Nosov Magnitogorsk State Technical University (Magnitogorsk, Russia):

M. V. Chukin, Dr. Eng., Prof., First Vice-Rector on Science and Innovations, Dept. "Materials Processing Technologies"
S. K. Sibagatullin, Dr. Eng., Prof., Dept. "Foundry Production and Material Science"
A. S. Kharchenko, Cand. Eng., Ass. Prof., Dept. "Foundry Production and Material Science"
V. P. Chernov, Dr. Eng., Prof., Dept. "Foundry Production and Material Science"

Magnitogorsk Iron and Steel Works (Magnitogorsk, Russia):
G. N. Logachev, Engineer, Scientific and Technical Center

E-mail: 10skt@mail.ru; as.mgtu@mail.ru; tchernov42@mail.ru; lokkigrom@mail.ru

The effect of coke nut introduction in charge material (in the amount 10.9–12.8 kg per ton of hot metal) on operation parameters of blast furnaces with volume 1370 and 2014 m³ have been established via industrial investigations. These blast furnaces are operating in the conditions of bottom and top areas determining by their gas dynamics. Parameters of gas dynamic conditions, fuel burning, iron reduction from FeO using different reducing agents, furnace thermal operation and hearth drainage capacity are analyzed. Introduction of coke nut in the iron ore part of charge material has increased its equivalent surface coarseness and thereby improved its gas permeability. It is shown that blast furnaces operating with the top area determining by gas dynamics are characterized by decrease of charge resistance coefficient on top throat by 7.1%. Each 10 kg of coke nut on 1 t of hot metal allowed to add 400 m³/h of natural gas without arise of difficulties of a furnace operation. It accompanied by rise of heat exchange intensity for the temperatures below 850 °C, by increase of Fe reduction degree from FeO by hydrogen and by rise of its usage degree. The maximal increase of technical and economical melting parameters has been observed for the furnace with volume 2014 m³. Lowering of specific coke consumption (both actual and adduced to the equal conditions) made 0,76 and 0.88 kg per 1 kg of coke nut respectively. Usage of coke nut in the furnace operating with bottom limiting area by its gas dynamics was characterized by the negative nut effect on filtrating ability of coke packing in the furnace hearth. Introduction of 12.8 kg of nut per 1 t of hot metal has accompanied by increase of the amount of slag remaining in the furnace from 7 to 9 m³, by enlargement of the time interval between the beginning of hot metal tapping and slag appearance from 9.5 to 8.4 min and by toughness rise from 0.40 to 0.45 Pa·s.

The study has been carried out under financial support of the RF Ministry of education and science in the framework of realization of the complex project on creation of high-tech production with participation of a high school (Agreement No. 02.G25.31.0178 dated 01.12.2015).

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