In 2008 the European Union Raw Materials Initiative (RMI) documented, further recognised by the Strategic Implementation Plan (SIP) of the European Innovation Partnership (EIP) on Raw Materials (EIP-SIP), that Raw Materials (RM) are essential for the sustainable and sound functioning of Europe’s industries. The Commission is committed to the promotion of the competitiveness of industries related to RM as stressed by the COM/2017/0479: Investing in a smart, innovative and sustainable industry, leading to a renewed EU Industrial Policy. Securing undistorted access to raw materials is crucial to stimulate investment in innovation and new technologies for a European Industrial Renaissance.
According to the raw material scoreboard 2021, the EU is highly dependent on imports of several metal ores from international markets. On the other hand, the EU is a producer of several basic metals such as copper, lead, iron ore and precious metals. The EU also has mines of several Critical Raw Materials (CRM) such as graphite, rare-earth elements (scandium, yttrium and the lanthanides), tungsten, phosphate and vanadium. Nevertheless, depletion of easily available high-grade ores, environmental issues related to waste disposal and miner’s health, and low social acceptance, emphasise the need to develop processes for alternative unexploited sources.
Looking for Alternatives
A current alternative for raw materials is recycling, which accounted for more than 8% of overall material inputs to the EU economy in 2017. However, recovery might not always be technically or economically feasible and there are dissipation losses during or after use, also due to improper disposal. Hence, moving toward reusing and recycling would complement the current supply, but current and new primary resource extraction will be still needed to meet the EU’s materials demand, such as shifting towards a circular economy and promoting local supply.
The recovery of valuable minor and trace metals and minerals (M&M) for commercial purposes from seawater desalination plants (SWDP), is an innovative potential source of resources which has raised interest over the past few years. Focusing on the use of SWDP brines has the competitive advantage of using an already preconcentrated stream compared to extraction of raw materials directly from seawater.
In order to accomplish the objectives of the EIP Raw Materials, it is essential to explore new raw materials sources. A potential source of RM is the sea, which contains over 40 different elements and minerals of economic interest. Taking into account that oceans and seas cover nearly three-quarters of the earth’s surface and contain about 1.3 × 10^18 tonnes of seawater composed by around 96.7% of water and 3.3% dissolved metals and minerals, seawater is a vast and easily accessible source of RM.
The challenge with extracting low concentration elements from seawater lies in:
- the huge amounts of water that need to be processed and removed
- the preparation of commodity grade metals and minerals from complex matrices, such as seawater brines, requires a completely new generation of separation technologies able to selectively recover target elements, which has proven technically and cost-effectively unfeasible with current separation technologies
- the need of developing flexible processes and technologies able to work synergistically to recover different elements in the same integrated process increasing the economic and environmental feasibility.
On the other hand, SWDP brine contains all the components of seawater at a higher concentration, but it is currently discharged into the sea which is producing negative effects on some important marine ecosystems.
A New Approach
The concept of SEA4VALUE is based on the belief that mining minerals from the seawater is possible but relies on three key steps: (i) apply a circular supply model, (ii) develop highly efficient separation technologies and, (iii) integrate these and existing technologies into a modular brine mining process able to obtain multiple resources at the same time.
The SEA4VALUE project targets the higher concentration of seawater brines to boost technology development for the recovery of metals. The benefits are clear: less amount of water will be processed, and less energy will be required, as pumping seawater from the sea will be avoided.
“the project targets the higher concentration of seawater brines to boost technology development for the recovery of metals”
Seawater desalination can consume up to 3-10 kWh/m3, depending on many factors (seawater source, salinity, technologies used, pre- and post-treatments required, etc.). The use of SWDP brine as a starting point will avoid the need for this energy to catch, pre-treat and concentrate the seawater, making the proposed technologies more cost-effective. SEA4VALUE aims to convert SWDP into the mines of the future, and consolidate a new cost-effective and more sustainable streamline of metals and minerals.
Using SWDP as a raw material ‘mine’ provides several advantages compared to conventional primary raw material sources, such as mines. Saltwater desalination plants are a multi-mineral and virtually inexhaustible source, with a low energy consumption for extraction, and is vastly accessible as 19,744 SWDP are installed worldwide (according to the IDA Desalination Yearbook 2017 – 2018). It is expected to grow around 7.8% yearly with a further potential for additional water use and more gained metals. As mentioned, this approach is also an opportunity for SWDP operators and the environment, by increasing water production at SWDP and reducing the concentrated brines discharged into the sea.
To achieve this, SEA4VALUE proposes to make use of the knowledge from several stakeholder groups including RM producers and consumers, but also from the desalination operators, in order to transform the actual linear model of extracting minerals to a circular one. Nine key elements will be recovered from the brine. The project started in June 2020 and will last until end of May 2023. So far, the collection and analysis of the samples, coming from sea-water desalination plants and brackish water sources from mines, is completed, and the results published. Other tasks are ongoing and will likely have concrete results in mid-2022.
Technologies and Methodologies
Such ambitious – but realistic – aims need the development of innovative technologies and methodologies such as:
- Quantification of the metals potential of SWDP brines as resources: To provide knowledge, all information on brines composition, especially the trace metal content, will be published open source in a database. Brines from SWDP have been collected from different countries all over the world.
- Development of advanced concentration and crystallisation technologies: Concentration of the SWDP brines is essential to enable downstream processing into minerals and metals production. Target technologies include Membrane Crystallisation and Multi-Effect Distillation, based on polymer composite materials.
- Development of novel ion-selective separation technologies: Highly selective technologies at low TRL based on new adsorption materials, ion-selective membranes and solvent extraction processes will be brought into at least a pilot plant test stage.
- Establishment of new approaches for the recovery of metals: A Multi-mineral Modular Brine Mining Process (MMBMP) will be developed by combining concentration and crystallisation technologies with the novel ion selective technologies to maximise yield recovery, quality and cost-effectiveness.
- Validation of technical feasibility and cost-effectiveness of SEA4VALUE multi-mineral modular brine mining process and technologies developed: Design and deployment of a moving lab that includes the developed technologies to validate SEA4VALUE.
Collection, Analysis and Publication of Samples
Although the SEA4VALUE project is mainly focussing on nine defined elements (Mg, Sc, V, Ga, B, In, Li, Mo and Rb), the characterisation also includes the analysis of some major elements (Na, Cl, Mg, K, Ca and S) alongside the most relevant trace elements in the brine, including the Critical Raw Materials (CRM, as defined by the European Commission, such as Ba, Sb, Be, Bi, Co, Ge, Ta), rare earth elements (REE), precious metals (Au, Ag) and other elements of economic interest. These elements have been analysed from more than 100 samples, collected from seawater and brine desalination plants all over the world.
The analysis of the major elements was performed using ion chromatography (IC). Analysing trace elements in brines is more challenging due to the combination of the high and variable total dissolved solids (TDS) in solution, the potential interferences that arise from the matrix, and the low detection limits that must be achieved. To overcome these challenges, trace elements are analysed using inductively coupled plasma mass spectrometry (ICP-MS) incorporating a High Matrix Introduction (HMI) system. Organic matter content was also determined, considering that organic compounds could mask or adsorb the M&M to be recovered.
The methodology was regularly updated and validated during the task, taking into account the variability of the samples collected. The results of the analytical work were directly implemented into an online database. As samples are still being collected and analysed, the catalogue will grow steadily throughout the remaining project lifetime.
A geographical worldwide map with zoom option shows the position of participating SWDP in combination with their main analytical values. All information is available at http://sea4valuedb.eu.
Bringing the Idea to Life
Although all the technical tasks need to be demonstrated in a relevant environment, one also needs to bring the elements to a market. SE4VALUE will validate the technical feasibility and cost-effectiveness of its combined processes and the developed technologies to generate a route for material use in relevant industries.
In the long term, once the proposed solutions have reached maturity, the added value of SEA4VALUE technology will impact on stakeholders. Considering the dependence of EU raw material accessibility, the new resources will enhance the need and viability of downstream companies to transform the recovered metals as final, or to be incorporated in final products. Third, and although less directly, new economic value chains need to be explained to society, especially when it could help to cut the current environmental impacts relating to desalination plants. As previously stated, converting SWDP brines into a streamline of resources will help break the dependence of EU raw material accessibility, thus moving toward the concept of in-place production, reducing supply-risk, and dependency on foreign and unreliable markets. These economic benefits are set to be achieved in Europe, as the SEA4VALUE process will either be industrially implemented by current SDWP operators or by current or new raw material-based companies.
Acceptance by the Market
Processing industries work in an extremely competitive market and any change in their production line, provider and/or equipment, must be carefully evaluated before any decision is made. The high-quality characteristics and requirements that the industries have set up, is also a key challenge to be addressed when it comes to market exploitation.
SEA4VALUE will not only have to prove the feasibility of their proposed solution, but also build confidence in their target markets. A key factor for all players in the market is the purity of the metals, their ‘production’ costs, and the amount that can be delivered. Within the next two years, the project consortium will elaborate these factors and identify relevant stakeholders willing to collaborate.
The European industrial base is an essential building block for EU growth and competitiveness. The acceleration of technological innovation cycles and the rapid growth of developing countries have led to an increased demand for these coveted metals.
Within the European industries, the process industry sector plays a major role. However, the value chain of raw materials is not completely and homogeneously covered. The need for access to primary sources, including ores, concentrates, processed or refined materials, is enormous and crucial for the prosperity and survival of European industries, as well as for economic benefits and related jobs.
However, most primary sources come from non-EU countries. One way to reduce this dependency is by moving towards circular economy and leveraging secondary sources for critical raw materials.
Energy consumption (and the associated CO2 emissions and other airborne emissions) and water consumption are typically much lower for secondary CRMs than for primary CRMs. Strengthening the EU economy’s commitment to securing valuable RM requires the development of new solutions for the sustainable supply of RM. If we look into the actual existing markets and the usage of metals, based on the critical raw materials list of the European Union and personal research, the recovery of said metals from brine will make sense as the markets are prospering, and the materials need to be imported.
The EU consumes about 4,200 tonnes of lithium annually. In Europe lithium is mainly used in ceramics and glass industries. However, in a global context, lithium is increasingly used to manufacture rechargeable batteries. There is a strong demand for lithium due to its application in batteries for e-mobility (AAGR 2019-2025: +19% p.a.). In addition, there are no major lithium resources available in Europe, thus resulting in strong dependence on imports. In 2017 57% of lithium was produced from mining brine. High CAPEX requirements for new project development delays add-on new resources, thus new technologies placed close to SWDP’s could overcome this hurdle.
Boron and borates are mainly used in glass and fiberglass applications in Europe. EU consumption is estimated at approximately 285,000 tonnes. The consumption of borates is anticipated to increase in the coming years, mainly in the ceramic, glass and agricultural sector in South America and Asia. As a result of improvements in the building standards, in Europe and the majority of developing countries, an increase of demand for borates used in fiberglass building insulations is expected.
China is dominating the market by exporting $937 million from a total market of $1600 million. Main exports go to Canada and Netherlands, followed by Japan and Germany in the top four trade flows from China. A reliable estimate of the annual consumption of magnesite and magnesia in the EU is approximately 1,280,000 and 1,830,000 t MgO respectively. A steady demand for magnesium oxide from the refractory industry, coupled with increasing demand for industrial applications, is expected to drive the growth of the global magnesite market in coming years.
The largest producer of molybdenum is China (also having the biggest reserves) followed by the US and Chile. Its market has been very volatile in the last 10 years. Apparent consumption of molybdenum ores and concentrates in the EU amounts to 53,000 tonnes per year on average during 2010–2014. If ferro-molybdenum is considered, the consumption would be around 61,000 tonnes. In Europe, its main applications are mainly metal products and alloys. A steady increase in both demand and supply is expected for the coming years.
Most of the scandium is used in solid oxide fuel cells and Sc-Al alloys. Scandium exhibits typical characteristics and challenges of an immature and undeveloped commodity market, meaning that a lack of demand suppresses supply, and a non-existent supply reciprocally inhibits possible future demand. Obtaining a steady source of scandium will help to increase the stability of the market and increase the demand of the metal.
“although the consortium is optimistic that a recovery of all metals from brine would be both economically and environmentally beneficial, the project allows changes in the strategy”
The EU consumption of vanadium is around 10,700 tonnes. Most of the vanadium is used in metal alloys. Demand for vanadium in the EU is projected to increase in all sectors (steel, titanium, chemicals and energy storage), especially driven by increased steel production, heightened by an increasing unit consumption of vanadium per ton of steel. Vanadium is mostly obtained from Russia.
Europe exports as much indium as it imports. However, the values suggest that the EU imports standard refined indium and exports indium with a higher added value. In the EU, indium metal apparent consumption (i.e. ‘production’ + ‘imports’ – ‘exports’) amounted to 22.2 tonnes per year on average. Most of the indium is used in the flat panel display industry.
Consumption of gallium in Europe is approximately 10-50 tonnes per year. Currently, the greatest consumption of gallium is in semiconductors for the manufacturing of integrated circuits. Global conversion to general LED lighting and wireless communication systems is expected to continue up to 2030. Most of the gallium is imported from China and other non-European countries, but a significant part is also produced in Germany and Hungary.
Although the consortium is optimistic that a recovery of all metals from brine would be both economically and environmentally beneficial, the project allows changes in the strategy of which recovery technologies will be part of a future full scale recovery plant.