In their previous paper (This Journal, 25, 141-147 (1971)), the authors wrote a report on the equilibrium values of the five-component system, Na, K, Mg, Cl, SO₄-H₂O saturated with NaCl at 110°C, which were gained by partial modification of the values found in the classical work of D'Ans.
In the present paper, the authors treated graphically the isothermal evaporation of the sea wate at 110°C, and computed the changes of the compositions of solutions and the kinds of crystalls deposited during the process. Also, they calculated the composition of the solution at which the deposition of NaCl began, by the theoretical equation introduced by Amirkhanov (Zhur. Neorg. Khim., 9, 2465 (1964)). Furthermore, the authors discussed the validity of such method by using the data of Harada (This Joumal, 13, 238 (1959)) and of Maeda (J. Chem, Soc. Japan, Ind. Chem. Sec., 23, 1129 (1920)). As the result, the authors reached the following conclusion:
1. When the authors'calculated values were compared with those of Harada which were calculated by using the equilibrium values of D'Ans, they coincided fairly well with the evaporation rate of water and the deposition rate of NaCl, at an early stage. However, at the later stage of evaporation after the beginning of sulphate deposition, they showed a considerable difference at the composition of solution, also, and a slight difference in the Kinds of deposited crystalls.
2. The calculated composition at which NaCl began to deposit coincided completely with that determined experimentally by Harada.
3. The compositions of solutions determined experimentally by Harada after the deposition of NaCl differed greatly from the authors'calculated ones. The authors considered that this phenomenon were due to the supersaturation of sulphates such as löweite (Na₂SO₄·MgSO₄·5/2H₂O), kieserite (MgSO₄·H₂O), etc..
4. The calculated value at which the deposition of löweite began, coincided fairly well with the value determined by Maeda. From this fact, the authors considered that their calculation was highly credible.

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In order to recover potassium from sea water and brine, acid salts of zirconium and polybasic acids were prepared as potassium-selective inorganic ion exchanger, and their physical properties, structure and chemical properties of ion-exchange groups were also examined.The kinds of exchangers prepared were as follows:
Zirconium phosphate
Amorphous (ZP)
Crystalline (CZP)
Zirconium polyphosphate (ZPP)
Zirconium tripolyphosphate
Zirconium pyrophosphate
Zirconium trimetaphosphate
Zirconium hexametaphosphate
Zirconium phosphate silicate (ZSP)
Zirconium phosphate tungstate (ZWP)
Zirconium phosphate molybdate (ZMP)
1.Most of the prepared exchangers were hard and glassy granule.Water contents of the fully water-swollen exchangers were 6 to 40%, and apparent densities of the swollen exchangers were 0.7 to 1.8g/cm³.
2.All the other exchangers were considered to be amorphous as compared with CZP. However, they differed considerably in their crystallinity. Therefore, they could be classified to more crystalline and amorphous exchangers by X-ray diffractionmetric and thermogravimetric analysis.
3.Ion exchange capacities of the exchangers indicated an increase with pH value in alkaline side, and the maximum exchange capacities of ZP, ZPP, ZWP and ZSP amounted to 3.5 to 4.5 meq./g. exchanger. However, partial dissolution of the exchanger was observed at pH 10.
4. In general, the potassium-selectivity of these prepared exchangers were found to be excellent. For example,the distribution coefficients of potassium ion of ZPP was about 17.

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The behavior of water coordinated with the surface of several kinds of Nylon was investigated by high resolution NMR measurements. The half-width of water signal became narrower in proportion to an increase in the amount of water added, and its chemical shift changed for the lower magnetic field. The change of the half-width in proportion to the change of the amount of water well consisted with the change of the chemical shift. The chemical shift of water on each Nylon in case the amount of water was extrapolated zero was as mentioned below:
Nylon 4 was -1.8 ppm, Nylon 6 was -1.85 ppm, Nylon 66 was -1.9 ppm, Nylon 610 was -2.1 PPm and Nylon 12 was -2.1 ppm, where acetone was used as the exterior standard.
These results suggested that the larger the number of carbon atom per acid-amide-bond became, the weaker the coordination of water with the Nylon became.
Similar results were obtained when the 0.5N NaCl aqueous solution was added to the Nylon, but its coordination with the Nylon was a little weaker than that of pure water with the Nylon.

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The specific heaf Cp (cal·g^-1·deg^-1) of the brine (sp. gr. d²⁵₄=1.1258) produced by electrodialysis of sea water with ion exchange membranes and its six kinds of concentrate were determined at 30.0, 50.0 and 70.0°C.
The relation between the specific gravity d²⁵₄(=1.126-1.204) and the specific heat Cp of the solutions up to the saturation point of sodium chloride was analyzed by statistical procedure of quality control, and thus there was found a very significant regressive relation. The following were the regression line at each temperature and the estimated error E from each line:
Cp₃₀=-0.849d+1.785, E=0.001
Cp₅₀=-0.812d+1.735, E=0.002
Cp₇₀=-0.809d+1.722, E=0.003

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In order to recover potassium from sea water and brine, a study was made on the mechanism of selective adsorption of potassium by using irorganic ion exchangers. In this study were examined the effects on the selective adsorption of pH, temperature, composition and concentration of the raw solution, and also the effect of the molar ratio of phosphate to zirconium (P/Zr) in the preparation of these exchangers. The Kinds of exchangers prepared were as follows:
Zirconium phosphate:
Amorphous (ZP)
Crystalline (CZP)
Zirconium Polyphosphate:(ZPP)
Zirconium tripolyphosphate
Zirconium pyrophosphate
Zirconium trimetaphosphate
Zirconium hexametaphosphate
Zirconium silicate phosphate:(ZSP)
Zirconium tangstate phosphate:(ZWP)
Zirconium molybdate phosphate:(ZMP)
Phospho antimonic acid:(SbP)
(1) All the inorganic ion exchangers test showed selective adsorption properties for potassium dissolved in sea water and brine.
(2) Incase 1g of exchanger was used for 950mlof brine (16°) produced by ion exchange membrane method, the adsorption capacity of zirconium phosphate for potassium amounted to 25mg K⁺/g, and zirconium pyrophosphate proved to be the best capacity among the tested exchangers.
(3) The selective adsorption property for potassium ion increased with a rise in the drying temperature of exchangers. However, the selectivity decreased with a rise in the temperature of cation exchange reaction. In case the variation of the drying or reaction temperature became greater, exchangers of higher degree of crystallinity showed a greater variation in the adsorption capacity and selectivity. On the other hand, the amorphous exchanger was less influenced by the variation of temperature.
(4) The adsorption rate of potassium ion was found to be the fastest as compared with other cations, and the amount of potassium adsorbed to the saturated capacity for a short time.
(5) The selective adsorption property for potassium, which was evaluated by the selective adsorption coefficient of a cation (i) to potassium ion (αⁱ_k), was classified easily by apparent volume of wett exchanger (ν'). When the value of ν' was less than 1cm³/g,α^Na_K>α^Mg_K, and when the value was more than 1cm³/g,α^Na_K<α^Mg_K.

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A study was conducted on determination of water insolubles in common salt by using millpore filter, glass filter, and Gooch crusible equipped with small filter paper. Results were as follows:
1. Error of each filtrating apparatus in reaching the constant weight amounted to below 0.001%, and each filter showed no difference in practical use.
2. Variation in analytical values mostly derived from sampling error, but variation in quality of glass filter was not negligible.
3. Determination by using glass filter 1G3 and filter paper No.5A yielded a negative value, but the error resulting from the glass filter 1G3 was decreased by using the filter repeatedly.
4. The above-mentioned results proved that millipore filter, glass filter 1G4, filter paper No.5B and No.5C were suitable as filtrating materials for the determination of water insolubles in common salt.

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