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Volume 28 (1974 - 197･･･
- Issue 6 Pages 379-
- Issue 5 Pages 321-
- Issue 4 Pages 196-
- Issue 3 Pages 146-
- Issue 2 Pages 85-
- Issue 1 Pages 4-
Volume 28, Issue 2
Displaying 1-5 of 5 articles from this issue
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Norio TAKEUCHI, Totaro GOTO, Seiichi ISHIZAKA1974 Volume 28 Issue 2 Pages 85-92
Published: 1974
Released on J-STAGE: February 19, 2013
JOURNAL FREE ACCESSThe simultaneous dissolution of sodium and potassium chlorides into sodium hydroxide aqueous solutions of below 48 wt% was experimentally made under the atmospheric pressure of 5.5-70°C. This was made to determine their compositions when the aqueous solutions were saturated by the both chlorides. The results thus obtained served to make clear the following points:
1. It is possible to calculate from the equilibrium data the differential enthalpy and entropy changes in the solution of sodium and potassium chlorides simultaneously saturated in the alkali hydroxide aqueous solutions.
2. In case sodium and potassium chlorides are either simultaneously or separately saturated in the aqueous solutions having the same concentration of hydroxide ion in (1) the NaOH-KOH-NaCl-KCl-H2O system,(2) the NaOH-NaCl-H2O system, and (3) the KOH-KCl-H2O system, the differential enthalpy and entropy changes for the dissolution of the chloride in the (1) systems are larger than those for the same chloride in the systems of (2) and (3). In the aqueous solutions having sufficiently high concentration of hydroxide ion, however, the differences between the thermodynamic values showed a decline.
3. In case sodium and potassium chlorides are saturated in the systems of (1),(2), and (3), the differential enthalpy and entropy changes,ΔH and ΔS, of the chlorides can be expressed as a function of the total ionic concentration.CT. I, by
4. In case sodium and potassium chlorides are added into the alkali hydroxide aqueous solutions, the possible behaviors of the chlorides can be presumed from the equilibrium data.View full abstractDownload PDF (5271K) -
Norio TAKEUCHI1974 Volume 28 Issue 2 Pages 93-97
Published: 1974
Released on J-STAGE: February 19, 2013
JOURNAL FREE ACCESSIn this study a method for estimating the composition of the solution saturated by sodium and potassium chlorides in the NaOH-KOH-NaCl-KCl-H2O system from the equilibrium values of the NaOH-NaCl-H2O system and the KOH-KCl-H2O, is proposed. This method is based on the relation between the activity and the solubility product of a solute in anaqueous solution, and is characterized by the use of the activity coefficients of sodium and potassium chlorides in the corresponding solutions of the NaOH-NaCl-H2O system and the KOH-KCl-H2O system instead of the activity coefficients of sodium and potassium chlorides in the solution of the NaOH-KOH-NaCl-KCl-H2O system.
Therefore, the activity coeffilcients of sodium and potassium chlorides which have been respectively saturated in the sodium and potassium hydroxide aqueous solutions at 25°C, are derived from. the known equilibrium values of the NaOH-NaCl-H2O system and the KOH-KCl-H2O system, and they are related to the total ionic strength in the solutions. The activity coefficients of sodium and potassium chlorides which have been simultaneously saturated in the alkalihydroxide aqueous. solutions at 25°C, are also derived from the equilibrium values measured in this study.
This method is comparatively effective to the estimation of the solubilities of chlorides in the alkali hydroxide aqueous solutions with hydroxide concentration of less than 6g-ion/1kg H2O, but it can not precisely estimate the solubilities of chlorides in the alkali hydroxide aqueous solutions. containing more hydroxides.View full abstractDownload PDF (3501K) -
Tsutomu MASUZAWA, Yoshio YONEI1974 Volume 28 Issue 2 Pages 98-103
Published: 1974
Released on J-STAGE: February 19, 2013
JOURNAL FREE ACCESSOn the assumption that those impurity-salts attached to the surface of common-salt crystals be single salts (MgCl2 M, KCl K, Na2SO4 N, and CaCl2 C) crystallized from the oceanic quinary system, sample salts were prepared by adding the impurity-salts to refined salt, and their caking tendency was examined by both the fundamental caking test and the piling test. The following were the results obtained from this study:
1. The fundamental caking test by the pressure method indicated that the samplesalts had the caking strength of 4-12kg/cm2 (4kg/cm2 for MgCl2). In the fundamental test by the recrystallization method, they proved to have the caking strength of 0.2-6kg/cm2, but in this test such impurity-salts as causing the critical humidity lower showed a less caking tendency.
2. In the piling test conducted in a warehouse, the wet sample salts showed a caking strength of 0.4-1.6kg/cm2, while the dry sample salts showed a caking strength of 0.2-11kg/cm2, according to the kind of the impurity-salts {0.2kg/cm2 for C, M and X (mixture of C, M and K) and 8-11kg/cm2 for K, N and Blank}.
3. In the piling test made in the room having the constant temperature and humidity (E1; 40% R. H. and E2; 70% R. H. at 25°C), the sample salts of Cand M showed nocaking tendency regardless the packing conditions. However, the sample salts of K and Blank showed a caking strength of 0.2-2.7kg/cm2.
4. The above caking tests showed that the impurity-salts had effects on the caking of common salt in relation to packing and environmental conditions. The conclusion of this study was that for the prevention of caking of common salt appropriate packing and environmental conditions must be selected according to the property of the salt.View full abstractDownload PDF (3983K) -
Kenzaburo OBATA, Kunio SUGINO, Koichi TAWARA1974 Volume 28 Issue 2 Pages 104-109
Published: 1974
Released on J-STAGE: February 19, 2013
JOURNAL FREE ACCESSDeaeration by vacuum is most commonly used for preventing the sea-water desalination plant from corrosion. In this study, a packed tower was employed for the vacuum deaeration to examine the effects of operating conditions, especially the flash of the feed solution on the tower capacity. The tower was 130mm in diameter, having 1.5m packed bed of 12mm ceramic Raschig ring. The experiment was carried out mainly under the conditions that were encountered normally in a practical plant.
The results showed that the capacity of the tower increased in proportion to an increase in the degree of vacuum or an elevation of the feed temperature, and that it decreased with an increase in the feed loading. In the range where no flash evaporation of the feed took place, the relation between the mass transfer coefficient and the operating conditions of the deaerater and the characteristics of the liquid could be expressed in the following dimentionless formula:(kLdp/DL)=0.56(4L/atμL)0.64(Po/PT)0.56
When a portion of the feed was flashed, the residual dissolved oxygen decreased to a half, and the capacity of the tower showed a sudden increase of 20% under the experimental conditions, proving that the flash evaporation of the feed was effective.View full abstractDownload PDF (3397K) -
Takashi NAKANE1974 Volume 28 Issue 2 Pages 110-124
Published: 1974
Released on J-STAGE: February 19, 2013
JOURNAL FREE ACCESSDownload PDF (10201K)
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