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Graphical Abstract:

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.

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: The present communication describes an investigation on the preparation of metallized composite pellets from ilmenite concentrate. It was observed that the pellet size in the range of 8–12 mm, a binder dosage of 4 wt%, and internal carbon of 5 wt% are the optimum levels that help the pellets attain the desired drop number (~ 10) and dry strength (~ 30 kg/pellet). When subjected to reduction tests at a temperature of 1200 °C for 6 h, the composite pellets show better metallization (~ 80%) than the raw ilmenite pellets with an equal amount of reductant. The reduced ilmenite composite pellets also display a reasonable decrepitation value of 4.9%, thereby making them suitable to be used directly in arc furnaces for titania slag production. A comparative characterization study by SEM–EDS indicated that larger amounts of metallic grains are uniformly distributed throughout the matrix in the composite pellets. Graphical Abstract:

Abstract: 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. Graphical Abstract:

Banded hematite quartzite (BHQ) and banded hematite jasper (BHJ) ores represent a promising potential iron ore resource in the near future. The hematite and quartz in BHQ and the hematite and jasper in BHJ are closely related and require fine grinding for the liberation of hematite phases. The present study investigates the mineralogical features and comminution properties of BHQ and BHJ ores. In the BHQ ore, it is observed that thick bands of hematite have fine inclusions of silicate minerals, whereas silica bands have few grains of iron-bearing minerals. The hematite and quartz minerals in the iron and silicate bands of the BHJ ore appear to be more intricately associated and complex in nature, presenting difficulties for liberation. Bond work index studies were carried out for the BHQ and BHJ ores with different product fineness in order to evaluate the energy requirements in fine grinding. A higher Bond work index value was found for the BHJ ore (15.4 kWh/ton) than for the BHQ ore (12.4 kWh/ton). A decrease in the product particle size was associated with an increase in the work index value. Single-particle breakage experiments were designed by varying feed particle size and input energy. The specific energy consumption for the BHJ ore was higher than that for the BHQ ore. The comminution parameters showed that the BHJ ore is harder to grind than the BHQ ore, which may be due to the mineral composition and association of hematite phases with the silicates.

Siliceous manganese ore, associated with the banded iron formation occurs in large volume in northern Odisha, India. It is a sub-grade ore containing 21% Mn, 60% SiO2and 3% Fe, hence do not find any use and considered as waste. Such ore does not respond to any physical beneficiation techniques because of intricate microstructure and poor liberation of Mn-phase. It could only be up-graded to 32% Mn with 36% yield and 52% recovery by processing it through mineral separator followed by WHIMS. Siliceous manganese ore along with calcite and coke in appropriate ratio, when charged to a plasma reactor, a product with slag metal ratio of 2.5:1 was obtained within a period of 10 min. Electron probe micro-analysis of the metal confirmed it to be ferrosilicomanganese while the slag constitute of tricalcium silicate (C3S) with around 5% Mn in adsorbed state.

The removal of iron from an Indian diaspore sample was studied using magnetic separation and leaching techniques aided by an in-depth mineralogical characterization study involving quantitative mineralogical evaluation by scanning electron microscope (QEMSCAN), electron probe micro-analyzer (EPMA) and X-ray diffraction (XRD). The characterization studies indicate that extremely fine-sized hematite grains are associated with several other mineral phases in a complex manner with around 60% of the hematite not liberated even below the size of 38 μm limiting the scope of physical separation processes to remove the iron. Wet high intensity magnetic separation (WHIMS) studies reveal that only 49% of iron can be removed. Further, leaching studies using oxalic acid suggest that around 76% of the iron can be removed under conditions such as a solid to liquid ratio of 0.05:1, a temperature of 90 °C, a time period of 120 min and an acid concentration of 1 mol/L. The dissolution of iron in oxalic acid is found to be controlled by chemical reaction and the activation energy is calculated as 35.15 kJ/mol.

Abstract: 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.

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.

We describe a case of a ruptured gravid uterus, secondary to motor vehicle accident, in a 20-year-old woman. Maternal and fetal injuries associated with blunt trauma are described along with the use of CT in pregnant patients.

Abstract: 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: 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.