活性炭盒法测定矿井氡采样方法的初步研究

Preliminary study on radon sampling method in mine by activated carbon box

目的本文研究了活性炭盒法测氡采样过程在炭盒吸附面增设滤膜、改变吸附面朝向等因素对测量结果的影响,为该方法应用于矿井高湿、高粉尘环境氡浓度检测提供技术支持。方法按照实验方案布置活性炭盒,到吸附时间后盖上密封盖称重,放置5 h后用HD-2001型低本底γ能谱仪测试氡浓度。用RAD7氡浓度检测仪同步检测测试间氡浓度,以便于对测量结果进行比较。结果活性炭盒吸附面朝上或朝下测得空气中氡浓度分别为(227.2±3.0)Bq/m3、(229.8±3.7)Bq/m3,两种放置方式测量结果相对偏差仅为1.1%。在活性炭盒吸附面增加定量滤纸或HI-Q型积尘滤膜后测得空气中氡浓度分别为(224.3±3.0)Bq/m3、(231.8±3.0)Bq/m3,与无滤膜时的测量结果相对偏差分别为-1.3%和2.0%。在相对湿度89.5%的环境下,活性炭盒法测得空气中氡浓度在221.5~238.1 Bq/m3之间,相同条件下RAD-7测氡仪测量结果为243 Bq/m3,两种检测方法测量结果相对偏差仅为-6.1%。结论本次测试条件下,采样时在活性炭盒吸附面增加定量滤纸或HI-Q型积尘滤膜并将活性炭盒吸附面朝下放置,对测量结果无显著影响。该采样方法可避免由于采矿作业场所粉尘、矿渣等杂质落入活性炭盒影响检测结果。

Objective In this paper, the influence of factors such as adding filter membrane on the adsorption surface of the carbon box and changing the direction of the adsorption surface in the radon sampling process of the activated carbon box method on the measurement results was studied. It provides technical support for the application of this method to the detection of radon concentration in high humidity and high dust environments in mines. Methods Arranged the activated carbon box according to the experimental scheme. After the adsorption time, put on a sealed lid and weighed it. After 5 hours, used the HD-2001 low background gamma spectrometer to test the radon concentration. In order to compare the measurement results, RAD7 radon concentration detector was used to measure the radon concentration in the test room synchronously.Results Radon concentrations in the air measured with the adsorption surface of the activated carbon box up or down were(227.2 ± 3.0) Bq/m^3 and(229.8 ± 3.7) Bq/m^3 respectively. The relative deviation of the measurement results of the two placement methods was only 1.1%. The radon concentrations in the air were(224.3 ± 3.0) Bq/m^3 and(231.8 ± 3.0) Bq/m^3 respectively after quantitative filter paper or Hi-Q dust accumulation filter membrane added on the adsorption surface of the activated carbon box. The relative deviation between the measured results with and those without filter membrane were-1.3%and 2.0%, respectively. At 89.5% ambient humidity, the radon concentrations in the air measured by the active carbon box were between 221.5 Bq/m^3 and 238.1 Bq/m^3. Under the same condition, the radon concentration measured by the RAD-7 instrument was 243 Bq/m^3, and the relative deviation between the two methods was only-6.1%. Conclusion Under this test condition, a quantitative filter paper or hi-q dust filter membrane was added to the adsorption surface of the activated carbon box during sampling, and the adsorption surface of the activated carbon box was placed downward, which had no significant effect on the measurement results. This sampling method can avoid the dust, slag and other impurities in the mine falling into the activated carbon box and affecting the measurement results.