COMPOSITION AND PROPERTIES OF THE MAIN TYPES
OF ALUMINOTHERMIC SLAG AT THE KLYUCHI FERROALLOY WORKS
V. A. Perepelitsyn,
V. M. Rytvin,
I. V. Kormina,
and V. G. Ignatenko
Translated from Novye Ogneupory, No. 9, pp. 15 – 20, September, 2006.
Original article submitted July 21, 2006.
The results of an integrated study of high-alumina slag generated in the production of ferrotitanium, ferro
chrome, and metallic chromium by the aluminothermic method at the Kluchi Ferroalloy Works are described.
The chemical and mineral composition and refractoriness of the main varieties of slag are identified. The pros
pects for application of refractory slag are considered.
The Klyuchi Ferroalloy Works is the only company in
Russia and the CIS producing over 30 unique ferroalloys and
alloying compositions using the method of aluminothermic
reduction of metals from oxides and other compounds.
Aluminothermic reduction of metals (Me) proceeds accord-
ing to the following reaction:
+4/3Al ® 2n/mMe+2/3Al
Consequently, in contrast to all other ferrous and non
ferrous metallurgical slags, aluminothermic slag (ATS) is
based on silica whose average content in the slag is at least
60 wt.%. The purpose of this study was to determine the
mineral composition, microstructure, and physicochemical
properties of the main ATS varieties and to issue recommen
dations for their more extensive application. The objects of
the investigation included old (dump) slag and current-pro-
duction slag generated in smelting ferrotitanium, ferro-
chrome, and metallic chromium. Methods used in the study
were petrography using reflected light microscopy with a
SIAMS system and x-ray phase analysis (a DRON diffracto-
meter). The refractoriness was determined according to
GOST 4060 “Refractories and refractory materials. Methods
for determining refractoriness.”
The chemical compositions of the main varieties of cur
rent-production slags and old ATS taken from the slag dump
are listed in Table 1. The highest content of Al
tered in the ATS resulting from metallic chrome production
(sample Nos. 8 and 9) and the lowest content is found in the
ATS from carbon-free ferrochrome production (sample
Nos. 6 and 7). Aluminothermic slag formed in the production
of ferrotitanium takes the intermediate position with respect
to this parameter. The content of CaO in the considered sam
ples is 7.5 – 18.1%, SiO
— 0.1 – 5.0%, and MgO —
1.0 – 17.0%. All slags contain oxides of the target alloys
(ferrochrome, ferrotitanium) and metallic chrome. The high
est content of titanium dioxide is found in the dump ATS
generated in ferrotitanium production.
The mineral composition of samples is listed in Table 2.
With respect to the mineral composition, all melted materials
can be divided into the following four groups: phases of the
system (slag from production of Cr, samples 8,
9); phases of the CaO – Al
system (slag from FeTi
production, sample Nos. 4 and 5); phases of the CaO –
Refractories and Industrial Ceramics Vol. 47, No. 5, 2006
1083-4877/06/4705-0264 © 2006 Springer Science+Business Media, Inc.
VostIO JSC, Klyuchi Concentration Works, Dinur JSC, Russia.
TABLE 1. Chemical Composition of Slag, %
CaO MgO FeO
Slag from metallic chrome production
8 81.3 9.5 0.1 7.5 1.0 0.7 —
9 80.1 8.4 0.1 9.7 1.1 0.5 —
Slag from ferrochrome production
6 46.5 13.1 5.0 17.8 17.0 0.6 —
7 57.3 6.5 0.7 18.1 16.4 0.8 —
4 62.3 0.1 0.1 16.0 2.4 1.1 18.0
5 63.6 0.2 0.3 9.9 2.8 0.6 22.7
Note. Current production slag samples have even numbers, dump
slag — odd numbers.