Minerals Ilmenite Research Articles

The Petrology of the Tarosero Volcanic Complex: Constraints on the Formation of Extrusive Agpaitic Rocks

Abstract The Quaternary Tarosero volcano is situated in the East African Rift of northern Tanzania and mainly consists of trachyte lavas and some trachytic tuffs. In addition, there are minor occurrences of extrusive basalts, andesites and latites, as well as peralkaline trachytes, olivine trachytes and phonolites. Some of the peralkaline phonolites contain interstitial eudialyte, making Tarosero one of the few known occurrences for extrusive agpaitic rocks. This study investigates the genetic relationships between the various rock types and focuses on the peculiar formation conditions of the extrusive agpaitic rocks using a combination of whole-rock geochemistry, mineral chemistry, petrography, thermodynamic calculations, and major and trace element modelling. The Tarosero rocks formed at redox conditions around or below the fayalite–magnetite–quartz buffer (FMQ). During multi-level magmatic fractionation at depths between ∼40 km and the shallow crust, temperature decreased from >1100 °C at near-liquidus conditions in the basalts to ∼700 °C in the peralkaline residue. Fractional crystallization models and trace element characteristics do not indicate a simple genetic relationship between the trachytes and the other rock types at Tarosero. However, the genetic relationships between the primitive basalts and the intermediate latites can be explained by high-pressure fractional crystallization of olivine + clinopyroxene + magnetite + plagioclase + apatite. Further fractionation of these mineral phases in addition to amphibole and minor ilmenite led to the evolution towards the peralkaline trachytes and phonolites. The eudialyte-bearing varieties of the peralkaline phonolites required additional low-pressure fractionation of alkali feldspar and minor magnetite, amphibole and apatite. In contrast to the peralkaline trachytes and phonolites, the peralkaline olivine trachytes contain olivine instead of amphibole, thus indicating a magma evolution at even lower pressure conditions. They can be modelled as a derivation from the latites by fractional crystallization of plagioclase, clinopyroxene, magnetite and olivine. In general, agpaitic magmas evolve under closed-system conditions, which impede the escape of volatile phases. In the case of the extrusive agpaitic rocks at Tarosero, the early exsolution of fluids and halogens was prevented by a low water activity. This resulted in high concentrations of rare earth elements (REE) and other high field strength elements (HFSE) and the formation of eudialyte in the most evolved peralkaline phonolites. Within the peralkaline rock suite, the peralkaline olivine trachytes contain the lowest HFSE and REE concentrations, consistent with mineralogical evidence for formation at a relatively high water activity. The lack of amphibole fractionation, which can act as a water buffer of the melt, as well as the evolution at relatively low-pressure conditions caused the early exsolution of fluids and loss of water-soluble elements. This prevented a strong enrichment of HFSE and REE before the magma was finally extruded.

A Comprehensive Investigation alongwith the Statistical Evaluation for the Characterization of Ilmenite Mineral by X‐ray Fluorescence Spectrometry and Optical Emission Spectrometry

AbstractA comparative investigation on characterization of ilmenite manuscript was performed by energy dispersive X‐ray fluorescence spectrometry (EDXRF) and carrier distillation direct current arc atomic emission spectrometry (D.C. Arc AES) along with the statistical evaluation of the data obtained. 5 % AgCl was used as carrier in AES to avoid spectral interference arising out of the emission rich matrix elements. An exercise was performed to evaluate the total uncertainty associated with the methodology for characterization of base reference materials. The developed methodologies were validated using synthetic samples. ∼30 % Fe and ∼35 % Ti as major elements alongwith Ca, Mg, Cr, Si, Al, Ni, Mn, V, Zr, Eu, Mo, Na and Cd as minor and trace level were reported in real ilmenite samples. Student t test was performed at 95 % confidence limit with 10 degrees of freedom revealed that the null hypothesis persisted, i. e. the data obtained by both the methods are reliable and within the limit of statistical fluctuation. The F test on variance revealed that all the variance estimated for all the analytes were less than the critical value (Fc=2.98) and hence the variance is also within the statistical fluctuation

Alteration and paragenesis of the basalt-hosted Au deposits, southwestern Guizhou Province, China: Implications for ore genesis and exploration

Carlin-type Au deposits are dominantly hosted in sedimentary rocks. Recent exploration has identified two deposits (Jiadi and Damaidi) hosted in the Emeishan basalt in southwestern Guizhou Province, China, that contain Carlin-type mineralization. In this study, ore and alteration minerals from the two deposits were examined, mineral parageneses were established through detailed petrography, whole-rock chemistry and mineralogical studies, and results were compared with the sediment-hosted Carlin-type Au deposits.In both deposits, pre-ore stage minerals are mainly igneous minerals in basalt, including orthopyroxene, clinopyroxene, plagioclase, magnetite, and minor ilmenite and apatite. These minerals formed during the eruption and formation of the Emeishan Large Igneous Province. The Au ore-stage mineral assemblage consists of arsenian pyrite, arsenopyrite, illite, jasperoid quartz, (Fe)-dolomite (locally Ca-Mg-siderite), rutile, and apatite. This transition indicates that pre-ore basalt was altered to minerals that characterize Carlin-type ore.Electron probe microanalysis and laser ablation-inductively coupled plasma-mass spectrometry analyses show that the arsenian pyrite and arsenopyrite contain ~457 ppm and ~556 ppm Au, respectively, and are enriched in As, Cu, Sb, Hg, and Tl. Gold is ionically bound in the disseminated arsenian pyrite and arsenopyrite which formed during sulfidation. During the late-ore stage, open space-filling realgar, calcite, quartz, stibnite, and orpiment precipitated as the hydrothermal system cooled and collapsed. Post-ore stage minerals include hematite and chlorite, reflecting post-ore oxidation.Comparison studies indicate the two deposits share remarkable similarities to the Guizhou sediment-hosted Carlin-type Au deposits. The basalt-hosted and sediment-hosted Au deposits in Dian-Qian-Gui area formed in response to the same widespread metallogenic event. This study confirms that basalt can host Carlin-type Au mineralization. Future exploration for Carlin-type Au deposits in Dian-Qian-Gui area can be expanded into regions dominated by basalt, especially the anticlines above the unconformity between the Maokou limestone and Emeishan basalt.

Synthesis of a Novel Composite Hydrous Titanium Oxide- Hydroxyapatite for Adsorbing Uranium from Waste Effluents

In this paper; a novel composite (HAP@HTO)derived from hydrous titanium oxide (HTO) extracted from Rosetta ilmenite mineral and hydroxyapatite (HAP) was formed by co-precipitation method,specified and used for uranium preconcentration from its solutions. Batch tests were performed to investigate its selectivity towards uranium; maximum adsorption efficiency reached at pH 2.5, 120 minutes contact time, 900 mg L–1 uranium concentration and adsorbent ratio (0.1g/75 mL). The equilibrium data fitted well with Langmuir adsorption isotherm. From Kinetics and thermodynamics data; process was fast, fitted well with pseudo-second order, spontaneous and exothermic. The percentage desorption of uranium reached its maximal at 15 minutes equilibrium time using 1 mol L-1 H2SO4. Thereby, (HAP@HTO)composite has promising potential applications in extracting U (VI) from its aqueous solutions in nuclear fuel field and environmental pollution cleanup.

Combustion Synthesis of TiC Powders from Ilmenite Mineral and Activated Carbon

Titanium carbide (TiC) powder was combustion-synthesized in argon from mineral ilmenite and activated carbon (C) using magnesium (Mg) as a fuel. The reactant powders were taken at FeTiO3 : C : Mg molar ratios of 1 : 1 : 3 and 1 : 1.5 : 4.5. The as-combusted products were leached with 1 M HCl at 80 or 90°C to remove byproducts and impurities. Best results (fewer impurities) were obtained for combustion products derived from FeTiO3 : C : Mg green mixtures taken at a molar ratio of 1 : 1.5 : 4.5 and subjected to acid leaching at 90°C for 150 min. After leaching, agglomerated TiC particles have a size of around 100 nm. Ilmenite mineral can be recommended as an alternative source of TiO2 for fabrication of titanium carbide powders.

Assessment of the mineral ilmenite for U–Pb dating by LA-ICP-MS

The mineral ilmenite is analysed by LA-ICP-MS for elemental and U–Pb isotopic compositions. A methodology is presented for accurate results using the mineral rutile for U–Pb ages and basaltic reference materials for major and trace elements.

СИЛИКАТНЫЕ, ЖЕЛЕЗО-ОКСИДНЫЕ И ЗОЛОТО-МЕДЬ-СЕРЕБРЯНЫЕ МИКРОСФЕРУЛЫ В РУДАХ И ПИРОКЛАСТИКЕ КОСТЕНЬГИНСКОГО ЖЕЛЕЗОРУДНОГО МЕСТОРОЖДЕНИЯ (ДАЛЬНИЙ ВОСТОК РОССИИ)

Iron-oxide ores and pyroclastics from the Kostenginskoye deposit in the Malyi Khingan (Russian Far East) contain numerous silicate, iron-oxide, and copper-gold-silver microspherules. Silicate spherules are composed of immiscible iron- and silica-rich glasses, gas cavities and mineral inclusions. Iron-oxide spherules include magnetite with minor ilmenite and Fe-rich silicate glass. Copper-gold-silver spherules contain inclusions predominantly of copper oxide compositions. The studied microspherules are considered to have formed during the rapid ascent of metal-silicate melts from depth and their degassing controlled by liquid immiscibility differentiation. The paper discusses the possible volcanic origin of iron-oxide ores and the associated noble metal mineralization for the deposits of this type.

Gemstones-bearing sediments in the Mbiame floodplain, northwestern Cameroon

Sediment samples obtained from pits in the Mbiame floodplain gemstone prospect in the northwestern part of Cameroon were studied for their bulk geochemical properties together with the mineral composition of the gemstones found therein to decipher their provenance. Five main layers were isolated in each pit comprising an organic rich humus layer, muddy layer, unconsolidated and poorly sorted sandy layer, clay layer and gravel layer. The gravel layer is the most high-yielding in terms of gemstones content. The sediments have high rare earth element (REE) concentrations varying between 135 and 456 ppm with variable light/heavy rare earth element (LREE/HREE) ratio values (5.8–21.5). REE chondrite normalized patterns show similar high LREE enrichment and no Eu anomalies (Eu/Eu* = 0.9 − ~ 1) for all samples. The gemstones selected from the various horizons range in color from light gray, light blue/green, dark blue, pale brown and red. Some of the grains have zircon and ilmenite mineral inclusions while some of the zoned grains show simple core—rim zonation as well as oscillatory and sectorial zoning patterns. Bulk sediment geochemistry of sediments from the Mbiame gem prospect suggests an igneous provenance generally of felsic intermediate source input. The alluvial gemstones from the Mbiame gem prospect are the sapphire variety of corundum and the grains combined with zircon and ilmenite inclusions and megacrysts suggest a derivation from felsic to intermediate igneous rocks.

Geological and Geotechnical Characteristics of Ntem Formations: Insight of its Applications in the Memve’ele Dam Construction (Southern Cameroon)

This paper discusses the geological and geotechnical potentialities of Ntem formations from the Memve’ele dam construction. Stratigraphic formations on the dam site consist from top to bottom sand, silty sand, silty, silty clay, very to moderate weathered rocks with a thickness of about 0.5–3 m above a sound bed rock which are represented by Ntem formations. These rocks have main mineral associations represented by orthopyroxene, clinopyroxene, quartz, plagioclase and garnet, display reaction textures, idiomorphic crystals, straight boundaries between crystals, the iron bearing amphibole, biotite and epidote, quartz ribbons and iron minerals (ilmenite and magnetite) are also present. All these permit to class them from granulite to amphibolite facies metamorphic conditions; therefore they are very hard and appear good for civil applications. The permeability has thickness from 0 to 13 m in the depth with Lugeon values higher than 15 UL. The RQD values are permitted to class these rocks as being moderated to good resistant. These character features which improve their geophysical properties (e.i. hard quality) have permitted that the dam and powerhouse foundations refitting on them. According to geophysical properties and rock mass rating, the rock mass is fair and good and is classified to class II and III. All these indicate that the rock mass is well compacted and sound with sparsely spaced discontinuities. The Ntem formations have uniaxial compressive strength under saturated condition generally higher than 40 Mpa, dry density or specific weight not less than 2.7 g/cm3, low porosity (average from 0.69 to 0.83%), low coefficient of water absorption (average from 0.012 to 0.04%), deformation modulus from 82.3 to 87.86 Gpa, Los Angeles and Micro Deval values are lower than 40% and 20% respectively, swelling risks are very limited with low values (1.07–1.11%) of sulphate, under 4.5% of cement and low values (0–0.07%) obtained during alkali-reaction test. All these have permitted that to obtain concrete aggregate and rip rap by crushing and processing these rocks from quarry during the dam, spillway, powerhouse and road constructions. These results confirm use of these formations during Memve’ele dam constructions.

Effects of Sample Shapes and Thickness on Distribution of Temperature inside the Mineral Ilmenite Due to Microwave Heating

The study of interaction between microwave radiation and minerals is gaining increasing interest in the field of minerals and material processing. Further studies are, however, still required to deepen the understanding of such microwave heating mechanisms in order to develop innovative techniques for mineral treatment using microwave heating. In this paper, effects of sample shapes and thickness on the distribution of temperature inside the mineral ilmenite (FeTiO3) due to microwave heating were numerically studied using the finite element (FE) method. The analysis was carried out in such a way that the flux of microwave energy was converted into an equivalent amount of heat generation in the mineral through the Poynting theorem of conservation of energy for the electromagnetic field. In this study, as a first attempt, the cylinder and slab of ilmenite were modeled to be irradiated from top and bottom surfaces with the variation of cylinder and slab thicknesses. Temperature-dependent material properties of ilmenite were taken into account in the FE simulation. Corresponding boundary conditions were then applied accordingly to the cylinder and slab of ilmenite with comparable characteristic length. Numerical results showed that, in terms of temperature differences between locations having maximum and minimum temperatures, slab geometries tended to produce higher values in comparison to those of cylinder geometries with the thickness variation, while the profiles of temperature inside the ilmenite samples were similar for both geometries. For the same duration of microwave heating, the slab geometry, hence, induced greater non-uniformity of temperature inside the ilmenite. It was also observed that, for the ilmenite samples with thickness value greater than 1.5 cm, the hotspot locations were not in the center of the sample, but on the surface of sample. Moreover, from several thickness values considered in this study, the ilmenite sample with thickness value of 3 cm gave a good trade-off between the maximum temperature value attained and temperature differences inside the sample, for both geometries. Thus, the shape and thickness of ilmenite samples affect the effectiveness of microwave heating of ilmenite, in terms of maximum temperature attained, temperature differences, and uniformity of temperature.

Resource warfare, pacification and the spectacle of ‘green’ development: Logics of violence in engineering extraction in southern Madagascar

Bringing political ecology's concern with the critical politics of nature and resource violence into dialogue with key debates in political geography, critical security studies and research on the geographies and phenomenology of violence and warfare, this paper explores strategies ‘from above’ in relation to the establishment and operation of the Rio Tinto QIT-Madagascar Minerals (QMM) ilmenite mine in southeast Madagascar. While QMM claims to be a responsible ‘green’ self-regulator and sustainable development actor, it has triggered serious social, environmental and legal conflicts since its inception, including allegations of a ‘double land grab’ to accommodate mining activities and compensatory biodiversity offsetting. We argue that ‘pacification’, theorised as a productive form of violence that works through the re-ordering of socio-nature, underwrites the forms of ‘security’, ‘stability’ and even ‘sustainability’ that facilitate multiple and overlapping strategies of value extraction in the territorial and extra-territorial spaces occupied by the QMM mine partnership. By situating these dynamics historically, we identify ways in which pacification draws upon sedimented and evolving logics of racialised violence to facilitate operations and silence opposition.

Satellite-based spectral mapping (ASTER and landsat data) of mineralogical signatures of beach sediments: a precursor insight

Detailed investigation on texture and mineralogy of beach sediments helps to understand their nature of deposition and potential targets of strategic mineral deposits. The beach sediments from the coast of Thiruvananthapuram, the southernmost district of Kerala, India, have been studied to understand the variation in grain size by using the spectral indices as derived from the visible-NIR-TIR bands of Landsat and ASTER remote sensing data. Further, an attempt has been made to map the distribution of strategic minerals present in beach sands using standardized hyperspectral analysis techniques. The grain size shows a remarkable variation from medium sand to fine sand. The THM (Total Heavy Minerals) content was estimated to about 80.04% and 52.33% along the coast of Kovalam and Varkala, respectively. The ilmenite mineral predominantly exists in these areas, followed by monazite, sillimanite, rutile, zircon, garnet, leucoxene, and Kyanite. The hyperspectral analysis extracts two endmembers of ilmenite and light minerals from the Landsat and ASTER imagery, which could be successfully, mapped using the SAM classification algorithm. The satellite-derived map showing texture and mineralogy has been validated with the results of laboratory analysis and shows strong correlation almost in all locations. This study illustrates the potential use of satellite remote sensing techniques for the mapping of natural resources, especially mineral resources.

KAJIAN SUSEPTIBILITAS MAGNETIK PASIR BESI PANTAI ARTA SEBAGAI FUNGSI JARAK DARI TEPI LAUT

Magnetic Susceptibility measurements and the identification of elements of iron sand from Arta beach of Pariaman West Sumatera have been done. The samples were dried first under the sun before the separation between magnetic particles of iron sand and non-magnetic particles using Iron Sand Separator. Identification elements of iron sand was done using X-Ray Fluorescence. The total value of magnetic induction was measured using a magnetic Pasco probe PS-2162 using a solenoid 2000 coils turns, dimensions of 3 cm in diameter and 10 cm in length. The solenoid was given an electric current with variations ranging from 2 A – 8 A. The distance between magnetic probe and one end of solenoid was kept constant that was 1 mm. The next experiment was to measure the function of distance ranging from 1 – 5 mm with constant applied current of 8 A. When electric current increase then the total magnetic induction also increase. Total magnetic induction value decreases as the distance increases. Magnetic susceptibility was calculated based on total magnetic induction and magnetic induction of core currents with constant current of 8 A and distance of 1 mm. The value of magnetic susceptibility obtained in the range (2164,71-3159,99)x10-5 which consist of ilmenite mineral (FeTiO3; Antiferromagnetic).Keywords : iron sand, magnetic suseptibility, iron sand separator, solenoid, magnetic induction, and x-ray fluorescence.

Stratigraphy, provenance and localisation of the titanomagnetite placer at Waikato North Head, South Auckland, New Zealand

The sequence of coastal and river sands of Pleistocene to Holocene age at the north head of the Waikato River is ~80-m thick; the sands are located in a fault-angle depression at the southern end of the Awhitu Peninsula, a 40-km-long coastal sand barrier. The sequence at Waikato North Head (WNH) consists of three main formations: Awhitu Sands, Hood Sands and Mitiwai Sands. The Waiuku Black Sand member of the Hood Sands and the Entrican Sand member of the Mitiwai Sands contain titanomagnetite-rich dune sands, which are currently mined by New Zealand Steel and constitute a giant placer deposit that has a total resource of ~90 Mt Fe. A tephra at the top of the Awhitu Sands is correlated with the ~1000 ka Waiuku (Potaka) tephra. The Mitiwai Sands overlie the 1.85 ka Taupo Pumice. Comparison of electron probe microanalyses (EPMA) of titanomagnetites in heavy mineral separates of surface and drill-hole samples indicated that the bulk of the titanomagnetite in the Waiuku Black sand and the Entrican Sand is derived from andesitic rocks of the Taranaki Volcanoes 220 km to the south. The Waiuku Black Sand may correlate with an influx of andesitic clasts and mafic minerals in the cover beds of the ~400 ka Ararata Terrace in south Taranaki. There is also a contribution of titanomagnetite and minor ilmenite from the ignimbrites of the Taupo Volcanic Zone (TVZ), particularly in the Lower Hood and Entrican sands. Automated mineralogy data collected on selected sand samples contain silicate and resistate minerals that indicate other potential sources in addition to the Taranaki andesites and TVZ ignimbrites. Minor olivine was likely derived from the late Pleistocene basalts of the South Auckland volcanic field, whereas almandine and epidote were likely sourced from metasedimentary rocks of the Murihiku and Waipapa terranes. The formation of the giant placer at WNH was a multistage process involving (1) a supply of titanomagnetite-bearing sand eroded from the late Pleistocene–Holocene andesites of the Taranaki volcanoes that was transported northwards along the coast by the prevailing longshore drift; (2) concentration of titanomagnetite by wave action on beach faces and collection in a coastal embayment on the northern side of a headland of basement rocks at Port Waikato; (3) further concentration by wind action into dune sands during interglacial low sea levels; and (4) preservation by coeval subsidence in a fault-angle depression on the down-thrown north side of the Waikato Fault.

Petrography and chronology of lunar meteorite Northwest Africa 6950

Northwest Africa (NWA) 6950 is an olivine-gabbro lunar meteorite that has a distinctly different petrographic texture from other lunar basalts. In this contribution, we report the petrography, mineralogy, and U-Pb geochronology of baddeleyite and phosphate in this lunar meteorite and make a comparison with other NWA 773 paired meteorites. NWA 6950 consists mainly of coarse-grained olivine, pyroxene, and plagioclase, with minor ilmenite, chromite, troilite, baddeleyite, taenite, and apatite. The abundant rounded to euhedral olivine has a limited Fo ranging from 68 to 69. Pyroxenes include both augite and pigeonite, with a narrow range of Mg#=71–80, and composition, respectively, ${\rm~En}_{46\text{-}52}{\rm~Fs}_{12\text{-}16}{\rm~Wo}_{32\text{-}41}$ and ${\rm~En}_{58\text{-}68}{\rm~Fs}_{19\text{-}28}{\rm~Wo}_{7\text{-}20}$. Plagioclase is mainly anhedral, conforming to the crystal margins of olivine and pyroxene. The plagioclase grains are elongated and several hundreds of microns in length. Raman spectra shows that plagioclase has been transformed into maskelynite, which is very calcic (${\rm~An}_{87\text{-}95}$) with low sodium and very low potassium (${\rm~Ab}_{4\text{-}9}{\rm~Or}_{0.6\text{-}3.7}$). The weighted mean $^{207}{\rm~Pb}/^{206}{\rm~Pb}$ ages of baddeleyite and phosphate measured using a sensitive high resolution ion micro probe (SHRIMP II) are $3119\pm16$ Ma ($n=9$, MSWD = 2.5) (meansquared weighted deviates, MSWD) and $3119\pm18$ Ma ($n=15$, MSWD = 2.1), respectively, giving the crystallization age of the meteorite.NWA 6950 has similar mineral compositions, geochemical characteristics, and an almost identical age of crystallization to the magnesian gabbro of the NWA 773 clan. We conclude that NWA 6950 and NWA 773 are paired meteorites, which crystallize at ca. 3119 Ma, and represent magmatic activities in the KREEP (potassium (K), rare earth elements (REE) and phosphorus (P) rich lunar material) region of the Moon.

Selective sediment transport during Hurricane Sandy on Fire Island (New York, USA): Inferences from heavy-mineral assemblages

ABSTRACT In October 2012, Hurricane Sandy caused severe erosion on beaches and dunes of Fire Island (New York, USA). Major shoreline changes occurred with erosional dominance in the upper shoreline and aggradation in the lowermost section of the beach due to the deposition of eroded upper-beach and dune sediment. Sand laminae with a high concentration of heavy minerals (“black sand laminae”) were observed in three excavated trenches located on a washover terrace and fan on the east side of Fire Island. The mineral composition of these laminae reveals the presence of high quantities of magnetite, ilmenite (as opaque minerals), and garnet (as the main translucent mineral). These heavy-mineral-enriched laminae were formed as waves eroded and transported sand from the primary dune and smaller relict dunes under specific hydrodynamic conditions that promoted grain sorting according to differences in size and specific gravity. Based on the concentrations of certain heavy minerals, the threshold for primarily density-driven sorting probably lies between the specific gravity of less dense opaque mineral (ilmenite, 4.7) and almandine (4.3), the most common transparent heavy mineral. The number of laminae and concentrations of heavy minerals vary between trenches on the overwash terrace and appear to be controlled by their distance from sediment sources. The trench with the greatest number of laminae and higher heavy-mineral concentrations is located farthest from the main dune but is just 10 m inland of a relict dune that acts as the primary source of sediment of the washover deposit in this trench. A conceptual model for deposition of heavy-mineral layers is presented based on geomorphological and sedimentological evidence allowing the definition of a density threshold.

Mixed-valence hydrated iron fluoridotitanate: Synthesis, optics and calorimetry

Mixed-valence hydrated fluoridotitanate with idealized formula FeTiF6·6H2O is the main product of fluoride processing of natural mineral ilmenite with hydrofluoric acid. Its single crystals were grown and optical and calorimetric experiments were carried out in the temperature range 200–350 K. Charge re-distribution, Fe2+Ti4+ to Fe3+Ti3+, in the compound studied was evident in XPS spectra. A first order ferroelastic phase transition occurs at temperatures T0↓ = 271.5 K, T0↑ = 274 ÷ 275.5 K with the symmetry change P3‾↔ P1‾. The structural transformation is accompanied by the appearance of a very weak optical anisotropy in the slice (001), a small anomaly of the heat capacity (ΔS = 1.5 J/mol K = 0.2R), and positive baric coefficients dT0/dp ≈ 30 ± 10 K/GPa.

Characterization and application of C–TiO2 doped cellulose acetate nanocomposite film for removal of Reactive Red-195

This article introduces research on the synthesis and characteristics of C–TiO2 doped cellulose acetate (CA) nanocomposite film. TiO2 nanoparticles were synthesized from Ilmenite mineral in Binh Dinh, Vietnam, and modified by Stevia Rebaudiana plant in order to serve as a cheap, stable, and eco-friendly photocatalyst that could perform under visible light. Nanocomposite film was obtained by dispersing C–TiO2 on cellulose acetate polymer using a supersonic generator. The prepared material was characterized by X-ray diffractions (XRD), N2 adsorption, Raman spectroscopy, Fourier-transform infrared spectroscopy (FT-IR), energy-dispersive X-ray analysis (EDX), UV–Vis diffuse reflectance spectroscopy (UV–vis DRS), photoluminescence (PL) emission spectra, scanning electron spectroscopy (SEM), and thermogravimetric/differential thermal analysis (TG-DTA). The film’s photocatalytic efficiency was evaluated via the decomposition of Reactive Red-195 (RR-195) under visible irradiation at room temperature. The results showed that the maximum conversion of RR-195 reached 99.15% at pH = 3 and the activity of the catalyst had a slight decrease after up to four times of recycling, for which the conversion of the fourth reaction was 90.02% for RR-195. This result suggests an efficient treatment method to eliminate organic pollutants from wastewater and stimulate these industrial activities in Vietnam.

Preparation of alternative raw materials for resource development to use in Indian ferro alloy and steel industrial applications

The present paper deals mainly with iron bearing titania enriched ilmenite raw mineral, its production, exports and imports and consumption of Ferro alloy industries. This paper not only reveals the recovery of iron from iron bearing titania mineral ilmenite with physical beneficiation methods but also gives the process of preparation and separation of titania slag and iron metal by using microwave heat treatment. The process of recovery of iron as a by-product from ilmenite mineral, which abundantly available along the coastal line of India, is economical and by which the conservation of some higher grade iron ores of the country will be possible for future. The products obtained from this process can be treated as alternative raw materials resources for steel and iron making industries.

Літологічна та мікропалеонтологічна характеристика донних відкладів Stella Creek (західний шельф Антарктичного півострова)

Main objective of the study – comprehensive research of material, particle size, mineral, chemical and micropaleontological composition, together with analysis of depositional environment of the Stella Creek bottom sediments. Material – bottom sediments samples of the Stella Creek, a small inter-island section, which is the terminal drainage basin of the Galindez and Winter islands from the water area adjacent to the Ukrainian Antarctic Akademik Vernadsky station were studied. Methods: particle size, mineral and chemical composition analyses were carried out using a scanning electron microscope with microprobe analysis; ultrasonic disintegration of rocks was used to remove paleontological remains; photographing and determining the taxonomic composition of microalgae were performed with light and electron microscopes. Results. The mineral composition of the bottom sediments is represented by quartz, plagioclase, chlorite (iron-containing clinochlore), illite, opal (biogenic), amphibole (hornblende), siderite. Among terrigenous minerals of heavy fraction, ilmenite (with manganese), zircon, and monazite are determined. Authigenic minerals are represented by bacteriomorphic framboidal clusters of iron sulfide microcrystals, calcium sulfate, and barite. Among the organic residues in sediments, diatom frustules predominate. Diatoms have three intervals, which coincide with the layers defined by particles size distribution analysis. Conclusions. Bottom sediments were formed in Late Quaternary time in cold-sea conditions and low hydrodynamic activity with local conditions favorable for early diagenetic biogenic sulfate reduction.