MANUFACTURING AND EQUIPMENT
HEAT-RESISTANT CONCRETE BASED ON ALUMINOTHERMIC SLAGS
OF THE KLYUCHEVSKII FERROALLOYS PLANT
A. N. Abyzov,
V. A. Perepelytsyn,
V. M. Rytvin,
V. G. Ignatenko,
and O. A. Klinov
Translated from Novye Ogneupory, No. 12, pp. 15 – 18, December, 2007.
Original article submitted June 19, 2007.
Substance and grain compositions, parameters of physicochemical properties, and ranges of application of
heat-resistant concretes produced on the basis of aluminothermic slags are presented. A wide range of fillers
and lime-aluminate cements of refractory and heat-resistant concretes is considered. Experience in the use of
slag concretes in linings of various heating units is described.
The range of initial materials for preparing components
for heat-resistant concretes, i.e., binders, fillers, finely milled
additives, and hardeners, can be widened by using various
technogenic mineral materials, refractory ferroalloy slags in
particular . Analysis of the chemical and mineral compo-
sitions and properties of slags of the Klyuchevskii
Ferroalloys Plant has shown that many of them can serve as
valuable initial materials for preparing components of
heat-resistant concretes. These slags can be used to fabricate
fillers and finely milled additives for heat-resistant concretes
with a service temperature of up to 1800°C [2 – 4]. In this
way we can not only widen the raw materials base but also
lower the cost of heat-resistant concretes, save a considerable
amount of refractories and cement, and make the environ
ment healthier due to transition to a wasteless technology.
Binders from slags of carbonless ferrochrome. Binders
for heat-resistant concretes can be slags due to melting
carbonless ferrochrome. These slags have the form of a ma
terial with dense porphyritic structure of a red-brown color
with spinel inclusions. The chemical composition of the
slags in mass percent is as follows: 50 – 60 Al
CaO, 15 – 25 MgO,2–7Cr
, 1.0 – 2.5 Fe
The phase composition of the slags is represented by
aluminates and alumo
magnesia chromium-bearing spinel. With respect to the con
tent of the main oxides these slags are close to some kinds of
lime-magnesia aluminous cement widely used in foreign
countries [4 – 6]. An advantage of lime-magnesia cements is
the elevated content of spinel, which is responsible for such
properties as high refractoriness, resistance to aggressive
media, low water demand, and low shrinkage after heating.
All these factors make such cements promising materials for
the production of heat-resistant concretes.
After crushing and milling, carbonless ferrochrome slags
acquire the properties of a rapidly solidifying hydraulic
binder. In order to control the time of cementation it is neces
sary to introduce 0.05 – 0.2% plasticizer or superplasticizer.
The ultimate compressive strength of hydrated binder after
3 days of solidification ranges from 25 to 48 MPa; after a
year of storage under conditions of moisture it increases by a
factor of 1.5 – 2.
Physicochemical studies have shown that hydration of
milled slags yields metastable potassium hydroaluminates
that acquire a stable form after 6 months of solidification.
When studying the heat resistance of a hydrated slag
binder we established that after a heat treatment at 1200°C
the minimum retained porosity was 35 – 60% of the initial
value and the firing shrinkage was 1.3 – 16%. After heat
treatment at 1400°C, the firing shrinkage was 2.3 – 4%, the
refractoriness was 1520 – 1540°C; at a load of 0.2 MPa soft
ening began at 1220 – 1230°C and fracture occurred at
1400 – 1500°C. The temperature coefficient of linear expan
sion (TCLE) due to heating from 20 to 1000°C was 5 ´ 10
8 ´ 10
. Heating of a hydrated binder obtained on the
basis of slags without carbon ferrochrome was accompanied
by recrystallization and dehydration of the hydration pro
Refractories and Industrial Ceramics Vol. 48, No. 6, 2007
1083-4877/07/4806-0397 © 2007 Springer Science+Business Media, Inc.
Klyuchevskii Dressing Works Company, VOSTIO Company,