Investigation of morphological and mineralogy characteristics of dust around the lead and zinc mine in Mehdiabad, Yazd, Iran, using the SEM and XRD analyzes

Dust created by mining activities is one of the most important concerns regarding human health and the environment protection. This is due to the fact that dust particles have a high potential to carry heavy metals or they can produce a dangerous contaminant when combined with a special mineralogy or morphology. The aim of this study was to identify the mineralogical and morphological characteristics of dust particles found around the lead and zinc mine of Mehdiabad.

First of all, dust samples were collected around the mine by installing 8 passive marble dust collectors using a combined systematic random method during February, March and April in 2020. Then, using two methods of X-ray diffraction (XRD) and scanning electron microscopy (SEM) mineralogy, shape and distribution of the particles of dust samples were investigated.

The highest frequency of particles with sizes less than 10, 10-60, and 60-100 microns were determined and observed in S1 station in the northwest, and S5 and S2 stations in the southwest of the mine, respectively. The results of SEM analysis revealed that the appearance of dust particles is mostly spherical, irregular, elongated, prismatic, and rhombic. The results of XRD analysis showed that the minerals anorthite (Ca (Al2Si2O8)), dolomite (Ca Mg (CO3)2), albite (NaAlSi3O8), calcite (CaCO3), quartz (SiO2) and muscovite (KAl2 (Si3AlO10)) (OH2) have the highest frequency in dust samples.

The findings show that the predominant mineralogical composition of dust particles includes carbonates (dominant mineral: calcite) and silicates (dominant mineral: quartz) which are found in all stations. Thus, dust particles, with high frequency of quartz, have a high potential to result in respiratory diseases in the inhabitants living around the mine.