Periodic Reporting for period 3 - RemovAL (Removing the waste streams from the primary Aluminium production and other metal sectors in Europe)
Reporting period: 2021-05-01 to 2023-04-30
The answer to the current Raw Material supply challenge faced today in Europe, lies in technological innovations that increase the efficiency of resource utilization and allow the exploitation of yet untapped resources such as industrial waste streams and metallurgical by-products. One of the key industrial residues which is currently not or poorly valorised is Bauxite Residue (BR, more commonly known as “red mud”) from alumina refineries. Bauxite residue reuse solutions do exist as stand-alone but pooling them together in an integrated manner is the only way to render bauxite residue reuse viable from an economical point of view and acceptable for the industry
Bauxite Residue from the alumina industry is stockpiled at a rate of 7 Million tons on dry basis per year in Europe:
• With an average iron oxide content of 40wt%, can be considered as an equivalent of 3.4 Mt of iron ore available in Europe. This results into a 4% decrease in iron ore imports and a 18% increase in European iron ore production.
• With an average alumina content of 20wt% and an inherent clay-like behaviour BR is a valuable raw material for various building applications; Recycling the alumina and soda (2-4%wt) of the BR back to the alumina refinery will lead to practically 100% extraction efficiency of alumina from bauxite ore.
• BR is a considerable resource for REE. Extracting the REE from AoG’s annual BR production can meet the needs of approximately 10% of the European REE demand.
• Ga is found in bauxite ores at levels of 30-80 g/t and is dissipated in the alumina and BR streams; extracting Ga from both the BR and Bayer liquor from a single European alumina refinery would amount to global levels of Ga production (annual world production 284 t in 2012)
The RemovAl project will combine, optimize and scale-up developed processing technologies for extracting base and critical metals from such industrial residues and valorising the remaining processing residues in the construction sector. In RemovAL, 6 innovative pilot plants will be run in 5 EU countries. Combined they will form a network of technological nodes, enabling optimum processing flow sheets for valorising the produced Bauxite Residue (BR) from alumina refineries along with other industrial by-products like Spent Pot Lining (SPL) from aluminium smelters. These technologies can then be adjusted to suit all kind of BR compositions around Europe. The validation will be done for 3 European alumina producers (represeanting 44% of the European alumina production) and one legacy site owner, present in the consortium
Bauxite Residue from the alumina industry is stockpiled at a rate of 7 Million tons on dry basis per year in Europe:
• With an average iron oxide content of 40wt%, can be considered as an equivalent of 3.4 Mt of iron ore available in Europe. This results into a 4% decrease in iron ore imports and a 18% increase in European iron ore production.
• With an average alumina content of 20wt% and an inherent clay-like behaviour BR is a valuable raw material for various building applications; Recycling the alumina and soda (2-4%wt) of the BR back to the alumina refinery will lead to practically 100% extraction efficiency of alumina from bauxite ore.
• BR is a considerable resource for REE. Extracting the REE from AoG’s annual BR production can meet the needs of approximately 10% of the European REE demand.
• Ga is found in bauxite ores at levels of 30-80 g/t and is dissipated in the alumina and BR streams; extracting Ga from both the BR and Bayer liquor from a single European alumina refinery would amount to global levels of Ga production (annual world production 284 t in 2012)
The RemovAl project will combine, optimize and scale-up developed processing technologies for extracting base and critical metals from such industrial residues and valorising the remaining processing residues in the construction sector. In RemovAL, 6 innovative pilot plants will be run in 5 EU countries. Combined they will form a network of technological nodes, enabling optimum processing flow sheets for valorising the produced Bauxite Residue (BR) from alumina refineries along with other industrial by-products like Spent Pot Lining (SPL) from aluminium smelters. These technologies can then be adjusted to suit all kind of BR compositions around Europe. The validation will be done for 3 European alumina producers (represeanting 44% of the European alumina production) and one legacy site owner, present in the consortium
- 25 tonnes of Dealkalised BR have been produced. Samples of the treated material have been sent to 12 different research and commercial organisations for testing in the production of supplementary cementitious materials, geoploymers, dense phase monoliths and slip bricks.
- A 500 m road has been built in the BRDA of AAL. Environmental and mechanical monitoring in the past year have revealed no problems.
- 2 tons BR converted to Smart Spheres. Pilot test trials when used in prefabricated slabs are lightweight and perform similar behaviour as lightweight concrete produced from other methods.
- 2 tons of granulated, vitrified BR has been produced. VBR was tested succesfully in cementitious applications by KUL and used by Resourcefull for producing brick slips. Testing by ACC confirmed that VBR can be used as addition in lightweight concrete and as partial replacement of cement in hydraulically bounded materials.
-More than 20t of BR were processed to produce more than 11 of slag and 3.6t of pig iron in 3 different campaigns producing pig iron and slag for various applications.The BR pig iron may be used for production of grey iron.
-Prototype microwave furnace with a processing capacity of up to 30kg/h was developed and commissioned. Testing with BR successfully produced a magnetite concentrate. Wet magnetic separation experiments of the produced concentrate at NTUA indicate an 82% iron recovery in the magnetic fraction
-Leached successfully 70% of alumina from the BR slag; demonstrated that 75% Sc contained in the leaching residue (grey mud) can be leached and extracted into Sc concentrate. Demonstrated the extraction of Ga >99% pure from 100 L of Bayer liquor with an efficiency >90%.
-Tested 200 kg of vitrified BR slag as a as a potential alternative to conventional blast furnace slag in CEM II/B-S - formulations. At a 30 wt.% replacement level, the BR slag cements met the strength criteria for cement according to EN 197-1.
- 7 t of BR-slag where utilized at ROCKWOOL factory in Hungary The BR-slag was capable to replace existing raw materials, with up to 10% charge substitution.
-Α number of building products have been developed using processed BR, including Brick Slips, pavement tiles, conctrete furniture, fire-resistant panels and others. Such building products were used in the construction of the ‘Bauxite House’ at Aspra Spitia, the housing settlement next to the MYTILINEOS alumina plant. The ‘Bauxite House’ after the end of the RemovAl project will serve as an informational pavilion, showcasing BR valorisation technologies
-Contribution to “Scoping possible further EU-wide end-of-waste and by-product criteria” organised by JRC. In this frame, the benefits of bauxite residue classification as by-product were highlighted by providing key case-studies and stress the need for proper adapting legislation and harmonised criteria. Industry recommendations document finalized.
- A 500 m road has been built in the BRDA of AAL. Environmental and mechanical monitoring in the past year have revealed no problems.
- 2 tons BR converted to Smart Spheres. Pilot test trials when used in prefabricated slabs are lightweight and perform similar behaviour as lightweight concrete produced from other methods.
- 2 tons of granulated, vitrified BR has been produced. VBR was tested succesfully in cementitious applications by KUL and used by Resourcefull for producing brick slips. Testing by ACC confirmed that VBR can be used as addition in lightweight concrete and as partial replacement of cement in hydraulically bounded materials.
-More than 20t of BR were processed to produce more than 11 of slag and 3.6t of pig iron in 3 different campaigns producing pig iron and slag for various applications.The BR pig iron may be used for production of grey iron.
-Prototype microwave furnace with a processing capacity of up to 30kg/h was developed and commissioned. Testing with BR successfully produced a magnetite concentrate. Wet magnetic separation experiments of the produced concentrate at NTUA indicate an 82% iron recovery in the magnetic fraction
-Leached successfully 70% of alumina from the BR slag; demonstrated that 75% Sc contained in the leaching residue (grey mud) can be leached and extracted into Sc concentrate. Demonstrated the extraction of Ga >99% pure from 100 L of Bayer liquor with an efficiency >90%.
-Tested 200 kg of vitrified BR slag as a as a potential alternative to conventional blast furnace slag in CEM II/B-S - formulations. At a 30 wt.% replacement level, the BR slag cements met the strength criteria for cement according to EN 197-1.
- 7 t of BR-slag where utilized at ROCKWOOL factory in Hungary The BR-slag was capable to replace existing raw materials, with up to 10% charge substitution.
-Α number of building products have been developed using processed BR, including Brick Slips, pavement tiles, conctrete furniture, fire-resistant panels and others. Such building products were used in the construction of the ‘Bauxite House’ at Aspra Spitia, the housing settlement next to the MYTILINEOS alumina plant. The ‘Bauxite House’ after the end of the RemovAl project will serve as an informational pavilion, showcasing BR valorisation technologies
-Contribution to “Scoping possible further EU-wide end-of-waste and by-product criteria” organised by JRC. In this frame, the benefits of bauxite residue classification as by-product were highlighted by providing key case-studies and stress the need for proper adapting legislation and harmonised criteria. Industry recommendations document finalized.
The European aprimary aluminium industry in 2016 utilized about 12 million tonnes of bauxite to produce about 7 million tons of alumina (out of the 115 million tonnes worldwide), and imported an additional 4 million tonnes of alumina to produce about 4 million tonnes of primary aluminium (out of the 59 million tonnes worldwide). The alumina and primary aluminium sector in Europe employs directly about 16,000 people. The alumina and primary aluminium sector in Europe are at the basis of the whole European Aluminium industry, which employs directly and indirectly more than 1,000,000 persons in more than 600 plants and generates about 40 billion Euros in annual turnover. This sector is associated with two by-products that undermine its sustainability: Bauxite Residue (BR) from the alumina production and Spent Pot Lining (SPL) from the primary aluminium production.
Plerimianry economo-technic analysis of RemovAL technologies shows that there is potential for viability and combination between them. Main target of the project remains near zero-waste and near break-even holistic processing of BR and other wastes.
RemovAL will not only provide a sustainable solution for the management and valorisation of BR and SPL– a significant social, environmental and economic problem of the alumina and primary aluminium industry – but it will further demonstrate the overall potential for sustainable industrial processing through process and material cascading and cross-sectorial financial joint ventures. This paradigm of enhanced industrial ecology is by far a greater benefit for the European industry and the European technology research community than the individual technological breakthroughs and product innovations established in each processing step of the flow sheet. Industrial symbiosis and waste-to-resources/zero-waste processing have long been identified as key pillars for a more sustainable and resilient EU industry.
Plerimianry economo-technic analysis of RemovAL technologies shows that there is potential for viability and combination between them. Main target of the project remains near zero-waste and near break-even holistic processing of BR and other wastes.
RemovAL will not only provide a sustainable solution for the management and valorisation of BR and SPL– a significant social, environmental and economic problem of the alumina and primary aluminium industry – but it will further demonstrate the overall potential for sustainable industrial processing through process and material cascading and cross-sectorial financial joint ventures. This paradigm of enhanced industrial ecology is by far a greater benefit for the European industry and the European technology research community than the individual technological breakthroughs and product innovations established in each processing step of the flow sheet. Industrial symbiosis and waste-to-resources/zero-waste processing have long been identified as key pillars for a more sustainable and resilient EU industry.