length of the machine and when they are changed, there is no need to redistribute the
length of the machine into the zones.
The zonal factors are the moisture of green pellets (drying zone), limestone
additive, solid fuel, heating rate and its duration (firing zone), final temperature of the
finished pellets and heat capacity of the cooling air (cooling zone).
CONCLUSION
Based on the research conducted for the iron ore pellets induration process, it has
been determined that it is the firing stage to be crucial for ensuring the efficient
operation of the firing machine and this can be implemented by the means written
below: (i) the total value of dehydration in the drying zone should be no less than 90–
95%, in order to prevent their destruction with the further rapid heating; (ii) the
decarbonization of the limestone begins in the preheating zone and occurs as much as
50% or more of the reaction; (iii) the magnetite oxidation begins in the preheating zone
and completes in the firing zone; (iv) the temperature and the gas flow rate in the
cooling zone should provide pellets cooling down to the acceptable temperature of
100–150 °C.
BIBLIOGRAPHICAL REFERENCES
Eisele, T.C. and Kawatra, S.K. (2010). A review of binders in iron ore
pelletization. Mineral Processing and Extractive Metallurgy Review, 24(1), 1–90.
DOI: 10.1080/08827500306896
Kater, T. and Steeghs, H.R.G. (1984). Organic binders for iron ore pelletization.
In: Proceedings of the 57th Annual Meeting of the Minnesota Section of AIME, Duluth,
MN, 13.1–13.29.
Martinez, N. P., Trejo, M. H., Estrella, R. M., Castro Román, M., Esparza R. M.,
Villareal, M. C. (2014). Induration process of pellets prepared from mixed magnetite–
35%
hematite
concentrates.
ISIJ
International,
54(3),
605–612.
DOI:
10.2355/isijinternational.54.605
Metso
(2012).
Iron
ore
pelletizing.
Grate-Kiln
system.
https://www.metso.com/globalassets/saleshub/documents---episerver/great-kiln-
system-brochure.pdf. Accessed 31.05.2019
Meyer, K. (1980). Pelletizing of Iron Ores. Springer Verlag, Berlin, ISBN:
3540102159.
Mourão, J.M. (2012). Guidelines for selecting pellet plant technology. In: 6th
International Congress on the Science and Technology of Ironmaking-ICSTI, Rio de
Janeiro, RJ, Brazil, October 14–18, 2162–2175.
- 468 -