How does the Norsk Hydro process prepare magnesium chloride for electrolysis?

In the Norsk Hydro process, the preparation of magnesium chloride for electrolysis involves a multi-stage dehydration of magnesium brines.1

The process follows these steps:

• Purification: Impurities are first removed from the brine through precipitation and filtering.1
• Concentration: The purified brine, which contains approximately 8.5 percent magnesium, is concentrated via evaporation until it reaches a concentration of 14 percent.1
• Prilling: The concentrated solution is converted into particulates using a prilling tower.1
• Final Drying: These particulates are further dried to create water-free particles, which are then conveyed to the electrolytic cells for the production of magnesium metal and chlorine gas.1