NEW OBJECTS OF SLIFORM GRADE FOR LINING CEMENT KILNS
Translated from Novye Ogneupory, No. 6, pp. 125 – 128, June 2011.
Original article submitted May 12, 2011.
A new form of periclase-forsterite refractory is presented as an alternative to magnesia-spinel objects used for
lining rotary kilns for firing cement clinker.
Keywords: periclase-forsterite objects, SLIFORM, rotary kiln, corrosion.
It is well known that at a time of crisis, when there is a
drop in production, in order to preserve a market it is neces-
sary to reduce production costs, and therefore it is important
to find the optimum price/quality ratio for a consumer. This
is a complex task for technologists since production may be
cheapened by using cheaper starting materials, but there is a
risk of an increase in operating costs. In the Slovmag Plant a
new product has been developed, i.e. periclase-forsterite ob-
jects grade SLIFORM, intended for use in the same zones of
linings as periclase-spinel objects. SLIFORM objects are
cheaper with an optimum price/quality ratio. Industrial tests
of the new objects have been carried out in service.
CEMENT INDUSTRY — AN IMPORTANT USER
OF REFRACTORY PRODUCTS
An important use of refractories based on periclase is the
cement industry. For a long time the lining of rotary cement
kilns has been made from periclase-chromite objects with an
optimum price/quality ratio. In view of the appearance of
more stringent conditions for environmental protection in or-
der to make the lining of high-temperature zones of rotary
kilns often there is use of periclase-spinel objects, in spite of
higher const compared with periclase-chromite refractories.
Rotary cement kilns play an important role in utilization
of industrial wastes of different form and composition.
Wastes are treated containing sulfur, alkali, chlorides, and
various metals. This creates increased thermal and mechani-
cal loads on a refractory lining. A wish of cement producers
is to obtain a quite inexpensive universal lining, which could
withstand any production process conditions for cement
manufacture over the whole of its campaign. For now, the
optimum solution is making a lining zone by zone, combin-
ing different forms of refractory in relation to service condi-
SLIFORM is a periclase-forsterite object of medium
quality, intended for zones of rotary cement kiln with a stable
covering. Forsterite (magnesium silicate with t
by comparison with chromite or magnesia spinel, is most re-
sistant to the chemical action of cement clinker. The lining
wear mechanism involves the following: at the operating
temperature readily melting components of cement clinker
are melted and impregnate a refractory lining; here Fe
, and Al
from refractory pass into molten clinker,
increasing its melting temperature and viscosity; the melt en-
riched with oxides (secondary) solidifies within pores, and a
refractory acquires a zonal structure. Due to the different
thermomechanical property indices there is periodic chip-
ping of a working surface of objects. After renewal of a
working surface the process commences again from the be-
In the case of contact with periclase-chromite refractory
a secondary melt contains bicalcium ferrite 2CaO·Fe
1436°C), melilite 4CaO·Al
and mayenite 12CaO·7Al
1390°C). In contact with
periclase-spinel refractory calcium aluminate of different
composition passes into the secondary melt with a low melt-
ing temperature, mainly mayenite.
At the contact of molten clinker with periclase-forsterite
refractory it is possible to form silicates with a higher melt-
ing temperature and with increased viscosity, such as
1575°C), and bellite 2CaO·SiO
2130°C). In addition, there is a reduction in formation of
substances containing iron and aluminum oxides.
Refractories and Industrial Ceramics Vol. 52, No. 3, September, 2011
1083-4877/11/05203-0227 © 2011 Springer Science+Business Media, Inc.
Slovmag (AS Lubenik), Lubenik, Slovakia.