Decarbonising production of a key metal
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The new method extracts magnesium from seawater without generating emissions
Spotted: According to the US’ 2020 Energy Act, critical minerals are defined as materials that are a key component of energy technologies and have a ‘high risk of supply chain disruption’. This includes magnesium, which is mainly produced in China. Now, US-based Tidal Metals has devised a cleaner magnesium extraction method that could enable the metal to be produced locally.
Traditional magnesium extraction either involves heating dolomite ore in kilns (often using energy derived from coal) or large solar brine evaporation ponds (which can pollute surrounding soil and vegetation). Instead, Tidal Metals has turned to the huge amounts of magnesium that are dissolved in our oceans.
To do this, the company uses a range of efficient, low-energy physical processes (rather than chemicals), including filtration, crystallisation, and dehydration to extract magnesium salts from seawater or brine. Then, Tidal Metals uses electrolysis to convert the salts into pure magnesium metal. The process can be completely powered using renewable energy sources, which would fully decarbonise magnesium extraction.
Because it’s so lightweight, magnesium has the potential to decarbonise many technologies, including making more energy-efficient wind turbine blades and electric cars, and Tidal Metals’ process could allow the metal to be extracted much more sustainably. And beyond providing low-emission, low-cost magnesium, the company’s process could make water desalination more cost-effective. CEO Dr Howard Yuh explains: “As the world faces water scarcity for billions, we also see huge benefits to reducing the cost of desalinated water through the coproduction of high-value minerals such as magnesium.”
In September this year, the startup completed a seed funding round led by DCVC that raised $8.5 million. This capital will allow Tidal Metal to build a commercial pilot plant where it can demonstrate its technology at scale.
Written By: Matilda Cox