光谱和能谱法测定磷矿渣中放射性元素的含量和比活度

本文用红外光谱和X－射线衍射法研究了磷矿渣的基本成分，其主要相组成为玻璃体。用偶氮胂Ⅲ光度法测定了矿渣中铀和钍的含量，并用γ谱测定了放射性核素^226Ra,^232Th和^40K的比活度，为了解磷矿渣对环境的污染程度及其综合利用提供理论依据。

Determination of Content and Specific Activity of Radioactive Elements in Phosphate Slag by Spectral and Energy Spectrum Analysis

Phosphate slag is the slag discarded after phosphate ore is smelted. The content and specific activity of radioactive elements in slag must be determined accurately for environmental protection and comprehensive utilization. This paper discusses how IR spectrum and X-ray diffraction method are used to study its components. The main phase composition is glassy slag. The samples are decomposed with HF-HNO3-HClO4. After anion-exchange separation, arsenazo III is used to determine the content of uranium and thorium in slag. The average content of U is 32.11 micrograms.g-1 and 8.5 micrograms.g-1 for Th. gamma spectrum is used to determine the specific activity of radioactive nuclear elements in it. The specific activities of 226Ra, 232Th and 40K are 112 +/- 2.0% Bq.kg-1, 18.8 +/- 6.4% Bq.kg-1 and 77.6 +/- 3.7% Bq.kg-1, respectively. The values are calculated as follow: M(Ra) = 0.6 Bq.kg-1, M gamma = 0.5 Bq.kg-1. The results show that the values are below 1.0 Bq.kg-1, which is stipulated by national GB6566-86 standard for radioactivity of building materials. The slag is therefore can be utilized to produce slag cement. This provides theoretical basis for the treatment of it.