How to do this, the production of fresh water into the salt in salt rock. Then pump solution, NaOH aqueous solution by filling with Ca2 + and Na2CO3 to eliminate Mg2 +.
Method for manufacturing. Do by compression freshwater melt into salt in rock salt) and smoke to ทำให้บริสุทธิ์ solution by adding solution NaOH oh. " He Na2CO3 with Boeing to get rid of the Ca2. ") and Mg2.