伴生尾矿库矿井涌水中总α的测量

Measurement of Total α in Mine Water Inflow of Associated Tailings Pond

本研究采用厚源法测定伴生尾矿库矿井涌水中总α放射性,为保证仪器的稳定性对仪器的甄别阈值和工作高压进行最佳工作条件调节,并在国标基础上改用与伴生矿矿井涌水总α贡献率高的天然铀进行探测效率标准源试验,使标准源与样品的基体和总α贡献核素的能量接近一致,绘制拟合的质量厚度-效率刻度曲线不局限于特定某一质量厚度,此方法可运用于不同含盐量的矿井涌水检测。结果表明,该方法探测下限为0.012 Bq/L。选取低、中、高三种浓度的矿井涌水进行6次平行测定,最大相对偏差为26.2%,小于国标方法精密度要求30%,进行加标回收率实验,回收率在98.8%~120%之间,满足一般化学分析的准确度范围要求。故本方法可用于伴生尾矿库矿井涌水中总α的测量。

The thick source method is used to determine the total content of the mine water in the associated tailings pond α Radioactivity,in order to ensure the stability of the instrument,the screening threshold and working high pressure of the instrument are adjusted under the best working conditions,and the total water inflow of the associated mine is used on the basis of the national standard α The natural uranium with high contribution rate shall be subject to the detection efficiency standard source test,so as to make the standard source and the sample matrix and total α The energy of the contributing nuclides is close to the same.The fitted mass thickness-efficiency scale curve is not limited to a specific mass thickness,and can be applied to mine water inrush with different salt content.The results show that the detection limit of this method is 0.012 Bq/L.Six parallel determinations of mine water with low,medium and high concentrations were carried out.The maximum relative deviation was 26.2%,which was less than 30% of the precision requirement of the national standard method.The recovery rate of spiked water was 79.6%~120%,which met the accuracy range requirements of general chemical analysis.Therefore,this method can be applied to the total α Measurement.