Extracting Magnesium from Seawater

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Richland, Washington
Project Term:
01/01/2014 - 06/30/2016

Technology Description:

Pacific Northwest National Laboratory (PNNL) is developing a radically new process to produce magnesium from seawater. Today’s methods are energy intensive and expensive because the magnesium concentration in seawater is so low that significant energy is needed to evaporate off water and precipitate magnesium chloride salt. Further, conventional technologies involve heating the salt to 900°C and then using electric current to break the chemical bond between magnesium and chlorine to produce the metal. PNNL’s new process replaces brine spray drying with a low-temperature, low-energy dehydration process. That step is combined with a new catalyst-assisted process to generate an organometallic reactant directly from magnesium chloride. The organometallic is decomposed to magnesium metal via a proprietary process at temperatures less than 300°C, thus eliminating electrolysis of magnesium chloride salt. The overall process could be significantly less expensive and more efficient than any conventional magnesium extraction method available today and uses seawater as an abundant, free resource.

Potential Impact:

If successful, PNNL would enable a low-cost, low-energy metal-organic process for producing magnesium from seawater without the energy intensive steps associated with conventional processes.


Light-weighting vehicles to improve fuel efficiency could reduce U.S. dependence on foreign fossil fuel resources used in the transportation industry.


Efficiencies in magnesium extraction technologies could offer a 50% reduction in energy consumption and result in substantially fewer CO2 emissions over conventional methods.


Seawater represents a virtually unlimited source of magnesium, which could supply worldwide demand for centuries given an economic and environmentally sound method for its extraction.


ARPA-E Program Director:
Dr. Eric Rohlfing
Project Contact:
Dr. Peter McGrail
Press and General Inquiries Email:
Project Contact Email:


US Magnesium LLC
Global Seawater Extraction Technologies LLC

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