How do you obtain pure sodium chloride from a crude sample?

Explanation

Crude sodium chloride is obtained by the crystallisation of brine solution.
Crude sodium chloride contains sodium sulphate, calcium sulphate, calcium chloride and magnesium chloride.
`CaCl_2 and MgCl_2` are the impurities in the Crude NaCl Because these absorb moisture easily from the atmosphere.
Pure sodium chlorides obtained by dissolving crude NaCl because these absorb moisture easily from the atmosphere.
Pure sodium chlorides obtained by dissolving Crude NaCl in minimum amount of water and filtered to remove insoluble impurities.
This solution is saturated with HCl gas. Then crystals of pure NaCl are separated out.
Ca and Mg chloride are more soluble in solution than NaCl and these remained in the solution.