The author discussed a relation of liquid attached to the surface of the crystals to the caking tendency of common salt from two view-points;deposit of salt from liquid when cooled and vapor pressure of liquid (reported later).
In this paper, the author treated the liquid on the surface of common salt as an oceanic quinary system saturated with sodium chloride, and discussed the kind and quantity of deposited salts other than sodium chloride when the liquid was cooled by applying phase diagram in graphical method. Calculation results were;
1. When the liquid saturated with sodium chloride and more than one salt other than sodium chloride at 55° and 110° is lowered to 25° as a standard temperature, salt other than sodium chloride deposits in the area near K₂axis in Jänecke's figure.
2. When 10° was set as a standard temperature as discussed in 1., salt other than sodium chloride deposits in the both areas near K₂and SO₄axes.
3. When 0° and 10° were taken as a standard temperature, as discussed in 1., salt other than sodium chloride deposits in all the areas.
4. When 0° and 10° were taken as a standard temperature, transition of double salts occurs in the cooling process especially near Mg-S0₄line. And this was supposed to cause common salt to cake.

View full abstract

In his preveous paper, the author discussed a relation of liquid attached to the surface of crystals to the caking of common salt from the view-point of the deposition of salt when cooled. In this paper, caking tendency was discussed from the view-point of vapor pressure of the liquid. And vapor pressure of the liquid was calculated from Sugiyama's formula by treating it as an oceanic quinary system.
1. The liquid saturated only with sodium chloride has higher vapor pressure. Therefore, higher caking tendency (shown in Fig. 2) is observed as purity of sodium chloride increases and the content of either potassium or sulfate ion increases.
2. The liquid saturated with sodium chloride and more than one salt other than sodium chloride has higher vapor pressure and higher caking tendency (shown in Fig. 3), as the content of either potassium or sulfate ion increases.
3. The vapor pressure and caking tendency of common salt made from the oceanic quinary system are discussed from the above-mentioned figures.

View full abstract

A study was made on the mechanism of causing the lattice defects by the foreign positive ions contained in NaCl crystals and on the relation between the lattice defects and the transparence of crystals. The following were the results obtained from the above study:
1 It was assumed that the mechanism of causing the lattice defects by the foreign positive ions contained in NaCl crystals was more complicated than is generally considered, Namely, the impurity ions were considered to exert an influence on the thermal lattice vacancies.
2 The density of free positive vacancies caused at a temperature specialized to a respective impurity ion were considered equal to that of pure NaCl crystals. The author called this special temperature an equivlaent-vacancy temperature. In the temperature range lower than the abovementioned temperature, the impurity ions contained restricted the causing of the thermal vacancies, but they promoted it in the higher temperature range on the other hand.
3 Therefore, the constitution of the lattice vacancies in NaCl crystals was considered to differ according to the range of temperatures. Especially, what was worthy of attention was that in the range of lower temperatures the. Cl^-vacancies gradually decreased with the gradual increase in impurity ions and they finally became none at a certain content of respective ion.
4 The liquid cavities which provoke an opacity of crystals were understood to be produced in close connection with the form of adsorption layers and steps, i. e. when the adsorption layers are thick or when they are produced very often or when the steps are crooked irregularly, more cavities are enclosed.
5 It was presumed that the deformation of the adsorption layers and steps was caused by the disorder of crystal lattice and that the disorder of crystal lattice occurred only when Cl^-vacancies existed in crystals and would not occur even if the Na⁺vacancies existed.
6 Thus, it may be considered that the Cl^-vacancies are the major factor governing the transparence of crystals. The smaller the CI^-vacancies become, the more transparent will become the crystals, and the perfect transparency can be accomplished when there exist no Cl^-vacancies.

View full abstract

In order to study an influence which non-counter ions exert by their kinds on the diffusion transfer of electrolytes ion-exchange membranes, the authors measured the diffusion velocity of several kinds of chlorides through the anion-exchange membranes. The results obtained were summerized as follows:
1. The diffusion velocity of chlorides increased as the concentration of the original solution became higher, but no linear relationship was found between the velocity and the concentration.
2. The velocity of hydrogen chloride was especially higher than that of the other kinds of chlorides.
3. The velocity of bivalent chlorides was lower than that of monovalent chlorides, and the order of the latter was as follows:
KCl>LiCl>NaCl
4. The amount of cations adsorbed by the membrane increased in proportion to the concentration of the original solution, and no big difference was found between these chlorides.
5. From the relationship between the amount adsorbed and the diffusion velocity of chlorides, it was presumed that the mobility of monovalent cation in the anion-exchange membrane decreased in the order mentioned below:
K⁺>Na⁺>Li⁺

View full abstract