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Boboluyieh bauxi te-laterite deposit of south-cast
Kemlan is presented at the base of the Naiband Formation
(upper Triassic) and was directly formed on a Karstic surface
of dolomitic parts of the Shotori Formation. This dcposit has
a reserve of 15 mill ion lonnes. Diaspore, boehmite, chlorite,
hematite, goethite, kaolinite, anatase and rutile arc the major
minerals in this deposit. The common texture of tbis unit is
oolitic to pisolitic. The presence of some volcanic rock
fragments with pi lotaxitic texture as well as bipyramid
pseudol11orphic shape of olivine and clinopy roxene gra ins
reveal thai the protolith of bauxites was probably a volvan;c
rock of basaltic type.
Geochemical studies indicate that Bolboluy ieh bauxite is
composed of40.37% AI20 3, 24.64% Fe20) and 13.92% Si02•
Based on the geochemical characteristics, Bolboluyieh
bauxi te is formed under condition of high silica leaching and
concomitant enrichment of aluminium and iron which
corrcsponds with pH between 4 to 8.5 and Eh of +0.4 to + I.

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Single crystals of Cd_.96Zn_.04Te (CZT) with 14 mm in diameter were grown by seedless modified Bridgman method. Also, crystals with the same chemical composition were grown by vapor phase inert gas-transport method (VPGT), and single crystals up to 3.5 mm in diameter were obtained. Structural studies by XRD and back reflection Laue method show that the grown crystals are single phase with high purity, which preferentially have been grown along [111] crystal axis. The energy gap of as-grown crystals is about 1.2 eV. The electrical properties measured by Van der Pauw method, show that the resistivity is in order of 10⁴ W.cm. The electrical conductivity of crystals grown by Bridman method is p-type, and for VPGT-crystals is n-type.

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In Khoy ophiolitic massif (NW of Iran) three types of quartzite and also quartz bearing veins can be distinguished: massive quartzite, quartz bearing veins in the amphibolites and siliceous veins in the radiolarian cherts. Massive quartzites contain quartz porphyroclasts associated with very   small- deformed quartz neoblasts. These quartzites are deformed in regime I and recrystallized as grains bulging. Siliceous veins in the cherts have       Cu-carbonate impregnations in the field. Very large grains of quartz with well-developed triple point junctions can be distinguished in thin section. Their pattern of c-axes distributions doesn’t show any special orientation.  The pattern of c-axes distributions in the quartz bearing veins in the amphibolites is consistent with prism and rhomb slip system along direction. Water in these veins is at the origin of soluble structures and precipitation of clay minerals. SEM analysis on the soluble fovea as the result of water operation has revealed high amount of water.

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The Jajarm Bauxite deposit 16 kilometers E-W trending and
overlis, the Karstic dolomite rocks of the Elika Formation. The study of
texture and different phases has been carry out in order to understand the
degree of crashing, particles size, condition of formation, degree of
crystallization, porosity, distribution of constituent elements and
beneficiation for the propose of digestion and potential of physical
beneficiation. The phase analysis indicates that the Jajarm Bauxite is typical
diasporic bauxite accompanied with Kaolinite, hematite and anatase. Hard
bauxite is the high quality bauxite with Al2O3>50% and SiO2 < 9%. Mineral
chemistry shows that out of 58% of Al2O3, 54.39% constituting diaspore
structure, 1.6% is in kaolinite and 0.94% in topaz. where as out of 5.78%
SiO2, 3.72% occurring in kaolinite structure, 1.5% as free and inactive quartz
and the rest of it is located in topaz structure. The Jajarm bauxite shows a
politomorphic, micro granular texture with several secondary textural
elements. The size of main minerals component are generally below 10
micron, with homogeneous matrix. Kaolinite minerals forms stacks of very
thin (<0.1 micron) crystal platelets. In addition, in a very hard bauxite,
separation between the crystal grains and the matrix can not be done because
of similar hardness for both with closely packed space filling and in
consequence of the missing defined borderlines of the grains. Based on the
above studies, the Jajarm bauxite can be enriched neither by grain analysis
nor by the magnetic separation. Laboratory study shows, only it can be
improve by water treatment.

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Shahid Nilchian (Dopelan) deposit, located in high mountains of Chahar-Mahal Bakhtiari Province within the Zagros Thrust structural unit, is one of the main bauxite and argillite deposits of Iran. Many highly folded and faulted sedimentary successions are cropped in the area. The bauxite of Shahid Nilchian deposit is of lateritic type and belongs to Permo-Triassic in age. Five bauxite types with different quality have been recognized in the area. Mineralogical investigations have carried out using thin and polished sections, XRD and XRF analysis. According to these studies, it is verified that the major minerals are diaspore and kaolinite. Anatase and boehmite has identified as minor minerals. Some other elements such as iron, zirconium and vanadium are also presented in different minerals. The main identified textures are brecciated and pisolitic. In its application as refractory material, minerals containing iron, silica and titanium are the important gangues of bauxite. The main objective of this mineralogical study is to identify the minerals of the above mentioned elements. It is concluded that kaolinite, anatase and different iron oxides are the main sources of these elements.

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In this research, the properties and characteristics of Biglar refractories bauxite mines have compared with two types of industrial China's and Iranian (Doplan super) refractory grade bauxite in order to use in refractory industries. At first, physical, chemical and thermal properties, phase and microstructural characteristics have been measured and sintered samples of Biglar Bauxite at different temperatures were analyzed and then were compared with China's and Doplan calcined bauxite properties. The results showed that the refractory bauxite minerals obtained from Iranian Biglar mines contains the proper amounts of alumina and other oxides. So it could be concluded that these properties are comparable to the China's and Doplan bauxite and this refractory grade bauxite is suitable for refractory industries for using in the production of many kinds of shaped and monolithic refractory product.

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Permian bauxite deposits in north of Saqqez occurred as stratiform lenses of carbonate within Ruteh Formation. Field evidence show that these deposits formed in swampy environment in which the water table was relatively high during their evolution. According to petrographic considerations, these deposits contain ooidic, pisoidic, spastoidic, nodular, skeletal, and spongy textures and have an authigenic origin. Based on mineralogical studies, these deposits are composed of minerals of diaspore, boehmite, corundum, hematite, goethite, magnetite, rutile, anatase, montmorillonite, quartz, illite, pyrophyllite, talc, nacrite, dickite, k-feldspar, muscovite, chlorite, chloritoid, plagioclase, pyroxene, amphibole, chamosite, gypsum, calcite, and fluorite. The presence of high quantities of silicate minerals indicates immaturity and poor draining system of these deposits. Comparison of the range of stability fields of major constituent minerals of the bauxite ores with the pH and Eh variations of natural environments show that  the surface waters with oxidizing-acidic nature and underground waters with reducing-basic nature played crucial roles in developing of these deposits. Combination of mineralogical and geochemical data of immobile elements indicate that Saqqez bauxite deposits were developed from alteration and weathering of basaltic-andesitic rocks.

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In this research, a thermodynamic model used to describe the growth of  single crystals by chemical vapor transport technique with iodine as the transporting agent. The optimum growth condition in the  system has been predicted theoretically based on partial of different components. Some experiments were carried out for growing  crystals by the chemical vapor transport method using iodine as a transporting agent in the closed ampoule under various conditions. The experimental results showed that the  single crystals, which have been grown with growth parameters close to the theoretically predicted optimum growth conditions, have better quality in comparison with crystals grown under other conditions.

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The Jajarm bauxite deposit is a part of the Irano-Hymalayan karst bauxite belt which is located about 175 km southwest of Bojnourd. This deposit has been developed as a stratiform horizon along the contact of Triassic dolomites and the Jurassic shales and sandstones. The basal contact zone of the bauxite horizon is mainly undulatory, and bauxite fills cavities in the footwall dolomite, whereas the upper contact zone is concordant with the hanging-wall shales and sandstones. Textural analysis indicates both allochthonous and autochtonous origins for the bauxites. Diaspore, bohemite, gibbsite, chamosite, hematite, goethite, clay minerals, anatase, cancrinite, crandallite, pyrite, and quartz were identified in the ore paragenesis. These minerals are developed during three stages of weathering, diagenetic and epigenetic processes. Combination of mineralogical and geochemical data show that this deposit formed during two main stages. First, bauxite materials, Fe and Ti oxides and clay minerals were developed as authigenic bauxitization processes of alkaline basaltic parent rock. During the second stage, these materials were transported to karst depressions, where they accumulated as a relatively thick bauxite horizon.

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The Alborz structural zone in northern Iran is the host of a number of bauxite deposits. The Gheshlagh bauxite deposit is one of them with more than 2 km long and a thickness of about 20 m in the eastern part of the Alborz structural zone. This deposit has been developed as a stratiform horizon along the contact zone of Permian limestones and Triassic dolomitic limestones. The basal contact zone of the bauxite horizon is mainly undulatory, whereas the upper contact zone is concordant with the hanging-wall dolomitic limestones. Based on mineralogical and textural evidences, the horizon can be divided from top to bottom into five distinct units: (1) upper bauxite unit with a thickness of about 5 m, is composed of boehmite, hematite, kaolinite, rutile and svanbergite, 2) upper kaolinite unit approximately 2-3 m thick and is composed mainly of clay minerals, 3) hard bauxite unit with a thickness of approximately 1.5 m, mainly consists of hematite, kaolinite, boehmite and diaspore, 4) lower kaolinite unit approximately 1-4 m thick and is composed of kaolinite, boehmite and diaspore, and 5) lower bauxite unit about 4-6 m thick. Textural analyses indicate both allochthonous and autochtonous origins for these deposits. Combination of geological, textural and mineralogical data of the Gheshlagh bauxite deposit correspond to a boehmitic-diasporic karst bauxite deposit type.     

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(Bi₂Te₃)_0.25(Sb₂Te₃)_0.75 solid solution is a p type thermoelectric compound with optimum efficiency among the (Bi₂Te₃)_x (Sb₂Te₃)_1-x compounds with variable x. Increment of Bi₂Te₃ segment in the Bi-Sb-Te system decrease in hole concentration, which result in carriers transport tuning, an increment of Seebeck coefficient and decrement of electrical and thermal conductivities. An excess of Tellurium up to 4wt% further elevates the thermoelectric efficiency (η), thus resulting in an increase in the figure of merit. Structural characterizations of this compound in the absence and presence of added Te were carried out by means of X-Ray diffraction measurement, electron backscattering diffraction and atomic force microscopy. Detailed analyses carriers transport behavior reveal the intrinsic structures formation and minimum defects during crystallization resulted in the excess of Te. The analysis show a maximum figure of merit at 3wt% excess Te.

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Micromorphological studies were carried out on the surfaces of the ZnS single crystals grown by chemical vapour transport (CVT). Different micromorphological patterns such as layers, steps, kinks, stripes and pits were observed using Scanning Electron Microscope. Formation of these patterns was correlated to the growth of crystals under theoretically predicted optimum and nonoptimum conditions.

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In this research, MASnICl₂ and FASnICl₂ thin layers were synthesized by the one-step spin coating method, and then their structural, optical and electrical properties were investigated. The study of these samples (structural properties) showed that the layers have a tetragonal structure (α- phase perovskite), and with the change of organic cation, the crystallinity and morphology of the layers significantly change. These changes also have influences in the optical and electrical properties of the samples. The perovskite layers have a high absorption coefficient (of the order of 10⁵ cm^-1) in the visible range. The bandgap for the FASnICl₂ layer was 1.48 eV and for the MASnICl₂ layer was 1.54 eV. A strong peak close to bandgap was observed in the room temperature PL of the layers, which was remarkably more intense for the FASnICl₂ sample. This study showed that the FASnICl₂ layers have better crystallinity, lower electrical resistance, higher optical sensitivity and acceptable optical response comparing the MASnICl₂ layers, and therefore, they can be suitable options for use as an adsorbent layer in perovskite solar cells.