Bao P Y
Department of Chemistry, Guizhou University, Guiyang 550025, China.
Guang Pu Xue Yu Guang Pu Fen Xi. 2001 Oct;21(5):630-1.
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.
磷渣是磷矿石冶炼后废弃的炉渣。为了环境保护和综合利用，必须准确测定炉渣中放射性元素的含量和比活度。本文讨论了如何利用红外光谱和X射线衍射方法研究其成分。其主要相组成为玻璃态炉渣。样品用氢氟酸 - 硝酸 - 高氯酸分解。经过阴离子交换分离后，用偶氮胂III测定炉渣中铀和钍的含量。铀的平均含量为32.11微克·克⁻¹，钍为8.5微克·克⁻¹。用γ能谱测定其中放射性核素的比活度。镭 - 226、钍 - 232和钾 - 40的比活度分别为112±2.0贝可·千克⁻¹、18.8±6.4贝可·千克⁻¹和77.6±3.7贝可·千克⁻¹。这些值按以下方式计算：M(Ra)=0.6贝可·千克⁻¹，Mγ = 0.5贝可·千克⁻¹。结果表明，这些值低于国家GB6566 - 86建筑材料放射性标准规定的1.0贝可·千克⁻¹。因此，该炉渣可用于生产矿渣水泥。这为其处理提供了理论依据。
