かん水中のストロンチウムの沈殿挙動

抄録

This paper describes the behavior of strontium in bittern shown when the strontium is precipitated as carbonate, oxalate, and phosphate. In this study, sodium carbonate, sodium oxalate, sodium phosphate or sodium hydroxide was used as precipitant. The behavior of strontium was traced by using radioactive isotope ⁸⁹Sr, while calcium and magnesium were determined by EDTA titration.
When sodium carbonate and sodium oxalate were used as a precipitation agent, the behavior of strontium and calcium were almost the same. When sodium oxalate was used, the precipitation ratio of strontium was the most remarkable. In the case of adding sodium oxalate of 0.6 times as much to the equivalent quantity of calcium and strontium in brine, approximately 60% of them were deposited, but the precipitation ratio of magnesium was extremely small. When using sodium phosphate, on the other hand, the precipitation ratio of strontium was higher than those of calcium and magnesium. When sodium hydroxide was added to brine, a portion of strontium was considered to coprecipitate with magnesium hydroxide. After the deposition of magnesium in brine reached more than 90%, the deposition of calcium became rapid, and the precipitation ratio of strontium was about 56%.