NiFe Research Articles

Forecasting open-pit slope runout distances

Geotechnical engineers are routinely tasked with advising suitable stand-off distances below high-risk sections of slopes in open-pit mines that are identified to have potential to deform or collapse. Accurate prediction of failed material runout can mean the difference between continuous safe mining and unwanted high-potential incidents that result in loss of production, equipment damage, injury, or loss of life. This paper updates previous empirical relationships presented by the authors for estimating the volume and runout distance of excavated slope failures, in an open-pit mine operation, using slope geometry as the primary predictor. Cases are sourced from varying slope geometries (fall heights up to 385 m, slope angles up to 80°) and a range of commodities (iron ore, coal, nickel, gold, copper, boron, and limestone), excavated in sedimentary, banded-sedimentary, epithermal, and copper-porphyry deposits, across all six inhabited continents. Analysis of these cases identified positive correlations between slope height and runout distance, and slope height and failed material volume. In general, negative correlations were identified between Fahrböschung angle and slope height, and Fahrböschung angle and failed material volume; however, significant scatter is observed in these datasets. A definitive relationship could not be derived comparing Fahrböschung angle with failed material runout. Slope angle was also found to be a poor indicator of runout. Of the parameters analysed, slope height (i.e., fall height) was found to be the simplest and best predictor of runout distance. This paper presents new charts for predicting failed material runout distance for rock slopes. Relationships are defined for structurally and rock-mass driven slope failure mechanisms at average, 75%, and 95% prediction intervals.

Study on the Catalytic Activity and Selectivity of Manganese Dioxide-Modified Nickel–Iron-Based Hydroxide Electrodes for Initiating the Oxygen Evolution Reaction in Natural Seawater

Transition metal oxides, particularly NiFe(OH)2, are recognized for their high oxygen evolution reaction (OER) activity and structural stability. However, their performance in natural seawater electrolysis remains insufficiently studied. Manganese dioxide (MnO2), which is known for its multiple crystal phases and high OER selectivity, can be incorporated to enhance the catalytic properties. In this study, the OER catalytic performance of carbon cloth-supported manganese dioxide-modified nickel–iron bimetallic hydroxide (MnO2-NiFe-LDH/CC) electrodes was explored in both alkaline and natural seawater. Electrochemical tests demonstrated that the MnO2-NiFe-LDH/CC electrode achieved overpotentials of 284 mV and 363 mV at current densities of 10 mA·cm−2 and 100 mA·cm−2, respectively, with a Tafel slope of 68.6 mV·dec−1 in alkaline seawater. Most importantly, the prepared MnO2-NiFe-LDH/CC electrode maintained stable OER performance over 120 h of testing. In natural seawater, the MnO2-NiFe-LDH/CC electrode outperformed the NiFe-LDH/CC electrode by exhibiting an oxygen evolution selectivity of 61.1%. This study highlights the potential of MnO2-modified nickel–iron-based materials for efficient and stable OER in seawater electrolysis, which offers a promising approach for sustainable hydrogen production in coastal desert regions.

Estimate of Water and Hydroxyl Abundance on Asteroid (16) Psyche from JWST Data

Our understanding of solar system evolution is closely tied to interpretations of asteroid composition, particularly the M-class asteroids. These asteroids were initially thought to be the exposed cores of differentiated planetesimals, a hypothesis based on their spectral similarity to iron meteorites. However, recent astronomical observations have revealed hydration on their surface through the detection of 3 μm absorption features associated with OH and potentially H2O. We present evidence of hydration due mainly to OH on asteroid (16) Psyche, the largest M-class asteroid, using data from the James Webb Space Telescope (JWST) spanning 1.1–6.63 μm. Our observations include two detections of the full 3 μm feature associated with OH and H2O resembling those found in CY-, CH-, and CB-type carbonaceous chondrites, and no 6 μm feature uniquely associated with H2O across two observations. We observe 3 μm depths of between 4.3% and 6% across two observations, values consistent with hydrogen abundance estimates on other airless bodies of 250–400 ppm. We place an upper limit of 39 ppm on the water abundance from the standard deviation around the 6 μm feature region. The presence of hydrated minerals suggests a complex history for Psyche. Exogenous sources of OH-bearing minerals could come from hydrated impactors. Endogenous OH-bearing minerals would indicate a composition more similar to E- or P-class asteroids. If the hydration is endogenous, it supports the theory that Psyche originated beyond the snow line and later migrated to the outer main belt.

Copper-doped nickel–iron metal/metal oxide electrode with improved performance by promoting synergistic effects in the oxygen evolution reaction

Advancing the performance of NiFe catalytic systems for oxygen evolution reaction (OER) is challenging, notably upon incorporating a third transition metal to create a trimetallic configuration. This study introduces a Cu-doped NiFe electrocatalyst, synthesized via a streamlined redeposition technique. The catalyst exhibits a Tafel slope of 38 mV dec−1 and a low overpotential of 248 mV at a current density of 100 mA cm−2, plus a 2.5-fold boost in intrinsic activity. Density Functional Theory (DFT) and spectroscopic analyses demonstrate that Cu doping refines the electronic structure, enhancing charge density around the Fermi level and multiplying active OER sites. The Cu1Fe6Ni18 catalyst features robust Cu–O and Fe–O bond interactions, enhancing charge transport and OER kinetics. Our research elucidates the synergistic effects of Cu and Fe in a trimetallic system, offering an impactful approach to elevate trimetallic catalyst performance.

Isotopic evidence for a common parent body of IIG and IIAB iron meteorites

Magmatic iron meteorites are thought to sample the metallic cores of differentiated planetesimals and are subdivided into several chemical groups, each representing a distinct parent body. The only exceptions are the groups IIAB and IIG, which have been proposed to sample two immiscible melts from the same core. To test this model, we report the first Fe, Ni, O, and Cr isotope data for IIG iron meteorites and the first high-precision O isotope data for IIAB iron meteorites. The new data demonstrate that IIG iron meteorites belong to the non-carbonaceous (NC) meteorites. This is evident from the isotope anomaly of each of the four elements investigated, where the IIG irons always overlap with the compositions of NC meteorites but are distinct from those of carbonaceous (CC) meteorites. Moreover, among the NC meteorites and in particular, the NC irons, the isotopic composition of the IIG irons overlaps only with that of the IIAB irons. The combined Fe-Ni-O-Cr isotope data for IIAB and IIG iron meteorites, therefore, reveal formation from a single isotopic reservoir, indicating a strong genetic link between the two groups. The indistinguishable isotopic composition of the IIAB and IIG irons, combined with chemical evidence for the formation of IIG irons as late-stage liquids of the IIAB core, strongly suggests that both groups originate from the same core. The results underscore the strength of utilizing multiple elements and their isotopic compositions to establish genetic links among meteorites, rather than using a single element. They also highlight the significance of integrating multiple geochemical tracers and petrologic observations to accurately determine genetic relationships and the formation of meteorites within the same parent body.

Study on low-frequency fatigue performance of HT700P nickel–iron based high-temperature alloy

Study on low-frequency fatigue performance of HT700P nickel–iron based high-temperature alloy

Structural Regulation of NiFe LDH under Spontaneous Corrosion to Enhance the Oxygen Evolution Properties.

Electrochemical water splitting holds promise for sustainable hydrogen production but restricted by the sluggish reaction kinetics at the anodic oxygen evolution. Herein, we present a room-temperature spontaneous corrosion strategy to convert inexpensive iron (Fe) on iron foam substrates into highly active and stable self-supporting nickel iron layered hydroxide (NiFe LDH) catalysts. The corrosion evolution mechanisms are elucidated combining ex-situ scanning electron microscopy (SEM) and X-ray photo electron spectroscopy (XPS) techniques, demonstrating precise control over the concentration of Ni2+ and reaction time to achieve controllable micro-structures of NiFe LDH. Taking advantage of the self-supporting morphology and hierarchical micro-/nano- structure, the NiFe LDH with optimized Ni2+ concentration and reaction time exhibits significant small overpotentials of 160 mV and 200 mV for the OER at current densities of 10 mA cm-2 and 100 mA cm-2 respectively, showcasing excellent OER activities. Furthermore, this catalyst demonstrates superior reaction kinetics, high electrochemical stability, and excellent integral water splitting performance when coupled with a commercial Pt/C cathode. The energy-efficient, cost-effective, and scalable spontaneous corrosion strategy opens new avenues for the development of high-electrochemical-interface catalysts.

Impactor identification with spallogenic Cr isotopes: The Wabar impact craters (Saudi Arabia)

AbstractPrecise measurements of Cr isotopic composition of terrestrial impactites have successfully provided evidence for the presence of extraterrestrial material and have, in some cases, allowed the identification of the type of impactor responsible for the formation of the impact structure. The high Cr abundance in most meteorite groups aids in detecting extraterrestrial contamination while their distinct isotopic compositions can help with the identification of the nature of the projectile. However, this common approach of detection and identification of extraterrestrial contamination using mass‐independent 53Cr and 54Cr variations fails when the impactor type is an iron meteorite because of their low Cr abundances (which are in a similar range to terrestrial rocks). The present study demonstrates the viability of a spallogenic Cr contribution in iron meteorites (resulting from their long cosmic ray exposure times), which compensates for their low Cr abundances and facilitates the identification of iron‐meteoritic contamination in terrestrial impactites. Thus, it broadens the scope of impactors (and impactites) that can be investigated using mass‐independent Cr isotopes from solely chondrites and primitive achondrites to include iron meteorites. The Wabar impact craters are an optimal candidate for this study, characterized by low weathering, diverse impactites, partial meteorite survival, substantial impactor material contamination, and a felsic target lithology with low background Cr concentration. The Cr isotopic composition of the Wabar background sand, which represents the target lithology, is indistinguishable from the terrestrial Cr isotopic composition range, whereas the Wabar iron meteorites show coupled spallogenic excesses in ε53Cr and ε54Cr. The Cr isotopic compositions of Wabar impactites show resolved deviations from the terrestrial Cr isotopic composition, thereby indicating the presence of Wabar meteoritic contamination. Moreover, the study demonstrates that even an impactor with a non‐carbonaceous chondritic origin, such as a IIIAB iron meteorite, can have a carbonaceous chondrite‐like signature in ε54Cr anomalies due to spallogenic Cr contamination. The study advocates for a comprehensive investigation combining platinum group elements and Cr (and/or Ni, Ru) isotopes to accurately characterize impactor types.

Synthesis of Copper–Nickel and Iron–Nickel Alloys by Hydrogen Reduction of Mixtures of Metal Oxide Powders

The vast majority of metals production is based on the use of carbon as a reductant and/or a heating fuel. This results in a large amount of carbon dioxide emissions and should be minimized to limit global warming. In this study, powders of copper–nickel alloy and iron–nickel of varying compositions were produced in a single step by reduction of mixtures of Cu2O-NiO and Fe2O3-NiO powders, respectively, using hydrogen as a reductant. Reduction was performed in a horizontal tube furnace at 700 °C for 45 min. All processing was in the solid state and alloys were produced directly from elemental metal oxides. Exhaust gases were analyzed using a gas analyzer to measure the water content to track the progress of the reduction. Reduction was declared complete when the water content in exhaust gases matched the level before hydrogen was introduced. Both copper–nickel and iron–nickel alloys were produced successfully. X-ray diffractometry confirmed the absence of oxides in the product and the presence of solid phases in agreement with the relevant binary phase diagram. Energy-dispersive X-ray spectroscopy in a scanning electron microscope showed macroscopic homogeneity at the expected composition for each powder mixture directly after reduction, with microscopic fluctuations of the order of several mass percent, within the limits of fluctuations observed following typical casting processes. These promising results warrant further investigation to apply this concept to more chemistries and to scale up the process to a pilot scale.Graphical

Nucleation Mechanisms of Electrodeposited Magnesium on Metal Substrates

AbstractMagnesium rechargeable batteries (RMBs) are a promising alternative to lithium‐based ones. However, a major challenge in their advance concerns the development of aprotic electrolytes from which magnesium can be electrodeposited with high efficiency and without the formation of dendrites. Of note, the mechanism of the magnesium electrodeposition from aprotic electrolytes remains largely unexplored. In this study, we propose a combined experimental and theoretical approach based on the Scharifker‐Hills (S−H) mathematical model for the potentiostatic transients to analyse the nucleation and growth of magnesium during electrodeposition in order to shed light on the nucleation process and increase battery safety and cycle lifetime. The model is used to investigate the electrodeposition of magnesium from a Magnesocene (MgCp2)‐based electrolyte onto metal current substrates such as copper, nickel, aluminium and stainless steel.

Innovative ceramic pigments from recycled lithium-ion battery cathodes for inkjet applications

The booming of the electric mobility together with the need of storing renewable energies have increased the demand of lithium-ion batteries which will bring about increasing amounts of electronic waste. Besides, the need for alternative sources of certain raw materials considered critical has changed the perception of determined wastes, which are no longer considered residues but sources of raw materials. In this work, the active cathode material present in end-of-life lithium-ion batteries (Ni, Co, and Mn) was used as secondary raw material, after being properly separated, in the synthesis of a cobalt iron nickel manganese chromium black spinel ((Co, Fe, Ni, Mn) (Fe,Cr)2O4). The pigment was used in the formulation of a ceramic inkjet ink which was deposited over a single-fired porous tile and porcelain tile. Texture and brightness of the ink were not affected by the use of this waste, thus presenting excellent prospects for the industrial ceramic application.

Rational Designing of Nickel–Iron Containing Layered Double Hydroxide [NiFe@LDH] Electrocatalysts for Effective Water Splitting

Rational Designing of Nickel–Iron Containing Layered Double Hydroxide [NiFe@LDH] Electrocatalysts for Effective Water Splitting

Design and Application of High-Density Cold Plasma Devices Based on High Curvature Spiked Tungsten Structured Electrodes

Advances in radar technology have driven efforts to develop effective countermeasures. Plasma is recognized as a highly effective medium for absorbing electromagnetic waves. Recent research has focused on enhancing plasma element performance. This paper achieved ultra-high-density, low-pressure cold plasma with a density of 1.15 × 1012 cm−3, surpassing similar studies by more than an order of magnitude. Tungsten electrodes with high-curvature spiked structures were invented to replace traditional iron–nickel alloy electrodes, increasing plasma density by 88.2% under the same conditions. Lightweight and cost-effective tubular and annular ultra-high-density, low-pressure cold plasma devices were developed, demonstrating exceptional performance in electromagnetic wave absorption, plasma transient antennas, and radar stealth technology. The influence of plasma on electromagnetic waves and its numerical relationship were analyzed. By measuring the radar cross-section (RCS), the reduction in radar detection rates was quantified. The results show that the ultra-high-density cold plasma devices exhibit very low intrinsic RCS values, suitable for plasma antenna applications. The array of plasma elements generates a large-area high-density low-pressure cold plasma. This plasma effectively reduces the radar cross-section (RCS) of metallic equipment in the S and C bands and shows attenuation in the X band. These effects highlight the superior characteristics of plasma technology in electronic warfare. This exploratory research lays the groundwork for further defense applications.

Unveiling the Mechanism in Nickel Loss During the Neutralization of Pregnant Acid Leach Solution by Various Alkaline Chemicals Using Electron Imaging, X-Ray Diffraction, and Electron Energy Loss Spectroscopy Analyses

ABSTRACT Removal of iron and aluminum from nickel-bearing pregnant leach solution is imperative prior to recovering nickel. However, the mechanisms into the loss of both nickel and cobalt in precipitate products during the neutralization process remained unclear and debatable. In this study, the precipitation ratios of nickel, as well as other valuable metals in iron precipitate products, were investigated by examining bulk and surface properties of iron precipitates using X-ray diffraction, infrared spectroscopy, scanning electron microscopy, and electron energy loss spectroscopy. Amorphous ferrihydrite was identified as the major phase for iron precipitates. Over 99% precipitation ratio for iron and aluminum was achieved at pH 3. The loss of nickel in iron precipitates was strongly dependent on solution pHs, and the losses of nickel were found to be 3%, 8%, and 28% at pHs of 3, 4, and 5, respectively. The type of alkaline chemicals impacted the mineralogical composition of iron precipitate products and loss of valuable metals but had a minor impact on iron precipitation ratio. This work revealed three major mechanisms for the loss of nickel and cobalt during iron precipitation process: (1) entrainment of nickel-bearing PLS in filtered products, (2) surface adsorption on iron precipitates, and (3) lattice incorporation of nickel in iron precipitates. Additionally, the result of desorption experiments by H+ and Na+ ions showed that approximately 55–85% of lost nickel was incorporated within the lattice structure of iron precipitates, while the degree of nickel incorporation depends on the type of neutralizing reagents, precipitation conditions, and washing media.

Effect of Isothermal Ageing on Microstructure and Corrosion Behavior of Nickel and Molybdenum-Free High Nitrogen Austenitic Stainless Steel

Effect of Isothermal Ageing on Microstructure and Corrosion Behavior of Nickel and Molybdenum-Free High Nitrogen Austenitic Stainless Steel

Manitou Asinîy and the Strategies of Systemic Colonial Injustice

Manitou Asinîy, known to the Nêhiyawak (Four Spirit/Plains Cree) as the Man from the Sky, is a living Sacred Being that can heal all who come to him. To the Royal Alberta Museum (RAM) he is a 320 lb (145 kg) Group IIIAB medium octahedrite iron meteorite ( Scott et al., 1973 ). Through the autoethnography of myself, Dr. Paulina Johnson, who attended to Manitou Asinîy at the RAM, I address two strategies of systemic colonial injustice: (1) Classifying and (2) Fatiguing by Delay used by the RAM, the Government of Alberta (GoA), and the Alberta Human Rights Commission (AHRC) to maintain possession and control. This case study examines how whiteness and settler colonialism are deeply rooted in colonial institutions and systems to ensure that Indigenous voices and representations are silenced or forced to compliance. This case study is aimed to address how the politics of refusal to be silenced allows for Indigenous resurgence and a recentering of self as an Indigenous woman.

SEARCH FOR STABLE STRUCTURES FOR THE NICKEL-SULFUR SYSTEM AND COMPARISON WITH THE IRON-SULFUR SYSTEM

The core of the Earth consists mainly of iron and nickel, forming an iron-nickel alloy. At the same time, sulfur is one of the potential candidates for the role of a light element in the inner core. To date, many theoretical studies have been conducted by quantum chemical modeling to search for intermediate compositions and structures in systems such as Fe-C, Fe-H, Fe-O, Fe-Si, Fe-S and Fe-P up to pressures of 400 GPa.Despite extensive research on the iron-light element systems, to date no mineralogical model of the Earth's core has been created that fully corresponds to the observed seismological data. A possible reason for this discrepancy may be insufficient consideration of the influence of the core's key alloying element, nickel. Theoretical studies for the nickel-light element system at high pressures have not been sufficiently carried out. Therefore, it is necessary to conduct more in-depth studies of these binary systems in order to further study and identify possible intermediates in triple Fe-Ni-S systems.

Enhancing Magnetic Performance of FeNi50 Soft Magnetic Composites with Double-Layer Insulating Coating for High-Frequency Applications

Soft magnetic composites (SMCs) such as FeNi50 are indispensable in modern electronics due to their high magnetic permeability and low-loss characteristics, meeting the requirements for miniaturization and high-frequency operation. However, the integration of organic materials, initially aimed at reducing the total losses, presents challenges by introducing thermal stability issues at high frequencies. To overcome this obstacle, we propose a double-layer insulating coating method, applying a complete inorganic/organic composite insulation layer to the surface of iron–nickel magnetic powder. The double-layer insulating coating insulation method aims to reduce the total losses, particularly the eddy-current losses prevalent in SMCs. Additionally, the double-layer insulating coating method helps alleviate the thermal stability issues associated with organic materials at high frequencies, ultimately enhancing the magnetic properties of SMCs. We systematically investigated the influence of different resin types on the microstructure of the double-layer insulating coating, accompanied by a comprehensive comparison of the magnetic properties of the resulting samples. The experimental findings demonstrate a significant reduction in the eddy-current losses through the double-layer insulating coating method, with the total losses decreasing by over 95% compared to the initial FeNi50 magnetic powder composite (MPC) materials. Notably, the sodium silicate and silicone resins exhibited superior performances as double-layer insulating coatings, achieving total loss reductions of 1350 W/kg and 1492 W/kg, respectively. In conclusion, the double-layer insulating coating method addresses the challenges related to the total losses and thermal stability in SMCs, offering a promising approach to improve their performance in various electrical and electronic applications.

Production of high-carbon-number naphthenes for bio-aviation fuels from bio-crude prepared by fast pyrolysis of lignocellulose

Lignocellulose has been suggested as a cost-effective, environmentally sustainable substitute for paraffins, aromatics, and naphthenes in aviation fuel. However, bio-crude derived from the fast pyrolysis of lignocellulose poses challenges because of its high acidity and viscosity arising from oxygenates and water; in addition, the low-carbon-number hydrocarbons obtained from lignocellulose-derived sugars and phenols are unsuitable for aviation fuels. In this investigation, high-carbon-number hydrocarbon fuels are generated from bio-crude through condensation reactions between phenols and saturated cyclic alcohols, achieving a heavy fraction similar to that of aviation fuels. The one-pass, four-step continuous-flow reaction of bio-crude is conducted using a catalysis reactor equipped with carbon-supported palladium, titania-supported nickel–iron, hydrogen-form zeolite Y, and tungstate–zirconia-supported ruthenium. In contrast with conventional two-step hydrodeoxygenation methods yielding 1.1% dimeric cycloalkanes, the suggested multi-step reaction produced 4.5 to 4.7% yields of heavier naphthenes containing twelve or more carbon atoms.

Surface modification of mild steel to circumvent challenges in chemical vapour deposition of graphene coating for durable corrosion resistance

Graphene possesses unique combination of characteristics (i.e., inertness, impermeability and toughness) to qualify as ideal coating material for corrosion resistance, and graphene coatings on nickel and copper have been shown to provide excellent and durable corrosion resistances. However, growing graphene directly on mild steel by chemical vapour deposition (CVD), is prohibitively challenging due to high solubility of carbon in mild steel at high temperatures. The non-trivial challenge was circumvented through surface modification of steel by electroplating with Cu and Ni, accounting for the critical consideration, i.e., the inter-diffusivity of iron in nickel or copper. However, the key finding was that the undesirably high thicknesses of the electroplated Cu and Ni layers were detrimental, and optimization of their thicknesses was essential for successful deposition of the required quality graphene. The optimised thicknesses were derived on the basis of the fundamental diffusion calculations. The uniform multi-layered graphene coating on the suitably modified mild steel surface provided remarkable corrosion resistance in an aqueous chloride solution, and electrochemically validation of the corrosion durability for extended exposure (>1000 h) was characterised.