Circular Processing of Seawater Brines from Saltworks for Recovery of Valuable Raw Materials

Project Information

SEArcularMINE

Grant agreement ID: 869467

DOI

10.3030/869467

Project closed

EC signature date 16 April 2020

Start date 1 June 2020

End date 31 August 2024

Funded under

• SOCIETAL CHALLENGES - Climate action, Environment, Resource Efficiency and Raw Materials

Total cost

€ 5 834 016,25

EU contribution

€ 5 834 016,25

Coordinated by

UNIVERSITA DEGLI STUDI DI PALERMO
Italy

Periodic Reporting for period 3 - SEArcularMINE (Circular Processing of Seawater Brines from Saltworks for Recovery of Valuable Raw Materials)

Reporting period: 2023-06-01 to 2024-08-31

Summary of the context and overall objectives of the project

THE CHALLENGE
Europe currently depends on imports of raw materials that are critical for economic development. These EU classified Critical Raw Materials (CRM) are increasingly needed in a range of high growth industrial sectors, including advanced battery technology and polymer production, alongside pharmaceutical and nutraceutical applications. There is an urgent need for technological innovation, allowing for CRM production within Europe, which meets the highest expectations in terms of performance, cost and green credentials.

PROJECT OBJECTIVES
SEArcularMINE builds on the ancient and still widely used process of saltworks, where seawater goes through natural evaporation and crystallization in shallow basins. The resulting brine (bittern) contains high concentrations of valuable elements. The project developed sustainable and cost-effective technologies that will contribute to securing European access to CRMs through a circular processing of the abundant bittern resources.

The consortium brings together leading experts from academia and industry to:
• Develop 3 innovative technologies to target the extraction of Magnesium (Mg), Lithium (Li) and other trace-elements (Rb, Sr, Cs, Ga, Ge, Co, B).
• Establish multiple auxiliary processes to provide full circularity during the production process.
• Produce the required energy from salinity gradient power.
• Generate modelling tools for simulation, sizing and evaluation of the processes to ensure optimal use of the resource for given framework conditions.
• Characterise and map bittern availability in Europe and the whole Mediterranean basin.
• Demonstrate the impact of coupling desalination with saltworks for cogeneration of freshwater and salt.
• Construct and operate a pilot-scale integrated plant for assessing the feasibility of the technology with real bitterns from saltworks
• Pave the way for further development, ensuring wide adoption and acceptance.

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

Mapping and Characterisation of Bittern Availability in the Mediterranean Basin: We've interacted with numerous saltworks and analysed bittern samples from 30 locations, giving us a sounds basis for wide application of our results in the future.

Our results show potential for more than 50% increase in saltwork productivity when integrating them with desalination and feeding the brine to them.

The Real Environmental Laboratory has been set up in Trapani (Italy), using a building already present inside the ancient saltworks, to house a laboratory that allows to conduct bittern characterization analysis directly on site.

Magnesium Recovery: We' have achieved 100% recovery of the Mg present in the bitterns with over 99% purity of the recovered mineral. The crystalliser design has been optimised and the pilot plant has been constructed tested.

Lithium Recovery: Our newly developed Li-selective membranes meet most target specs at lower production costs. A pilot plant has been developed both for the Li separation and for the Li crystallisation. The ceramic membranes scaling-up was not achieved on time and the pilot was tested for Lithium recovery from battery recycling instead with good results.

Trace Elements Recovery: We've identified promising sorbents for various elements`(B, Sr, Co, Ga and Ge) and developed new ones for Cs and Rb separation. Test with sorption columns and cycling operation were being performed in order to evaluate also the scalability of the system and to better characterise the optimal desorption/regeneration conditions.

Auxiliary Equipment: We've explored the optimal conditions for acid/base production via ElectroDialysis with Bipolar Membranes and energy production from bittern via Reverse ElectroDialysis. Several pre and post-concentration technologies have been tested and chosen, with a pilot scale osmotic membrane distillation unit, a mechanical vapor compression pilot and a diffusion dialysis pilot unit now built.

Integration of Technologies: Auxiliary technologies were adapted for optimising species-specific separation layout. Final process scheming were defined including control strategies, and equipment layout.

Development of Multi-Scale Modelling Tools: We've created and validated multi-scale modelling tools compared against experimental data. A simulation platform integrating these tools enables analysis and optimisation of the SEArcularMINE prototype system.

Life Cycle Assessment (LCA) and Life Cycle Costing (LCC) studies have been performed identifying the hotspots and informing the development process.

Pilot plant: An integrated pilot plant bringing all systems together in a circular scheme operated for several months in a controlled environment in the UNIPA labs. After that it was moved to operate by ResourSEAs srl in a real environment in Trapani, using real bitterns from the saltworks of SOSALT. The operation is successful and continues after the end of the project, with a fully circular strategy (no chemicals from external sources) and a capacity of 100 kg/d of Magnesium hydroxide. The pilot plant in a real environment was visited during the final event and is visited periodically by potential end-users.

Exploitation and dissemination. Over 85 presentations in conferences, 26 peer-reviewed papers and 6 patent families resulted from the project.

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

Progress Beyond State of the Art

In our efforts to advance beyond the current state of the art, we're making strides in several key areas:

Magnesium Crystallisation: We're employing cutting-edge modelling techniques and tools to revolutionise the crystallisation process of Magnesium Hydroxide, which led to the creation of an innovative Magnesium crystallization unit (Mg-CGCR).

Lithium Separator: We developed high-performing, cost-effective Lithium membranes, a significant improvement over existing market offerings. We also constructed a unique Lithium-selective electro-membrane device (Li-MFCDI) for testing these breakthroughs.

Trace Element Recovery from Seawater: With novel, highly selective sorbents, we've achieved continuous extraction of trace elements from seawater, proven through pilot scale tests.

Closed Loop Circular Process: We're pioneering auxiliary technologies for concentrating and separating solutions, and generating chemicals and energy in-situ, with the goal of realising a circular, self-sustaining system using saltwork bitterns.

We have prototyped and patented a range of innovative technologies, such as a Magnesium Crystalliser, lithium selective membranes and separation cell, and trace element recovery units. We also patented integrated water desalination processes with saltworks and an innovative waste-stream valorisation process.

The SEArcularMINE circular process aims to bolster sustainable access to vital trace elements like Mg, B, and Li within the EU, advance a clean, low carbon economy, and unlock significant reserves of underused resources. This environmentally conscious approach, leveraging only seawater and eliminating the need for external chemicals, will significantly reduce the demand for energy and freshwater. Furthermore, our technology aims to mitigate freshwater scarcity cost-effectively by incorporating seawater desalination within existing saltworks facilities.

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