Reduction Of Nickel Research Articles

Coupled Preparation of Ferronickel and Cementitious Material from Laterite Nickel Ores.

Nickel slags can be produced through ferronickel preparation by the pyrometallurgical processing of laterite nickel ores; however, such techniques are underutilized at present, and serious environmental problems arise from the stockpiling of such nickel ores. In this study, a modification to the process of ferronickel preparation by the direct reduction of carbon bases in laterite nickel ores is proposed. The gangue from the ore is used as a raw material to prepare a cementitious material, with the main components of tricalcium silicate and tricalcium aluminate. By using FactSage software, thermodynamic calculations are performed to analyze the reduction of nickel and iron and the effect of reduction on the formation of tricalcium silicate and tricalcium aluminate. The feasibility of a coupled process to prepare ferronickel and cementitious materials by the direct reduction of laterite nickel ore and gangue calcination, respectively, is discussed under varying thermodynamic conditions. Different warming strategies are applied to experimentally verify the coupled reactions. The coupled preparation of ferronickel and cementitious materials with calcium silicate and calcium aluminate as the main phases in the same experimental process is realized.

Моделирование совместного восстановления железа и цветных металлов (никеля, меди, свинца и цинка) из оксидных расплавов конвертированным метаном

The purpose of the article is to assess the application possibility of methane of various conversion methods (СО2, Н2О, О2) for combined reduction of iron and non-ferrous metals (nickel, copper, lead and zinc) from B2O3-CaO-Fe2O3-МеО oxide melts in the temperature range of 1273-1673 K. Thermodynamic modeling is carried out using a technique, which allows to estimate the variations in phase compositions depending on the amount of the reducing agent induced. The technique differs from the known ones by sequential calculation cycles with the removal of the formed gases and the metal phase from the working fluid composition. It is found that regardless of gas composition the process goes on in several stages. In the case of the combined reduction of iron and nickel (lead or zinc), the first stage is reduction of Fe2O3 to Fe3O4 and FeO. The content of Fe2O3 decreases, while the contents of FeO and Fe3O4 increase (at the end of the stage the content of Fe3O4 reaches its maximum value). At the second stage, there is the transition of Fe3O4 → FeO when the values of the contents of Fe2O3 and Fe3O4 decrease to negligible values. The third stage features the manifestation of the metallic phase. In the case of the combined reduction of iron and copper, the process can be divided into three stages according to the variations of the content of iron oxides, and into two stages according to the variations of the content of CuO and Cu2O. The first stage of iron reduction ends at the moment when the content of magnetite reaches its maximum value, the second stage finishes when the metallic phase appears. The first stage of copper reduction includes the transition of CuO to Cu2O and achievement of the maximum value of Cu2O content. The second stage includes the reduction of copper from Cu2O. A gas with the increased content of hydrogen, which corresponds to methane steam reforming is shown to be the most effective reducing agent. The results obtained make it possible to predict the parameters of the metal reduction process during oxide systems bubbling by methane conversion products. The results will be useful for the development of technologies for selective reduction of metals.

Simultaneous removal of Co, Cu, Cd and Ni from zinc sulfate solution by zinc dust cementation

Instead of conventional two or three-stage zinc dust cementation purification, one-stage purification was proposed to remove copper, cadmium and nickel as well as cobalt by CuSb activation simultaneously from solution for an electrolytic zinc production process under development by MMG Limited. Copper was rapidly removed, forming a porous copper shell around a zinc particle. The shell acted as a cathode for the reduction of cobalt, cadmium, and nickel while the zinc particle dissolved anodically. The measurement of hydrogen evolution as well as slurry potential explains how the reduction and re-dissolution of cobalt, cadmium and nickel as a function of time is influenced by temperature, pH, and antimony and zinc dust dosages, providing a deeper understanding of impurity removal. Cobalt, cadmium and nickel were initially removed without back reaction. When zinc dissolved to a certain degree, the shell potential exceeded their redox potentials and the impurities started to re-dissolve. The shell potential was determined by the electrical contact between a zinc particle and the shell, the portion of the remaining zinc and the surface product on the zinc particle. The zinc dissolution weakened the electrical contact and therefore increased the shell potential. Temperature, pH, and antimony and zinc dust dosages not only affect the impurity reduction but also zinc dissolution, the shell potential and finally the impurity re-dissolution in different degrees. Copper, cadmium, cobalt and nickel can be completely removed in one step. The optimal conditions for impurity removal are recommended.

Selective Reduction of Southeast Sulawesi Nickel Laterite using Palm Kernel Shell Charcoal: Kinetic Studies with Addition of Na2SO4 and NaCl as Additives

The aim of the reduction process is to concentrate nickel at high temperatures with a certain carbonaceous material as a reducing agent. The use of chemicals like Na2SO4 and NaCl in the reduction process can increase the content and recovery of nickel in ferronickel concentrates. A selective reduction of laterite nickel was carried out in a non-isothermal and an isothermal using palm kernel shell charcoal as a reductant and with Na2SO4 and NaCl as additives. Firstly, the raw material is made into a pellet and dried in an oven at 100 °C for two hours. The pellets are weighed before and after the reduction process. The non-isothermal reduction process used the Thermal Gravimetric Analysis (TGA) method from a temperature of 100 to 1300 °C, with a heat rate of 10 °C per minute. The isothermal reduction at temperatures 500, 600, 700, 950, 1050, and 1150 °C occurred with a reduction time of 30, 60, and 90 minutes. The analysis is Inductively Coupled Plasma (ICP) to determine the content of nickel and iron from the reduction process, X-ray Diffraction (XRD) to see changes in the phases formed after the selective reduction process, and Scanning Electron Microscopy (SEM-EDX) for viewing the microstructure of the phase. The Differential Thermal Analyzer-Temperature Gravimetric Analysis (DTA-TGA) results show the endothermic at 256 °C, and the exothermic peak at 935 °C with a total mass loss of 42.15% at 1238 °C. The shrinking core model was used for the kinetic studies of the reduction process. The closest kinetic model to the experimental results is the Ginstling-Brounshtein model, with an activation energy value of 8.73 kcal/mol. Copyright © 2020 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

Preparation of an ultrafine nickel powder by solid-phase reduction with a NaCl separator agent

This paper explored a solid-phase reduction method to prepare ultrafine nickel powder under different conditions. The effect of a NaCl separator agent on the morphology, primary particle size and specific surface area of the prepared nickel powder is discussed. The results show that direct contact among primary Ni particles can be effectively inhibited during the reduction of nickel oxalate due to the presence of the NaCl separator agent. An ultrafine nickel powder with a primary particle size of between 80 and 150 nm can be prepared with NaCl as the separator agent at temperatures from 400 °C to 460 °C. The powder reduced at 430 °C has a uniform particle distribution and a decreased amount of agglomeration.

Thermodynamic simulation of silicothermal process of nickel and iron reduction from oxides

For stainless steel production, chromium and nickel-containing ferroalloys are used. Oxidized nickel ores are reduced by carbo- and metal-thermic methods for obtaining ferronickel. The nickel and iron reduction process from oxide system studied by method of thermodynamic simulation. The system composition was as follows, %: 1.5 CaO, 53.6 SiO 2 , 18.4 MgO, 4.8 Al 2 O 3 , 20 FeO, 1.5 NiO, 0.05 P 2 O 5 , 0.15 SO 3 . As the reducing agent the composition of the iron-containing alloy with a silicon content of from 5 to 65% was used. The flow rate was calculated by stoichiometry for the full reduction of Ni and Fe. The HSC Chemistry 6.12 software package developed by Outokumpu (Finland) was used for the thermodynamic simulation. The chemical compounds Ni 3 Si and Ni 5 Si 2 were added into the database. The calculation was accomplished by application the “Equilibrium Compositions” subroutine at a gas pressure of 1 atm, containing 2.24 m 3 of N 2 . The simulation results indicate the thermodynamic possibility of nickel and iron reduction from the CaO-SiO 2 -MgO-Al 2 O 3 -FeO-NiO system by silicon of ferrosilicon. It was found that increasing the silicon concentration in [Si] FeSi ferrosilicon from 5 to 65% results in increasing the nickel content in the [Ni] alloy from 1.24 to 6.55% at t = 1500°C, increasing the degree of iron reduction η Fe from 88.8 to 91.4%, and nickel η Fe remaining almost unchanged, in the amount 99.8-99.7%. The Gibbs energy of the reactions ∆ r G°( T ) of NiO and FeO reduction by silicon was calculated at temperatures of 1500, 1600 and 1700°C using the “Reaction Equations” subroutine. The change in the degree of silicon helpful usage φ Si on the temperature at various Si concentrations in ferrosilicon was studied. The highest value of φ Si of 94.5% was obtained at t = 1500°C and FeSi65, and the lowest of 89.4% at t = 1700°C and FeSi5. The TM results of the NiO reduction process with iron (at 0% Si) were obtained at other factors being equal. The degrees of nickel reduction η Fe i of 56.6% and iron η Fe of 0.68% were calculated at consumption of the reducing agent by stoichiometry. The degree of nickel reduction η Fe was 80.6% and iron - 2.13% at the increase of the consumption of the reducing agent - iron - 1.5 times. The chemical composition of the alloy was as follows, %: 1.24-6.55 Ni, 98.3-91.7 Fe, 0.35-1.28 Si, 0.063-0.334 S, 0.023-0.122 P. The results of simulation can be used for elaborating a technology of Fe-Si-Ni production from oxidized nickel ore by silicothermic method.

Evaluation of lead and nickel in wheat (Triticum aestivum L.) using sugarcane biochar

Today, heavy metal contamination in soil due to toxicity, stability, high shelf life in soil, and elemental accumulation in foods is considered to hazardous biologically and ecologically. This study aimed to investigate the distribution of lead and nickel in wheat using sugarcane biochar. The experimental design was factorial with a completely randomized design in triplicate, and the factors included sugarcane biochar at four levels of zero (control), 2, 4, and 6% of soil weight and soil type (contaminated and non-contaminated with lead and nickel). Lead (500 mg/kg) and nickel (250 mg/kg) were added to each pot based on the threshold and critical levels of contaminated agricultural soil. The maximum lead in roots (1,771.8 mg/kg), stems (119.73 mg/kg), and grains (32.36 mg/kg) and maximum nickel in roots (562.5 mg/kg), stems (39.54 mg/kg), and grains (9.4 mg/kg) were measured in the contaminated soil. The maximum reduction of lead and nickel in the plants was measured using 6% biochar, and the reduction rate of lead in roots, stems, and grains with 6% biochar was 22.2, 75.7, and 83.3%. The reduction rate of nickel in roots, stems, and grains was 16.9, 81, and 62.8% compared to the biochar absence, respectively. In the contaminated soils, 6% biochar was effective in reducing the lead below the standard level in foods, especially in the grains, while the grain nickel was slightly higher than the food standards, and further investigations should increase food safety.

Thermal and electrochemical reduction of nickel (II) ferriteunder the influence of polymer stabilizers

Thermal and electrochemical reduction of nickel (II) ferriteunder the influence of polymer stabilizers

The Influence of Autoclaving on Diamond Burs Fabricated via Different Methods.

To evaluate the influence of repetitive autoclaving on diamond burs fabricated via different methods. A total of 96 diamond burs were divided into 12 groups according to fabrication method (single-element electroplating, multi-element electroplating, or brazing) and number of times autoclaved (0, 5, 10, or 15). The surface characteristics and components of the diamond burs were examined using scanning electron microscopy (SEM) and x-ray photoelectron spectroscopy (XPS). The cutting efficiency of the diamond burs was tested with a constant-pressure cutting appliance. Compared to the nonautoclaved group, the cutting efficiency of the multi-element and single-element electroplated diamond burs decreased significantly after autoclaving 5, 10, and 15 times (P < .05). The cutting efficiency of the brazed diamond burs started to decrease significantly after 10 cycles (P < .05). Cracks appeared on the surfaces of multi-element electroplated diamond burs after 10 and 15 cycles, but were absent in the single-element electroplated and brazed diamond burs. A reduction of nickel was detected in the multi-element electroplated and brazed diamond burs, but not in the single-element electroplated diamond burs. Repetitive autoclaving could reduce the cutting efficiency of diamond burs. The extent of the reduction was related to fabrication method and number of autoclaving times, suggesting that used diamond burs should be separately autoclaved to avoid shortening the life spans of unused ones.

A Study of Nickel and Iron Reduction Silicothermic Process by Thermodynamic Simulation

The results of studying the effect of silicon concentration of ferrosilicon: FeSi5 (5% Si), FeSi20 (20% Si), FeSi35 (35% Si), FeSi50 (50% Si), FeSi65 (65% Si) on the degree of nickel (ηNi) and iron (ηFe) reduction of the CaO-SiO2-MgO-Al2O3-FeO-NiO-P2O5 multicomponent oxide system at a temperature of 1500 °C by thermodynamic simulation are given2. The HSC Chemistry 6.12 software package developed by Outokumpu (Finland) was used for the simulation. The chemical compounds Ni3Si and Ni5Si2 with the corresponding thermodynamic characteristics are entered into the database. The calculations were performed by the “Equilibrium Compositions” subroutine at a gas pressure of 1 atm, containing 2.24 m3 N2, as a neutral additive. The obtained modeling results indicate the thermodynamic possibility of nickel and iron reduction from the CaO-SiO2-MgO-Al2O3-FeO-NiO-P2O5 oxide system by silicon of ferrosilicon. The degree of iron reduction increases from 88.8 to 91.4%, with an increase in the silicon concentration of ferrosilicon [Si]FeSi from 5 to 65%. The degree of nickel reduction with an increase in the silicon concentration of ferrosilicon remains almost unchanged and amounts to 99.8-99.7%. The degree of use of silicon is 92.1–94.5%. The chemical composition of the complex alloy – ferrosiliconickel is determined. The obtained simulation results can be used to develop the technology for producing ferrosiliconickel from nickel ore by silicothermic method.

Thermal Properties of High-Magnesia Oxidized Nickel Ore

The content of elements in the main mineral components of the ore, such as serpentine, talc, and chlorites, were determined. It was shown that, during heat treatment of the ore, in addition to the decomposition of hydrates and carbonates, serpentine decomposes and new phases (forsterite and enstatite) form. On the bases of analysis of the properties of the ore, patterns of phase transitions during heated in inert and reducing atmosphere were identified. It was found that the coal-thermal reduction of nickel and iron from oxides begins at temperatures above 800 °C, and from serpentines begins at temperatures above 1250 °C. It was found that, when heating the ore above 1200 °C in a mixture with a reducing agent, the metals reduce and form iron-nickel alloy. During electro-thermal smelting, the mode of which was determined by the melting points of slag (SiO2– MgO – FeO – CaO – Al2O3system) and ferronickel, the ratio of Ni / Fe in the metallic phase was determined by the consumption of reducing agent (coal, coke).

Nickel oxide reduction in CO/CO2 gas mixtures in reverberatory furnaces

This study present laboratory experiments carried out for nickel oxide reduction in a reverberatory furnace at medium pressure and a temperature range of 400˚C-1050˚C. Analyses were carried out on nickel nanostructures and their partially reduced metallic nickel products using Zeiss Leo Supra 35 SEM. It became evident from the experimental processes that the reduction process of nickel oxide under those given pressure and temperature conditions can result in fractionation of a dense layer of nickel from the melt surface which is in association with continuous growth of gaseous pores in nickel oxide. Therefore thermodynamic processes and temperature conditions are regarded as the most important factors which play a fundamental role in the reduction process of nickel oxide (gas-metal, or/and oxide-metal). The results indicate a positive correlation between formation mechanism and the rate of reduction of metallic nickel phases upon inter. Our research took a step-by-step assessment of technological processes and a scientific observation on nickel reduction at chemical equilibrium state of an ideal gas was made, and an account was taken with regards to limitations of variables and melting parameters.

Nickel(I) salen-catalyzed reduction of 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113): CO2-mediated carbon–fluorine bond cleavage

Cyclic voltammetry, controlled-potential (bulk) electrolysis, gas chromatography (GC), gas chromatography–mass spectrometry (GC–MS), and high-performance liquid chromatography–electrospray ionization–mass spectrometry (HPLC–ESI–MS) have been used to investigate the direct and nickel(I) salen-catalyzed reduction of 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) in both Ar- and CO2-saturated dimethylformamide (DMF) containing 0.10 M tetra-n-butylammonium tetrafluoroborate (TBABF4). Cyclic voltammograms show one irreversible cathodic peak for direct reduction of CFC-113 in CO2-saturated DMF to afford 1-chloro-1,2,2-trifluoroethene (CFC-1113), whereas cyclic voltammograms in Ar-saturated DMF exhibit two irreversible cathodic peaks. Bulk electrolyses of CFC-113 in CO2-saturated DMF at a potential 400 mV more negative than the resolved cathodic peak cause partial reduction of CFC-1113 to yield di-, tri-, and tetrafluoro species. Cyclic voltammograms for reduction of nickel(II) salen in the presence of CFC-113 in CO2-saturated DMF show two cathodic peaks attributable to formation of CFC-1113 and HFC-1123; cyclic voltammograms in Ar-saturated DMF exhibit similar behavior. Bulk electrolyses involving electrogenerated nickel(I) salen in CO2-saturated DMF yield mixtures of HFC-1123, isomers of difluoroethene, and traces of other species. No electrocarboxylation of CFC-113 or its derivatives was seen in the presence of CO2; however, excess CO2 increases the extent of dechlorination of CFC-113 during bulk electrolyses when compared with analogous electrolyses in an Ar-saturated medium. Structural modification of nickel(II) salen during catalytic reduction of CFC-113 in the presence of CO2 was determined with the aid of HPLC–ESI–MS.

Nickel-rhodium nanoparticles as active and durable catalysts for hydrogen liberation

Herein, synthesis, characterization, and catalytic utilization of rather efficient carboxymethyl cellulose-stabilized nickel-rhodium nanoparticles (4.5 ± 0.7 nm) in hydrogen liberation from ammonia borane and hydrazine borane by hydrolysis are reported. The catalysts are prepared by simultaneous reduction of appropriate nickel and rhodium salts in aqueous solution by sodium borohydride by using carboxymethyl cellulose as a stabilizer. Transmission electron microscopy, ultraviolet-visible spectroscopy, and X-ray photoelectron spectroscopy are used to characterize the catalysts. The catalysts are highly durable and effective to liberate hydrogen from ammonia borane and hydrazine borane in aqueous solution at lower concentrations and temperature. Among prepared catalysts, Ni0.50Rh0.50@CMC provides 200 min−1 and 188 min−1 of average turnover frequencies and 46.8 ± 2 kJ/mol and 60.3 ± 2 kJ/mol of activation energies for ammonia borane and hydrazine borane hydrolysis reactions, respectively.

Oscillatory Behavior in Oxidation of Propane Over Nickel Foil and Films

The oxidation of propane was studied over Ni foil, a thick Ni/Si film, and a thin Ni/Si film in a flow reactor under oxygen-deficient conditions at a total pressure near 1 mbar. The thickness of the foil was 125 µm, while the thickness of the films was 20 and 1.5 µm, respectively. It was shown that regular self-sustained reaction-rate oscillations arise only over the Ni foil and the thick Ni/Si film. The relaxation-type oscillations appear at 700 °C after an induction period of approximately 50 min, which is accompanied by the formation of a rough and porous structure over their surfaces. According to krypton adsorption measurements, the effective surface area of the treated catalysts increases significantly. CO, CO2, H2, and H2O were detected as products in the gas phase. The results of operando X-ray absorption spectroscopy study indicate that the oscillations originate due to periodical oxidation and reduction of nickel. The highly active state is Ni in the metallic state, while the transition to the poorly active state is accompanied by the growth of NiO layer on the catalyst surface. The upper layer of the catalysts with a thickness of at least 15 nm is involved in the oxidation/reduction process. In contrast, no oscillations appeared in the oxidation of propane over the thin Ni/Si film. In this case, the thickness of the Ni layer is not sufficient for the formation of a porous structure over the thin Ni film. As a result, the thin Ni film cannot provide high activity in the catalytic oxidation of propane that is sufficient for the self-sustained oscillations to occur. The reasons that lead to oscillatory behavior in the oxidation of propane over nickel are discussed.

Self-sustained Oscillations in Oxidation of Propane Over Nickel: Experimental Study and Mathematical Modelling

The regular reaction rate oscillations were observed by mass-spectrometry in the oxidation of propane over the Ni foil. CO, CO2, H2, and H2O were detected as products. The oscillations of products and reactants in the gas phase were accompanied by the oscillations of the catalyst temperature. It was shown by using isotopic labeling 18O2 that CO and CO2 formed simultaneously by the propane oxidation when the catalyst was in the highly active state. The non-isothermal model of a continuous stirred-tank reactor based on a microkinetic scheme including 50 reaction steps was developed. The model takes into account periodic oxidation and reduction of nickel and formation of main products. Using the method of quasi-steady-state approximations, it was shown that the observed self-sustained oscillations are associated with periodic changes in the coverage of the Ni surface by adsorbed oxygen and carbon as well as nickel oxide species. It was shown that the microkinetic scheme coupled with a continuous stirred-tank reactor model qualitatively describes the experimental data if the model also considers the periodic processes of oxidation and reduction of the Ni bulk.

Photocatalytic Reduction of Nickel using Synthesized nano Titanium Oxide - Acidified neem saw dust Composite from Battery waste

The heavy metals, present in the battery waste water released from industries are extremely toxic and pose a serious threat to public health. The physical adsorption methods are effective, but require an additional adsorbent regeneration step. The degradation of heavy metals in industrial effluents through chemical remediation has also gained tremendous attention due to its enormous applications. Photo catalytic degradation using renewable UV / sun light is one of the most promising techniques due to its simplicity and economy. Till date, various metallic/bimetallic oxides such as TiO2, ZnO, Fe2O3 have been tested for degradation of photo catalytic components due to their superior activity, low price. Attempts have been made to study the photo catalytic degradation of heavy metals using nano Titanium Oxide and Acidified neem saw dust (nTO/ANSD) composite as a photo catalyst.In this present research, nTO/ANSD composite was synthesized and assessed for photo-chemical degradation of nickel in presence of UV light. It was observed that 96.4% Nickel was reduced using photo catalytic process. The X-Ray Diffraction(XRD) and Scanning Electron Microscopy (SEM) for nTO/ANSD studies were also performed. The recovery process of the nTO/ANSD composite photo catalyst is easier and reusability studies shows that the catalyst can be reused to remove the traces of heavy metals with slight reduction in efficiency.

Improved beneficiation of nickel and iron from a low-grade saprolite laterite by addition of limonitic laterite ore and CaCO3

As is well known, the process of direct reduction and magnetic separation is effective route to deal with low-grade saprolite laterite, but generally limited by the reduction of nickel (iron)-bearing minerals and growth of Fe-Ni alloy particles in the reduction process, causing the low recovery of nickel and iron. To improve beneficiation of nickel and iron from low-grade saprolite laterite with 1.29wt.%Ni and 16.31wt.%Fe, co-reduction with limonitic laterite ore and basicity optimization were adopted as strengthening measures in this paper with better economic efficiency than before. The enhancing mechanism was investigated via the thermodynamics analysis and mineralogical study. The phase transformation and growth behaviors of metallic alloy particles during reduction process were revealed as well. The results indicated that co-reduction with limonitic laterite ore is capable of promoting phase transformation from Ni2SiO4 in saprolite laterite to NiFe2O4. CaCO3 can not only destroy the structure of magnesium silicate to release nickel(iron)-bearing phase, but also enhance the reduction of Fe2SiO4 to form efficiently iron-based eutectoid with nickel and liquid phases to accelerate the growth of Fe-Ni fine particles larger than 40μm. A superior crude alloy was obtained with 5.11wt.%Ni and 82.15wt.%Fe with corresponding recovery rates of 91.89% and 85.15% respectively.

Improved Redox Cycling Durability in Alternative Ni Alloy-Based SOFC Anodes

Repeated reduction and oxidation of metallic nickel in the anodes of solid oxide fuel cell (SOFC) causes volume changes and agglomeration. This disrupts the electron conducting network, resulting in deterioration of the electrochemical performance. It is therefore desirable to develop more robust anodes with high redox stability. Here, new cermet anodes are developed, based on nickel alloyed with Co, Fe, and/or Cr. The stable phases of these different alloys are calculated for oxidizing and reducing conditions, and their electrochemical characteristics are evaluated. Whilst alloying causes a slight decrease in power generation efficiency, the Ni-alloy based anodes have significantly improved redox cycle durability. Microstructural observation reveals that alloying results in the formation of a dense oxide film on the surface of the catalyst particle (e.g. Co-oxide or a complex Fe–Ni–Cr oxide). These oxide layers help suppress oxidation of the underlying nickel catalyst particles, preventing oxidation-induced volume changes/agglomeration, and thereby preserving the electron conducting pathways. As such, the use of these alternative Ni-alloy based cermets significantly improves the redox stability of SOFC anodes.

Изучение силикотермического процесса восстановления никеля и железа методом термодинамического моделирования

The results of studying the effect of silicon concentration of ferrosilicon: FeSi5 (5% Si), FeSi20 (20% Si), FeSi35 (35% Si), FeSi50 (50% Si), FeSi65 (65% Si) on the degree of nickel (? Ni ) and iron (? Fe ) reduction of the CaO-SiO 2 -MgO-Al 2 O 3 -FeO-NiO-P 2 O 5 multicomponent oxide system at a temperature of 1500 0 C by thermodynamic simulation are given 2 . The HSC Chemistry 6.12 software package developed by Outokumpu (Finland) was used for the simulation. The chemical compounds Ni 3 Si and Ni 5 Si 2 with the corresponding thermodynamic characteristics are entered into the database. The calculations were performed by the “Equilibrium Compositions” subroutine at a gas pressure of 1 atm, containing 2.24 m 3 N 2 as a neutral additive. The obtained modeling results indicate the thermodynamic possibility of nickel and iron reduction from the CaO-SiO 2 -MgO-Al 2 O 3 -FeO-NiO-P 2 O 5 oxide system by silicon of ferrosilicon. The degree of iron reduction increases from 88.8 to 91.4% with an increase in the silicon concentration of ferrosilicon [Si] FeSi from 5 to 65%. The degree of nickel reduction with an increase in the silicon concentration of ferrosilicon remains almost unchanged and amounts to 99.8-99.7%. The degree of use of silicon is 92.1–94.5%. The chemical composition of the complex alloy – ferrosiliconickel is determined. The obtained simulation results can be used to develop the technology for producing ferrosiliconickel from nickel ore by silicothermic method