SELF-DISINTEGRATING FERROCHROME ALUMINOTHERMAL SLAG –
SEMIFUNCTIONAL TECHNOGENIC RAW MATERIAL
V. A. Perepelitsyn,
V. M. Rytvin,
S. I. Gil’varg,
V. G. Ignatenko,
V. G. Kutalov,
and N. N. Arzamastsev
Translated from Novye Ogneupory, No. 10, pp. 9 – 14, October 2009.
Original article submitted September 15, 2009.
On the basis of studying the chemical and mineral compositions, microstructure and properties of self-disinte
grating ferrochrome aluminothermal slag a fundamentally new highly effective waste-free technology has
been developed for preparing fuzed alloyed spinel Mg(Al, Cr)
. The test slag exhibits binding properties.
After spinel extraction its limestone-silicate-aluminate component may be used for producing more than ten
forms of product: cement, pigments, building and other materials.
Keywords: ferrochrome aluminothermal self-disintegrating slag, spinel, silicates.
In view of the high content of Al
(50 – 85%) and in-
creased refractoriness of many classes of slags from
aluminothermal production of metals and alloys they are of
considerable practical interest as a technogenic refractory
raw material [1 – 3]. The overwhelming majority of
aluminothermal slags are not only a valuable refractory raw
material, but also a promising starting material for producing
a broad range of different products [4, 5]. The aim of this
work is a detailed study of the substance and grain size com
position and microstructure of self-disintegrating ferro
chrome aluminothermal slag (SFAS) for the development of
effective areas of its comprehensive use in refractory and
other branches of industry.
The main components of an aluminothermal ferrochrome
charge are chromium ore (concentrate), aluminum powder
and fired limestone. During melting there is complete fusion
and chemical reaction of the original materials with forma
tion of two immiscible melts: metal (ferrochrome) and
polycomponent silicate (slag). The products of hardening
and crystallization of aluminothermal slag are ferrochrome,
spinel, calcium-containing silicates and aluminates of vari
able composition. The overall scheme of chemical conver
sion and crystallization of the process for preparing ferro
chrome from ore raw material may be presented as follows:
(MgO, Fe)(Cr, Al, Fe) O Al CaO
Mg(Al, Cr) O CaO SiO
( CaO MgO SiO + CaO Al O
The substance composition of the charge and physio
chemical processes of aluminothermal smelting of ferro
chrome govern the chemical and mineral compositions, and
correspondingly all of the slag properties.
SFAS in contrast to other monolithic high-strength
aluminothermal, silicothermal and carbothermal slags is a
granular polydispersed powder material, within which the
main and secondary components in different fractions are
distributed very unevenly. The chemical composition and
some properties of the gross samples and individual fractions
of typical contemporary SFAS of the OAO Klyuchi Ferroally
Plant (KZF) are provided in Table 1.
As follows from the data provided in Table 1, the main
fluxing (reducing the melting temperature) oxides CaO and
are concentrated in the fine fraction (finer than 50 mm),
and the highly refractory oxides Cr
, MgO, Al
centrated in the granular part of the SFAS (fraction
>0.5 mm). The relative concentration of fluxing oxides in the
fine fraction is for SiO
20.4/2.19 = 9.3, for CaO
40.5/4.22 = 9.6, i.e. greater by almost a whole order of mag
nitude. The relative enrichment of the coarser fractions with
Refractories and Industrial Ceramics Vol. 50, No. 5, 2009
1083-4877/09/5005-0328 © 2009 Springer Science+Business Media, Inc.
OOO Klyuchi Enrichment Plant.
OAO UK RosSpetsSplav.
OAO NPO VOSTIO-Ural.