放射性同位元素による鉱液比重測定

抄録

If the γ-rays radiated by radioisotopes are allowed to traverse any kind of material, they will cause mutual reaction such as photoelectric effect, Compton effect and pair production with this material and hence, pursuant to the following equation, they will be absorbed and will decrease and weaken in their intensity.
I=I₀e-μmpt
I: intensity of γ-rays passed through absorber I₀;intensity of incident γ-rays
μm: mass adsorption coefficient of a particular materia1
ρ: density of the material t: thickness of the material (absorber)
The writer planned to utilize the radioactive γ-rays radiatedby radioisotopes for undertaking continuous measurement of pulp density in flotation and also medium density in sink-float separation. Thus, various basic experiments were performed on numerous samples such as silica sand, ilmenite sand, copper bearing pyrite, galena and ferrosilicon by means of absorption method usingγ-rays radiated by Co⁶⁰.
The results of these experiments agreed completely with those obtained by the aforesaid theoretical calculation. Moreover, it was ascertained that by means of this method of determination, it would be quite possible to ascertain the density accurately to the extent of knowing the desired detection limits in actual operation, namely, the concentration ofore pulp (the solid percentage of pulp by weight) amounting to 2% in the case ofore pulp and the density of heavy medium totalling 0.025. We also succeeded in obtaining useful information and data on such items as the method of determination, measuring instruments and apparatus, and source of the γ-rays for use in actual operation.
As we are now continuously undertaking experiments on their application in actual operation basing on these, we are thinking of submitting a further report on them at a later date.