Ilmenite Concentrate Research Articles

Phase Transitions and Microstructural Changes During Oxidation and Reduction of a Weathered Ilmenite Concentrate

The present work aims to investigate the link between the oxidation and reduction of a weathered ilmenite concentrate in terms of phase transitions, microstructural changes, and element distribution. An ilmenite concentrate sample was pelletized and fired at 1000 °C in air, and as a result, the pellets were oxidized. The oxidized pellets were reduced by hydrogen gas at 1000 °C, which yielded almost complete metallization of the iron content of the pellets. The ore and the pellets were characterized in each step by XRD and SEM techniques, and distribution of elements and phases were investigated. Ilmenite, pseudorutile, and rutile were the main phases detected in the ilmenite concentrate sample, and depending on the weathering degree of the particles, different fractions of the phases were identified in their microstructure. It was found that irregular rutile grains dispersed in a pseudobrookite matrix is the morphology of the oxidized ilmenite phase. However, increasing microcracks and porosities were the only microstructural changes in the pseudorutile phase after oxidation in air. Studying the specific types of the ore particles and their oxidized and reduced forms indicated that the phase distribution in the ilmenite ore particles dictates the phase distribution in the oxidized and reduced ones. Results show that the morphology of the reduced particles includes a titanium (III) oxide matrix in which reduced iron globules are dispersed.

Строение, состав и условия формирования четвертичных отложений в Кельтминском погребенном каньоне (юго-восток Республики Коми)

Our lithological study of the Quaternary strata in the section of the well 17843 resulted in identification of three sediments sequences of various thickness and composition. In the lower part of the well, at depths of 43.2—27 m (layers 5, 4d and 4c), the sediments were formed probably in fluvioglacial conditions. The sediments are characterized by high content of ilmenite — 7—14 %, and group of titanium minerals — 7—12 %, where concentrations of leucoxene and titanite are increased. The content of chromespinellides increases downwards from 2 to 4.4 %. In the depth interval 25.9—23.6 m (lay 4b), a dense, poorly-sorted silty clay without clastic material is exposed; its genesis is unclear. Clay is characterized by the highest amount of heavy fraction in the section — 1.91 %, and contains an abnormally high amount of magnetite — on average 31 %. The upper 22 m of the sequence (layers 4a and 3—1) are represented by alluvium — well-sorted medium-fine-grained sand with amphibole-ilmenite-garnet-epidote association of heavy minerals and increased amounts of metamorphic minerals — 7—10 %, chromespinellides — 4—6 %, and magnetite — 4—8 %. Such complex of heavy minerals in the sediments, forming the canyon, testifies to the participation of the Ural magmatic and metamorphic complexes in their formation; the supply of minerals from the Kama seems to be very problematic. Palynological analysis data obtained from layers 5, 4d, and 4b reflect a regular vegetation change of the final stages during the interglacial. Spruce-pine forests with fir, cedar, treelike and dwarf birches, alder and willow were gradually replaced by tundra plant communities, where, along with bog-tundra formations, there were xerophytic communities with wormwood Artemisia sp., Chenopodiaceae, and rare Ephedra sp.

Roles of SiO2 Additive on Preparation of Ferrotitanium from Ilmenite Concentrate by Electrochemical Reduction in CaCl2 Molten Salt

The effect of the content of an SiO2 additive on the electrochemical reduction of ilmenite concentrate to prepare ferrotitanium is investigated in CaCl2 molten salt. A thermodynamic analysis of the Ti-Fe system and possible reactions has been carried out, and it demonstrated that SiO2 and FeTiO3 can be readily reduced to Si and intermediates (Fe and CaTiO3), respectively. The experimental results demonstrated that the optimal molar ratio of Ti:Fe:Si in the cathode mixtures is 1.2:1:0.2. The porous ferrotitanium with uniform particle sizes were successfully obtained by electrolysis at 1173 K with a cell voltage of 3.2 V for 2 h. The SiO2 additive plays an important role during the formation process of ferrotitanium, which is first reduced to Si and then serves as a reductant to catalyze CaTiO3 and Fe to form FeTi alloys.

Influence of Ferrous Sulfide on Carbothermic Reduction of Panzhihua Ilmenite Concentrate

To elucidate the effects of FeS on the carbothermic reduction of ilmenite, a series of tests were conducted using non-isothermal thermogravimetric analysis at heating rates of 10°C/min, 15°C/min, 20°C/min, and 25°C/min. The Malek method was used to analyze the reduction mechanism and obtain a kinetic model, and the Starink method was used to calculate the apparent activation energy. The morphology of the reduction products was examined by scanning electron microscopy. A complementary series of isothermal carbothermic reductions tests was also performed in a vertical tube furnace to study the effect of FeS on the metallization of Fe and TiO2 grade in the slag phases. The results show that the carbothermic reduction of the ilmenite concentrate in the presence of FeS proceeds in four stages. FeS showed a negative effect to the carbothermic reduction of ilmenite as its addition of 2.5 wt.% increased the apparent activation energy from 486 kJ mol−1 to 565 kJ mol−1 and decreased metallization by 11.1% and TiO2 grade in the slag phases by 7.2%.

Sulfuric Acid Leaching of Altered Ilmenite Using Thermal, Mechanical and Chemical Activation

The kinetics of the sulfuric acid leaching of altered ilmenite, mechanisms, and process intensification methods were studied. The effect of changing the chemical composition during grinding was determined. The content of ilmenite and pseudorutile decreased from 5.3% to 3.1% and from 90.2% to 63.1%, respectively. Rutile increased from 4.5% to 28.7%, while a pseudobrookite new phase appeared in the amount of 5.1% after 2 h of grinding. It was found that the modification of raw material by sulfuric acid led to the increase of the decomposition rate, and at the same time, decreased when the ore was utilized due to an increase of insoluble TiO2 content. Isothermal conditions were evaluated with H2SO4 concentration varying from 50 to 96%. The data obtained were described with the approximation of the contracting sphere model. It was shown for the first time that H2SO4 > 85 wt% causes a sharp constant decrease of titanium. Correlating these phenomena allows for the consideration of H2SO4·H2O as reagents, rather than H2SO4 molecules. It was experimentally proven that at a temperature above 190 °C, the Ti leaching degree dropped, which is explained by the formation of polymerized TiOSO4. Finally, it was shown that adding NaF reduced the activation energy to 45 kJ/mol.

Prospects for the titanium carrying Triassic formations of the Bolshaya Synya depression of the Pre-Uralian marginal flexure

It was established potentially industrial titanium-containing terrigenous rocks from the Lower and Middle Triassic formations of the southern part of the Bolshaya Synya depression, Pre-Uralian marginal flexure. Sandstones contain the bulk of productive mineralization and makeup about 80% of the Triassic section. Sandstones are represented by weakly lithified, finely grained lithoclast greywackes scattered in the hands with weakly rounded unsorted fragments, with pore, film, and contact type of cement form by hydrogetite and illite and chlorite. The proportion of relatively strong sandstones with calcite-siderite cement does not exceed 10% of the studied section. The deposits are formed in alluvial and pluvial, lacustrine depositional environments within the wide alluvial plain. The rocks belong to the upper part of the thick Permo-Triassic continental molasses formed in compensated depressions as a result of the destruction of the Paleo Uralian Orogeny. The main minerals of the heavy fraction are epidote, ilmenite, titanomagnetite, and amphibole; the minor minerals are chlorite, goethite, martite, pyroxene, chrome spinel and a group of garnets. The share of zircon does not exceed the first percent. The main mineral concentrator of titanium is ilmenite, the minor minerals are manganilmenite, titanomagnetite, titanite, leucoxene aggregates, rutile, and pyrophanite. The hypothetical primary source of ilmenite was epidote and amphibole contains shale or epidote containing amphibolite formed from a mafic substrate. The thickness of titanium contains layers is 1–4 m with an ilmenite content of more than 30 kg/m3. At the local level, ilmenite and titanomagnetite mineralization is concentrated in the form of small jets, lenses, puffs, and interlayer bodies. The average contents of ilmenite are comparable with those of the well-known titanium and zirconium placer deposits in Russia. The data presented in the article make it possible to predict the existence of new titanium contains region in the Triassic deposits of the south part of the Bolshaya Synya depression. The productivity of the region should be associated with continental ilmenite placers.

Vacuum sintering behavior and magnetic transformation for high-Ti type basalt simulated lunar regolith

Lunar regolith in-situ utilization receives increasing attentions due to development of lunar exploration research. The complex composition of lunar regolith leads to its complicated phase reaction and composition evolution at high temperature, whereas few studies focus on the alteration of physicochemical properties for simulated lunar regolith at high temperature. This paper focuses on physicochemical variation characteristics and magnetic transformation for high-Ti type basalt lunar regolith simulant CLRS-2 during vacuum sintering process. Importantly, the effect of heat-treatment on magnetic properties of CLRS-2 and the magnetic properties difference between high-Ti and low-Ti type basalt lunar regolith simulant have been investigated. The results would help us understand how the micro-morphology and chemical composition of ilmenite change in lunar regolith during sintering process. What can be inferred is that the ions substitution between ilmenite and other minerals or amorphous phase would occur during sintering process of lunar regolith at high temperature in vacuum, which would lead to the evaporation of Fe-containing components. Besides, the results of micro-hardness indicate that the ilmenite content difference between CLRS-1 and CLRS-2 have no influence on the micro-hardness of the sintered samples, while the density of samples and the sintering condition such as temperature have a greater influence.

An Empirical Model to Estimate Abundance of Nanophase Metallic Iron (npFe0) in Lunar Soils

Lunar soils gradually become mature when they are exposed to a space environment, and nanophase metallic iron (npFe0) generates within them. npFe0 significantly changes the optical properties of lunar soils and affects the interpretation of the remotely sensed data of the lunar surface. In this study, a correlation analysis was conducted between npFe0 abundance and reflectance spectra at short wavelengths for lunar soil samples in four size groups based on their spectral and compositional data, collected by the Lunar Soil Characterization Consortium (LSCC). Results show that 540 nm single scattering albedo (SSA) of lunar soils correlates well with their corresponding npFe0 abundance for each size group of lunar soil samples. However, it is poorly correlated with npFe0 abundance when all size groups were considered because of the strong interference from grain size variation of lunar soils. To minimize the effect of grain size, the correlation of npFe0 abundance with the spectral ratio of 540 nm/810 nm SSA of all size groups for LSCC samples was calculated and results show that a higher correlation existed between them (R2 = 0.91). This ratio can serve as a simple empirical model for estimating npFe0 abundance in lunar soils. However, bias could be introduced to the estimation result when lunar soils possess a high content of agglutinitic glass and ilmenite. Our future work will focus on improving the model’s performance for these lunar soils.

Propagation of Solid-Phase Iron Reduction in a Layer of Ilmenite Concentrate

Processing of titanium-containing ores together with the extraction of all the major elements is currently an urgent problem for the usage of mineral products. It is shown that none of the existing processing schemes allows the simultaneous extraction of all the major useful elements such as iron, titanium and vanadium from titanium-containing iron ores. This problem can be solved using a selective extraction of these elements based on ideas regarding the electron reduction mechanism. The following has been experimentally studied: the reaction propagation of solid-phase selective iron reduction that is deep in the grain layer of ilmenite concentrate from the surface of its contact with the powder of carbon-containing material. The results are presented for determining the amount of released metal phase depending on the distance from the concentrate–reducing agent contact boundary. Based on the results regarding the amount of the released metal phase, a conclusion was made for the diffusion processes in a layer of concentrate grains that contact only between themselves, thus determining the rate of iron reduction process. It is shown that near the contact surface between the solid reducing agent and the layer of concentrate grains, the rate of iron reduction is higher than the formation rate of the phases with high iron content from ilmenite. Deep in the ilmenite concentrate layer, the process of iron reduction is preceded by the formation of an iron-containing silicate phase from the concentrate grains, where iron is reduced earlier than it is in the ilmenite grains. The formation of iron-containing silicate phase promotes ilmenite grains to be sintered. Thus, upon the concentrate layer contacting with solid reducing agent in the absence of contact between each ilmenite grain and solid reducing agent, the point contact between grains and void presence within the layer do not prevent the reduction process propagation in the grain layer that contact only with each other.

Lunar ilmenite content as assessed by improved Chandrayaan-1 M3 data

We map ilmenite abundance on the Moon surface using Chandrayaan-1 M3 data, exploiting the strength of the ilmenite absorption band near 1550 nm. The mapping is carried out for an area comprising the border between Mare Serenitatis and Mare Tranquillitatis. We use an improved filtration of the strip noise that is characteristic of Chandrayaan-1 M3 data. The relation between ilmenite and TiO2 abundances determined with UV–Vis color-ratios is discussed. We compare the total titanium distributions with what is assess from the ilmenite content, finding in all cases TiO2total → TiO2ilmenite. This suggests that titanium is a component of not only ilmenite. A map of the difference between total and in-ilmenite titanium abundances is presented.

A Comparative Study of Different Machine Learning Algorithms in Predicting the Content of Ilmenite in Titanium Placer

In this study, the ilmenite content in beach placer sand was estimated using seven soft computing techniques, namely random forest (RF), artificial neural network (ANN), k-nearest neighbors (kNN), cubist, support vector machine (SVM), stochastic gradient boosting (SGB), and classification and regression tree (CART). The 405 beach placer borehole samples were collected from Southern Suoi Nhum deposit, Binh Thuan province, Vietnam, to test the feasibility of these soft computing techniques in estimating ilmenite content. Heavy mineral analysis indicated that valuable minerals in the placer sand are zircon, ilmenite, leucoxene, rutile, anatase, and monazite. In this study, five materials, namely rutile, anatase, leucoxene, zircon, and monazite, were used as the input variables to estimate ilmenite content based on the above mentioned soft computing models. Of the whole dataset, 325 samples were used to build the regarded soft computing models; 80 remaining samples were used for the models’ verification. Root-mean-squared error (RMSE), determination coefficient (R2), a simple ranking method, and residuals analysis technique were used as the statistical criteria for assessing the model performances. The numerical experiments revealed that soft computing techniques are capable of estimating the content of ilmenite with high accuracy. The residuals analysis also indicated that the SGB model was the most suitable for determining the ilmenite content in the context of this research.

Thermogravimetric analysis of chemical reduction processes to produce oxygen from lunar regolith

Various processes exist for extracting oxygen from lunar regolith via chemical reduction for In-Situ Resource Utilization (ISRU). Reduction with hydrogen, methane, possibly carbon monoxide, or gas mixtures are the processes that have predominantly been studied and discussed for this purpose over the past decades. However, it remains unclear how applicable these processes are to lunar highland regolith and how well they compare at temperatures below 1000 °C, above which the material starts sintering and melting. To approach this knowledge gap, a direct comparison of the reduction of pure ilmenite and the highland type lunar regolith simulant NU-LHT-2M was performed by means of thermogravimetric analysis (TGA). Pure nitrogen, hydrogen, and methane were used as process gases for the TGA. The results show that ilmenite is a good reference material for the reduction with hydrogen, which starts at temperatures around 500 °C. Hydrogen can also be used to reduce the very low ilmenite content in NU-LHT-2M, but due to the low weight loss and additional thermal decomposition of several impurities in the simulant this reduction is hardly visible in the TGA. The reduction of ilmenite via methane was demonstrated to be possible in the investigated temperature range. However, the deposition of carbon on the sample lead to a strong contamination of the measurement setup and a steep weight increase that overcompensated the weight loss expected from the release of oxygen. For NU-LHT-2M the reduction via methane is more difficult to assess because of the low weight change and the less pronounced weight loss. Several potential side reactions with decomposition products, such as water, carbon dioxide, and carbon monoxide, at higher temperature additionally complicate the interpretation of results.

Prevention of Barite Sag in Oil-Based Drilling Fluids Using a Mixture of Barite and Ilmenite as Weighting Material

Drilling high-pressure high-temperature (HPHT) wells requires a special fluid formulation that is capable of controlling the high pressure and is stable under the high downhole temperature. Barite-weighted fluids are common for such purpose because of the good properties of barite, its low cost, and its availability. However, solids settlement is a major problem encountered with this type of fluids, especially at elevated downhole temperatures. This phenomenon is known as barite sag, and it is encountered in vertical and directional wells under static or dynamic conditions leading to serious well control issues. This study aims to evaluate the use of barite-ilmenite mixture as a weighting agent to prevent solids sag in oil-based muds at elevated temperatures. Sag test was conducted under static conditions (vertical and inclined) at 350 °F and under dynamic conditions at 120 °F to determine the optimum ilmenite concentration. Afterward, a complete evaluation of the drilling fluid was performed by monitoring density, electrical stability, rheological and viscoelastic properties, and filtration performance to study the impact of adding ilmenite on drilling fluid performance. The results of this study showed that adding ilmenite reduces sag tendency, and only 40 wt.% ilmenite (from the total weighting material) was adequate to eliminate barite sag under both static and dynamic conditions with a sag factor of around 0.51. Adding ilmenite enhanced the rheological and viscoelastic properties and the suspension of solid particles in the drilling fluid, which confirmed sag test results. Adding ilmenite slightly increased the density of the drilling fluid, with a slight decrease in the electrical stability within the acceptable range of field applications. Moreover, a minor improvement in the filtration performance of the drilling fluid and filter cake sealing properties was observed with the combined weighting agent. The findings of this study provide a practical solution to the barite sag issue in oil-based fluids using a combination of barite and ilmenite powder as a weighting agent to drill HPHT oil and gas wells safely and efficiently with such type of fluids.

The Dissolution of Fe in HCl from the Ilmenite Concentrate; Evaluating the Effect of Operating Parameters and Mutual Interactions

Selective HCl dissolution of ilmenite components for obtaining Ti or titanium dioxide (TiO2) has been highly recognized due to its advantages, greater environmental friendliness, and simplicity, compared to H2SO4 and Cl2 methods. The effect of numerous parameters has been studied with the one-factor-at-a-time method. The present study aimed to evaluate the effect of key operation parameters, such as acid-to-solid ratio (A/S: 5 to 20 mL/g), reaction temperature (T: 70 °C to 100 °C), and acid concentration (A pct: 15 to 30 wt pct), on the dissolution of Fe in HCl solution with the minimum Ti losses to the leachate from its abundant, domestic, and low-cost mineral source (Kahnooj ilmenite concentrate) using central composite design–response surface methodology. After 90 minutes of leaching, the Ti/Fe (pct) in terms of dissolved amounts was selected as the process assessment response function. Based on the conducted experimental and statistical analysis, increasing the levels of parameters in the studied domain leads to an increase in Ti/Fe (pct), in the order of A pct > T > A/S. Two statistically significant mutual interactions between A/S-T and T-A pct, with 95 pct confidence level, were revealed for the first time in this study. The optimization strategy was set to the minimization of Ti/Fe (pct) by considering the objective of study and the selected response function. The A/S, T, and A pct were determined to be 5 mL/g, 70 °C, and 15 pct, respectively, for maximum impurity dissolution and minimum Ti loss to the leachate.

A Combined Barite-Ilmenite Weighting Material to Prevent Barite Sag in Water-Based Drilling Fluid.

Barite sag is a serious problem encountered while drilling high-pressure/high-temperature (HPHT) wells. It occurs when barite particles separate from the base fluid leading to variations in drilling fluid density that may cause a serious well control issue. However, it occurs in vertical and inclined wells under both static and dynamic conditions. This study introduces a combined barite–ilmenite weighting material to prevent the barite sag problem in water-based drilling fluid. Different drilling fluid samples were prepared by adding different percentages of ilmenite (25, 50, and 75 wt.% from the total weight of the weighting agent) to the base drilling fluid (barite-weighted). Sag tendency of the drilling fluid samples was evaluated under static and dynamic conditions to determine the optimum concentration of ilmenite which was required to prevent the sag issue. A static sag test was conducted under both vertical and inclined conditions. The effect of adding ilmenite to the drilling fluid was evaluated by measuring fluid density and pH at room temperature, and rheological properties at 120 °F and 250 °F. Moreover, a filtration test was performed at 250 °F to study the impact of adding ilmenite on the drilling fluid filtration performance and sealing properties of the formed filter cake. The results of this study showed that adding ilmenite to barite-weighted drilling fluid increased fluid density and slightly reduced the pH within the acceptable pH range (9–11). Ilmenite maintained the rheology of the drilling fluid with a minimal drop in rheological properties due to the HPHT conditions, while a significant drop was observed for the base fluid (without ilmenite). Adding ilmenite to the base drilling fluid significantly reduced sag factor and 50 wt.% ilmenite was adequate to prevent solids sag in both dynamic and static conditions with sag factors of 0.33 and 0.51, respectively. Moreover, HPHT filtration results showed that adding ilmenite had no impact on filtration performance of the drilling fluid. The findings of this study show that the combined barite–ilmenite weighting material can be a good solution to prevent solids sag issues in water-based fluids; thus, drilling HPHT wells with such fluids would be safe and effective.

Separation of Monazite from Placer Deposit by Magnetic Separation

In this study, mineralogical analysis and beneficiation experiments were conducted using a placer deposit of North Korea, on which limited information was available, to confirm the feasibility of development. Rare earth elements (REEs) have vital applications in modern technology and are growing in importance in the fourth industrial revolution. However, the price of REEs is unstable due to the imbalance between supply and demand, and tremendous efforts are being made to produce REEs sustainably. One of them is the evaluation of new rare earth mines and the verification of their feasibility. As a result of a mineralogical analysis, in this placer deposit, monazite and some amount of xenotime were the main REE-bearing minerals. Besides these minerals, ilmenite and zircon were the target minerals to be concentrated. Using a magnetic separation method at various magnetic intensities, paramagnetic minerals, ilmenite (0.8 T magnetic product), and monazite/xenotime (1.0–1.4 T magnetic product) were recovered selectively. Using a magnetic separation result, the beneficiation process was conducted with additional gravity separation for zircon to produce a valuable mineral concentrate. The process resulted in three kinds of mineral concentrates (ilmenite, REE-bearing mineral, and zircon). The content of ilmenite increased from 32.5% to 90.9%, and the total rare earth oxide (TREO) (%) of the REE-bearing mineral concentrates reached 45.0%. The zircon concentrate, a by-product of this process, had a Zr grade of 42.8%. Consequently, it was possible to produce concentrates by combining relatively simple separation processes compared to the conventional process for rare earth placer deposit and confirmed the possibility of mine development.

Non-isothermal Reduction Kinetics of Iron During Vacuum Carbothermal Reduction of Ilmenite Concentrate

The non-isothermal reduction kinetics and mechanism of iron during vacuum carbothermal reduction of ilmenite concentrate were investigated by X-ray diffraction, backscattered electron imaging, and energy-dispersive X-ray spectroscopy at temperatures from 1273 K to 1673 K (1000 °C to 1400 °C). The pressure dropped and the increasing trend of mass loss and metallization ratios slowed down when the temperature was higher than 1573 K (1300 °C). The reaction products were iron, Ti2O3, and silicate. Iron was mainly obtained by carbothermal reduction of FeTiO3 and FeTi2O5. The irons continued to nucleate, aggregate, and grow during the reduction process. Comprehensive consideration of Satava–Sestak method and Coats–Redfern method, the apparent activation energy of the reduction process was 587.4 ± 2.98 kJ/mol, and the forms of both integral and differential for the mechanism function were G(a)= [(1−a)−1/3−1]2 and f(a) = 3/2(1−a)4/3[(1−a)−1/3−1]−1, respectively.

Influence of nearshore sediment dynamics on the distribution of heavy mineral placer deposits in Sri Lanka

Beach sediments in Sri Lanka contain industrial-grade heavy mineral occurrences. Samples of both offshore and onshore sediments were collected to examine the provenance, mineralogy and geochemical compositions of the heavy mineral occurrences. Coastal morphodynamic changes along the coastline of Sri Lanka were analyzed using the time-series satellite images. These coastal morphodynamic changes were used to identify the prominent directions of monsoon-influenced longshore currents, coastal sediment accretion and depositional trends and their relationships to the provenance of the heavy minerals. Results show the concentrations of detrital ilmenite, zircon, garnet, monazite, and rutile vary in the onshore and offshore sediments. The heavy mineral potential of the northeastern coast is high (average contents of about 45–50% in the Verugal deposit, 70–85% in the Pulmoddai deposit, and 3.5–5.0% in offshore samples stretching from Nilaveli to Kokkilai), compared to sediments in southwest (average content about 10% in onshore sediments and 2% in offshore sediments from the mouth of the Gin River). Therefore, no economic-grade heavy mineral placers were identified in the offshore environments. The high concentrations of heavy minerals in beach sediments and low concentrations in offshore sediments suggest operation of a panning system in the surf zone to form enriched placer deposits. Major and trace element compositions of beach sediments show marked enrichments of TiO2, Fe2O3, La, Ce, Zr, Cr, Nb, Th and V compared to average Upper Continental Crust (UCC) values. Analysis of prominent coastal longshore transport patterns identifies bidirectional sediment transport in the northeast coast of Sri Lanka. In the southwestern coast, two transport directions occur with anti-clockwise transport from Galle to Hambantota, and clockwise transport from Hikkaduwa to Wadduwa. The heavy minerals in the placers were mainly derived from Precambrian metamorphic rocks, and transported to the coast through the river systems of Sri Lanka.

Effect of a Coating Deposited on Foam Glass on the Ability to Absorb High-Frequency Electromagnetic Radiation

The effect of a modified coating, deposited on the surface of foam glass, on the ability to absorb electromagnetic radiation in the high frequency range was studied. It was established that a coating obtained on the basis of a liquid glass composition with ilmenite with 3 μm particles improves the radio absorption characteristics of the foam glass. For 1.5% ilmenite concentration in the coating composition the absorption coefficient of foam glass increases four-fold at 120 GHz and two-fold at 260 GHz compared with uncoated foam glass.

The genesis of the newly discovered giant Wuben magmatic Fe–Ti oxide deposit in the Emeishan Large Igneous Province: a product of the late-stage redistribution and sorting of crystal slurries

A giant Fe–Ti oxide deposit hosted by the Wuben mafic intrusion has recently been discovered in the Pan–Xi area of the Emeishan Large Igneous Province (ELIP). The evolved compositions of the gangue minerals within the Fe–Ti oxide ores indicate that they formed during later stages of magma differentiation than those within the neighboring Panzhihua intrusion or other ore-bearing intrusions in this area. The rocks from the Wuben intrusion and MZb of the Panzhihua intrusion contain compositionally similar silicate minerals and have similar titanomagnetite/ilmenite ratios, suggesting that the former is related to and probably connected to the latter by subsurface magmatic conduits. This indicates that unconsolidated minerals that formed in the MZb flowed as crystal slurries into the Wuben magma chamber during the later stages of evolution of the parental magma. The later secondary enrichment of Fe–Ti oxides by mechanical redistribution and the sorting of crystals as a result of density and size differences generated the Wuben massive Fe–Ti oxide bodies. The ilmenite was commonly saturated in the magma at late stage of differentiation in the ELIP, thereby the associated deposit contains much higher contents of ilmenite. This indicates that future exploration for Fe–Ti oxide mineralization in the ELIP should not merely focus on the lower parts of large layered intrusions but should also include nearby relatively small intrusions or even the upper parts of large intrusions, especially as ilmenite-enriched Fe–Ti oxide deposits may have greater economic value than ilmenite-poor deposits.