Titaniferous Magnetite Research Articles

The changing technology trends in processing titaniferous magnetite

ABSTRACT Titaniferous magnetite deposits are a significant source of vanadium for use in high-strength steel alloying and other chemical applications as well as producing titanium slag for the chloride production of titanium pigment. Ore beneficiation is practised to generate an iron-based mineral concentrate containing much of the vanadium with low combined silica and alumina levels of less than 4%. If higher than 4% increased sodium salt is used in roasting lower vanadium recovery is achieved. Typical processing problems encountered are fine liberation size, potential over-grinding of the magnetite, and variable response to magnetic separation as a result of the weathering profile. Magnetic separation is the standard route to produce iron vanadium concentrates. Salt roasting to extract vanadium followed by water leaching has been the standard processing route for many years and this locks up the remaining titanium in a glass phase. The cost of suitable sodium salts, availability of capital and increasing energy costs and energy availability are critical factors in determining the viability of aspiring vanadium producers. In this paper, factors influencing the recovery of vanadium are reviewed and emerging processing trends are explored. The growing demand for vanadium electrolytes in vanadium redox flow batteries (VRFB) now adds another value-added product, which can assist vanadium project economics.

Thermodynamic analysis of vanadium distribution behavior in blast furnaces and basic oxygen furnaces

Abstract Production data from a vanadium (V)-containing titaniferous magnetite (VTM) smelting blast furnace (BF) ironmaking plant and a V-recovering basic oxygen furnace (BOF) shop were collected over a period of 1 year. The corresponding thermodynamics was analyzed in terms of V reduction in the BF operation and V oxidation in the BOF operation. The thermodynamic calculations were performed using the software Multi-Phase Equilibrium (MPE), in which generalized central atom model was introduced into the description of molten slag and applied for the slag database. The effects of operating conditions on V distribution ratios between slag and hot metal/semi-steel were analyzed and compared with the plant data. The simulated results could reproduce the variation of V distribution ratios with slag temperature and composition and provide the guidance for operators to control V distribution behavior for the better process operation.

Petrogenetic peculiarities of Fe-Ti oxide minerals in the processes of crystallization and evolution of late Cretaceous volcanic complexes of the Lesser Caucasus


 
 
 
 Drawing from the determined differences between iron-titanium oxide minerals, we analyzed the conditions of crystallization and evolution of late-Cretaceous magmatic complexes of the Lesser Caucasus. It was found that the rocks of basalt-andesibasalt complex, which correspond to the early substage (upper Coniacian-lower Santonian) of late-Cretaceous volcanism in the Qazakh, Agjakand, Agdara depressions, have crystallized in the conditions of relatively highly- thermobaric crystallization of titanomagnetite, poorly differentiated and evolutionized according to the Fenner trend. In the second substage of volcanism, due to decrease in permeability of the Earth’s crust, the elevation of the remaining magma to the upper horizons was hindered. Therefore, within the Qazakh depression, shallow intermediate sites of crystallization developed where moderately titaniferous magnetite crystallized with the participation of oxidized fluids earlier than hornblende, pyroxene and plagioclase. Thus, the remaining magma evolutionized its composition through Bowen’s reaction series. In the Agjakand and Agdara depressions, change of previous expansion to compaction was the cause of hindering of partly fractioned portion of the magma. The latter thermally interacted with the above-embedded maghemite, hematite and in a number of cases magnetite. In the Khojavand depression, rocks of trachibasalt- trachiodolerite complex, which characterize the late substage of the Santonian volcanism, contain moderately titanium magnetites and maghemites. In the second substage of volcano-plutonism, rocks of tephrite-teshenite complex developed. There, accompanied by oxidized fluids, highly-clayey titanomagnetite crystallized before chrome-diopside and salite. However, the ulvospinel titanomagnetite in teshenites, having associated with barkevikite and kaersutite, crystallized at a relatively higher temperature. Within the Senonian volcanites of the Azykh depression, along with the moderately-titanium magnetite, chromic titanomagnetite and rarely chromite was determined. Similar mineralogical diversities are also characteristic for the Gochas depression.
 
 
 

An investigation of Fe‐Ti, V in the north‐east Karbi Hills, Shillong Plateau, north‐east India: Implication for mineralization

The Kulamati gabbro‐anorthosite complex in the Karbi Hills of the Shillong Plateau, north‐east India is a newly discovered stratified Fe‐Ti‐V‐bearing magmatic body that has been classified as a titano‐magnetite ore. The host gabbro‐anorthosite is found intruded into the Mesoproterozoic Shillong Group. The stratified Fe‐Ti‐V oxide body consists mostly of magnetite‐rich and magnetite‐poor layers. The magnetite‐rich bands are composed of titanomagnetite, haematite, ilmenite, and coulsonite with minor Al‐spinel, while the mineral constituents of silicate bands contain plagioclase, clinopyroxene, olivine, apatite, and chlorite. Titaniferous magnetites display a wide variety of subsolvus features, including Al‐spinel–magnetite–ulvöspinel exsolutions and crystallographically oriented ilmenite exsolutions, but magnetites are exclusively vanadiferous. Comprehensive chemical analyses show that the ore is rich in TiO2 (10.98–12.78 wt%) and V2O5 (1.32–1.47 wt%). Ti is attributed by the presence of rutile, titanite, and ilmenite, while V is attributed by coulsonite as a solid solution component in the titanomagnetite. It records moderate to high Al2O3 (4.51–5.46 wt%), with enrichment of FeO and Fe2O3 (26.22–28.32 wt% and 39.34–42.86 wt%, respectively), which can be attributed to the presence of magnetite‐spinel‐ulvospinel. Higher Fe2O3 and lower FeO are indicative of oxidizing conditions of the ore‐forming environment. The rare earth element (REE) patterns have (La/Yb)N and (Ce/Yb)N ratios comparable to an evolved basaltic melt, with light REE being enriched compared to heavy REE and a positive Eu anomaly. The electron probe micro analyser data of magnetite is conformable with the bulk chemistry, and shows consistently high FeO (70.87–88.06 wt%), Cr2O3 (1.02–2.44 wt%), TiO2 (0.16–6.20 wt%), and V2O3 (1.47–2.26 wt%), with trace amounts of Al, Si, Mg, Mn, and PGE. As per targeted parameters, the ore occurrence distinctly belongs to a stratified Fe‐Ti‐V class, where alternate thick (>1.0 m) and thin (<20 cm) strata resulted from the late magmatic crystallization of the original tholeiitic composition.

Beneficiation of fluxed titaniferous slag to a marketable titania product using the modified upgraded slag process

ABSTRACT Smelting production of a limestone-fluxed titaniferous slag with low MgO content for subsequent beneficiation using the modified Upgraded Slag (UGS) process was investigated, with the aim of producing a marketable titania product. Smelting of titaniferous magnetite (titanomagnetite) with a carbon reductant and limestone flux was conducted in a water-cooled copper crucible in an iron-suscepting induction furnace under argon. The resulting titaniferous slag contained high residual iron (from the susceptor and incomplete iron reduction in the titanomagnetite), which caused crystallization of an ulvospinel. The slag was beneficiated using the modified UGS process, an industrial roast–leach process used for beneficiation of low-titania slag to a feedstock suitable for production of titania pigment. The upgraded product contained 90.5 mass% TiO2, with a recovery of 83%. Although the TiO2 grade met the feedstock specification for pigment production via the chloride route, SiO2, Al2O3, CaO, and Cr2O3 concentrations exceeded the specification and the particle size distribution was too fine.

Leaching Titaniferous Magnetite Concentrate by Alkaline Aqueous Solution

Leaching titaniferous magnetite concentrate with alkali solution of high concentration under high temperature and high pressure was utilized to improve the grade of iron in iron concentrate and the grade of TiO2 in titanium tailings. The titaniferous magnetite concentrate in use contained 12.67% TiO2 and 54.01% Fe. The thermodynamics of the possible reactions and the kinetics of leaching process were analyzed. It was found that decomposing FeTiO3 with NaOH aqueous solution could be carried out spontaneously and the reaction rate was mainly controlled by internal diffusion. The effects of water usage, alkali concentration, reaction time, and temperature on the leaching procedure were inspected, and the products were characterized by X-ray diffraction, scanning electron microscope, and energy dispersive spectroscopy, respectively. After NaOH leaching and magnetic separation, the concentrate, with Fe purity of 65.98% and Fe recovery of 82.46%, and the tailings, with TiO2 purity of 32.09% and TiO2 recovery of 80.79%, were obtained, respectively.

Optimization of Soda ash Roasting-water Leaching Conditions for Vanadium Recovery from a Vanadium-bearing Titaniferous Magnetite Ore

함바나듐 티탄철광으로부터 바나듐 회수를 위한 소다회 (Na2CO3) 염배소-수침출 조건 확립에 대한 연구를 수행하였다. 주요 광물로 자철석 및 티탄철석을 함유하고 있는 광석의 자력선별 정광을 연구에 사용하였으며, 정광 중 바나듐 함량은 V2O5로써 약 0.8%로 분석되었다. 본 연구에서 고려한 염배소 및 수침출 영향인자는 Na2CO3 첨가량, 염배소 온도 및 시간 (이상 염배소 인자), 염배소 산물의 D50 입도, 수침출 온도 및 시간 (이상 수침출 인자) 등이다. 연구 결과, 정광을 20 wt% Na2CO3, 1,000°C, 3시간 조건에서 염배소한 후 D50 2.1 µm, 80°C, 1시간 조건하에서 수침출하였을 때, 바나듐의 최대 침출율 85.2%가 달성되었다.

Production of Metallic Iron from the Pudo Magnetite Ore using End-of-Life Rubber Tyre as Reductant: The Role of an Underlying Ankerite Ore as a Fluxing Agent on Productivity

This research work investigated the nature of a nonmagnetic ore from Pudo in the Upper West Region of Ghana and its fluxing effect on the extent of reduction of the Pudo titaniferous magnetite ore using pulverised samples of charred carbonaceous materials generated from end-of-life vehicle tyres (ELT) as reductants. Reduction studies were conducted on composite pellets of the Pudo titaniferous magnetite iron ore containing fixed amounts of charred ELT and varying amounts (0%, 10%, 15%, 20%, 30%, 40% and 50%) of the nonmagnetic fluxing material in a domestic microwave oven and the extent of reduction was calculated after microwave irradiation for 40 minutes. Analyses by XRF, SEM/EDS and XRD of the nonmagnetic ore revealed an Ankerite type of ore of the form Ca0.95Fe0.95Mn0.1 (CO3)2. From the microwave reduction studies it was observed that premium grade metallic iron could be produced from appropriate blends of the Pudo iron ores using ELT as reductant, with a measured extent of reduction up to 103.8%. Further, the extent of reduction was observed to increase with an increase in the amount of the nonmagnetic fluxing material (Ankerite) that was added as fluxing agent.
 
 Keywords: Ankerite, End-of-life Rubber Tyres, Fluxing Agent, Extent of Reduction

Evaluation of Titania-Rich Slag Produced from Titaniferous Magnetite Under Fluxless Smelting Conditions

Titanium-bearing magnetite ore is generically defined as magnetite with > 1% titanium dioxide (TiO2) and is usually vanadium-bearing. The iron and titanium occur as a mixture of magnetite (Fe3O4) and ilmenite (FeTiO3) with vanadium oxide usually occurring within the solid solution of the titanium-bearing magnetite phase. These ores are currently widely processed in blast furnaces via modified ironmaking processes. Typically, vanadium is recovered as a by-product from the ironmaking process, while the diluted titania slag is stockpiled. Fluxless smelting in a direct-current open-arc furnace is proposed as an opportunity to improve iron and vanadium recovery and potentially unlock the titanium as a slag product. Slags produced from a pilot study are compared to industrial slags produced from ilmenite. The findings from the pilot test show that slag produced under fluxless smelting conditions in an open-arc electric furnace is remarkably similar to industrial ilmenite slags. The test conditions were varied to evaluate the slag and metal composition, and furnace operation, under increasing reducing conditions. The study showed that the slag and metal product was remarkably similar to industrial slag produced from ilmenite.

Mineralogical and geochemical signatures of Quaternary pyroclasts alterations at the volcanic Trindade Island, South Atlantic

This paper reports the composition and alteration products of pyroclasts in the Holocene Paredão volcano (pyroclast 1) and Late Quaternary Morro Vermelho Formation (pyroclasts 2 and 3) of Trindade Island, South Atlantic, Brazil using combined macromorphological, micromorphological, mineralogical and geochemical techniques. The pyroclasts 1 and 2 are interpreted as volcanic tuff breccia deposits, whereas pyroclast 3 is a lapilli deposit. They are dark gray in color with some altered reddish regions and show vesicles and amygdales structures with small greenish crystals of 2.0 mm scattered throughout the matrix. The eruptions can be regarded as Strombolian-type by producing pyroclastic deposits with coarse fragments with high vesicularity and fluidal shape that indicate magmatic degassing and fragmentation. Petrologic and XRD data revealed a mixture of biotite, goethite, ilmenite, anatase, magnetite, hematite, pyroxene, zeolites, and olivine as their main mineral components. Optical microscopy analysis confirms the vesicular and amygdaloid structures, with a hypocrystalline texture and a pale brown stained vitreous mass classified as sideromelane, due to its basaltic composition. The sideromelane changes to a reddish brown and yellowish-brown staining material identified as palagonite, clearly indicating a hydrovolcanic eruption that occurs when the ascending magma comes into contact with water. Infrared analyses in the palagonitized regions revealed the presence of halloysite, suggesting alteration of sideromelane to tubular clay minerals. Amygdales and microfractures are partially or totally filled with zeolites, which are formed by the percolation of water that reacts with the palagonite and precipitation of chemical elements of hydrothermal fluid. Reddish dark brown iddingsite and anhedral crystals of titaniferous magnetites occur in the fractures and edges of the olivine. These crystals are also dispersed in the matrix while some of them are zoned with Cr-rich core and Cr-poor edge, suggesting a deep mantle origin of the magma. The high trace elements content can be related to clinopyroxene (diopside) that include these elements. Geochemical data show that the pyroclasts are undersaturated in silica, plotting in the ultrabasic and foidites fields on the TAS classification diagram.

Episodic mafic magmatism in the Eyre Peninsula: Defining syn- and post-depositional BIF environments for iron deposits in the Middleback Ranges, South Australia

Banded iron formation (BIF)-derived iron ore deposits of the Middleback Ranges, Eyre Peninsula, South Australia, are hosted within Archean to Paleoproterozoic basement in the southeastern Gawler Craton. Mafic sills and dikes are associated with the orebodies throughout the belt and although described previously, have never been studied in detail. Two main types of mafic rocks, amphibolites and dolerites, are distinguishable from field occurrence and mineralogy. Amphibolites interbedded with BIFs from the southern Iron Magnet deposit are characterized by extensive overprinting. These amphibolites contain metamorphic assemblages of coexisting Mg-Fe- and Ca-amphiboles, garnet, corundum, biotite and relict titaniferous magnetite displaying ilmenite exsolution. Amphibolite petrography and geochemistry in the southern part of the belt indicate formation in a complex BIF depositional environment, with possible detrital input of titaniferous magnetite from igneous rocks. In contrast, NW-trending dolerite dikes occur throughout the belt and contain assemblages consisting of igneous magnesiohornblende and plagioclase. SHRIMP U–Pb zircon ages for amphibolites and dolerites yield two age groups. Amphibolite from Iron Magnet yields a 207Pb/206Pb weighted mean age of 2542 ± 15 Ma. The most robust 206Pb/238U weighted mean age of 782 ± 23 Ma for dolerites comes from the Iron Queen deposit in the central part of the Middleback Ranges. LA-ICP-MS U–Pb geochronology of U-bearing hematite from the Iron Knight South deposit yields ages of ~680 Ma. Taken together, these results suggest mafic magmatism contemporaneous with Archean BIF deposition followed by a high-grade metamorphic event (~2.47–2.41 Ga Sleafordian Orogeny). Dikes from Cape Donington, the southernmost point on the Eyre Peninsula are, instead, associated with the 1.73–1.69 Ga Kimban Orogeny, as evidenced by zircon from a pyroxene-rich dolerite, which yields a 206Pb/238U weighted mean age of 1711 ± 14 Ma. The dolerite ages from the Iron Queen deposit provide the first evidence for the presence of the ~800 Ma craton-scale Gairdner Large Igneous Province in the Middleback Ranges. The young U–Pb hematite age from Iron Knight South and post-emplacement alteration of dikes of Gairdner age from the central part of the Middleback Ranges belt provide additional support for multiple events leading to upgrading of iron ores.

Hematite geochemistry and geochronology resolve genetic and temporal links among iron-oxide copper gold systems, Olympic Dam district, South Australia

The Wirrda Well and Acropolis prospects, ~25 km south from the Olympic Dam deposit, are among several dozen examples of iron-oxide copper gold (IOCG) mineralisation forming a 600 km-long province in the eastern Gawler Craton, South Australia. IOCG systems across the province differ in terms of host lithology, iron-oxide mineral associations, intensity of brecciation, and grade of Cu-(U)-Au mineralisation. Previous efforts to provide a geochronological framework for mineralisation, and correlate this with igneous activity, were inhibited by a lack of clear crosscutting features (particularly in breccia-hosted systems) and a scarcity of reliable hydrothermal mineral geochronometers. The earliest generation of hematite, characterised by enrichment in U-W-Sn-Mo and previously reported from Olympic Dam, provides confident U-Pb dates and insights into hydrothermal fluid signatures. Similar hematite is recognised from Wirrda Well and Acropolis, allowing direct comparison between the three IOCG systems. Relationships between early, silician (Wirrda Well) and titaniferous (Acropolis) magnetite and U-bearing hematite at the two prospects differ. Inferred martitisation of magnetite at Acropolis has generated zoned hematite with U-W-Mo-enrichment at constant Sn concentration, but with a marked loss of REE + Y (REY) and Ti, whereas at Wirrda Well, single-crystal zoned hematite, resembling that from Olympic Dam, retains high REY and Sn concentrations. Although morphologies, textures and compositions of U-bearing hematite at Olympic Dam, Wirrda Well and Acropolis vary significantly, a common U-Pb (laser ablation-inductively coupled plasma-mass spectrometry) age of ~1590 Ma is obtained from the most reliable data (207Pb/206Pb: 1598.9 ± 6.3 Ma at Wirrda Well and 1590.6 ± 6.5 Ma at Acropolis). The geochemical signatures of iron-oxides from the two prospects share common trends for U, W, Sn, Mo, high field strength and siderophile elements, comparable with signatures of Fe-oxides from the ‘outer shell’ of the Olympic Dam deposit. Given that datable iron-oxides would seem to be ubiquitous phases throughout the eastern Gawler Craton, the commonality in geochemistry and age of U-bearing hematite from the Olympic Dam district is significant, as it provides a single, traceable mineral to compare IOCG systems across the province.

Copper mineralization and alterations in Gercus Basalt within the Gercus Formation, northern Iraq

The Gercus Basalt is a recently discovered body within the Gercus Formation, which is exposed on both limbs of the large, double-plunging, NW/SE-trending Bekhair Anticline to the north of Duhok city, northern Iraq. The basalt is mostly basanitic and alkaline in nature, greenish to grayish black in color, and very fine-grained, vesicular, amygdaloidal and microscopically porphyritic in texture. It consists of anorthoclase, diopside, forsterite and accessory titaniferous magnetite, ilmenite and apatite as well as their alteration products. The primary minerals are pervasively altered by calcitization, zeolitization, serpentinization, chloritization, silicification, iddingsitization, martitization, and possibly anorthoclasization. Copper mineralization has taken place as veins and fracture/joint-filling which is mostly observed near the northwestern plunge of the anticline where the basalt attains its maximum thickness of about 16 m. Twelve copper minerals were found within veins and fractures, including primary minerals (bornite, chalcopyrite and an unidentified sulfide – Cu2.3FeS3) and their secondary alteration and replacement products represented by sulfides (covellite, digenite, and chalcocite), native copper, cuprite, carbonates (malachite and azurite), silicate (chrysocolla) and possibly sulfates. The copper minerals are in many cases zonally arranged as spherules where the primary minerals acted as cores, surrounded outward by secondary minerals. Primary copper mineralization is of late magmatic hydrothermal origin, postdating the emplacement, consolidation, deuteric alterations, and fracturing/jointing of the Gercus Basalt; followed by the formation of secondary supergene copper minerals as a result of alteration and replacement of the primary copper sulfides along mineralized veins and fractures/joints due to chemical weathering by meteoric and/or groundwater during Eocene time.

Optimization of Reduction Parameters of Quenched Titaniferous Magnetite Ore by Boiler Grade Coal Using Box–Behnken Design

To improve the reducibility of titaniferous magnetite ore (TMO), a technique of high-temperature heating followed by water quenching has been adapted. This quenching technique imparts cracks into the dense TMO which in turn leads to the enhancement of reducibility during carbothermal reduction using boiler grade coal. A major problem associated with TMO is that the reducibility of the ore is very less as compared to haematite owing to its compact dense interlocking structure with polymetallic elements. In this context, a method of effective pre-treatment, i.e., heating at high temperature followed by rapid quenching using water has been used to impart cracks and fissures in the TMO lump to increase the extent of reduction. The quenching parameters, namely quenching temperature (1323, 1373 and 1423 K), quenching time (5, 10 and 15 min) and number of quenching (1, 2 and 3), have been optimized using Box–Behnken design (3-factors, 3-levels) with extent of reduction as the response. A maximum extent of reduction of 81.57% has been achieved at the following optimized conditions: quenching temperature—1373 K, quenching time—15 min and number of quenching—3. Under the identical conditions of reduction for untreated TMO, the extent of reduction is only 56.6%. This confirms the novelty of the repeated heating and quenching process of TMO prior to reduction.

PGE-Enrichment in Magnetite-Bearing Olivine Gabbro: New Observations from the Midcontinent Rift-Related Echo Lake Intrusion in Northern Michigan, USA

The Echo Lake intrusion in the Upper Peninsula (UP) of Michigan, USA, was formed during the 1.1 Ga Midcontinent Rift event in North America. Troctolite is the predominant rock unit in the intrusion, with interlayered bands of peridotite, mafic pegmatitic rock, olivine gabbro, magnetite-bearing gabbro, and anorthosite. Exploratory drilling has revealed a platinum group element (PGE)-enriched zone within a 45 m thick magnetite-ilmenite-bearing olivine gabbro unit with grades up to 1.2 g/t Pt + Pd and 0.3 wt. % Cu. Fine, disseminated grains of sulfide minerals such as pyrrhotite and chalcopyrite occur in the mineralized interval. Formation of Cu-PGE-rich sulfide minerals might have been caused by sulfide melt saturation in a crystallizing magma, which was triggered by a sudden decrease in fO2 upon the crystallization and separation of titaniferous magnetite. This PGE-enriched zone is comparable to other well-known reef-like PGE deposits, such as the Sonju Lake deposit in northern Minnesota.

A study on isothermal reduction kinetics of titaniferous magnetite ore using coke dust, an industrial waste

ABSTRACTIn the present study, isothermal reduction kinetics of titaniferous magnetite ore (TMO) fines (below 75 µm particle size) using coke dust, an industrial waste, in the form of briquettes have been performed at temperatures ranging from 1273 to 1473 K over varying reduction times: 5, 10, 20, 30, 40 & 60 min. This process aims at the efficient utilisation of TMO which can serve as an alternate potential source of iron, titanium and vanadium. Chemical analysis of the briquette reduced at 1473 K for 60 min, yields a maximum of 89.56% degree of metallisation. Contracting geometry (CG3) is found to be the dominant driving mechanism involved and the activation energy of the reaction is evaluated as 59.52 KJ mol−1.

Optimization of Quenching Parameters for the Reduction of Titaniferous Magnetite Ore by Lean Grade Coal Using the Taguchi Method and Its Isothermal Kinetic Study

In the present study, a unique method is adopted to achieve higher reducibility of titaniferous magnetite lump ore (TMO). In this method, TMO is initially heated followed by water quenching. The quenching process generates cracks due to thermal shock in the dense TMO lumps, which, in turn, increases the extent of reduction (EOR) using the lean grade coal as a reductant. The optimum combination of parameters found by using Taguchi’s L27 orthogonal array (OA) (five factors, three levels) is − 8 + 4 mm of particle size (PS1), 1423 K of quenching temperature (Qtemp2), 15 minutes of quenching time (Qtime3), 3 times the number of quenching {(No. of Q)3}, and 120 minutes of reduction time (Rtime3) at fixed reduction temperature of 1473 K. At optimized levels of the parameters, 92.39 pct reduction is achieved. Isothermal reduction kinetics of the quenched TMO lumps at the optimized condition reveals mixed controlled mechanisms [initially contracting geometry (CG3) followed by diffusion (D3)]. Activation energies calculated are 69.895 KJ/mole for CG3 and 39.084 KJ/mole for D3.

Sorting out of Gusevogorsk deposit titaniferous magnetite ore by technological types by methods of geoinformation modeling and preliminary estimation of their washability

A more complete and complex extraction of valuable components in the development of mineral resources is achieved through the separation of technological types and grades of ores, their separate extraction and processing, which allows to increase the yield, quality and nomenclature of commercial products and to raise the economic efficiency of the extraction and preparation processes. An important element of the separate processing of types of ores is the technology used for their zoning by grades in the open-pit space. Innovative direction in the development of the forecast of quality and preparation characteristics of mineral resources is the methods of geoinformation modeling with the use of Geological and Mining Information System technologies. The paper describes the technique of modeling and separation of ores into technological grades on the example of the Gusevogorskoye deposit of titanomagnetites, and presents the method of express ore preparability analysis with the estimation of the degree of contrast of qualitative characteristics.

Origin and prospectivity of heavy mineral enriched sand deposits along the Somaliland coastal areas

Sixty-one heavy mineral enriched samples along the Somaliland coast from Eil Sheikh to Ras Khatib, a distance of about 130 km, were analyzed using X-ray Fluorescence, X-ray Diffraction and SEM-EDS techniques. This study reveals that a considerable amount of heavy minerals is present along the Somaliland coast and confirms the presence of high concentration titanium and iron bearing minerals. However, the backshore deposits in the mouths of Waaheen and Biyo Gure ephemeral rivers as well as raised paleo-beaches in the east of port city of Berbera demonstrate the highest level of titaniferous heavy minerals with most samples showing concentration greater than 50 wt %. The titanium detected in geochemical analysis occurs in the form of ilmenite, rutile, titanite and titaniferous magnetite. Also, present in minor or trace amounts, are garnet, zircon and monazite.Heavy mineral accumulations in the east and west of Berbera have different mineralogical assemblages. The east of Berbera is dominated by quartz with moderate concentration of plagioclase, K-feldspar, magnetite, hematite and titanium bearing minerals, whereas in the west of Berbera, the dominant minerals are quartz, K-feldspar and plagioclase with variable proportions of ilmenite, rutile, mica, amphibole and pyroxene. These variations in mineral assemblages suggest different composition of the catchment areas that supply sediment to these deposits. The catchment area in the east of Berbera consists mainly of Proterozoic crystalline basement of the Qabri Bahar complex, Gabbro-Synenite belt and granitic intrusions that outcrop in Hudiso, Tulo Dibijo and surrounding areas. The primary sources of heavy minerals in the west of Berbera comprise of high-grade metamorphic rocks of the Mora and Qabri Bahar complexes as well as the Miocene volcanics that outcrop in Laferug and Hagabo areas.The heavy mineral sand deposits observed along the Somaliland coast have the potential to provide commercially important heavy minerals, in particular ilmenite. It appears that prospects for development of the heavy mineral sands in the east of Berbera are better than those to the west of Berbera. In general, east of Berbera has wider beaches, better heavy mineral sands in the upper horizons and dune areas with heavier mineral sands. Furthermore, a series of raised paleo-beaches with high concentrations of heavy mineral sands are observed 1–2 km behind the shoreline. However, further investigation, including drilling and laboratory analyses, still needs to be carried out, particularly close to the entrance of Waaheen and Biyo Gure ephemeral rivers to evaluate the potential quality and scale of the deposits.

Fe–Ti(–V) Oxide Deposits of the Kunene Anorthosite Complex (SW Angola): Mineralogy and Thermo-Oxybarometry

The Kunene Intrusive Complex (KIC), in NW Namibia and SW Angola, is one of the largest Proterozoic anorthosite massif-type exposures in the world. A geochemical, mineralogical and petrological study of four Fe–Ti(–V) oxide bodies located in the understudied Angolan part of the KIC has been performed. The massive Fe–Ti(–V) oxide bodies, locally apatite-rich (nelsonites), are lenticular or dike-like. They consist mostly of titaniferous magnetite, ilmenite and minor aluminous spinel, apatite, olivine and graphite. Titaniferous magnetite displays a wide variety of subsolvus features, including aluminous spinel–magnetite–ulvöspinel exsolutions and ilmenite (Trellis) exsolutions. This work estimated the composition of the titaniferous magnetite prior to the exsolution, in order to calculate the temperature and oxygen fugacity of the different lithologies of each ore body. The thermo-oxybarometry results obtained range from 600 °C to 820 °C and fO2 from 10−24.7 to 10−14.7. These values do not correspond to magmatic crystallization in equilibrium, but to a later re-equilibration. In addition, the mineralogical and geochemical results indicate that the studied ore bodies contain economic reserves of Ti, V, and possibly of P and REE.