Exploration of Clays for Cement Production Using 2D Electrical Resistivity Imaging, and Mineralogical and Geochemical Evaluation in Bazyan and Takya Sites, Kurdistan Region, NE Iraq

Clay materials are widely used in the production of cement due to the presence of good amounts of silicon oxide (SiO2), aluminum oxide (Al2O3), and ferric oxide (Fe2O3) that play an effective role in mixing with limestone to make Portland cement. However, exploring for good specifications of clay has become an important requirement for cement factories in general and in particular in both Bazyan and Takya regions due to the existence of more than five factories producing millions of tons from Sinjar Formation annually. Therefore, two sites were selected: site 1 in the Bazyan area near Kani-Shaya village and site 2 near Takya district. A 2D Electrical Resistivity Imaging (ERI) is conducted using the Wenner-Schlumberger array to detect clay layers in the Quaternary Sediments. Mineralogical and Geochemical studies are carried out to determine the quality of the detected clay layers. Thirteen clay samples were collected from different locations and depths depending on the results of the 2D ERI by digging 9 trenches to a depth of 12 m as well some other samples were collected in clay layers that appeared on several vertical cliffs of 7 – 10 m high. In addition, the 2D ERI profile identifies a cliff of about 9 m in height on clay layers. Geochemical analysis was carried out on seven clay samples to determine the major and minor element proportions. Six samples were analyzed to determine the grain size and mineral composition by XRD. The results of the 2D ERI survey showed that there are large quantities of clay bodies in the Quaternary sediments at depths between 2 – 80 m with electrical resistivity ranging between 7 – 11 Ohm.m and the average thickness of the clay layer ranges between 5 – 45 m. The chemical composition analysis indicates the existence of a high ratio of silica, alumina, and iron oxide equal to 65.9 %, 11.66 %, and 4.4 % respectively in the Takya study area and equal to 33.58 – 37.63 %, 9.96 – 9.56 %, and 4.9 – 4.33 % respectively in the Bazyan study area. Grain size analysis shows that the majority is silt size, ranging from 48 to 58%, especially in the trenches, and then clay size ratio, ranging from 36 to 47%. The sand size in both study areas has the lowest ratio, ranging from 4% to 6%. The result is represented by silty clay and silty clay loam, according to the USDA diagram. Eventually, the mineralogical study indicates that the major portion of clay samples is montmorillonite, the minor portions are palygorskite and kaolinite, and the non-clay minerals include quartz, feldspar, and calcite. The result of the integrated studies is the detection of thick clay layers with optimal quality that can be used for several years as a raw material for the cement industry.