我国南方某铀矿井下典型工作场所气溶胶浓度分布特征调查

Investigation of the distributive status in-situ of the aerosol concentrations in typical working face under the uranium mine in China South

为了解我国铀矿井下典型工作场所内气溶胶粒子浓度及粒径分布特征,采用APS3321对我国南方某生产地下铀矿井典型场所内气溶胶粒子个数浓度和质量浓度进行了监测,得到了各监测点的PM2.5及PM10质量浓度,并分析了不同监测场所的气溶胶粒子个数浓度和质量浓度分布规律。结果表明:1)在机械通风条件下,风机房的气溶胶粒子个数浓度谱为双峰谱,南风机房与北风机房气溶胶个数浓度谱主峰在0.626μm左右出现(位于积聚模态区),次峰在4.698μm左右出现(位于粗粒子模态区);其他监测场所的气溶胶粒子个数浓度谱为单峰谱,峰值在0.626μm左右出现(位于积聚模态区);2)不同监测场所的气溶胶粒子个数浓度中位直径和质量浓度中位直径不同,其中气溶胶粒子个数浓度中位直径的均值主要分布在积聚模态区,质量浓度中位直径的均值分布在粗粒子模态区;3)部分监测场所的PM2.5与PM10质量浓度较大,超过了国家对大气环境的质量浓度限值。PM2.5与PM10的质量浓度比值代表了PM2.5占PM10的比例,在所监测的场所中,采场、风机房、物探站和坑口的PM2.5与PM10的质量浓度均值比小于50%,其中风机房的比值最小,约为4.8%;中段运输巷道、独头巷道和中段信号房的PM2.5与PM10的质量浓度均值比大于50%,其中独头巷道的比值最大,高达78.2%。

This paper aims to present the investigation results of the distribution of the aerosol concentrations in the typical working faces under the uranium mine in southern China by using a software known as the APS 3321. The measured results help us to obtain the mass concentrations of PM2. 5,PM10 in the monitored sites,and,then,we have analyzed the distributions of aerosol particles in the place with the number concentration and mass concentration in the different points of the working face. The final analysis results demonstrate that：（ 1） Under the condition of mechanical ventilation,the spectral distribution of the aerosol particle number concentrations in the fan-placed rooms tend to be double-impacted with. What is more,the main peak values of the southern and northern fan rooms account for about 0. 626 μm（ the peaks are mainly located at the accumulation mode） whereas their secondary peak values are located at about 4. 698 μm（ peaks mainly locating at Coarse mode）. In addition,the spectral distribution of the aerosol particle number concentrations in other points is single-peaked,whose peak values are at about 0. 626μm（ peaks mainly located at the accumulation mode）.（ 2） The median diameters of the number concentrations and the median diameters of mass concentrations are not the same among different monitored sites. The average median diameters of number concentrations are mainly located at the accumulation mode,with the average diameter of mass concentrations mainly are located at Coarse mode.（ 3） The mass concentrations of PM2. 5and PM10 under monitoring and control in some places are high,that is to say,their mass concentrations exceed the national standard limit in the air control. Actually,the mass concentrations＇ ratio between PM2. 5and PM10 accounts for the ratio of PM2. 5to PM10 in the aerosol particles in the places,such as in the fan rooms,the geophysics station and the pithead,whose average mass concentrations ratios tend to be just 50% as much as that in the stope,among which the fan rooms may have only its lowest ratio about 4. 8%. And,the places where the ratio of average mass concentrations between PM2. 5and PM10 are likely to be higher than 50% are the lateral intermediate transport station,the dead-end tunnel,the intermediate signal-delivery room and the pithead, among which the dead-end tunnel may have the highest ratio of about 78. 2%.