Study of Si-domains enabling local reduction of laser-melted iron ore for iron-making during 3D-printing

Abstract

One main issue for global warming are CO2-emissions from iron ore reduction during steelmaking. This study presents a new approach, to merge iron ore powder with a suitable reducing agent, here silicon powder. By laser melting of the powders, some of the generated grains are composed of homogeneous slag, O-Fe-Si about 60-30-10 at.-%. However, other grains indeed contain small domains with high iron content, 90-100 at.-%. Manifold appearances of the iron particles were identified, surrounded preferably by slag but also by accompanying domains of high Si-content. These appearances indicate how ore reduction took place, like spherical growth or irregular drop conglomeration. If the iron particles can be extracted as drops, direct 3D-printing from ore can be enabled, including tailored alloying of iron to steel. Such short value chain would not only be efficient but also aims to cause solely environment-friendly by-products, for example SiO2 instead of CO2.