Aluminothermic Reduction of Manganese Oxide from Selected MnO-Containing Slags.

Artur Kudyba,Shahid Akhtar,Jafar Safarian,Inge Johansen

doi:10.3390/ma14020356

Artur Kudyba, Shahid Akhtar + Show 2 more

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https://doi.org/10.3390/ma14020356

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Abstract

The aluminothermic reduction process of manganese oxide from different slags by aluminum was investigated using pure Al and two types of industrial Al dross. Two types of MnO-containing slags were used: a synthetic highly pure CaO-MnO slag and an industrial high carbon ferromanganese slag. Mixtures of Al and slag with more Al than the stoichiometry were heated and interacted in an induction furnace up to 1873 K, yielding molten metal and slag products. The characterization of the produced metal and slag phases indicated that the complete reduction of MnO occurs via the aluminothermic process. Moreover, as the Al content in the charge was high, it also completely reduced SiO2 in the industrial ferromanganese slag. A small mass transport of Ca and Mg into the metal phase was also observed, which was shown to be affected by the slag chemistry. The obtained results indicated that the valorization of both Al dross and FeMn slag in a single process for the production of Mn, Mn-Al, and Mn-Al-Si alloys is possible. Moreover, the energy balance for the process indicated that the energy consumption of the process to produce Mn-Al alloys via the proposed process is insignificant due to the highly exothermic reactions at high temperatures.

Highlights

Aluminum is the most abundant metallic elements in the Earth’s crust, posing an excellent combination of chemical, mechanical, and physical properties which makes it suitable for many applications [1]
The aluminothermic reduction of MnO-containing slags was studied through using pure Al and two types of white Al dross, and the following results were obtained
Pure Mn-Al alloys were obtained via the aluminothermic reduction of highly pure synthetic CaO-MnO slag by pure Al, and with Al dross from the primary Al production process

Summary

Introduction

Aluminum is the most abundant metallic elements in the Earth’s crust, posing an excellent combination of chemical, mechanical, and physical properties which makes it suitable for many applications [1]. In 2019, the global production of metallic aluminum was approx. As a result of the exposure of liquid aluminum to the oxidizing atmosphere that is present during the process of melting and alloying, a surface oxidation takes place, leading to the formation of a semisolid skin over the molten Al metal, which hinders further oxidation. Al is called aluminum dross and consists mainly of aluminum oxide, metallic aluminum, magnesium spinel, periclase, and quartz [6,7].

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