The Lovisa Mine in Örebro County is one of the sites where IVL has taken water samples. Photo: Mikaela Boltenstern
IVL shows the way for recycling critical metals from mining wastewater
IVL Swedish Environmental Research Institute has demonstrated on a pilot scale that rare earth elements can be recovered from mine wastewater with over 90 per cent efficiency. The membrane technology tested can help reduce Europe's reliance on the import of critical raw materials that are essential for the green transition.
Rare earth elements (REE) are crucial for green technologies such as wind turbines, electric cars and energy-efficient lighting. However the EU currently imports almost one hundred percent of its requirements. In a recently published report from the Mistra TerraClean research programme, IVL Swedish Environmental Research Institute shows that membrane-based technology can recover these critical metals even from highly diluted and complex aqueous solutions.
We have used mine wastewater as a test matrix because it is a difficult environment to work with; it has low concentrations of the metals we want and high levels of interfering substances. If the technology works here, it will also work in simpler applications
, says Johan Strandberg, project manager at IVL Swedish Environmental Research Institute.
Mine wastewater contains rare earth elements in concentrations ranging from nanograms to micrograms per litre, along with large amounts of iron, zinc and calcium. IVL's pilot tests show that membrane technology can manage this complexity and still achieve a recovery efficiency of over 90 per cent.
Large-scale application will probably be in other process streams where conditions are simpler. But by testing in mine water, we have shown that the technology is worthy of testing in industrial conditions
, says Johan Strandberg.
Tests in real-world conditions
IVL has tested HFSLM (hollow-fibre supported liquid membrane) technology on a pilot scale with continuous operation for one month, which is longer and with a higher yield than previously achieved. The technology achieved over 90 percent recovery and uses 10-100 times less chemicals than conventional methods. Through careful pH control, different metals can be separated from each other, which is crucial to their value.
The most important thing is that we have tested under real conditions, not ideal laboratory solutions. But we clearly state that significant development is required before industrial application
, says Johan Strandberg.
The next step is longer operational tests lasting three to six months, and economic analyses.
Read more in the report: Can mining wastewater be turned into a source of REE? External link, opens in new window.
For more information, contact:
Johan Strandberg, johan.strandberg@ivl.se, tel. +46 (0)10-788 65 98
More results from Mistra TerraClean
- Rare earth elements (REE) are a group of 17 elements that are crucial for green technology. Neodymium and dysprosium are used in permanent magnets for wind power and electric cars. The EU classifies several REE as ‘critical raw materials’ with a high supply risk.
- The project is led by IVL Swedish Environmental Research Institute and is being conducted together with Axolot Solutions, KTH, RISE and Stockholm University within Mistra TerraClean.
- Within the project, other process steps have been tested with good results. Electrocoagulation removed 79 per cent of the unwanted metals, while up to 99 per cent of the rare earth elements (REEs) remained in the liquid.
- Special sorbents developed by Stockholm University, KTH Royal Institute of Technology and RISE showed that they can absorb 55 mg of the rare earth element lanthanum per gram of material.