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This communication delves into a thorough examination of the reduction roasting–magnetic separation process for a low-grade Indian iron ore that is unresponsive to physical separation methods. The process was conducted in a bench-scale rotary kiln, and various parameters such as roasting temperature, roasting time, kiln rotational speed, and reductant dosage were analyzed to determine their effects on the yield and grade of the magnetic product. Additionally, characterization studies were carried out on both the feed and upgraded products to gain a better understanding of the phase transformations that occurred during the reduction roasting process. The experiments were conducted under specific conditions that included a roasting temperature between 650 and 850 °C, a roasting time of 10–60 min, a kiln rotational speed of 3–9 rpm, and a reductant dosage of 15–30%. The results showed that the low-grade iron ore could be upgraded from 56 to 65.3% Fe with a yield of 82.6% at a roasting temperature of 750 °C, a roasting time of 45 min, a kiln rotational speed of 5 rpm, and a reductant dosage of 20%. The reduction roasting experiments aided by optical and scanning electron microscopic studies helped understand the reduction sequence, while the scale-up studies indicated that the process is viable for commercial exploitation. [ABSTRACT FROM AUTHOR]

High-quality pellets have been developed from a low-grade Indian chromite overburden containing high silica in the present study. The thermodynamic, hot-stage microscopic, and thermogravimetric analyses of the overburden and pellet mixes predict the temperature of formation of low melting slag phases at various basicity. A temperature in the range of 1200 °C to 1300 °C and basicity between 0.10 and 0.15 have been found ideal for the initiation of the slag phases, whereas higher conditions lead to softening of the pellets. The effect of basicity, binder content, induration temperature, and time on the physical and metallurgical properties of the indurated pellets has been investigated. A binder content of 1 wt pct, basicity of 0.15, induration temperature of 1250 °C, and a time of 20 minutes are optimum to provide the desired properties to the pellets. X-ray diffraction and Scanning Electron Microscopy coupled with Energy Dispersion Spectroscopy analysis reveal that under the optimum conditions, hematite recrystallization and slag formation impart the needed strength (133.8 kg/pellet), porosity (27.8 pct), tumbler index (99.2 pct), RI (76.2 pct), and RDI (1.2 pct). Conversely, increasing the basicity and the induration temperature results in the melting of the slag phases and, therefore, impair the consolidation of the pellets. [ABSTRACT FROM AUTHOR]

The present article discusses the contrasting characteristics of fireclay from two stratigraphically and geologically different locations of Odisha, eastern India, viz. (i) Talabasta from Cuttack district (FC1) belonging to Upper Gondwana Formation and (ii) Basundhara coal mines (FC2) of Lower Gondwana Formation of Jharsuguda district. The study focuses on micro-morphological, mineralogical, and geochemical characteristics of fireclay from the above locations and compare between them in respect of their refractory applications. The micro-morphological and mineralogical analysis inferred the predominance of quartz, kaolinite in both samples along with minor halloysite, goethite, and ilmenite in their various fractions. Layered hexagonal kaolinite, nanohedral kaolinite aggregates, and cylindrical halloysite are recognized under FESEM in FC1. In contrast, in FC2, the kaolinite is poorly crystallized, appears as anhedral to subhedral grains, or aggregates of very fine clay. The compositional analysis using XRF of bulk and its two size fractions (−75 + 45 and −45 μm) indicates FC1 to be rich in SiO2 and shows relatively less Al2O3, Fe2O3, TiO2, and K2O content than FC2. FTIR pattern, DSC and TGA pattern, and ash fusion temperature between FC1 and FC2 also show some difference. It is surmised that both fireclay samples have desired heat resistance (> 1400 °C) needed for refractory application. However, the AFT of FC1 can be further enhanced by decreasing silica content, and the AFT of FC2 can be improved by reducing Fe content through its proper processing. [ABSTRACT FROM AUTHOR]

The effects of microwave and conventional oven drying on the drying kinetics and the quality of the ilmenite-coke composite pellets are presented. The drying time was substantially reduced in microwave drying (90 s) compared to conventional oven drying (10 min) for the exact size of composite pellets. The activation energy values in microwave drying were minimal for bigger-sized pellets. An 8–11 mm pellet size was suitable for achieving the desired pellet properties for both drying methods. The microwave-dried pellets showed quite similar dry strengths to that of the oven-dried pellets; however, the reduction performance of the microwave-dried pellets was better owing to the micro-cracks formation, as observed under the electron microscope, in several grains. [ABSTRACT FROM AUTHOR]

Physical separation of the organic and inorganic constituents in coal mostly depends on the degree of association and the manner of their distribution. The liberation of macerals and minerals in coal holds a vital role in the effectiveness of coal-washing technologies. The intent of the study is to observe the effect of particle size on the distribution of both macerals and minerals in coal. Different size fractions were generated, viz. −3350+1000μm, −1000+500μm, −500+212μm, −212+150μm, 150+75μm, 75+45μm and −45μm by using Indian standard sieves. Petrographic studies were carried out for all the size fractions to understand the distribution and the degree of liberation of macerals and minerals with respect to particle sizes. The results showed that the concentration of vitrinite gradually increases while inertinite and liptinite decrease with the decrease in particle size. Mineral matters decrease/increase with particle size depending upon the nature of associated minerals. Also, the particle size influences the type of mineral matter association depending upon their hardness. [ABSTRACT FROM AUTHOR]

The Rairakhol alkaline complex situated in western Odisha consists of litho assemblages such as mafic-rich nepheline syenite, mafic-poor nepheline syenite and leucocratic syenite. These rocks have been investigated with respect to their mineralogy and chemistry with a special focus on their rare earth element (REE) content. Petrographic study reveals that the rocks are mainly medium to coarse grained with hypidiomorphic granular texture and composed of variable proportions of microcline/orthoclase, perthite, nepheline, albite, amphibole, biotite. The accessory minerals are calcite, sphene, zircon, thorium uranium oxide, apatite and opaques (mainly ilmenite, magnetite, pyrrhotite). Petrochemical analyses confirm that these nepheline syenites are typically miaskitic to marginally agpaitic with agpaitic coefficient [(Na + K)/Al molar prop.] varying between 0.75 and 1.01. Scanning electron microscope study shows that some REE-bearing mineral phases occur as inclusions or in interstitial spaces of the major mineral phases of nepheline syenite. The REEphases are of RE-sillicates, RE-oxides, and RE-phosphates which are generally rich in their LREE content. The identified REE-bearing mineral phases are britholite, allanite, apatite and zircon. The leucocratic syenite shows a strong positive Eu anomaly whereas the mafic-rich and mafic-poor nepheline syenites show a slightly negative Eu anomaly indicating that the rock originated from a highly fractionated magma. A rare Tm anomaly found in the leucocratic syenite indicates some influence of refractory dusts derived from carbonaceous chondritic material during their formation. This study provides an insight into the mineralogical and petrological peculiarities of this alkaline complex which might guide further exploration programs. [ABSTRACT FROM AUTHOR]

With gradually diminishing Fe grade in tandem with the ever-increasing demand for high-grade iron ores, iron ore industries are now focusing on the beneficiation of low-grade iron ore fines, mainly considered waste. Besides, the scarcity of water at many of the mines' sites and the new water conservation policies of the governments have necessitated research on suitable dry beneficiation routes. In this context, an effort has been made to evaluate the efficacy of a dry classification unit, such as the VSK separator, in upgrading the iron values of two low-grade Indian iron ore fines, named Sample 1 and Sample 2. The mineralogical studies, involving scanning electron microscopy and X-ray diffraction, suggest that Sample 1 is a low-grade blue dust sample (51.2wt% Fe) containing hematite and quartz as the major minerals, while Sample 2 (53.3wt% Fe) shows the presence of goethite in addition to hematite and quartz. The experiments, carried out using Box—Benkhen statistical design, indicate that blower speed, followed by feed rate, is the most influencing operating parameter in obtaining a good product in the VSK separator. At optimum levels of the operating factors, a fines product with ∼55wt% Fe at a yield of ∼40% can be obtained from Sample 1, while Sample 2 can be upgraded to ∼56wt% Fe at a yield of ∼85%. The results suggest that the VSK separator can be employed as an efficient intermediate unit operation in a processing circuit to upgrade the iron contents of iron ore fines. [ABSTRACT FROM AUTHOR]

Lower Gondwana coals of Talcher coalfield extends along the south-eastern part of the Mahanadi valley. Coal samples from six different seams, viz. Seam-I, II, III, IV, VIII and IX of Nandira, Lingaraj and Hingula colliery of Talcher coalfield were taken for study. The detailed petrographic study was carried out with special emphasis on identifying and calculating the distribution of various types of liptinite macerals. The coal seams overall are found to be dominated by vitrinite followed by inertinite and liptinite. The liptinite group macerals were characterized with the help of fluorescence microscopy. It is observed that sporinites, particularly microspores, were predominant in all the above seams. Megaspores and resinites were identified in Seams-I and II only. Seams-I and VIII with comparatively higher liptinite content (3–16 vol.%) could be considered favourable for coal liquefaction and gasification. However, the overall low liptinite content (<5 vol.%) of Talcher coals indicates a telmatic swampy paleoenvironment of deposition. The generated data on various liptinite types can serve as facies indicators and help in seam correlation. [ABSTRACT FROM AUTHOR]

The Precambrian Eastern Ghats Group of rocks consisting of a series of regionally metamorphosed rocks such as khondalite, charnockite, calc-granulite and quartzite hosts several pockets to lensoidal Mn-ores in Odisha, Eastern India. The Mn-minerals identified in these deposits are Mn-silicates and lower Mn-oxides with Mn-oxyhydroxides. Lithiophorite, an aluminous Mn-oxyhydroxide mineral, is conspicuous with other secondary Mn-phases. It generally occurs in two habits, such as cryptocrystalline/crystalline aggregates either as vug fillings or as replacement of other minerals like cryptomelane/romanechite/goethite/graphite. Two morphological types of lithiophorite viz. globular and platy were examined in detail by optical and electron microscopy. The electron probe micro-analyses (EPMA) of these two morpho-types reveal the cryptocrystalline (globular) type to be rich in both CoO and NiO, while the platy crystalline type is preferentially enriched in NiO and depleted in CoO. Compositional map for both the types also supports such selective entrapment. Binary plots of electron probe data for MnO2 and Al2O3 versus CoO and NiO in the globular type show strong positive relation confirming to their presence in adsorbed state. In contrast, the NiO in platy type show strong positive relation with Al2O3 only indicating desorption of Co and a part of Mn from the structure during crystallisation and its subsequent diadochic substitution in the alumina lattice. [ABSTRACT FROM AUTHOR]

The concentration of different maceral groups and minerals in coal influence the quality as each of them behaves differently during heat treatment. The purpose of this study is to know how these are behaving at different temperature conditions. Therefore, various macerals and minerals were concentrated by using heavy liquids of different specific gravities (1.3, 1.7 and 1.9). The generated density fractions were treated with heat at 400, 600, 800 and 1000 °C. All the density fractions at various temperature conditions along with feed sample were investigated by optical microscopy, X-ray diffractometry, electron-probe microanalysis and Fourier transform infrared spectroscopy analysis. The results suggest that fusinite and sclerotinite are the most stable macerals, whereas quartz is the most stable mineral. Telocollinite is found to be oxidized very prominently at 400 °C. Siderite and pyrite alter to form hematite above 400 °C and 800 °C, respectively. Kaolinite converts to metakaolin followed by mullite with increasing temperature. [ABSTRACT FROM AUTHOR]

The microwave-assisted reduction behaviours of two low-grade iron ores having a similar Fe content of 49wt% but distinctly different mineralogical and liberation characteristics were studied. Their performances in terms of the iron grade and recovery as obtained from statistically designed microwave (MW) roasting followed by low-intensity magnetic separation (LIMS) experiments were compared. At respective optimum conditions, the titano-magnetite ore (O1) could yield an iron concentrate of 62.57% Fe grade and 60.01% Fe recovery, while the goethitic ore (O2) could be upgraded to a concentrate of 64.4% Fe grade and 33.3% Fe recovery. Compared with the goethitic ore, the titano-magnetite ore responded better to MW heating. The characterization studies of the feed and roasted products obtained at different power and time conditions using X-ray diffraction, optical microscopy, vibrating-sample magnetometry, and electron-probe microanalysis explain the sequential reduction in the iron oxide phases. Finally, taking advantage of the MW absorbing character of the titano-magnetite ore, a blend of the same with the goethite-rich ore at a weight ratio of 60:40 (O2: O1) was subjected to MW roasting that resulted in a concentrate of 61.57% Fe grade with a Fe recovery of 64.47%. [ABSTRACT FROM AUTHOR]

Manganese mineralization in the Precambrian Gangpur Group of rocks in Sundargarh district of Odisha occur as pockets or small ore bodies associated with metapelites and metapsamites. Different varieties of hypogene metamorphic manganese minerals belonging to Mn-oxides, Mn-carbonates, Mn-silicates, Mn-titanates have been reported from this Group. Although the Mn-bearing rocks and the Mn-ores host several supergene Mn-minerals, no detailed and comprehensive study on these minerals has been carried out so far. The present paper describes the microstructural and microchemical characteristics of the supergene Mn-minerals viz., vernadite, manganite, cryptomelane, romanechite, Fe-Mn sepiolite, nsutite, pyrolusite, and lithiophorite with a view to establish their paragenetic sequence and genetic evolution. These minerals have formed due to solution-remobilization-precipitation, oxidation and/or hydration, diagenesis and as a product of direct alteration. It is inferred that only one variety of manganite is formed due to retrograde metamorphism. While vernadite, cryptomelane and romanechite precipitated from Mn-rich solutions at low temperatures, Fe-Mn sepiolite formed as a direct alteration product of tephroite. Manganite and nsutite formed both as solution-precipitates as well as oxidation products of other Mn-minerals. While further oxidation leads to the formation of pyrolusite at a later stage, lithiophorite is the last mineral to form during weathering and lateritization. [ABSTRACT FROM AUTHOR]

The low-grade siliceous chromite ore from Ghutrigaon, Odisha, India, containing ~ 16% Cr2O3, with Cr/Fe ratio of 1.97 and ~ 55% of SiO2, does not find any use in metallurgical industry and hence considered as waste. Mineralogical investigation indicates the presence of chromite and quartz as major minerals with minor fuchsite and kaolinite. The beneficiation studies reveal that the product can be enriched to a Cr/Fe ratio of 3.35 and 3.02 by gravity concentration (wet shaking table) and wet high intensity magnetic separation, respectively. Tiny Cr-grains within quartz and fine silica dusts within chromite inhibit liberation of chromite resulting in poor response to physical beneficiation. As an alternative, processing of ore through pyro-metallurgical route was evaluated. Chromite fines mixed with carbon and lime in the form of pellets/granules was charged to a plasma reactor. In about ten minutes, the metal globules/prills were separated from the slag in 1:6 ratio. The metal, examined through XRD and optical microscope, was found to be ferrochrome alloy. In situ EDAX analysis indicated the metal to have 61.51% Cr, 26.52% Fe and 13.1% C with minor silica (2.42%), and the slag was composed of Ca2Al2SiO7 which revealed that both metal and slag so obtained could suitably be used in different industries. [ABSTRACT FROM AUTHOR]

The feasibility of producing direct reduced iron from pellets made up of mill scale by utilizing coal as a reductant has been investigated. The chemical and morphological characterization studies reveal that the mill scale contains around 71% Fe and comprises of a mixture of iron oxide phases such as magnetite and hematite with a little amount of wustite. The reduction study of the mill scale pellets has been carried out using the statistical design of experimental approach employing the response surface methodology. Under optimum conditions such as a temperature of 1246 °C, a time of 1.52 h, and coal-to-mill scale ratio of 0.58, around 88–89% metallization is obtained. Similarly, around 84% of metallization can be achieved at a temperature around 1150 °C, time of about 1.5 h with coal-to-mill scale ratio of 0.59. The characterization studies of the reduced pellets using X-ray diffraction and optical microscopy show the sequential growth of the metallic phase as the reducing parameters are increased. The properties of the mill scale pellets are found to match the desired specification for the direct reduction process, and the reduction behavior of the pellets as a function of temperature, time, and coal-to-mill scale ratio suggests that iron making from mill scale through this route is a promising process. [ABSTRACT FROM AUTHOR]

Potassium is an important mineral for biological functions. In this study, potassium was recovered from a low-grade potash mineral, feldspar through chlorination roasting followed by water leaching. NaCl and CaCl2 were used as additives for chlorination roasting independently The characterizations throughout the studies were carried out using a series of analytical and spectral techniques like XRD, SEM, FTIR, and Raman spectroscopy The effects of various experimental parameters such as particle size, roasting temperature, amounts of additives, and water leaching on potassium extraction were evaluated. Water leaching was found to be independent of leaching time, temperature, and agitator speed. During roasting, the formation of water-soluble phase was evident; this phase subsequently disappeared on water leaching. The potassium extraction kinetics in the presence of both the additives was satisfactorily corroborated by Ginstling-Brounshtein model. The activation energies for CaCl2 and NaCl roasting were calculated to be 90 and 122 kJ/mole, respectively. Under the same experimental conditions, 86% of potassium extraction (as potash value) was accomplished using CaCl2 as the additive, whereas the extraction in presence of NaCl was only up to 44%. The mechanism of potassium extraction was elucidated; the superior effectiveness of CaCl2 over NaCl in the extraction process was also explained. [ABSTRACT FROM AUTHOR]

Abstract: A novel approach for the complete utilization of a low-grade banded hematite jasper ore assaying ~ 47% Fe has been taken in order to address the issue of rapid consumption of high-grade iron ores and the rising concerns of waste disposal. The process includes the enrichment of Fe through reduction roasting followed by magnetic separation, and smelting of the non-magnetic fraction to produce ferrosilicon alloy. The optimum values of iron grade of ~ 66% Fe and recovery of ~ 72% as determined by the Taguchi-based statistical design of experiments have been achieved at a temperature of 900 °C, time of 90 min, coal-to-feed ratio of 0.15, coal of size − 3.35 + 1 mm and ore of size − 1 mm. The ore and the roasted products have been subjected to characterization techniques such as optical microscopy and X-ray diffraction that reveal the phase transformation under different conditions. Further, the smelting of the silica-rich non-magnetic part in a laboratory-scale electric arc furnace has resulted in a ferrosilicon alloy with ~ 20% Si as indicated by scanning electron microscopic studies. This innovative approach of recovering the maximum iron values using reduction roasting and exploiting the non-magnetic reject as a silica source for ferrosilicon production has the potential to reduce industry’s reliance on high-grade iron as well as silica resources.Graphical Abstract: [ABSTRACT FROM AUTHOR]

Shirozulite, ideally KMn(AlSi)O(OH), is recorded for the first time in metamorphosed manganese formation of Gangpur group in eastern India. It is associated with spessartine, jacobsite, calcite, rhodochrosite and muscovite which seemingly formed by the reaction of muscovite with rhodochrosite. In-situ chemical composition shows some variation in Mn-content from the original shirozulite reported from Japan. Powder X-Ray diffraction studies reveal the unit cell parameters of shirozulite in the triclinic system as a=5.14±0.02Å, b=9.21±0.01Å, c=10.17±0.13Å, β=94.14±0.31° and cell volume in Å = 487.22. [ABSTRACT FROM AUTHOR]

MRI was utilized to demonstrate the exact site of fistula between a ruptured saccular aneurysm of the infrarenal abdominal aorta and the inferior vena cava in a 64-year-old man. [ABSTRACT FROM AUTHOR]

Magnetic resonance imaging (MRI) was utilized to demonstrate an esophageal duplication cyst of the midesophagus in a 61-year-old woman. The radiographic, computed tomographic, and MRI features are illustrated. [ABSTRACT FROM AUTHOR]

Acute acalculous cholecystitis (AAC) is usually seen as a complication of major surgery or trauma. Although this entity is well-known in the surgical literature, little has been written about it in the radiologic literature. A review of patient records from 1975 through 1982 revealed 16 patients with pathologically confirmed AAC on whom at least 1 sonographic study had been performed. Thickening of the gallbladder wall, a subserosal 'halo' of edema, pericholecystic abscess, and marked gallbladder distention were consistent findings in AAC. In the proper clinical setting, these otherwise nonspecific findings allow a prompt and accurate diagnosis. [ABSTRACT FROM AUTHOR]

The diagnosis of acute tendon ruptures of the extensor mechanism of the knee or the Achilles tendon of the ankle may usually be made by clinical means. Massive soft tissue swelling accompanying these injuries often obscures the findings, however. Magnetic resonance imaging (MRI) can rapidly demonstrate these tendon ruptures. Examples of the use of MRI for quadriceps tendon, and Achilles tendon rupture are presented. [ABSTRACT FROM AUTHOR]

A primary leiomyosarcoma of the superior vena cava was diagnosed with magnetic resonance imaging. MRI demonstrated tumor extension into the right heart and innominate veins and compared favorably with the superior vena cavagram. [ABSTRACT FROM AUTHOR]

Gorceixite, a Ba-Al alunite supergroup mineral, associated with ferromanganese ores of the Precambrian Eastern Ghats Group is reported for the first time from Odisha. The characteristics of gorceixite are described using optical microscopy, XRD, FTIR, Raman, SEM-EDAX and EPMA techniques. The Odisha gorceixite is subhedral, with a broadly prismatic habit and occasional twinning. The calculated formula of present gorceixite is (Ba0.54 Ca00.39 Sr0.05)∑0.98 Al2.96 (PO4)2.05(OH)5.H2O. The Ba is partly substituted by Ca and Sr. Texture of the ores indicates that during supergene alteration, earlier silicate minerals, like celsian (Ba-feldspar), were replaced by gorceixite. [ABSTRACT FROM AUTHOR]

Extension of hepatic metastatic tumor along a biliary drainage catheter tract is an unusual occurrence. We believe this is the first report of such a case presenting as a calcified, subcutaneous mass at the catheter entry site. [ABSTRACT FROM AUTHOR]