Periodic Reporting for period 3 - ENSUREAL (Integrated cross-sectorial approach for environmentally sustainable and resource-efficient alumina production)
Période du rapport: 2020-10-01 au 2022-03-31
Global aluminium metal consumption is expected to grow during the coming years. Aluminium metal is produced through electrolysis from aluminium-oxide, also called alumina. Alumina is produced by the Bayer process from bauxite. The Bayer process has as main drawback that it does not utilize all elements in the bauxite ore and thus produces a lot of waste. This waste is called bauxite residue, or red mud because of its red colour. For every kilo of aluminium metal more than 1 kg of red mud is produced. This waste is usually land-filled in large ponds. The problem with red mud will increase during the coming decades as bauxite qualities gradually contain less aluminium and more of the mined material will end up as waste. The ENSUREAL project addresses the production of alumina, through the introduction of a new technology (improved Pedersen process) that enhances the process' yield and its energy and environmental performance. The increased costs of processing should be balanced with an increase in revenue from the different products, cheaper bauxite resources and no costs for land-filling.
The goal of the ENSUREAL project is to ensure zero waste production of alumina in Europe. This has been done by developing a zero-waste process for alumina production that can handle a wider range of bauxite than the existing process. This was carried out, along with the development of: key valorisation routes, realistic business scenarios based on life cycle and cost analyses and innovation, dissemination and communication strategies.
The main conclusions from the project are:
Alumina can be produced with the ENSUREAL process. The produced iron is suited for applications where a high wear resistance is of importance. The grey mud by-product can be used in the building sector as a cement replacement.
However, the quality of the produced alumina needs to be improved before it meets the requirements of the industry. Such as, the particle size needs be increased and the silica content decreased. The capital investment for a full-scale ENSUREL factory is high and it is difficult to argue for a ENSUREAL refinery compared with a Bayer refinery from a business case point of view. The best case from a business and environmental point of view is when the ENSUREAL process is used for the processing of bauxite residue. In this case the "Red mud" problem can be solved with a method that can give a positive operational income.
The goal of the ENSUREAL project is to ensure zero waste production of alumina in Europe. This has been done by developing a zero-waste process for alumina production that can handle a wider range of bauxite than the existing process. This was carried out, along with the development of: key valorisation routes, realistic business scenarios based on life cycle and cost analyses and innovation, dissemination and communication strategies.
The main conclusions from the project are:
Alumina can be produced with the ENSUREAL process. The produced iron is suited for applications where a high wear resistance is of importance. The grey mud by-product can be used in the building sector as a cement replacement.
However, the quality of the produced alumina needs to be improved before it meets the requirements of the industry. Such as, the particle size needs be increased and the silica content decreased. The capital investment for a full-scale ENSUREL factory is high and it is difficult to argue for a ENSUREAL refinery compared with a Bayer refinery from a business case point of view. The best case from a business and environmental point of view is when the ENSUREAL process is used for the processing of bauxite residue. In this case the "Red mud" problem can be solved with a method that can give a positive operational income.
The project has done work on identifying exploitable raw materials sources and giving recommendations to reduce EU imports’ dependence. The project group is in contact with several bauxite suppliers and has tested many different bauxite qualities in the ENSUREAL process. Moreover, a range of different waste materials (bauxite residue, limestone tailings,….) has been tested as raw material.
The work started in laboratory scale to optimise the pyrometallurgical and hydrometallurgical processes parts, so that the process parameters for the pilot plant could be established. In the last year of the project, the focus has been on running the process in pilot scale at Mytilineos in Greece. The final part of the alumina production (calcination) was done in pilot scale at Outotec in Germany. Odelewnie Polskie tested the iron that was produced in the pilot plant in their foundry. Luvena in Poland investigated whether the grey mud byproduct which is mostly limestone can be used in fertilizer production.
Based on feedback retrieved from the experimental work, the sustainability of the ENSUREAL process method has been examined for two regions: Greece and Norway. Furthermore, the LCCA compared the economic performance of the ENSUREAL project to the state of the art. The selection of most promising regions for the method has allowed to do an analysis of the business environment for ENSUREAL. The partners agreed to explore two different scenarios, using different raw materials’ compositions (including bauxite/pre-reduced bauxite and bauxite residue). The most promising scenario for exploitation is as an add on to the Bayer process. For example, at Mytilineos in Greece. The technical work has been documented in 23 scientific journal articles and many conferences and workshops have been attended to discuss the results with the scientific and business community.
The work started in laboratory scale to optimise the pyrometallurgical and hydrometallurgical processes parts, so that the process parameters for the pilot plant could be established. In the last year of the project, the focus has been on running the process in pilot scale at Mytilineos in Greece. The final part of the alumina production (calcination) was done in pilot scale at Outotec in Germany. Odelewnie Polskie tested the iron that was produced in the pilot plant in their foundry. Luvena in Poland investigated whether the grey mud byproduct which is mostly limestone can be used in fertilizer production.
Based on feedback retrieved from the experimental work, the sustainability of the ENSUREAL process method has been examined for two regions: Greece and Norway. Furthermore, the LCCA compared the economic performance of the ENSUREAL project to the state of the art. The selection of most promising regions for the method has allowed to do an analysis of the business environment for ENSUREAL. The partners agreed to explore two different scenarios, using different raw materials’ compositions (including bauxite/pre-reduced bauxite and bauxite residue). The most promising scenario for exploitation is as an add on to the Bayer process. For example, at Mytilineos in Greece. The technical work has been documented in 23 scientific journal articles and many conferences and workshops have been attended to discuss the results with the scientific and business community.
Most important progress beyond the state of the art are:
-Prereduction of the bauxite with hydrogen which makes it possible to produce the iron without CO2 emissions.
-Use of biocarbon as reductant
-Application of the grey mud as cement replacement material and liming agent
-Recycling of the grey mud into the process
-CO2 capture as part of the process
-Extraction of Scandium
The potential impact of the project is:
A 22,9% reduction in the yield losses when the ENSUREAL process is used instead of the Bayer process for the processing of bauxite. Moreover, a reduction in yield losses of 54% when the ENSUREAL process is used to process the bauxite residue after the Bayer process. This last solution can give up to 800 new jobs per Bayer refinery.
-Prereduction of the bauxite with hydrogen which makes it possible to produce the iron without CO2 emissions.
-Use of biocarbon as reductant
-Application of the grey mud as cement replacement material and liming agent
-Recycling of the grey mud into the process
-CO2 capture as part of the process
-Extraction of Scandium
The potential impact of the project is:
A 22,9% reduction in the yield losses when the ENSUREAL process is used instead of the Bayer process for the processing of bauxite. Moreover, a reduction in yield losses of 54% when the ENSUREAL process is used to process the bauxite residue after the Bayer process. This last solution can give up to 800 new jobs per Bayer refinery.