| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for obtaining a low α-ray bismuth having an α-ray emission of 0.005 cph/cmor less.SOLUTION: There is provided a low α-ray bismuth having a Pb content of 0.1 ppm or less, a content of each of U and Th of 5 ppb or less and an α-ray emission of 0.005 cph/cmor less. There is provided a method for producing a low α-ray bismuth by preparing a bismuth nitrate solution having a bismuth concentration of 5 to 50 g/L and a pH of 0.0 to 0.4 by electrolysis using bismuth having an α-ray emission of 0.2 cph/cmor less as a raw material, adding an adsorbent to the solution to adsorb polonium, filtering the resulting solution to separate into the adsorbent and a filtrate and electrolytically extracting the filtrate to recover bismuth.SELECTED DRAWING: Figure 2 |
