الفهرس 
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Abstract
aving in consideration the abundance and low price of bentonitic clays and their physical and chemical characteristics, they are materials to be in consideration for an efficient application in several industries and environmental remediation. The present thesis deals with detailed mineralogy, geochemistry and physico-chemical analyses of the surface and subsurface bentonitic clays of the Lower Miocene (Moghra Formation) of south west of El Alamein, Western Desert Egypt. It also, concerned with the appropriateness of the studied bentonitic clay for refining cottonseed oil and heavy metal removal from the effluents. Detailed isopach map for the bentonitic clay was constructed a scale of 1: 2000, covering an area of 0.25 Km . Four tranches and nine boreholes were measured and sampled throughout the studied area. Fourteen samples were mechanically analyzed for particle size distribution. The result shows that the studied bentonitic clays are mainly claystone proper except sample was hesitant between silty and sandy claystone. X-ray diffraction (XRD), derivatographic analyses (DTA, DTG and T.G) and scanning electron microscope revealed that smectite is the major clay minerals of the studied bentonitic clay followed by kaolinite, while illite is of subordinate. Also, small amount of quartz, are present in the investigated samples as non-clay minerals. The opinion of smectite neoformation is not recommended whereas the results of the x-ray analysis shows that mixed-layer (I/S) is nearly absent that suggesting smectite in the studied samples is of the Cheto - type. The conditions under which smectite is formed are not favorable for the formation of kaolinite. This suggests that these two minerals were inherited from different source rocks. Geochemically, the average silica content is 57.15% and the average alumina oxide is 17.59%. The SiO2/Al2O3 ratio is about 3.4; this value is slightly high with regards to the bentonite classic value of 2.7 due to the prevailed of basic environment. The high iron content recorded in some samples is attributed to iron may substitute alumina in the octahedral coordination of the clay structures. The positive correlations between Al2O3 % in one side and MgO and CaO% in the other side indicate that magnesium and calcium ions are the exchangeable cations in spite of the fact that Na—montmorillonite is a minor constituent. Acid activation modified the smectite chemistry, as is evident from the changes in chemical composition. Acid activation causes dramatic changes at the edges of smectite platelets, thereby increasing the surface area of the materials. The studied samples revealed that Acid activation modified the material with greater silica content and a significant lower abundance of oxides in the octahedral sheet. Also it reflects a progressive decrease in cation exchange capacity (CEC). The non activated and pillared sample (PN0) show no evidence of crystalline impurities and each tracing show a well-defined and intense first-order peak as revealed from XRD. However, the acid activated and pillared samples (PN2, PN3 and PN4) show small shifts of the (001) reflection indicating that the network of the pillars is influenced slightly by the degradation of the layer periodicity, probably from the acid-activation process before pillaring. Acid concentration affects the amount of the incorporated alumina by pillaring. The alumina pillars supports the adjacent silicate layers apart, increasing the interlayer spacing and enhancing micro-porosity. Among the acid activated -pillared smectite, the the 4 normal acid activated and pillared (PN4) material.