Magnetite Content Research Articles

Theoretical modelling of temperature changes during induction heating of magnetite suspensions

Although now it is customary to use magnetic hyperthermia in the treatment of oncological diseases as an auxiliary method, detailed modeling of the tissue heating process with parameters close to real ones will allow this method to be included in the main ones. Modelling of liquid heating with evenly distributed identical energy sources was presented. It allows choosing the optimal modes of using hyperthermia in real conditions. The model is based on experimental data and explains the dependence of the temperature of magnetite particles’ aqueous suspension versus the time. Newton's law equations were used for modelling of dependence of body temperature versus time at a constant temperature Tenv. It was hypothesized that the overheating problem could be avoided by using controlled concentrations of magnetite. The obtained results show that about 40 mg/cm3 of magnetite is required to avoid overheating.

Sedimentary response to the contrasting provenance and oceanographic conditions on the continental shelf of India

The present study sets out to elucidate how magnetic minerals derived from wide array of source regions respond to shelfal sedimentary processes in a complex shelf system. Bulk sediment magnetic mineralogy comprised of detrital magnetic (magnetite, titanomagnetite, titanohematite) particles with variable concentrations and grain sizes. A prominent change in magnetic mineral contribution from mafic to felsic dominated sediment province is clearly evident through a trend of decline in magnetite content manifested by fining of magnetic crystal size. Elevated magnetite content followed by the presence of fine and coarse-grained magnetic particles, and mere variations interms of mineralogy can be attributed with the enhanced magnetic contribution from the Deccan basalt (DcB) in the shelf sediments off Narmada, Tapti, Mahi, and Sabarmati (NTMS) River system, Arabian Sea. A distinct shift in magnetite content accompanied by abrupt fluctuations in clastic grain size in the sediment core off Ganga-Brahmaputra (G-B) shelf, Bay of Bengal indicate the major change in detrital sedimentation. A major change in the magnetic mineralogy linked with enhanced supply of titanomagnetite particles marks the onset of mafic sourced material in the sediments off Pennar – Swarnamukhi (P–S) shelf, Bay of Bengal. Magnetogranulometry data revealed that magnetic crystal size is independent of physical grain size above >40 μm in NTMS and G-B, and >20 μm in P–S samples. Decoupling is largely due to polycrystalline nature, where fine-grained magnetic particles occurred as inclusions within silt and sand fractions. We demonstrate that multi-proxy approach presented in this study can be effectively used to assess the influence of the contrasting provenance and oceanographic conditions on the shelfal sediment dynamics.

Slag heterogeneity of autogenous copper concentrates smelting

ABSTRACT Due to the deterioration of the raw material base of copper production, it becomes necessary to optimise the autogenous smelting of copper sulfide concentrates, intensify the thermal regime and reduce the loss of copper with slags. There were carried out physico-chemical studies of the properties of slag produced during smelting of copper sulfide concentrates from the Balkhash copper smelter (BCS) in Vanyukov furnaces (VF), using X-ray fluorescence, mineralogical, X-ray diffraction, X-ray microanalysis, thermal analysis. Slag samples were taken at various distances from the furnace bottom (800–2400 mm) when the furnace was stopped. An intermediate layer of variable composition and considerable thickness (250–400 mm), was detected especially at lower smelting temperature, it is located at the bottom of the slag melt, directly on the border with the matte in the VF furnace. The novelty in the obtained data consists in finding the dependence of the formation of the intermediate layer between the slag and matte on the temperature and the content of magnetite in the slag. In addition, it was found that the necessary condition for more complete separation of slag and matte and prevention of intermediate layer formation, is the melting of slag phases, regardless of its composition.

Synthesis and characterization of chalcone based benzoxazine-magnetite nanocomposites

Here, we proposed an approach to develop magnetic chalcone based benzoxazine using different contents of magnetite nanoparticles. A chalcone containing benzoxazine was prepared from 3-(4-hydroxyphenyl)-1-phenylprop-2-en-1-one), stearyl amine and paraformaldehyde through Mannich condensation reaction in a cosolvent of ethanol/toluene (1/1)(v/v). The chemical structure of the prepared benzoxazine monomer was confirmed by FTIR and 1H NMR. Both monomer and monomer mixed with different contents of magnetite were exposed to UV irradiation to induce dimerization via [2p + 2p] cycloaddition followed by thermal curing of oxazine moiety. The crystal structure of magnetite nanoparticles was studied by X-ray diffraction (XRD) analysis. Scanning electron microscope (SEM) was used to examine the surface morphology of the resulted materials. The average size of magnetite nanoparticles was determined by transmission electron microscope (TEM) to be 30–40 nm. The magnetization properties of these materials were measured by vibrating sample magnetometer (VSM). The thermal properties of thermosets were evaluated and compared with nanocomposites using TGA and DSC. The thermosets exhibited good thermal stability and improved with increasing the magnetite contents in the feed.

Recovery of matte from copper slag by using rubber seed oil as green reductant

The traditional fossil reductant used in the copper slag cleaning process cannot fulfill the requirements of sustainable development of the copper industry and environmental protection. Therefore, a new approach of employing renewable rubber seed oil (RSO) instead of a non-renewable fossil reductant to clean copper slag (reduce magnetite concentration and improve matte recovery) was put forward in this study. The cracking characteristics of RSO at high temperature and the effects of technical parameters (such as reduction temperature, oil amount and settling time) on the copper loss, magnetite concentration and RSO utilization degree were thoroughly investigated. The results indicated that the cracking products of RSO at high temperature were mainly composed of C and H2. Under the conditions of a temperature of 1250 °C, an injection of 4 mL of RSO, and a settling time of no less than 1.5 h, the content of magnetite was reduced to less than 1 wt.%, and the content of copper in the upper level of the slag was lowered to be less than 0.57 wt.%, which met the criteria for discarding slag industrially. The copper slag cleaning by RSO is a process of carbon neutrality. The results provide a theoretic basis for the application of bioenergy in non-ferrous metal smelting process.

Effect of Magnetic Interactions on Magnetic Remanence in a Fine Particle System

The magnetic field-dependent remanent magnetization and demagnetization of magnetite nanoparticles dispersed in a frozen isoparaffin oil have been measured as a function of magnetite concentration. Frozen ferrofluid samples with magnetite volume fractions between 7.1% and 0.03% were demagnetized using either thermal or dc demagnetization and were kept frozen at 77 or 4 K during measurement to restrict mechanical rotation and translation of the particles. The magnetization and demagnetization remanences of the frozen ferrofluid were measured and plotted parametrically in the magnetic field magnitude to produce Henkel and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\Delta M$ </tex-math></inline-formula> plots for comparison with the Wohlfarth model. The Henkel and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mathrm {\Delta }M$ </tex-math></inline-formula> plots of the ferrofluid samples with higher concentrations of magnetite deviated from the predictions of the Wohlfarth non-interacting model, consistent with demagnetizing interactions in the system. The magnitude of this deviation decreased with decreasing magnetite concentration. A simple model is presented that quantitatively explains the deviations from the expected relations and can be used in other systems to characterize magnetic interactions.

Study of the Effect of Fluxing Ability of Flux Ores on Minimizing of Copper Losses with Slags during Copper Concentrate Smelting

The article describes the effect of the fluxing ability (FA) of ores used as a flux on slag formation and copper losses. In Kazakhstan, at the Balkhash copper smelting plant (BCSP), currently used fluxes have a very low SiO2 content—about 62%—whereas the Al2O3 content is 12%. Its fluxing ability (FA) was estimated, and it was shown that currently used silica fluxes have an exceedingly low FA. Only half of the fluxes participate in the slag formation. To obtain slags with a low magnetite concentration, a considerable surplus of flux must be added, which will result in a sharp reduction in its melt temperature, increased slag output, and therefore copper losses. The slag structure was studied by means of scanning electron microscopy and electron probe microanalysis (EPMA). To determine one of the primary causes of flux ores’ low FA, it is necessary to use the microstructural pattern of experimental samples.

Magnetic characterisation of London's airborne nanoparticulate matter

Iron-bearing particulate matter produced by vehicle emissions is known to be toxic. To better quantify potential health risks, we have conducted the first magnetic study of a time-series of London's inhalable particulate matter (<10 μm, PM10), captured by three monitoring stations in central London (Marylebone Road, Earl's Court Road and Oxford Street) through 2010 and 2012. We conducted room-temperature analysis on all the samples, and a limited number of samples were analysed at both high and low temperatures. The high-temperature measurements identified magnetite as the dominant magnetic phase. The low-temperature measurements revealed high numbers of nanoparticles, which, assuming magnetite, are in the grain-size range 1–4 nm. It is estimated that as much as ∼40% of the total magnetic signal at 10 K is from particles <4 nm, that are magnetically ‘invisible’ at room-temperature and are being routinely under-estimated in room temperature-based magnetic studies. From the low-temperature measurements, the total concentration of magnetite was estimated at ∼7.5%, significantly higher than previously reported. The room-temperature magnetic data were compared with other pollution data, e.g., NOX and PM10, and meteorological data. Mass-dependent terms like the saturation magnetisation were found to display a strong correlation with NOX and PM10, indicating a common source for these pollutants, i.e., vehicle emissions. Magnetic coercivity measurements, which are independent of abundance, and provide information on grain-size, were consistent across all three sampling localities, again suggesting a major dominant source. Relatively small variations in coercivity were correlated with meteorological events, e.g., temperature and precipitation, suggesting preferential removal of larger airborne grains, i.e., >50 nm.

The Synthesis of Triamine Group Modified Silica Hybrid Material Coated on Muara Kencan Iron Sand for Hg (II) Adsorption

Hg metal was toxic and harmful to the environment because it does not biodegradation, can accumulate in living things, and pollute waters. One method that can be used was adsorption by inorganic-organic hybrid materials. This study aims to synthesize a triamine group modified silica hybrid material coated on iron sand or Magnetic Materials@Silica@Triamine (MM@SiO2@TA) to adsorb Hg(II) metal ions. The study began with the preparation of the iron sand of Muara Kencan Beach using magnets, washing using a solution of 1 M HCl and 0.5 M HF, and coating the material using sodium silica (SiO 25.5-28.5%) modified by a 99% triamine group with co-precipitation. The XRF characterization results showed that the magnetic material of the iron sand of Muara Kencan Beach has an iron oxide (magnetite) content of 73.31%. The iron oxide content increased after washing with HCl solution to 79.12% and HF solution to 81.81%. The results of FTIR, XRD, and TEM characterization showed that the MM@SiO2@TA was successfully synthesized with a size of 63.43 nm. The MM@SiO2@TA was tested to adsorb metal ion Hg(II) at a concentration of 100 ppm, pH 6, and a contact time of 1 hour. The AAS results showed that MM@SiO2@TA could adsorb metal ions Hg(II) as much as 60.82 ppm or 60.82%.

Provenance study of the Miocene hemipelagic sediments in the Shikoku Basin and implication for the earlier history of the Kuroshio Current

The Kuroshio Current (KC) is the biggest western boundary current in the northwest Pacific Ocean and plays an essential role in the Cenozoic climate evolution and ocean circulation changes. Paleoceanography of the Shikoku Basin, located downstream of the KC region, is sensitive to the evolution of the KC. In this study, the Miocene hemipelagic sediment supply in the Shikoku Basin has been investigated on sediments from lithologic Unit III of IODP Site C0011 using a combination of rock magnetism, Sr isotope composition, grain size analysis, and calcareous nannofossil study. Integrated results reveal that multidomain (MD) (titano-) magnetite concentration increases in the upper part of Unit III since ~10–11 Ma with elevated 87Sr/86Sr values (0.712–0.714) and fining up sediment grain size. Magnetic parameters, Sr isotope composition, and grain size, as reliable indicators of sediment sources, have been used to discriminate the geological sources of the sediments and attribute the increase in MD (titano-) magnetite concentration to the increasing detrital input from the East China Sea (ECS), which is rich in fine-grained particles and coarse-grained magnetite and have high 87Sr/86Sr ratio (0.712–0.727). Furthermore, the intensified western boundary current later became known as the KC is interpreted as a plausible reason for increasing fine-grained flux from the ECS. Our study provides a much earlier record of the KC at ~10–11 Ma, giving new insight into understanding the Cenozoic ocean circulation changes and climate evolution in the northwest Pacific Ocean.

Application of suspension magnetization roasting as technology for high-efficiency separation of valuable iron minerals from high-iron bauxite

A technology for suspension magnetization roasting−magnetic separation was proposed to separate iron minerals for recovery. The optimum parameters were as follows: a roasting temperature of 650 °C, a roasting time of 20 min, a CO concentration of 20%, and particles with a size less than 37 μm accounting for 67.14% of the roasted product. The total iron content and iron recovery of the magnetic concentrate were 56.71% and 90.50%, respectively. The phase transformation, magnetic transition, and microstructure evolution were systematically characterized through iron chemical phase analysis, X-ray diffraction, vibrating sample magnetometry, X-ray photoelectron spectroscopy, and transmission electron microscopy. The results demonstrated the transformation of hematite to magnetite, with the iron content in magnetite increasing from 0.41% in the raw ore to 91.47% in the roasted product.

In vitro and in vivo safety profile assessment of graphene oxide decorated with different concentrations of magnetite

In vitro and in vivo safety profile assessment of graphene oxide decorated with different concentrations of magnetite

An Overview of Late Quaternary Studies and Status of Mineral Magnetism from the Konkan Coast: Constrains on Degradation of the West Coast of India

We present here an overview of textural, sedimentological, magnetic, and remote sensing studies from different sectors of the west coast along with new mineral magnetic results. The emerging coastal erosion and growing incidences of extreme events with an increase in cyclones in the Arabian Sea are affecting these beaches at higher rates of dynamics. The sand characteristics, textures, sorting and clast composition have been studied to correlate them with energy conditions and interpret the transportation dynamics. Heavy mineral analyses delineated provenances and detrital pathways, the morphological and volumetric vicissitudes of beaches helped characterize western coast beaches into stable, eroding or depositing regimes aided by time elapsed satellite images. The multi-parametric studies unravel the relationship of hydrodynamics over a range of geomorphic features. The predominant controls of longshore and rip currents in altering the land-sea interfaces at less than decadal scales were observed. New mineral magnetic results from the Vengurla Beach of the Sindhudurg district are evaluated in above context and to establish semiquantitative relations amongst depositional and erosional patterns that can be further linked to the effects of degree and intensity of local monsoon. The beaches record systematic changes in the concentration of magnetite, haematite, maghaemite, and goethite as a result of a combination of the above beach processes. The studies from Vengurla beach successfully demonstrate mineral magnetism as a suitable quantitative approach to depict the quasi-decadal effects of long shore currents that are further governed by the shoreline changes resultant of increasing competitiveness between coastal erosion and depositional conditions in recent years. The status of studies over the west coast depicted an alarming increase in the rates of erosion at several beaches demanding quantitative monitoring using the integrative approach of mineral magnetism and satellite data. Keywords: West Coast, Magnetic Susceptibility, Curie Temperature, Provenance, Sindhudurg.

Modeling quality of concentration factory feedstock in ferruginous quartzite mining at the Lebedinskoe deposit

Statistical modeling of daily average or mean-shift content of useful component in ore hauled from a certain production face to a rehandling point, to an intermediate (including blending) storage, or to a concentration factory enables mine planning to proceed to the next level. This also allows meeting one of the major tasks of the modern mining industry, namely, stabilization of the useful component content in processing feedstock. The geological information quality and initial interpretation are the major factors of data reliability in modeling any mineral mining, production or processing chain. Currently, almost all mining companies in Russia have introduced operational exploration procedures. The analysis of the long-term operational exploration data collectively with the geological exploration data allows determining patterns of useful component in different areas and sites of a mineral deposit. The present research made it possible to obtain magnetite content variation per levels of the test deposit and to reveal correlations between different quality characteristics. Using the statistics on magnetite distribution in the ferruginous quartzite ore body of the Lebedinskoe deposit, as well as with regard to the current capacities of production faces, the simulation model has been constructed in the framework of this research. The model enables prediction of the daily mean content of the useful component in the mineral feedstock of the concentration factory at different number of sampling points and at the varied daily average production capacity.

Modified mortar for wireless powered lighting systems

AbstractA lighting system embedded in a mortar structure powered by an inductive system is described. Different additives with high magnetic permeability were tested to increase power transference efficiency. The best results were obtained using natural magnetite, therefore the impact of different natural magnetite concentrations on the mortar mechanical and electromagnetic properties was investigated. The best results were achieved for samples with 75 wt.% of magnetite. With this composition, three proofs‐of‐concept were fabricated to show the potential of the technology.

Conductivity improvement of magnetite and hematite nanoparticles via admicellar polymerization of polypyrrole

Polypyrrole (PPy) was used to obtain a coating on magnetite (Fe3O4) and hematite (Fe2O3) iron oxide nanoparticles (IONPs). PPy was synthesized on the surface of IONPs by admicellar polymerization for enhancement of electrical conductivity. Low surfactant and monomer levels enabled formation of films on the order of 1 nm thickness. The hydrophobic tendency of the modified IONPs was observed by aggregation in water and exclusion of water molecules. Coated IONPs were characterized by Fourier transform infrared spectroscopic techniques (FT-IR) and scanning electron microscopy (SEM) with particle size distribution analyzed by dynamic light scattering (DLS). Thermal stability of PPy-coated IONPs was investigated by thermogravimetric analysis (TGA). Lastly the magneticity and electrical conductivity of the modified IONPs were analyzed by VSM and multimeter measurements of packed IONPs in a circuit, respectively. Modified IONPs significantly enhanced electrical conductivity with greater effect related to the amount of PPy film coated on the IONP surface. Particle sizes of magnetite and hematite were found within the range between 50 and 2000 nm, depending upon PPy coating. The electrical property was successfully improved, but magnetic properties werenotstatisticallydifferentfrom the bare IONPs. The concentration of Py monomer at 30 mM shown as the critical concentration of both magnetite and hematite had the achievement of the high electrical conductivity.

An enigma in rock magnetism: can microstructures in magnetite cause a threefold increase in the efficiency of NRM acquisition in the Stardalur Basalts?

SUMMARY Quaternary lavas of the Stardalur Caldera, 20 km northeast of Reykjavik, Iceland, create a 27 300 nT magnetic anomaly visible in both ground and aeromagnetic surveys. Here, we provide a comprehensive mineralogical and rock magnetic data set to analyse NRM intensities and Koenigsberger ratios of 57 drill-core samples from the critical zone (CZ) of the anomaly high at depths between 41 and 131 m. This extends previous studies and verifies that the anomaly is due to an unusually high intensity of remanent magnetization carried by magnetite. The NRM of the CZ samples was acquired during the Olduvai subchron in a field of at most today’s strength. NRM intensities range from 20 to 128 A m–1 with a median of 55 A m–1, and an average of 61 A m–1, respectively, approximately 13–15 times higher than in typical Icelandic basalts (AIB) with an NRM intensity of 4 A m–1. Our new data set shows that the magnetite concentration throughout the CZ basalts is at most twofold higher than in AIB lavas. New data on domain state and TRM efficiency prove that these properties account for an additional factor of at most 2.3. Because magnetite is the most abundant remanence carrier in rocks on Earth, and its remanence acquisition is considered to be extremely well understood, we assert that the remaining discrepancy is a critical enigma in rock magnetism. Results from scanning electron microscopy show that a significant fraction of all CZ magnetite particles have dendritic shapes with grain sizes &amp;lt;1 μm, indicating rapid crystallization. Most large magnetite grains are heavily subdivided by very fine oxidation-exsolution lamellae of ilmenite, and subordinate amount of exsolved spinel as needles, blebs and blades. These common microstructures found throughout the CZ subdivide the initially homogeneous mineral into separate cubicles, here denoted as compartments. The magnetite compartments then have sizes below 1 μm. Hysteresis data, Preisach maps and FORC data consistently confirm that the coercivity distribution is dominated by values above 10 mT, such that multidomain behaviour is of little relevance in the CZ. Between 5 and 20 per cent of the IRM is carried by coercivities above 100 mT, which for magnetite indicates unusually high anisotropy effects in the individual particles. Based on the quantitative analysis of all magnetic contributions to the NRM, we can demonstrate that the average efficiency of NRM acquisition in the CZ Stardalur basalts must be at least a factor 3 higher than in typical basalts. We speculate that this is related to the observed focused compartment size distribution &amp;lt;1 μm, and indicates thermochemical remanence acquisition below the Curie temperature of magnetite. Yet, a detailed physical mechanism for the extreme overefficiency of NRM acquisition remains enigmatic.

Mineralogy of a rare Ediacaran epidote‐bearing trondhjemitic complex from the Nubian Shield: Insights into P‐T conditions of magma emplacement

Igneous epidote occurring in tonalite–trondhjemite–granodiorite (TTG) rocks provides valuable insight into the physiochemical parameters of their magmatic system. Epidote has been identified within a newly discovered, rare, Ediacaran, high‐Al TTG‐suite at the Fannani Igneous Complex (FIC), Nubian Shield. The objective is to assess P–T conditions of magma emplacement using petrographic‐, mineral chemical data, and thermobarometry methods. The TTG‐suite is made up of ubiquitous oligoclase, variable contents of quartz, K‐feldspar, amphibole, biotite, epidote, accessory titanite, zircon, apatite and magnetite. Feldspars vary from An14 to An26 in plagioclase, with K‐feldspar having near‐end‐member compositions (Or91–Or95). Amphiboles are Al‐rich (AlT = 1.65–2.04 atoms per formula unit [apfu]), calcic (Ca = 1.83–1.93, apfu), with average Mg/(Fe + Mg) of 0.44, and are ferroedenite–edenite–ferropargasite. Biotites are moderately Fe‐rich (Fe/(Fe + Mg) = 0.50–0.58) characteristic of type ‘C’–biotite of calc–alkaline orogenic rocks. Epidote exhibits pistacite components [Ps = Fe3+/(Fe3++Al)] of Ps24–Ps33, typical of magmatic epidote. The average crystallization pressure of 5.41 kbar (calculated using the Al‐in‐Hb barometer) is consistent with the presence of magmatic epidote and reflects the mesozonal crustal levels of emplacement. The Hb–Plag–geothermometer produced an average crystallization temperature of 721°C. These values fall within experimentally‐determined P–T ranges of stability of magmatic epidote with fO2 buffered from nickel‐nickel‐oxide (NNO) to hematite (HM). The FIC rocks were developed from a wet, subsolvus, orogenic, Al‐rich magmatic system. Findings reported here could have implications for conditions of magma emplacement and mineralogical characterization of TTGs occurring within various continental masses.

The hydrothermal footprint of the Crixás deposit: New vectors for orogenic gold exploration in central Brazil

The main gold deposits of the Archaean-Paleoproterozoic Terrain of Goiás, in central Brazil, occur in the Crixás Greenstone Belt, one of the five volcanosedimentary sequences of this terrain. The Crixás orogenic gold deposit consists of several orebodies structurally controlled by low to moderate angle thrust faults, hosted in different stratigraphic units that exhibit contrasting mineralization styles and hydrothermal alteration assemblages.This study characterizes the hydrothermal footprints of the Palmeiras Structure and Structure IV, which control the orebodies hosted in the hydrothermally-altered mafic metavolcanic rocks and carbonaceous schists, respectively. We assessed the magnitude of fluid-rock interactions by integrating mineralogical, geochemical, and petrophysical data with the reflectance spectroscopy results for drill core samples for both structures.The Palmeiras Structure hydrothermal footprint is characterized by a distal halo composed of Fe-Mg chlorite + biotite ± carbonates (calcite and Fe dolomite), followed by the intermediate halo defined by epidote + carbonates (dolomite, Fe dolomite, and ankerite) ± Fe-Mg chlorite, and proximal halo composed of muscovite + Fe-enriched chlorite ± paragonite, magnetite, tourmaline, Fe dolomite, and ankerite. Additionally, the chemical pattern of the hydrothermal alteration along the Palmeiras Structure has significantly increased concentrations of alkali (K2O, Na2O, Rb, Cs, Li, and Ba), as well as Fe2O3, Al2O3, TiO2, LOI, U, W, Th, and Ta towards the gold mineralization. Also, the high magnetite concentration resulted in high magnetic susceptibility and density, with values above 1432.00×10–3 SI. In Structure IV, the proximal alteration assemblage comprises muscovite + Fe dolomite, Fe-Mg chlorite + arsenopyrite. The lithogeochemical signature is characterized by enrichment in SiO2, CaO, Na2O, K2O, P, Ba, and pathfinder elements As, W, Sb, Te, that increase towards the gold mineralization. A new potential target hosted in the hydrothermalized metabasalt was identified, whose signature is defined by the occurrence of muscovite, chlorite and enrichment in K2O, Ba, Rb, Li Cs and pathfinder elements such as As, W, Sb, Te.This study demonstrates that the integrated application of reflectance spectroscopy, petrophysics and chemical analyses provide a powerful tool for characterizing the hydrothermal footprint and determining the vectors toward gold mineralization in regional-scale mineral exploration.

THE INFLUENCE OF MAGNETITE ON THE RADIO-ABSORBING PROPERTIES OF POROUS GLASS COMPOSITE IN THE HIGH-FREQUENCY REGION

The effect of the addition of magnetite in the form of pyrite stubs on the physico-mechanical and radio-absorbing properties of the synthesized glass composite by the method of “cold” foaming is considered. Replacing glass powder with magnetite in the initial liquid-glass composition reduces the foaming coefficient from 80 to 20 %, which is due to a decrease in the viscosity of the composition due to the particle size of the additive (160 ?m), their high density (5100 kg/m3) and porous structure. It has been established that the optimal content of magnetite for obtaining a material with radio-absorbing properties is no more than 10 %. A porous glass composite with an average pore size of 2, containing 10 % magnetite, has an absorption coefficient of electromagnetic radiation in the high-frequency range (120 – 250 GHz) on average 10 % more than a composite without an additive.