G. Jozanikohan; M. Nosrati Abarghooei; H. Sedighi
Abstract
The most extensive Iranian coal-bearing basin is located in an area of 30000 km2, situated approximately 75 km from the Tabas county, south Khorasan Province, Iran. In this work, the Tabas coal ash is studied and investigated for the purpose of determination of the rare earth elements (REE) content, ...
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The most extensive Iranian coal-bearing basin is located in an area of 30000 km2, situated approximately 75 km from the Tabas county, south Khorasan Province, Iran. In this work, the Tabas coal ash is studied and investigated for the purpose of determination of the rare earth elements (REE) content, and the identification of the distribution patterns of trace elements. The elemental and phase analysis experiments were conducted using the X-ray diffraction (XRD), inductively-coupled plasma spectroscopy (ICP-MS), wet chemical analysis, and field emission scanning electron microscopy equipped with energy dispersive X-ray spectroscopy (FE-SEM/EDS) techniques. The XRD results showed that the phases in the Tabas coal ash were quartz, clay minerals, alkali feldspar, magnetite, and pyrite in order of abundance. The elemental analysis showed that the major elements were Si, Al, K, Fe, Mg, S, and Na, which was in good accordance with the chemical composition of the recognized minerals by the XRD method. The concentration of REEs was varied from 0.10 ppm (for Tm) to 68.48 ppm (for Ce), with an arithmetic mean of 14.19 ppm. The abundance of 16 REE elements was or even below the average of the earth crust abundances. Only one rare earth element (Samarium) was about 4.4 and 2.2 times more abundant than in the earth crust and in the world coking coal ashes. In order to further assess the occurrence states of REEs in each of detected mineral, the Fe-SEM/EDX method was used. The SEM/EDS analysis showed that REEs were mainly concentrated in the clay minerals.
Exploitation
S. Barak; A. Bahroudi; G. Jozanikohan
Abstract
The purpose of mineral exploration is to find ore deposits. The main aim of this work is to use the fuzzy inference system to integrate the exploration layers including the geological, remote sensing, geochemical, and magnetic data. The studied area was the porphyry copper deposit of the Kahang area ...
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The purpose of mineral exploration is to find ore deposits. The main aim of this work is to use the fuzzy inference system to integrate the exploration layers including the geological, remote sensing, geochemical, and magnetic data. The studied area was the porphyry copper deposit of the Kahang area in the preliminary stage of exploration. Overlaying of rock units and tectonic layers were used to prepare the geological layer. ASTER images were used for the purpose of recognition of the alterations. The processes used for preparation of the alteration layer were the image-based methods including RGB, band ratio, and principal component analysis as well as the spectrum-based methods including spectral angel mapper and spectral feature fitting. In order to prepare the geochemical layer, the multivariate statistical methods such as the Pearson correlation matrix and cluster analysis were applied on the data, which showed that both copper and molybdenum were the most effective elements of mineralization. Application of the concentration-number multi-fractal modeling was used for geochemical anomaly separation, and finally, the geochemical layer was obtained by the overlaying of two prepared layers of copper and molybdenum. In order to prepare the magnetics layer, the analytical signal map of the magnetometry data was selected. Finally, the FIS integration was applied on the layers. Ultimately, the mineral potential map was obtained and compared with the 33 drilled boreholes in the studied area. The accuracy of the model was validated upon achieving the 70.6% agreement percentage between the model results and true data from the boreholes, and consequently, the appropriate areas were suggested for the subsequent drilling.
