASE-CARBON REFRACTORIES
BASED ON MODIFIED PHENOL FORMALDEHYDE RESIN
O. N. Borisenko,
G. D. Semchenko,
and T. V. Il’icheva
Translated from Novye Ogneupory, No. 11, pp. 41 – 44, November 2010.
Original article submitted January 12, 2010.
Results are provided for a study of the slag resistance of periclase-carbon specimens based on modified phenol
formaldehyde resin using different forms of filler, i.e., sintered and fuzed periclase. It is established that pene
tration of molten slag and its reaction with refractory is independent of the form of periclase filler. There is a
reduction in slag penetration into refractory with introduction of modifying additions.
Keywords: periclase, modified phenol formaldehyde resin, slag resistance, spinel.
In recent years interest in MgO–C- refractories has in-
creased due to there high thermal shock resistance and slag
corrosion resistance. Introduction of carbon into periclase
refractories improves a number of operating properties ;
there is a marked change in elasticity modulus, thermal con-
ductivity and depth of slag penetration into an object. How-
ever, a disadvantage of these refractories is oxidation of the
carbon contained within them , and antioxidants are used
in order to increase oxidation resistance and mechanical
strength [3 – 5].
Magnesium strongly affects the state of the oxide-carbon
contact both during carbonization of a binder, and also at
high temperature . Therefore the more dense the periclase
powder, the higher is object strength . Use of a porous
filler reduces ultimate strength in compression after carbon
ization, which is connected with additional oxidation of phe
nol formaldehyde binder by oxygen, absorbed by the porous
surface of periclase powder, and therefore in order to pro
duce high quality periclase-carbon refractories and retain a
stable structure of coke residue, dense fuzed periclase pow
der is used . Use of densely sintered periclase filler under
stable uniform conditions points to higher strength properties
[8, 9]. However, the strength of periclase-carbon refractories
is markedly affected not only by the form of periclase used,
but also by the binder.
Technology has been developed [10 – 12] for the produc
tion of unfired periclase-carbon refractories based on modi
fied phenol formaldehyde resin with high strength indices
and the possibility has been demonstrated of using sintered
periclase instead of fuzed material. From the multitude of
physical and chemical actions, which lead to a change in
composition and structure of periclase-carbon refractories,
the most intense breakdown is caused by reaction with mol-
ten slag. Therefore it is proposed to increase the specifica-
tions for slag resistance and resistance to cracking for these
Slag resistance of periclase-carbon specimens manufac-
tures according to technology developed in [11, 13], using
different forms of periclase as a filler, is studied in this work.
The composition of specimens is provided in Table 1.
In order to determine slag resistance by the crucible
method a blind hole was drilled over the center in test speci
mens with a diameter of 8 mm and depth of 13.5 mm into
which basic slag was poured. Slag composition, %: SiO
7.54, CaO 46.84, MgO 4.46, MnO 0.31, FeO
0.37, S 1.85; CaO/SiO
= 1.21. Specimens were heat treated
at 1400°C (soaking for 2 h, rate of temperature increase
300°C/h). After heat treatment and cooling specimens they
were cut perpendicular to refractory – slag contact surface.
The microstructure f specimens was studied by means of
MIN-8 and MI-2E microscopes in polished microsections
(polished sections) and in immersion preparations.
In all specimens there was no visually observed reaction
of slag with refractory; slag remained in the crater in the
form of a sintered conglomerate. A section of periclase-car
bon specimen No. 1 is shown in Fig. 1 after testing for slag
resistance. The least changed zone for mineral composition
and structure is similar to a specimen before testing, heat
treated at 180°C . The working zone has a thickness of
40 – 150 mm, over a single crack up to 300 mm. The follow
ing were observed within it:
Refractories and Industrial Ceramics Vol. 51, No. 6, March, 2011
1083-4877/11/5106-0433 © 2011 Springer Science+Business Media, Inc.
National Technical University “Khar’kov Polytechnic Institute”,