In the previous year, the United States classified magnesium as a crucial mineral, part of the “electric 18” essential for the energy transition. This lightweight metal is widely used in electronics and, being lighter than aluminum, is a favorable option for car manufacturers.
However, like many other minerals, China has established dominance in the magnesium market. This isn’t due to scarcity—magnesium is the eighth most common element in the Earth's crust and the third most abundant dissolved mineral in the oceans. In the U.S., though, only one company produces new magnesium metal; the rest is either imported or recycled from scrap.
“The key question is whether you can compete with the 90% of production coming from China today,” said Howard Yuh, co-founder and CEO of Tidal Metals.
Yuh believes his startup can. Initially known as GreenBlu, the company was focused on desalination technology but pivoted to magnesium production in late 2023 after recognizing the value of the leftover minerals.
At the time, the U.S. magnesium industry was struggling. Sensing an opportunity, the company rebranded and shifted its focus to magnesium production.
Magnesium, being lightweight, has the potential to lower carbon emissions in transportation if produced with minimal pollution. It’s commonly used in motorsports, particularly for wheels, where reducing weight improves performance. For regular cars, increased magnesium use could enhance fuel efficiency, reduce emissions, and extend the range of electric vehicles. Some battery companies are also exploring magnesium to boost energy density.
Currently, magnesium is primarily produced through two methods: processing dolomite rock or evaporating salt water in large, open-air ponds, both of which have environmental drawbacks. China mainly uses the former, which is highly polluting, especially when coal is used as a heat source.
Tidal Metals employs an evaporation method but skips the use of large ponds. Instead, it utilizes a temperature-swing vapor pump, a system that uses a material similar to silica gel to evaporate seawater or brine left over from desalination. The process is highly efficient, recycling about 97% of the energy used.
After evaporating one metric ton of seawater, the company ends up with roughly 4 kilograms of magnesium salt. The next step involves removing any remaining water molecules from the magnesium chloride, a process Yuh says the company has refined.
Tidal Metals is currently working on a pilot plant with a production capacity of 200 tons per year, funded by an $8.5 million seed round led by DCVC, along with Bidra Innovation Ventures and First Spark Ventures. The startup plans to scale up to a 10,000-ton facility by 2026.
The company’s method is expected to be much less polluting than traditional Chinese production, especially if powered by renewable energy. Moreover, using seawater and briny waste from desalination plants makes the resource almost limitless compared to mined dolomite.
“The desalination plant in San Diego processes 100 million gallons of seawater daily, enough to supply all of the U.S. with 180,000 tons of magnesium annually,” Yuh said. “Currently, all of that potential is being wasted.”