岩(矿)心放射性伽玛顺检铅套法与常规法

Comparison of the Common Lead Dating Method with the Lead-casing Dating Method of Detecting Radioactive Gamma for Rock or Ore Cores

辐射仪在标定时要带上铅套,放射性伽玛顺检之铅套方法和常规方法的区别是前者在测量时辐射仪要带上铅套,在龙岩市东宫下高岭土西矿段补勘岩(矿)心放射性伽玛顺检中铅套法和常规法的测量成果对比非常显著,即铅套法测量伽玛值偏低,异常下限也偏低,伽玛曲线平直;常规法测量伽玛值偏高,异常下限也偏高,伽玛曲线起伏变化较大,这些差别是因为常规方法测量受到散射射线,尤其是近旁岩(矿)心伽玛射线影响所致。但是,铅套法因其伽玛值偏小,致使听测时可能会漏掉狭缝里的伽玛偏高场或异常,这是铅套法的不足之处。为此,提出了在岩(矿)心或工程放射性伽玛顺检时铅套法和常规法结合使用的建议。

The lead casing must be put into the radiation meter during the standardization. The difference between the common lead dating method and the lead-casting dating method of detecting in sequence radioactive gamma is that the latter has to carry around a lead casing in a measurement. The measurement results obtained by the two dating methods from the rock and ore cores of the Longyan Donggongxia Kaolin Deposit are quite different, namely the gamma values by the lead-casting dating method are on the low side, their anomaly threshold is lower and the gamma curves show flat. And the gamma values by the common lead dating method are on the high side, their anomaly threshold is higher and the gamma curves show more mutative. By using the common lead dating method the difference results from the scattered gamma ray, particularly from the gamma ray around the rock or ore cores. But the lead-casting dating method has some deficiency because of the lower gamma values, so that during the measurement it maybe miss out more gamma highfield or anomaly in the slits. Therefore, it puts forward some suggestion about using together the lead-casing dating method and common lead dating method during detecting in sequence the radioactive gamma in rock and ore cores or engineering projects.