Description du sujet de thèse

The major obstacle to render steelmaking more sustainable is undoubtedly the decarbonization of its process chains. Currently, the production of 1 ton of steel is linked to the staggering emission of 2.1 tons of CO2, a fact that makes iron- and steelmaking responsible for 8% of the total CO2 emissions on the planet. This is because we have been extracting iron from its ores through chemical reactions that employ C-carrier substances, leading CO2 as the by-product [1]. Accompanied by this challenge, the scarcity of high grade iron ores to be exploited as feedstock is a near reality. This creates an absolute dilemma that will force steelmakers to produce green steel from low grade iron ores [2].
The hydrogen plasma smelting reduction of iron ores (HPSR) emerges as an attractive CO2-lean pathway to produce iron, where the ore is exposed to a reducing lean hydrogen plasma (10%H2) – in an electric arc furnace (EAF) – to get simultaneously melted and reduced, Fig. 1 [1,3]. When using hydrogen plasma species (H, H+) as a reducing agent for iron ores, the by-product is water rather than CO2 (FeO + 2 H → Fe + H2O) [4].
This doctoral work aims to investigate the fundamentals of HPSR to transform low-grade iron ores into sustainable and clean iron. The project will target low-grade iron ores containing less than < 59% Fe and substantially containing high quantities (~15%) of gangue-related oxides (i.e., less valuable constituents than iron oxides: Al2O3, SiO2, P2O5 etc.). Partially and fully reduced ores will be chemically and microstructurally characterized. The results will reveal important details about the reaction mechanisms and the efficiency of the process in terms of hydrogen consumption and iron formation. The composition of the slag (self-formed by the gangue oxides) will also be fully characterized, and it will be destined to cement industry. The hydrodynamic aspects resulting from the plasma/liquid interaction and temperature distribution will be monitored via high-speed and infrared cameras. Hydrogen plasma will be characterized via optical emission spectroscopy.

Contexte de travail

This doctoral work is part of the 4-years European project entitled “Decarbonized Steel Production with Novel Decarbonized Processes” whose acronym is ZEROSTEEL. It is a project fully funded by the European Union (550 k€ for 4 years) and pertaining to the recently launched Chair of Sustainable Metallurgy at IJL. Dr. Isnaldi R. Souza Filho and Dr. Thierry Belmonte are the main contact persons and responsible for the project. For more information, please, contact also isnaldi.rodrigues-de-souza-filho@univ-lorraine.fr or thierry.belmonte@univ-lorraine.fr. The work language will be mostly in English and French.

The Institute Jean Lamour (IJL) is a joint research unit of CNRS and Université de Lorraine.
Focused on materials and processes science and engineering, it covers: materials, metallurgy, plasmas, surfaces, nanomaterials and electronics.
The IJL has 263 permanent staff (30 researchers, 134 teacher-researchers, 99 IT-BIATSS) and 394 non-permanent staff (182 doctoral students, 62 post-doctoral students / contractual researchers and more than 150 trainees), of 45 different nationalities.
Partnerships exist with 150 companies and our research groups collaborate with more than 30 countries throughout the world.
Its exceptional instrumental platforms are spread over 4 sites ; the main one is located on Artem campus in Nancy.

We seek candidates with strong knowledge in physical and/or extractive metallurgy, materials science and engineering or physics and plasma characterization, good experience in metallography practices and thermodynamic calculations. Good command of spoken and written English is necessary. The selection of applications will be carried out in compliance with the principles of transparency and equal treatment of candidates after examination of the applications received. We are highly engaged with the gender and diversity equality and encourage and welcome applications from all backgrounds.

Le poste se situe dans un secteur relevant de la protection du potentiel scientifique et technique (PPST), et nécessite donc, conformément à la réglementation, que votre arrivée soit autorisée par l'autorité compétente du MESR.

Contraintes et risques

The project will be conducted under all safety rules of IJL aiming to preserve the integrity of all employees, incl. students, technicians and scientists, as well as the facilities and infra-structure of the laboratory. The concentrations of hydrogen to be employed in the experiments lie below any inflammability risk. The manipulation of the plasma reactor is a safe procedure as it contains all safety measurements against overpressure and displays adequately electric insulation. The reactor is customized for this purpose, also being produced by a specialized company with wide experience in the market.