Evaluation of Mass Transfer Coefficient during Scrap Melting

Abstract

Mass transfer is a critical scrap melting step. Herein, mass transfer coefficients (k) during scrap melting were calculated using laboratory-scale experiments. Correlation analysis and the entropy weight method were used to determine the effect of variables on k. The evaluation model under natural and forced convection was established. It was consistent with the experimental results. Under forced convection, at 1573 and 1673 K, when the rotation speed was increased from 141 to 423 r/min, k increased from 7.50 × 10−5 to 1.54 × 10−4 m/s and from 8.42 × 10−5 to 1.72 × 10−4 m/s, respectively. Furthermore, as the bath temperature was increased from 1573 to 1723 K, the k value of a stationary specimen increased from 3.14 × 10−5 to 5.31 × 10−5 m/s, respectively. Correlation analysis and the entropy weight method indicated that the effects of variables on k decreased as follows: molten pool stirring rate > bath temperature > scrap type. Moreover, the explicit functional relationships between k and the factors affecting k under natural and forced convection conditions were established, and the results were consistent with the experimental data. Our results can be used to determine the quantitative relationships between k and the factors affecting k.

Modeling and Simulation of Metallurgical Processes in Ironmaking and Steelmaking

“…The predicted temperature profiles are displayed for the operator to assist in their decision-making, thus helping to reduce the number of rejected heats. Gao et al [7] investigated the melting of scrap in hot metal and determined mass transfer coefficients during scrap melting based on laboratory-scale experiments. Subsequently, the authors determined the influence of the variables molten pool stirring rate, bath temperature, and scrap type on the mass transfer coefficient.…”

Study of Assimilation of Cored Wire into Liquid Steel Baths

“…When steel scrap is added into a Fe-C bath with a high carbon content, the assimilation Metals 2024, 14, 462 2 of 14 of the scrap is onset by a thermally driven shell period followed by a free-assimilation period governed by mass-transfer [7][8][9][10][11]. Many works have focused on the effect of forced convection [12][13][14][15][16][17][18], the carbon content of the scrap and/or bath [16,17], multi-piece scrap assimilation [19,20], and the modeling of industrial processes [21][22][23][24][25][26].…”