There are two problems in the purification of the crude KCl obtained by the decomposition of the carnallite which is usually containing NaCl, MgCl₂, MgSO₂, etc.
First, using the usual method of recrystallization, the mother liquor is available only several times. Second, the treatment of the mother liquor which is unavailable.
Utilization of the mutual solubility curve of NaCl and KCl has made possible the separation of KCl from NaCl. It is successful no matter how much NaCl exists in the mixture. And so the mother liquor can be used for the decomposition of the carnallite which causes the increase of NaCl content in crude KCl.

抄録全体を表示

Part 1. Boiling Point Raising of Sea Water Brine.
Several boiling point apparatuses each with a built-in Cottrel boiler and a boiling point apparatus of pure water were attached to a manostat capable of controlling pressure from the atmospheric down to 100 mm. Hg. and the temperature of the both kinds of boiling apparatuses were read off using copperconstantan thermocouples while the apparatuses were running steady. From the data obtained Diihring lines Were drawn the slopes of which are shown in Fig. 1. In Fig. 2 B.P.R. versus total chlorine (or equivalent to concentration ratio) are given for four pressures of 100,300,500, and 760 mm. Hg. In Fig. 3. influence of pressure is given for various lines of constant total chlorine.In Fig. 4. results of other workers on the subject are compared with the present data.
Part2. Degree of Salt Formation during Evaporation.
Using similar apparatusesbut with devices for drawing off of pure mother liquor while running for the purpose of obtaining samples for analysis, degrees of formation of both NaCl and gypsum crystals were determined. NaCl begins to crystalize out at (Cl^-) _T= 150 and the whole course is shown in Fig. 5. In Fig. 6. Similar curve is given for gypsum which starts at (Cl^-) _T=70 and quickly reaches 35%. Fig. 7. shows chlorine and sulfate ion concentrations of mother liquor during evaporation concentration.

抄録全体を表示

The application of centrifugal method was studied for the rapid determination of sulfate in bittern. The method was as follows: to the diluted bittern add BaCl₂ solution and centrifuge the precipitated BaSO₄, then measure the volume of the precipitation and calculate the SO₄ contents from it. We studied the effects by varying the conditions of precipitation and centrifuging, then decided the most appropriate procedures. Many samples were analysed by these procedures and good results were obtained withinn 0.1% errors for bitterns that involved about 5% sulfate.

抄録全体を表示

In this paper, some problems on the evaporation of running sea-water are theoretically mentioned, and it is verified that the theory agrees very well with the observations.
In the first part of this paper,(Vol.7 No.2) the author has chiefly mentioned a fundamental theory on the sloping salt field, that is (1) the relation between the depth and the mean velocity of running sea water,(2) the temperature rise of water which is controlled by the air temperature, relative humidity and wind velocity at a given height above the salt-field and the intensity of solar radiation,(3) the effect of the main temperature rise of running sea water and the valuable evaporation surface, while in a given location,(4) the relation between the concentration of salt and the change of the depth of water, and (5) the temperature of water at the source of the flow.
In the second part of this paper,(Vol.7 No.3-4) some, experimental data on the sloping salt-field is reported and compared with the author's theory.
Readers will easily find that the theory on the temperature rise of running water agrees very well with the observed data. The main temperature rise is about 6 meters or of the total length of the salt field. The effective part of the salt field is 75 or 80% of the whole surface.
The author bas calculated here the thermal efficiencies which are defined by him to be 86-91%, and also estimated the leakage of water in the earth bed of the salt-field.

抄録全体を表示

Vol. 7 No. 3 p. 41
修正箇所：本文
修正内容：
（誤） 2年
（正） 2時間

抄録全体を表示