Iodine/magnesium displacement

Magnesia is currently produced from sea water by adding lime to the sea water in the form of either dolomite or calcined oyster shells. The lime precipitates magnesium hydroxide, which is filtered, washed, and calcined to magnesia. Bromine is separated from sea water by displacement with chlorine or by adding both chlorine and aniline to the water to produce tribromoaniline. Iodine is produced indirectly from sea water by extraction from various forms of seaweed. 

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