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Five typical bauxite samples from three ore deposits from the wider area of Grebnik Mt. (Metohija, Serbia) were examined with the optical microscopic, X-ray powder diffraction (XRPD) and chemical methods. The occurrences in bauxites were studied and described and the presence of major minerals was determined: diaspore, boehmite and hematite; minor minerals: quartz, goethite, rutile, kaolinite and hydro-hematite; as well as anatase, brookite, magnetite and chromite, which occur only sporadically. According to the quantity of main Al-bearers, three types of bauxite ore were recognized: diaspore, boehmite and boehmite-diaspore. Unit cell dimensions of major minerals were determined, mostly with values within reference data. However, all of the studied hematites have smaller a 0 and V 0 values, most probably due to the substitution of Fe 3+ by Al 3+. All samples are further classi ied as iron-rich and ferritic bauxites. It was found that there were changes in origin conditions between major Al-hydroxides minerals and hematite, as well as between the diaspore and boehmite. Determined chemical compositions put this raw material into high-quality raw materials for obtaining the electro corundum and alumina. The synthesis of the obtained data indicate that Grebnik's bauxites have some unique characteristics, more or less different from most of the World's known bauxite ore deposits.

Content of potentially toxic elements was examined in soils from Srem (Vojvodina), to evaluate industrial facilities as pollution sources. Based on the distribution of the elements, the results of sequential extraction, enrichment factor (EF), ecological risk factor (Er), ecological risk index (RI), and statistical analysis, the current ecological status of the soils was determined. Elements in soils around the industrial facilities can be grouped into the five significant components derived by the principal component analysis (PCA), which explains 78.435% of the total variance. Al, Fe and Mg, and K and Mn are associated with two lithogenic components, respectively. Anthropogenic origin is identified for Hg and Cd. Mixed sources, geogenic and anthropogenic, are identified within two PCA components; one wich includes As, Pb, B, Zn, and the other: K and Cr, Ni and Cu. Cluster analysis (CA) corroborated the results obtained by PCA. The preliminary results revealed that the soils studied in a vicinity of industrial facilities in Srem have been exposed to different degrees of pollution. Among the characterized studied elements, Pb, Cd, Hg, Cu, Ni, and Cr are the main contaminants. Based on calculated EF, the studied soils show minor to severe enrichment with heavy metals. Ecological risk assessment results indicate that Cd and Hg carry the highest ecological risk level, and Zn and Cr the lowest.

In this paper, particular attention was paid to the presence of aerosol solid particles, which occurred mainly as a result of exploitation and coal combustion in the thermal power plants of the Kolubara basin. Not all of the particles created by this type of anthropogenic pollution have an equal impact on human health, but it largely depends on their size and shape. The mineralogical composition and particle size distribution in the samples of aero sediments were defined. The samples were collected close to the power plant and open pit coal mine, in the winter and summer period during the year 2007. The sampling was performed by using precipitators placed in eight locations within the territory of the Lazarevac municipality. In order to characterize the sedimentary particles, several methods were applied: microscopy, SEM-EDX and X-ray powder diffraction. The concentration of aero sediments was also determined during the test period. Variety in the mineralogical composition and particle size depends on the position of the measuring sites, geology of the locations, the annual period of collecting as well as possible interactions. By applying the mentioned methods, the presence of inhalational and respiratory particles variously distributed in the winter and in the summer period was established. The most common minerals are quartz and feldspar. The presence of gypsum, clay minerals, calcite and dolomite as secondary minerals was determined, as well as the participation of organic and inorganic amorphic matter. The presence of quartz as a toxic mineral has a particular impact on human health.

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