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Development of new methodologies for industrial CO2-free steel production by electrowinning

Periodic Reporting for period 2 - SIDERWIN (Development of new methodologies for industrial CO2-free steel production by electrowinning)

Reporting period: 2019-04-01 to 2020-09-30

The goal of SIDERWIN is to Develop a breakthrough innovation compared to the actual steel production process bringing together steel making with electrochemical process. The electrolysis process using renewable energies will transform any iron oxide, including those inside the by-products from other metallurgies, into steel plate with a significant reduction of energy use.

By offering a CO2-free steel production process, the project will contribute to the reduction of the total greenhouse gas emissions. Compared to traditional steelmaking plants, this innovative technology has several positive impacts such as:

a reduction by 87% of the direct CO2 emissions, a
reduction by 31% of the direct energy use, the ability to produce steel from by-products rich in iron oxides from non-ferrous metallurgy residues,
and an increased integration with renewable energies with a more flexible process.
The project is led by ArcelorMittal, the world’s leading steel and mining company.
The main results obtained at the end of the 1st period are in line with the project workplan and are:

The setting-up of the collaborative platform to share information between all partners.

The critical review of the ULCOWIN technology.
The specifications to be given to the SIDERWIN cell to operate an industrial plant in conditions of safety, maintainability and efficiency have been defined.
The definition of the key components of the pilot integrating the main components of the final version in terms of hydraulic loop for constant circulation of the electrolyte, of iron oxide supply, of exhaust gas circuit, of thermal regulation, of high current-low voltage electrical supply circuit and of iron production with a dedicated electrowinning cell.
The definition of the P&ID (process & instrumentation diagram) for this first pilot version.
Establishment of the equipment layout (basic design) and a list of equipment and auxiliaries for this first pilot version.
A simulation tool of mass and energy balances has been developed to check the consistency between electrical, chemical, thermal and kinetic phenomena to operate at steady state.

A detailed and comprehensive CFD simulation methodology has been developed to predict accurately the bubble path in the cell (task 3.1).
The methodology has been applied to define the optimal cell in link with task 4.3. Several design choices have been made along with important results (task 3.2): definition of a honeycomb anode with a global angle of 50° has been done. Top degassing channels are evaluated and the specific outlet degassing device is under investigations. Some hydraulic components of the installation have been defined using CFD simulation.

Electrolysis interruption analysis (task 3.3) has been investigated showing encouraging results in terms of global efficiency.

The definition of the P&ID (process & instrumentation diagram) for the new pilot SIDERWIN.
The definition of the sizes and specifications for the main equipment.
The definition of the equipment layout (basic design) and definition of the AMMR building.
The definition of all small equipment on the pilot (instruments, valves, pumps …)
Important progress on the cell design, including definition of new anode design.
On-Going: Progress on the design of different tanks (mixing tank, rinsing tank, drain tank, sump pit …).

Bauxite Residue is suitable to be used as alternative iron source.
The efficiency of Bauxite Residue electrolysis is currently at 50%, as the presence of other oxides lowers the efficiency of the process. Suitable pre-treatment options for the Bauxite Residue are being studied to increase this efficiency beyond 75%.

The definition of key elements building the technical basis for the environmental and the techno-economic studies.
A data collection template for the environmental and the techno-economic studies has been developed and is currently being completed with former projects or literature data.

The creation of the visual identity of the project.
The creation and update of the website.
The identification and description of the dissemination key elements.
The form available through website for people interested in registering to the Special Interest Group (SIG).
The five main scientific and technical objectives of SIDERWIN projects were addressed by dedicated work package. The work carried out during the first period (M1-M18) in order to address these objectives is reported below.

Progress toward Objective 1: Development of an electrochemical processing route for primary steel production.
Most of the efforts produce during the first 18 months were relative to this objective. Indeed, most of the technical characteristics of the SIDERWIN pilot have been addressed and developed.

Progress toward Objective 2: Industrially feasible new processing route
The first two key components of the technology have been developed.

Progress toward Objective 3: Iron metal production from renewable energy
This very new aspect in metal electrowinning is under study in WP3 with current interruption of the electrolytic process and in WP7 to estimate the most economically favourable conditions. In the experimental approach, interruptions have shown that there is a certain electrochemical inertia, to come back to the steady state voltage, and that the growth of iron can be continuous. The second approach conducted by simulations shows that long interruptions of more than 4 hours would most benefit to the grid balance.

Progress toward Objective 4: Raw material efficiency during steel production
The study of electrolysis of iron oxide from residues has started. It is currently under study among the academic partners. One of the most striking result is the improvement of Faradaic efficiency by decreasing current density. A level of 50% has been reached unlocking the low values of past studies where Faradaic efficiency was no higher than 15%.

Progress toward Objective 5: Close to market research
The economic model of the electricity based primary production is totally new. The WP7 is addressing the specificities of the SIDERWIN process as alternative of a well-established carbon intensive and as a large scale industrial flexible energy consumer. The data necessary to carry out the LCA methodology have been gathered and shared.
3D design of the basic layout of the equipment