Study of Preparation of Hydrphodic Surface of Sodium and Potassium Chloride by Saturated Fatty Acids.

Flotation is a very important method for separation, condensation, recovery and purification of substances and it is employed satisfactory for technical production. In order to investigate a mechanism of flotation for the soluble inorganic salts, subsequent experiments were carried out as a basic investigation.We observed whether or not the crystal surface of the soluble inorganic salts is changed to the hydrophobic one by adding a surfactant such as a saturated fatty acid or its sodium salt. Then we discussed the effect of pH on forming the hydrophobic crystal surface.The results showed that the crystal surface of the soluble inorganic salt was easy to change to the hydrophobic one in the pH range alkaline, and by more carbon number of saturated fatty acid than C8. The more carbon number of fatty acid increased, the more they changed to the hydrophobic one.Saturated fatty acid of carbon number C8-C18 or it's salts are effective to promote forming the hydrophobic surface of the soluble inorganic salts such as sodium or potassium chloride.