Modeling of Motion of Inclusions in Argon‐Stirred Steel Ladles

Abstract

A 3D discrete phase model (DPM)‐ and volume of fluid–coupled model is developed to investigate the multiphase flow in a 260 ton argon‐stirred ladle. The flow field and interfacial behavior in the argon‐stirred ladle are accurately predicted. Then, the Lagrangian DPM is used to trace the motion of inclusions in the liquid steel. Residence time maps, which provided the residence time required for inclusions travelling from the bulk liquid steel to the steel–slag interface, are proposed and plotted as functions of inclusion diameter and percentage of inclusions. For inclusions smaller than 10 μm, the average residence time is size‐independent but decreases from 175 to 93 s with an increment in the gas flow rate from 50 to 400 NL min−1. With increasing the inclusion size, the average residence time is dependent on both gas flow rate and inclusion diameter. When the inclusion diameter increases to 1000 μm, the average residence time is almost independent of the gas flow rate. The current model overestimates the inclusion removal rate. However, this overestimation indicates that only appropriately considering the behavior of inclusions at the steel–slag interface can accurately predict the removal of inclusions in argon‐stirred ladles.

Physical Model of Inclusions Removal at Static Steel–Slag Interface

“…Inclusion removal is a crucial step in the steelmaking process, and the removal effect directly affects steel quality [1][2][3][4]. At present, the main methods of inclusion removal include gas stirring in ladles [5][6][7][8][9][10], Ruhrstahl-Heraeus treatment [11][12][13][14], slag washing [15][16][17], bubble flotation [18], removal in tundishes [19][20][21][22], and continuous casting mold [23][24][25][26], among others. These methods promote inclusions to float to the slag-steel interface so that the inclusions are more easily removed by refining slag absorption.…”

Effect of Salt Solution Tracer Dosage on the Transport and Mixing of Tracer in a Water Model of Asymmetrical Gas-Stirred Ladle with a Moderate Gas Flowrate

“…The ladle, serving as an intermediary vessel between the steelmaking and casting processes, is not only utilized for the transportation and pouring of molten steel but also serves as a crucial container for implementing external refining. Presently, argon stirring ladles are widely employed in secondary refining [1][2][3][4][5], where they facilitate the uniform temperature and composition of molten steel [3,6], accelerate metallurgical reactions [7][8][9][10][11], promote alloy and scrap melting [12][13][14][15][16], eliminate non-metallic inclusions in the steel [16][17][18][19][20][21], effectively enhance steel product quality [22][23][24], improve ladle refining efficiency [3], and reduce production costs. Over the past several decades, numerous physical models [2,4,7,[25][26][27][28][29][30][31][32] and numerical models [33][34][35][36][37][38][39]…”