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LIGHT METALS, CARBON MATERIALS
ArticleName Simulating the process of magnesium alloy refining by argon blowing
DOI 10.17580/tsm.2023.03.04
ArticleAuthor Koltygin A. V., Pavlov A. V., Bazhenov V. E., Nikitina A. A.
ArticleAuthorData

Department of Casting and Material Working at the National University of Science and Technology MISiS, Moscow, Russia:

A. V. Koltygin, Associate Professor, Candidate of Technical Sciences, e-mail: koltygin.av@misis.ru
A. V. Pavlov, Postgraduate Student, e-mail: pavloveone@mail.ru
V. E. Bazhenov, Associate Professor, Candidate of Technical Sciences, e-mail: v.e.bagenov@gmail.com
A. A. Nikitina, Category I Trainer, e-mail: nikitina.misis@gmail.com

Abstract

This paper describes some physical models with an impeller that simulate the process of blowing molten magnesium with inert gas (argon) in model media (liquid and gas) aimed at removing non-metallic inclusions from the melt. A 7% aqueous solution of NaCl and air were used as model media selected on the basis of similarity principle. A prototype impeller designed in house was tested and a transparent physical model – used. It is shown that the blowing efficiency is determined by the bulk distribution density of gas bubbles, which is associated with the impeller RPMs and gas flow rate, as well as with the geometry of the impeller. It was established that when using the developed impeller design the amount of bubbles dispersed in liquid is to a significant extent dictated by the impeller RPMs and to a lesser extent – by the gas flow rate. When the gas flow rate exceeds a certain threshold, it won’t lead to any increase in the amount of gas bubbles, nor in the volume of the blown liquid. In the course of the study and when using the proposed impeller design, the authors defined a metal treatment regime that would ensure a distribution of small gas bubbles across almost the entire volume for a cylinder-shaped crucible with the diameter of 660 mm and the height of 1,140 mm of a commercial magnesium smelter (with the impeller speed equal to 488 min–1 at the argon flow rate of ~15.6 l/min).

keywords Magnesium, smelting of magnesium alloys, physical modelling, melt refining, argon blowing, impeller
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