Alkali and Alkaline Earth Metal Production by Molten Salt Electrolysis
Alkali and alkaline earth metals are reactive metals, and their compounds are very stable. The production of pure alkali metals is difficult due to their extreme reactivity with commonly used substances, such as water. The alkali metals are so reactive that they cannot be displaced by other elements, and molten salt electrolysis is therefore an option for producing many of these metals. Sodium and lithium are the most important alkali metals produced by electrolysis, while magnesium and calcium are the most important alkaline earth metals produced by electrolysis. For calcium and magnesium, thermal processes are currently more important than electrowinning. Magnesium, being the only of these metals that can be used for structural purposes, is a major industrial product. Therefore, a separate chapter is devoted to the electrolysis process for magnesium.
The annual production of sodium is around 100,000 t. The world capacity for lithium production is ∼25,000 t per year,...
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