Utilization of Metallurgy—Beneficiation Combination Strategy to Decrease TiO2 in Titanomagnetite Concentrate before Smelting

Excessive TiO2 in titanomagnetite concentrates (TC) causes unavoidable problems in subsequent smelting. At present, this issue cannot be addressed using traditional mineral processing technology. Herein, a strategy of metallurgy-beneficiation combination to decrease the TiO2 grade in TC before smelting was proposed. Roasting TC with calcium carbonate (CaCO3) together with magnetic separation proved to be a viable strategy. Under optimal conditions (roasting temperature = 1400 °C, CaCO3 ratio = 20%, and magnetic intensity = 0.18 T), iron and titanium was separated efficiently (Fe grade: 56.6 wt.%; Fe recovery: 70 wt.%; TiO2 grade 3 wt.%; TiO2 removal: 84.1 wt.%). X-ray diffraction, scanning electron microscopy, and energy dispersive spectroscopy analysis were used to study the mechanisms. The results showed that Ti in TC could react with CaO to form CaTiO3, and thermodynamic calculations provided a relevant theoretical basis. In sum, the metallurgy-beneficiation combination strategy was proven as an effective method to decrease unwanted TiO2 in TC.

Magnetic interference mapping of four types of unmanned aircraft systems intended for aeromagnetic surveying

Magnetic interference source identification is a critical preparation step for magnetometer-mounted unmanned aircraft systems (UAS) used for high-sensitivity geomagnetic surveying. A magnetic field scanner was built for mapping the low-frequency interference that is produced by a UAS. It was used to compare four types of electric-powered UAS capable of carrying an alkali-vapour magnetometer: (1) a single-motor fixed-wing, (2) a single-rotor helicopter, (3) a quad-rotor helicopter, and (4) a hexa-rotor helicopter. The scanner's error was estimated by calculating the root-mean-square deviation of the background total magnetic intensity over the mapping duration; averaged values ranged between 3.1 and 7.4 nT. Each mapping was performed above the UAS with the motor(s) engaged and with the UAS facing in two orthogonal directions; peak interference intensities ranged between 21.4 and 574.2 nT. For each system, the interference is a combination of both ferromagnetic and electrical current sources. Major sources of interference were identified such as servo(s) and the cables carrying direct current between the motor battery and the electronic speed controller. Magnetic intensity profiles were measured at various motor current draws for each UAS, and a change in intensity was observed for currents as low as 1 A.

Recovering Magnetization of Rock Formations by Jointly Inverting Airborne Gravity Gradiometry and Total Magnetic Intensity Data

Conventional 3D magnetic inversion methods are based on the assumption that there is no remanent magnetization, and the inversion is run for magnetic susceptibility only. This approach is well-suited to targeting mineralization; however, it ignores the situation where the direction of magnetization of the rock formations is different from the direction of the induced magnetic field. We present a novel method of recovering a spatial distribution of magnetization vector within the rock formation based on joint inversion of airborne gravity gradiometry (AGG) and total magnetic intensity (TMI) data for a shared earth model. Increasing the number of inversion parameters (the scalar components of magnetization vector) results in a higher degree of non-uniqueness of the inverse problem. This increase of non-uniqueness rate can be remedied by joint inversion based on (1) Gramian constraints or (2) joint focusing stabilizers. The Gramian constraints enforce shared earth structure through a correlation of the model gradients. The joint focusing stabilizers also enforce the structural similarity and are implemented using minimum support or minimum gradient support approaches. Both novel approaches are applied to the interpretation of the airborne data collected over the Thunderbird V-Ti-Fe deposit in Ontario, Canada. By combining the complementary AGG and TMI data, we generate jointly inverted shared earth models that provide a congruent image of the rock formations hosting the mineral deposit.

Millennial-Scale Environmental Variability in Late Quaternary Deep-Sea Sediments from the Demerara Rise, NE Coast of South America

We carried out a rock magnetic study of two deep-sea gravity cores from the Demerara Rise, NE South America. Our previous studies provided radiocarbon and paleomagnetic chronologies for these cores. This study presents detailed rock magnetic measurements on these cores in order to characterize the rock magnetic mineralogy and grain size as indicators of the overall clastic fraction. We measured the magnetic susceptibility, anhysteretic remanence, and isothermal remanence and demagnetized the remanences at several alternating field demagnetization levels. The magnetic intensities estimate the magnetic material concentration (and indirectly the overall clastic fraction) in the cores. Ratios of rock magnetic parameters indicate the relative grain size of the magnetic material (and indirectly the overall clastic grain size). Rock magnetic intensity parameters and rock magnetic ratios both vary systematically and synchronously over the last 30,000 years in both cores. There is a multi-millennial-scale cyclicity, with intervals of high magnetic intensity (high magnetic and clastic content) with low magnetic ratios (coarser magnetic and clastic grain size), alternating in sequence with intervals of low magnetic intensity with high magnetic ratios (finer grain size). There is also a higher-frequency millennial-scale variability in intensity superposed on the multi-millennial-scale variability. There are nine (A–I) multi-millennial-scale intervals in the cores. Intervals A, C, E, G, and I have high magnetic and clastic content with coarser overall magnetic and clastic grain size and are likely intervals of enhanced rainfall and runoff from the NE South American margin to the coastal ocean. In contrast, intervals B, D, F, and H have lower clastic flux with finer overall grain size, probably indicating lower continental rainfall and runoff. During the Holocene, high rainfall and runoff intervals can be related to cooler times and low rainfall and runoff to warmer times. The opposite pattern existed during the Pleistocene, with higher rainfall and runoff during interstadial conditions and lower rainfall and runoff during stadial conditions. We noted a similar pattern of Pleistocene multi-millennial-scale variability in a transect of deep-sea sediment cores along the NE Brazilian margin, from the Cariaco Basin (~10 N) to the NE Brazilian margin (~1° N–4° S). However the NW part of this transect (Cariaco Basin, Demerara Rise, Amazon Fan) has an out-of-phase relationship with the SE part of the transect (NE Brazilian margin) between warm–cold and wet–dry conditions. One possible cause of the high–low rainfall and runoff patterns might be oscillation of the Intertropical Convergence Zone (ITCZ), with higher rainfall and runoff associated with a more southerly average position of the ITCZ and lower rainfall and runoff associated with a more northerly average position of the ITCZ.

Application of electrical and magnetic geophysical methods in depth estimation of potential mineral depositat Olabisi Onabanjo University, Ago Iwoye, Southwestern Nigeria

Geophysical techniques are powerful tools in depth estimation of minerals deposits. This survey was carried out to evaluate the nature and depth of mineral deposits near the Sports complex of Olabisi Onabanjo University (OOU), Ago-Iwoye.’. A total of five (5) Vertical Electrical Soundings (VES) points were investigated using Pasi Terrameter. The spread across the area using the Schlumberger configuration was with a maximum current electrode separation of 100m. The results obtained were interpreted quantitatively and qualitatively using partial curve matching and computer iteration programs known as WINRESIST and SURFER 11. Also, forty one (41) survey profiles were taken at a station interval of 5m using the GEM Magnetometer to acquire the Total Magnetic Intensity reading. The Guassian filter-Oasis Montaj was used for the computation of regional field from the observed TMI readings of the area. The geologic andstructural map reveals a few visible fractured zones imbedded in the migmatite-gneiss deposits which spread from the northwest to the southern and eastern part of the study area and the granite gneiss was seen around the Southwestern and Northern parts. The delineated fractures could potentially serve as geologic traps for mineral localization. The 2D radial average power spectrum indicates that, the northeast part of the mapped area has a depth of 4.5mand a depth of 13m at the eastern part. It can be seen that the depth are shallow and there are visible outcrops at the study area.The approximate depth to the mineral deposit was determined using the standard Euler solution to be around 13 m and the elevation range obtained varies between 37 m – 50 m. The correlation of the electrical and magnetic techniques shows that both methods are able to give the estimated depth of shallow mineral deposit which range between 13 m – 18m. Keywords: Euler solution, Geophysical Techniques, Lithology, Total Magnetic Intensity, Vertical Electrical Sounding.

An Effective Inhibitory Strategy of Low Steady Magnetic Field on Ovarian Cancer

To estimate the effect of a steady-state magnetic field (SMF) with low magnetic intensity gradient on the apoptosis-promoting factors related to cancer cells, we systematically select SMF with 0.2T, 0.4T and 0.6T to study their effect on different ovarian cancer lines. An in vitro cell model system about two kinds of ovarian cancer lines is established, whose viability and intracellular factors are detected by CCK-8, confocal microscopy and flow cytometry method. The results demonstrate that the apoptosis rate of ovarian cancer cells is increased with the enhancement of SMF magnetic intensity. Furthermore, we detect an increasing ROS and intracellular Ca2+ levels in ovarian cancer cells, which can be caused by SMF. The results suggest that ROS and Ca2+ levels are the main reason for the significant apoptosis of ovarian cancer cell lines in SMF. Moreover, an in vivo experiment also reveals that SMF has a strong inhibitory effect on ovarian cancer. Therefore, the inhibitory strategy is an effective, which has a great potential in the treatment of drug-resistant ovarian cancer.

Computational investigation of non-uniform magnetic field on thermal characteristic of nanofluid stream inside 180∘ elbow pipe

The thermal efficiency of the heat exchanger is substantial in chemical and mechanical systems. The presence of the non-homogeny magnetic field considerably enhances the heat rate of nanofluid stream. In this exploration, the presence of the non-uniform magnetic intensity on the heat rate of nanofluid stream is noted inside the 180[Formula: see text] elbow pipe. FVM is used to model the flow characteristics and temperature distribution through the 180[Formula: see text] elbow pipe. Our major focus is to demonstrate the main influences of the non-uniform FHD on flow stream and heat transfer of nanofluid in various inlet velocities and magnetic intensities. Achieved outcomes display that growing the magnetic intensity from 1e + 6 to 4e + 6 enhances the average Nusselt number about 30%. Our findings show that increasing the inlet velocity to Re = 100 decreases the magnetic effects about 17% on the heat transfer growth.