Kieush L.
PhD, National Metallurgical Academy of Ukraine, Dnipro, Ukraine
Boyko M.
PhD, National Metallurgical Academy of Ukraine, Dnipro, Ukraine
Koveria A.
PhD, National Technical University “Dnipro Polytechnic”, Dnipro, Ukraine
Poliakova N.
PhD, National Metallurgical Academy of Ukraine, Dnipro, Ukraine
ANALYSIS OF MUTUAL INFLUENCE BETWEEN PARAMETERS
OF THE INDURATION PROCESS FOR IRON ORE PELLETS
Introduction. Iron ore pellets are formed from beneficiated or run of mine iron
fines. Iron ore pelletizing (Meyer, 1980) is a process that involves mixing very finely
ground particles of iron ore fines of size less than 0.074 mm with additives like
bentonite and then shaping them into oval/spherical lumps of 8-16 mm in diameter by
a pelletizer and hardening the balls by firing with a fuel. The pelletization process is
widely used, particularly when burden materials are intended to be shipped for
transporting at great distances between the mine and the blast furnace (BF), because
fired pellets are durable and easy to handle. The pellets capable of good performance
in the blast furnace are those with good bed permeability and reducibility. Further, the
pelletizing process can produce iron ore pellets not only for blast furnace process but
also for non-BF ones, such as direct reduced iron (DRI) process (Zhang et al., 2011).
Historically, the patent on iron ore pellets production was first taken in 1912 by
A.G. Andersson of Sweden in 1912 and in 1913 by C.A. Brackelsberg in Germany, it
was a successful solution to the problem of the thin iron ore concentrates sintering.
Contemporary iron ore pelletizing plant consumes coal, pet coke, oil and natural
gas to provide the required chemistry, physical and metallurgical properties to iron ore
pellets, consumed in steel industry (Praes et al., 2019; Wang et al., 2018).
The process of iron ore pelletizing consists of three main stages:
(i)
Raw material preparation. During the pelletizing process, the iron ore
concentrate is dried and heated to the temperature of approximately 120 °C. The dried
material is fed to the ball mill for grinding. Iron ore concentrate/ground iron ore of the
typical size of 80% and less than 45 microns should have the moisture content of 9%.
Suitable binder (for instance, bentonite or organic binders (Eisele and Kawatra, 2010;
Kater and Steeghs, 1984) and fluxing agents (like limestone or dolomite) are applied
in pellets preparation. If the ore-bearing material for the process is hematite, then coke
or anthracite coal are engaged as internal fuel. These are added to iron ore concentrate
and blend thoroughly in a high intensity-blending machine. Wet material is fed into the
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