75 YEARS OF THE CENTRAL LABORATORY
AT THE MAGNITOGORSK IRON AND STEEL WORKS
IMPROVING THE STEEL DEGASSING TECHNIQUE
BY USE OF LARGE-DIAMETER SNORKELS
V. M. Korneev,
V. G. Ovsyannikov,
E. V. Burmistrova,
V. I. Frolov,
and S. A. Samoilin
Translated from Novye Ogneupory, No. 1, pp. 12 – 15, January, 2005.
Original article submitted December 1, 2004.
Test results for degassers equipped with large-diameter snorkels are reported. Increasing the snorkel diameter
from 570 to 720 mm made it possible to accelerate the metal circulation through the degassing chamber, to re-
duce the metal processing time, and to minimize the air-duct crusting. A program is under way aimed at the
improvement of durability of the refractory lining for the snorkels, a new design of the lining brickwork, and
the development of advanced refractory materials.
Currently, circulation vacuum degassing is believed to be
the most advanced among various techniques employed in
the extra-furnace steelmaking process. A challenging prob-
lem for technologists has been to develop a technique that
would allow rapid decarburization of the finished steel.
A way of accelerating the metal processing is to intensify
the molten steel circulation using snorkels of larger diameter,
to increase increase the flow rate of the agitating gas, and to
decrease the pressure in the degassing chamber. To that end,
under a project for production of ultra-low carbon steels,
tests were carried out on degassers whose bottom was fitted
with snorkels of large cross-sectional area. The tests were
conducted at the MISW in late 2003 to early 2004; in the first
step, snorkels of elliptic shape were considered (see schemat
ics in Fig. 1a ). Geometrically, the shape of elliptic cross sec
tion is determined by the radii lying on the major and minor
semi-axes of the ellipse (Fig. 2). The cross-sectional area of
the elliptic snorkel was 2.7 times the area of conventional
circular snorkels — of diameter 570 mm.
The metal processing technique based on the use of an
elliptic snorkel was similar to the circulation degassing
method. The molten metal was transported to the chamber by
means of an argon jet injected through tuyeres mounted in
the lower section of the snorkel on a minor semi-axis of the
ellipse (Fig. 1b, position 1 ). To intensify agitation, one of the
Refractories and Industrial Ceramics Vol. 46, No. 3, 2005
1083-4877/05/4603-0153 © 2005 Springer Science+Business Media, Inc.
Magnitigorsk Iron and Steel Works (MISW) Joint-Stock Co.,
Fig. 1. Schematic diagram of the bottom of a vacuum degasser
equipped with an elliptic snorkel (a); arrangement of tuyeres in
the snorkel with respect to the bottom injection facility of the steel
ladle (b ); 1 ) zone for location of tuyeres; 2 ) zone for location of the
bottom injection facilities.