An investigation of chemical compositions, mineralogy, morphology and concentration measurement of diffused aerosols in digging tunnels of underground uranium mine in Saghand area

Electron microscopy studies (EPMA- WDS and SEM- EDS) provided detailed information about the morphology, source, transport, diffusion, properties, transformation reactions and environmental impacts of aerosol particles in digging tunnels of underground uranium mine in Saghand area. The size, aspect ratio and chemical composition of particles were studied by SEM-EDS but the mineralogical phase compositions of the particles were investigated by EPMA. EPMA analysis indicated that particulate matters (PM) were mainly composed of irregularly shaped mineral particles. Analysis of 46 individual particles showed that all particles were mineral aggregates and some of them contained sulfur. The X-ray diffraction (XRD) analysis showed that the main minerals were clay minerals, iron oxides, amorphous materials, quartz, calcite, pyrite and hornblende. Clay minerals were to the greatest illite/smectite mixed layers and kaolinite and chlorite as secondary elements. The particulate matters collected during the drilling episodes were characterized by high quartz/clay ratio and dominance of illite/smectite mixed layers in clay minerals. The concentration ofdusts in different parts of digging tunnels, in poorly ventilated parts of the mine was below the OSHA standard. The existence of aerosols of uranium minerals plus quartz indicated that the personnel of the mine were exposed to serious health hazards unless they were equipped with suitable environmental filters.