Russian Journal of Applied Chemistry, 2013, Vol. 86, No. 3, pp. 311−314.
Pleiades Publishing, Ltd., 2013.
Original Russian Text © V.A. Utkov, O.V. Zyryanova, 2013, published in Zhurnal Prikladnoi Khimii, 2013, Vol. 86, No. 3, pp. 336−339.
AND INDUSTRIAL INORGANIC CHEMISTRY
Modeling Dependence of the Strength of Agglomerates
on Their Basicity
V. A. Utkov and O. V. Zyryanova
St. Petersburg State Mining University, St. Petersburg, Russia
Received April 13, 2012
Abstract—An attempt was performed to clarify and summarize mathematically an extreme dependence strength–
basicity of agglomerate based on polymorphism of Ca
. Two main indicators underlaid the sinter production:
a mechanical strength and speciﬁ c performance of a sinter plant, which can be expressed by yield of a certain size
fractions after physical stress and by linear sintering rate, respectively.
It is known that at the most common basicity 1.4
(mass ratio SaO/SiO
) the agglomerate strength is
minimal that is highly undesirable. This is explained
by polymorphism of dicalcium silicate Ca
Its phase transformation from β- to γ-modiﬁ cation is
accompanied by an increase in a volume of the material
by 10%. This occurs in the body of iron ore sinter at
about 675°C, when it is in the solid state after sintering
with slag ligament at about 1200°C. Due to arising
internal tensions a sinter weakening occurs. The curves
shown in the ﬁ gure became standard  and entered the
main textbooks, monographs [3–5].
In this paper we attempted to describe mathematically
these curves. Two main indicators of sinter production
were assumed as main: mechanical strength and speciﬁ c
performance of sinter plant, which were expressed,
respectively, by yield of fractions of a certain size
after physical stress and by linear sintering rate. Yield
of a +5 mm fraction in a standard drum was taken as
With the same raw material quality and in view of
self-equalizing of a return in the form of independent
variables it was assumed: x
was humidity of charge (%);
, fuel consumption (%); x
, height of the charge bad
(mm), and optimization parameters: y
, linear sintering
rate (mm min
, yield of +10 mm fraction after a test
in the drum (%), y
, yield of 0–5 mm fraction after the
test in the drum (%).
Five experiments under zero conditions were
conducted to found average parameters of optimization
and reproducibility errors (Table 1).
On the ﬁ rst step the full factorial design of type 2
An effect of sinter basicity b on its strength P (conv. %)
depending on raw material quality . (1–3) Finely ground
concentrate, rich, middle, and poor in iron, respectively
(V.A. Utkov, V.Ya. Miller), (4) a mixture of ore (H. Tomomatsu,
N. Hayashi, M. Maekava, T. Takatsuhi), (5) a mixture of ﬁ ne
ore concentrate and silt (G. Vintser, K. Shmits), (6) magnetite
ore, (7) hematite ore (G. Mayer), (8) a mixture of ore averages
(Key Kuhi, Burden), (9) a mixture of ores rich in iron
(R. Limons, S. Felton).