This paper presents a part of work developed inside the ULCOS project, which aims at the radical reduction of CO2 emissions from iron and steel production, through new routes that must be sustainable, i.e. environmentally-friendly, economically viable and socially acceptable. In order to demonstrate their sustainability, Key Performance Indicators are the main tools developed inside the work package 9.4, “Sustainability Model & Process Selection Tool”, which aims at making complex issues more manageable. Key Performance Indicators (KPIs) are the most useful tools for evaluating and managing not only the environmental and economic impacts, but also the social impacts. The assessment of social aspect of sustainability must be taken into consideration, nevertheless the prediction of social impacts is often hard to be done, not only because of the lack of a clear cause-effect relationship but also because of the difficulty to analyse and to predict social phenomena, especially through a quantitative approach. The purpose of this work is to present a methodology, based on both quantitative and qualitative approaches, carried out in order to develop the social indicator (Local Community Impact Indicator), which has primarily taken into account possible impacts of a current integrated steelworks on the communities within the close vicinity of the plant operations.

Concevoir une nouvelle filière d'élaboration de l'acier fondée sur l'hydrogène semble prometteur si l'on considère les faibles émissions de CO2 qui en résulteraient. Dans le programme ULCOS, cette filière est we comme une option à long terme, essentiellement conditionnée par l'émergence d'une économie de l'hydrogène. Pour anticiper son possible développement, on a décidé d'évaluer le procédé de réduction directe en four à cuve par H2 pur et de déterminer ses conditions opératoires optimales grâce à une approche de modélisation mathématique, complétée par des expérimentations adaptées. Nous avons ainsi spécifiquement développé un modèle mathématique, appelé REDUCTOR, qui simule le procédé et prédit ses performances. Ce modèle est fondé sur une description mathématique détaillée des phénomènes physico-chimiques et thermiques réels. En particulier, la cinétique de réduction est tirée d'essais expérimentaux en laboratoire. La version actuelle du modèle ne tient compte que de la réaction par l'hydrogène mais une extension à la réduction par CO est prévue de manière à ce que ce modèle puisse aussi être utilisé pour simuler et optimiser les procédés de réduction directe existant actuellement. Les premiers résultats ont confirmé que la réduction par H2 était plus rapide que par CO, ce qui permet d'envisager un réacteur sous Hz bien plus compact que les fours actuels des procédés MIDREX ou HYL.

The hydrodynamics in an electrolysis pilot-cell has been modelled with the aim of upscaling the direct iron production process based on the alkaline electrolysis of an iron oxide suspension. Two dispersed phase flow involved in this threephase process have been evaluated: the solid and the gas phase hydrodynamics.The suspension flow characteristics are evaluated from existing litterature, and available correlations are applied to the case under study. The minimum velocity required for transportation of finely ground iron oxide along the cathode surface is fairly low, in the laminar regime, corresponding to minimum pressure drop.The behaviour of the oxygen phase produced on the anode is evaluated in at two scales. First, the trajectory of a single bubble sliding on the anode is depicted, predicting possible rising or dragging of the bubbles as a function of its diameter. The gas-phase pattern is then studied from litterature results for gas-liquid flow in pipes. A separation of the gas phase from the liquid is predicted, the lightest phase being in contact with the upper part of the cell. Obtained results confirm the potential of the selected design for transportation of particles and gas recovery with low energy consumption.

MOGADOR is a 2D mathematical model of the blast furnace at steady state. In this project, it is used to get a better insight of the internal state of the BF, as the new types of operation differ greatly from the conventional one. Three important applications for the project are illustrated.


In order to develop a new, efficient industrial process for producing high quality iron and steel with significantly reduced carbon dioxide emissions, we investigated the electrowinning of iron from an iron oxide ore in aqueous alkaline solutions. Hematite (Fe2O3) solid particles suspended in the concentrated aqueous sodium hydroxide (NaOH) solutions were transferred to the cathode (e.g., a rotating disk graphite electrode) and reduced to iron metal by applying a constant current; oxygen was evolved on the anode (e.g., a nickel screen mesh). Current efficiencies of above 90% with respect to iron deposition were consistently obtained under the specific conditions in a laboratory cell, and the corresponding energy consumptions were calculated to be around 3 kWh·kg-1 iron. The deposited iron crystals were the oriented clusters of stacked six-fold twins in a tetrahedron-shape grew growing in a direction perpendicular to the cathode surface. Influences of rotation rates of the cathode, cathodic current densities, contents of the Fe2O3 particles in electrolytes, and concentrations of NaOH solutions on current efficiency and morphology of deposits were studied.

The history of the LKAB's Experimental Blast Furnace is briefly reviewed and an introduction to the ULCOS new blast furnace is presented. The feasibility of the scale-up of the ULCOS New Blast Furnace - UNBF based on previous and new trials results at EBF are concisely discussed.
The historical trial results of using the EBF to simulate the conventional industrial blast furnace processes indicated that the EBF is able to imitate the commercial blast furnaces of different size and burden structure. The trial results can be directly extrapolated to the commercial furnaces. The discussions regarding the scale-up of the UNBF showed that based on the EBF as well as the trials of the UNBF concept it is completely feasible to determine the dimensions of a full scale furnace and the process parameters for an industrial scale trial of the UNBF concept.

In the development of the electrolysis technique for iron, the cell-design step is crucial to ensure that the results obtained on smaller scale experiments are scaled-up to industrial size. Design criteria, based on the theorem of equipartitioned irreversibility, are proposed for the alkaline electrowinning process. One of the specific features of the process is the treatment of a multiphase electrolyte, a genuine breakthrough for electroextraction processes. Each of the unit-operations necessary to obtain the separation of the iron and oxygen from iron oxide are depicted together with the corresponding physical limitations and available technologies. Optimal solutions to obtain uniform and steady variation of each of the involved phenomena can be readily deduced from this approach and a cell-design is proposed.

ThyssenKrupp Steel AG has developed a numerical model to study the combustion of coal particles which are fed into the blast furnace through the tuyeres. The basic aim is to evaluate various coal lance / tuyere configurations and assess their advantages or drawbacks for successful operation. In the ULCOS project, this model was used to check the feasibility of some tuyere configurations for the Top Gas Recycling Blast Furnace process, which is especially challenging regarding tuyere design, combustion kinetics and raceway size.


Within the ULCOS project, a pilot cell for iron electrowinning is being designed. Electrical energy is used to transform iron ore particles (hematite) suspended in a sodium hydroxide solution into iron metal and oxygen. The work developed by Labein-Tecnalia is focused on the study of the fluid flow for different electrolytic cell configurations to get knowledge of the interaction between the oxygen bubbles generated during the process and the electrolyte flow. The numerical algorithm used is the finite volume used in the commercial Computational Fluid Dynamics code FLUENT. The work developed is focused on vertical and horizontal parallel plates configurations, to analyze the removal of oxygen bubbles from the gap between anode and cathode, and the access of iron ore particles to the cathode. A user subroutine has been developed for the CFD code to compute the mass flow rate of oxygen bubbles generated at the anode, as a function of the local current density. A methodology has been developed to analyze the accessibility of the iron ore particles to the cathode. The knowledge obtained from this work has helped for the design of the pilot cell within the ULCOS project.