Slag Emulsification during Liquid Steel Desulphurisation by Gas Injection into the Ladle

Abstract

According to current practice, the desulphurisation of steel melts is mainly performed in the ladle with lime saturated top slags. The injection of argon gas into liquid steel provides for intensive mixing and accelerated sulphur transfer. During gas stirring treatment, an emulsification of top slag takes place. A numerical model describing the course of the desulphurisation reaction has been developed, which takes all relevant process parameters into account, including those of the emulsification effect. To check the validity of the model, operational tests have been performed on 185‐t‐heats. Results obtained from model calculations and operational tests show an excellent agreement.

Modeling of Three-phase Flows and Behavior of Slag/Steel Interface in an Argon Gas Stirred Ladle

“…1) Beskow et al 2) develop a sampler to observe the physical description of the slag-metal interface in industrial trial experiments. Lachmund et al 3) proposed a semi-empiric model to calculate the slag emulsification parameters. Han et al 4) investigated the effect of oil layer on the flow pattern and mixing time in a gas stirred liquid bath.…”

Proposal of a Novel Agitation Method using Swirl Motion of Molten Metal Jet

“…Three types of agitation methods are currently used: gas injection, [1][2][3][4][5][6][7] mechanical stirring, [8][9][10][11][12] and electromagnetic agitation. [13][14][15][16][17] At present, gas injection is most widely used because of its easy handling, relatively low cost, and high agitation efficiency.…”

Modeling of Slag Entrainment and Interfacial Mass Transfer in Gas Stirred Ladles

“…The increased ladle capacity and the number of bottom plug has resulted in smaller slope of ln(β)-ln(ε) plots that has pushed the break point to very small values of β and ε that the break point is virtually absent. The missing break point has been noted by the corresponding authors 27,30) although without a definite explanation. Thus, these analyses clarify that the point of transition between Regimes I and II will lower both in β and ε as the ladle capacity and number of bottom plugs increases.…”

“…It can be seen that as the ladle size increases the break point for transition from Regimes I to II decreases both in β and ε. Excluding Ishida et al's case and including the β − ε plots of Graham 27) and Lachmund et al, 30) Fig. 20(a) is replotted in Fig.…”

“…12 show that such high residence times are possible only for fine droplets ( < 1 mm) while their average droplet sizes were between 6 to 8 mm. On the other hand, Lachmund et al 30) also have used the Oeters' model for entrainment rate and predicted an average residence time of 5 s for a ladle of 185 ton. Given their measured droplet sizes to be smaller than 2.5 mm, their predicted residence time is quite low.…”