|The Natural Brine Process|
In the U.S., production is utilised by the concentration and purification of naturally occurring brines from salt lakes and salt deposits. Magnesium is removed by adding milk of lime, Ca(OH)2, which causes magnesium to precipitate in the form of magnesium hydroxide, Mg(OH)2. Sodium chloride, NaCl, is removed by precipitation; sodium chloride precipitates from the CaCl2 solution when the concentration of calcium chloride is increased during the evaporation of water.
The advantage of this source of calcium chloride is the low raw material cost and low environmental impact. However, the purity of the product is normally lower than the competing processes.