41. Magnesium Extraction Mechanisms

Metallic magnesium can be obtained from seawater, brines, minerals, in recycled scrap, and in alloys. It is the eighth most abundant element on the planet, using 2% of the earth’s crust, and it is the third most abundant element in the sea with approximate contents of 1.3% of magnesium, on the other hand, brines have around 0.3–1% magnesium. Also, it is considered the third most used structural metal after aluminum and iron. Regarding its extraction mechanisms, leaching is the most crucial stage for Mg extraction, the most common lixiviants being inorganic and organic acids and ammonium salts. The choice of the leaching agent depends on the raw material to be used. Organic acids are more selective in dissolving Mg, although with less dissolving power. While inorganic acids are more dissolving, they nevertheless generate greater corrosion of the equipment to be used.