A study was conducted on the behaviors of strontium and calcium in the concentrating process of sea water. In this study, sea water was gradually evaporated at 50-70°C or at the boiling temperature until it reached one twentieth of its initial volume, and the behaviors of strontium and calcium were traced by using radioactive isotopes,
89Sr and
45Ca. Strontium in sea water and brine was spectrophotometrically determined by ο-cresolphthalein complexon method after it was separated from other elements by coprecipitation with calcium oxalate and by cation-exchange method.
The following conclusions were obtained from the experimental results:
1. In the early stage of concentration, the loss of strontium from the sample solution was negligible. When 85%(in volume) of sea water was evaporated, the concentration of strontium reached the maximum and was four times as much as the concentration of sea water. Strontium indicated rapid precipitation after it reached the maximum point, and a trace of strontium was detected in the bittern.
2. The behavior of calcium was almost the same as that of strontium although the depositing tendency of strontium was a little more remarkable than that of calcium, and most of strontium was considered to be distributed in the gypsum deposit.
3. As shown in Table 3, the ratios of strontium concentration in sea water and brine samples were in good agreement with the results obtained from the evaporation experiments.
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