A producers of steel have questions about demand of steel products market, there are next: to produce the wide – grade steel; to be quickly reflecting for the changing demand of metal products; to reduce energy capacity of products; to increase the quality of products and level of competition/ This demands challenge the necessary of a ladle furnace.
The treatment process in ladle furnace has the stirring of metal by argon through a porous plug (-s) at the bottom of ladle. The main parameters of effective desulphur process is the consistence and amount of the refining slag, the dioxide degree of metal, the dispersion. The optimization of indicated parameters promotes to the increasing of the desulphur effect.
However, the deciding of tasks of ladle treatment requires fuller image about mechanism of structures forming introductions, such as:
-the gas phase in rising gas-liquid flow (“plume”) above nozzle;
-the distributing of liquid flows duration and values of its velocity;
-the area of the “open eye”
-the investigation of slag – metal behavior.
The reactions on surface of slag metal surface play main role in modern ladle process. Due to the mixing process there is the velocity of heat- and masstransfer. The velocity of reactions defines the time - limit of technological operations.
Now the technologies of manufacture of new grades steel demand the decreasing of the sulphur consistence up to 0,0025% and less, it will demand the deeper understanding of processes which are acting on interface, for the optimization.
We execute the investigations to this duration and it has the next steps.
The cool – model investigation. The observers of mixing of oil – water shown the horizontal – directing flows from gas – liquid rising jet to vessel’s wall along the oil – water surface, which are promoting for penetration o water into the oil and receiver process too. Such character indicates mechanism due to the displacement force.
The method of industrial probing. At this step was developed the method of the probing of slag – metal surface at industrial ladle at the stirring due to the specially designed prober.
The industrial probing. The probes were selected at 300-t ladle of OAS “AMP” from different part of the slag layer.
The analyze of results. The analyze shown that the slag part of probe has spherical and incorrect – formed metal droplets have diameter 50-60*E-06 m (fig. 1a), besides there is tendention of reducing of its quantity and enlarge to slag – metal surface direction. The flat droplets have incorrect form wide range of value from 150-200*E-06 m to 6 mm (fig.1b).
For conforming of the dispersion process of slag into the metal we made the template of the metal part of probe (fig.1c) and defined the value and amount of the slag droplets (fig. 1d) by metallographic methods. The slag droplets have diameter 50-60*E-06 m.
According to the upper results was executed the evaluate of slag and metal quality at dispersing process. The slag bulk through street has 80 kg, and the metal bulk through slag layer has 27 tones, during 60 min.
The evaluation of emulsion for the final desulphur results shown that the summary amount of removed sulphur from steel consist of 17 % from common amount of the removed sulfur from metal to slag sulphur during treatment period.
Email: Proskurenko2008@yandex.ru