Caustic soda concentration chlor-alkali

It would seem that the concentrated brine from the evaporators of a distillation plant could be utilized for the production of chlorine and caustic soda in a diaphragm cell. If the sea water had been originally stripped of calcium, magnesium, and other heavy metals (by phosphate precipitation as discussed below), the brine should be suitable for the chlor-alkali industry. It is necessary to remove calcium and magnesium from natural salt before preparing a charge for the diaphragm cells. 

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