| INFLUENCE OF IRREGULARITY OF HOT METAL AND SLAG TAPPING ON BLAST FURNACE PERFORMANCE AT NTMK-EVRAZ Yakov Gordon1; Sergei Zagainov2; Vladimir Panteleev3; Vladimir Mironov4; Mikhail Polovets2; 1HATCH, Mississauga, Canada; 2URAL FEDERAL UNIVERSITY, Ekaterinburg, Russian Federation; 3URAL FWDERAL UNIVERSITY, Ekaterinburg, Russian Federation; 4NTML-EVRAZ, Nizhniy Tagil, Russian Federation; PAPER: 44/Iron/Regular (Oral) SCHEDULED: 16:45/Mon. 28 Nov. 2022/Arcadia 1 ABSTRACT: <p>Timely and complete taping of hot metal and slag is the main precondition of blast furnace intensive operation. Irregular taping leads to fluctuation of the level of liquid products in the furnace hearth, change in rate of material charging to the furnace and variations in a burden residence time in the furnace. Also it effects the thermal state of the furnace and chemical composition of the hot metal and slag. Ratio of tapped hot metal and slag is determined by physical properties of slag, diameter and length of hot metal taphole. Analysis of NTMK-Evraz blast furnaces operation showed significant fluctuations of this ratio. At average slag volume between 340-360 kg/thm the actual range of slag volume changes from 200 to 850 kg/thm. The fundamentals of mechanics of fluid and gases were applied to study the problem and laminate flow of hot metal and slag was assumed for the taphole. The ratio of the metal and slag mass in the taphole and hot metal and slag velocities were described as a function of slag parameters and taphole geometry. This approach allowed to derive numerical relationship between volumes of tapped hot metal and slag, slag viscosity and taphole design. Results of mathematical modeling were confirmed by actual performance parameters of NTMK-Evraz blast furnaces. It was found, that increase in slag to hot metal ratio led to the reduction in blast furnace productivity and reduction in vanadium partition to hot metal.</p> References: <p>[1] Shao L., Saxén H. A simulation study of blast furnace hearth drainage using a two-phase flow model of the taphole // ISIJ International. 2011. Vol. 51, No. 2, p.p. 228–235.<br />[2]. Muller J., Zietsman J.H., Pistorius P.C. Modeling of Manganese Ferroalloy Slag Properties and Flow During Tapping // Metallurgical and Materials Transactions B: Process Metallurgy and Mater. Proc. Sci. 2015. Vol. 46, No. 6, p.p. 2639–2651.<br />[3] Abramowitz H., Goffney L.J., Ziegert W.L. Taphole mix properties and performance for the first year of operation on Inland’s No. 7 blast furnace / Proceedings of the 42nd Ironmaking Conference, Atlanta, GA. 1983, 17–20 April // Iron and Steel Society of AIME, Warrendale, PA, p.p. 681–694.<br />[4]. Ruther H.-P., Lungen H.-B. Refractory technology and operational experience with tapholes and troughs of blast furnaces in the Federal Republic of Germany // Metallurgical plant and technology. 1989, No. 3, p.p. 12–29.<br />[5] Shvidkiy V., Gordon Y., Yaroshenko Yu. a.o. Mechanics of liquids and gases, Textbook, 2-d addition, Мoscow, Academkniga, 2003, 464 p.</p> |
