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

2020 ◽  
Vol 989 ◽  
pp. 511-516
Author(s):  
V.A. Salina ◽  
Vladimir I. Zhuchkov ◽  
Oleg V. Zayakin
Keyword(s):  
Iron Reduction ◽  
Thermodynamic Simulation ◽  
Thermodynamic Characteristics ◽  
Chemical Compounds ◽  
Oxide System ◽  
Silicon Concentration ◽  
Complex Alloy ◽  
Multicomponent Oxide ◽  
Simulation Results ◽  
Hsc Chemistry

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.

Study on the Oxidation Behavior of LPPS MCrAlY Coatings at High Temperature: Part II Coating Microstructure Development

2021 ◽  
Vol 1035 ◽  
pp. 584-590
Author(s):  
Kang Yuan ◽  
Zhao Ran Zheng
Keyword(s):  
High Temperature ◽  
Thermodynamic Simulation ◽  
Thermal Barrier ◽  
Microstructure Development ◽  
Temperature Oxidation ◽  
Bond Coats ◽  
Β Phase ◽  
Mcraly Coatings ◽  
Coating Microstructure ◽  
Simulation Results

MCrAlY can be used as bond coats for thermal barrier coatings (TBCs) with good ductility and excellent resistance against high temperature oxidation and hot corrosion. The behavior of the microstructure development in the MCrAlY coatings plays a key role on the oxidation resistance. In this paper, the microstructure in the coatings oxidized at 750~1100 °C was analyzed. The formation of the phases and their fraction were studied by comparing thermodynamic simulation results with the experimental observations. At higher temperatures (>1000 °C) β-to-γ’-to-γ phase transformation took place while at lower temperatures (<1000 °C) β phase would transfer to γ directly. The results show that the simulation can semi-quantitatively predict the microstructure formed in the coating.

scholarly journals Design, Construction, and Testing of a Gasifier-Specific Solid Oxide Fuel Cell System

Energies ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 1985 ◽  
Author(s):  
Alvaro Fernandes ◽  
Joerg Brabandt ◽  
Oliver Posdziech ◽  
Ali Saadabadi ◽  
Mayra Recalde ◽  
...  
Keyword(s):  
Fuel Cell ◽  
Solid Oxide Fuel Cell ◽  
Exergy Analysis ◽  
Thermodynamic Simulation ◽  
Cell System ◽  
Solid Oxide ◽  
Oxide Fuel ◽  
Fuel Cell System ◽  
Simulation Results ◽  
Design Construction

This paper describes the steps involved in the design, construction, and testing of a gasifier-specific solid oxide fuel cell (SOFC) system. The design choices are based on reported thermodynamic simulation results for the entire gasifier- gas cleanup-SOFC system. The constructed SOFC system is tested and the measured parameters are compared with those given by a system simulation. Furthermore, a detailed exergy analysis is performed to determine the components responsible for poor efficiency. It is concluded that the SOFC system demonstrates reasonable agreement with the simulated results. Furthermore, based on the exergy results, the components causing major irreversible performance losses are identified.

scholarly journals Thermodynamic simulation of oxidation process of the Moss-Mo3Si hypoeutectic alloy, doped with scandium or neodymium

2019 ◽  
Vol 57 (2) ◽  
pp. 90-100
Author(s):  
Alexey V. Larionov ◽  
◽  
Ludmila Y. Udoeva ◽  
Vladimir M. Chumarev ◽  
◽  
...  
Keyword(s):  
Oxidation Process ◽  
Thermodynamic Simulation ◽  
Oxidation Products ◽  
Hypoeutectic Alloy ◽  
Protective Film ◽  
Chemical Transformations ◽  
Reaction Products ◽  
Moist Air ◽  
Condensed Product ◽  
Hsc Chemistry

In order to study the effect of yttrium additives on the oxidation of molybdenum silicide alloys, thermodynamic modeling of the interaction in Mo-Mo3Si-Sc5Si3 и Mo-Mo3Si-NdSi systems with dry and moist air was performed in the temperature range 25-2000 °C. The calculations were performed using the HSC Chemistry 6.12 software, into the database of which the calculated missing thermochemical characteristics silicates, molybdates of scandium and neodymium were entered. Based on the obtained dependences of the composition of phases on temperature and charge of the oxidant (air or vapor-air mixture), the sequence of phase formation was determined and the compositions of oxidation products were estimated. It is shown that, under equilibrium conditions, the oxidation process with dry and moist air proceeds almost equally, since the interaction of the components of the alloy with oxygen is thermodynamically preferable than with water vapor. According to the obtained thermodynamic models, the oxidation process of the Mo-5Si-3(Sc, Nd) (wt.%) alloys involves a sequence of the following chemical transformations: at the beginning Mo and Sc (Nd) silicides oxidize forming Sc2O3 ( Nd2O3), SiO2 and elemental Mo, then molybdenum is oxidized to MoO2 and Sc2O3 or Nd2O3 interacts with SiO2 with the formation of appropriate silicates Sc2Si2O7 или Nd2Si2O7. As a result of the complete oxidation of the alloy, MoO3 and Sc2(MoO4)3 or Nd2Mo4O15 are added to the condensed product, and molybdenum oxide (MoO3)n vapor appears in the gas phase. In addition, the formation of Nd2Mo2O7 and Nd2 (MoO4)3 is possible. During the oxidation of the Mo-5Si-3Nd alloy at T> 1700 oC, Nd(OH)3 can be formed in the condensed reaction products. According to the results of complete thermodynamic analysis, the formation of silicates and molybdates of scandium and neodymium can promote to the formation of a protective film on the surface of the alloys, which limits the diffusion of oxygen in them, and as a result, the oxidation resistance of alloys should increase.

scholarly journals Edge Mostar Indices of Cacti Graph With Fixed Cycles

2021 ◽  
Vol 9 ◽  
Author(s):  
Farhana Yasmeen ◽  
Shehnaz Akhter ◽  
Kashif Ali ◽  
Syed Tahir Raza Rizvi
Keyword(s):  
Upper Bound ◽  
Connected Graph ◽  
Thermodynamic Characteristics ◽  
Chemical Compounds ◽  
Fixed Number ◽  
Common Vertex ◽  
Topological Invariants ◽  
Cactus Graph ◽  
Number Of Cycles

Topological invariants are the significant invariants that are used to study the physicochemical and thermodynamic characteristics of chemical compounds. Recently, a new bond additive invariant named the Mostar invariant has been introduced. For any connected graph ℋ, the edge Mostar invariant is described as Moe(ℋ)=∑gx∈E(ℋ)|mℋ(g)−mℋ(x)|, where mℋ(g)(or mℋ(x)) is the number of edges of ℋ lying closer to vertex g (or x) than to vertex x (or g). A graph having at most one common vertex between any two cycles is called a cactus graph. In this study, we compute the greatest edge Mostar invariant for cacti graphs with a fixed number of cycles and n vertices. Moreover, we calculate the sharp upper bound of the edge Mostar invariant for cacti graphs in ℭ(n,s), where s is the number of cycles.

scholarly journals Thermodynamic modeling of composition and propereties of self-fluxing materials based on the nickel

2020 ◽  
Vol 329 ◽  
pp. 02026
Author(s):  
Nina Ilinykh ◽  
Anastasia Krivorigova ◽  
Boris Gelchinski ◽  
Sergey Ilinykh ◽  
Leonid Kovalev
Keyword(s):  
Melting Point ◽  
Gibbs Energy ◽  
Condensed Phase ◽  
Software Package ◽  
Total Pressure ◽  
Thermodynamic Simulation ◽  
Thermodynamic Characteristics ◽  
Equilibrium Composition ◽  
Argon Atmosphere ◽  
Temperature Dependences

Self-fluxing nickel or cobalt-based alloys that use boron, phosphorus or silicon, as melting point depressants and fluxing agents are thermodynamic simulation of self-fluxing materials Ni-0.5C-15Cr-3.2Si-2B (PGSR-2) and Ni-1C-17Cr-4.1Si-3.6B (PGSR-4) was performed. As the software for simulation of phase and chemical equilibrium the TERRA software package was used. The simulation was carried out in the temperature range 300–3000 K at a total pressure P = 105 Pa in an argon atmosphere. The temperature dependences of the equilibrium composition and thermodynamic characteristics (enthalpy, entropy, and Gibbs energy) of the alloys of the investigated systems were calculated. It is shown that Ni, Cr, C, Ni3B, Ni2B, NiB, Ni2Si, NiSi, CrB, CrSi can be formed in the condensed phase under equilibrium heating of PGSR-2. When PGSR-4 is heated in the condensed phase, along with the above components, Cr5B3, CrB2 and Cr3C2 compounds can be formed. The temperature dependences of the thermodynamic characteristics of the systems studied have kinks that can be explained by phase transformations.

scholarly journals Modeling of the refractory's and slag's phase composition, the slag adjustment optimization and the ladle refining slag's stabilization

2018 ◽  
pp. 4-8
Author(s):  
V. V. Kozlov ◽  
A. P. Shevchik ◽  
S. A. Suvorov ◽  
N. V. Arbuzova ◽  
D. V. Kuznetsov
Keyword(s):  
Phase Composition ◽  
Chemical Composition ◽  
Service Life ◽  
Phase Formation ◽  
Equilibrium Phase ◽  
Oxide System ◽  
Ladle Refining ◽  
Multicomponent Oxide ◽  
Equilibrium Phase Composition ◽  
Mineral Binding

The modeling technique was proposed for the phase formation in the CaO‒MgO‒Al2O3‒SiO2‒FeO‒Fe2O3multicomponent oxide system. The technique can be used to predict the equilibrium phase composition for both the refractory and refractory-slag systems, as well as to modify the metallurgical slag's chemical composition, to extent the metallurgical unit's refractory service life, and in order to attaint the refractory-slag systems the mineral binding properties.Ill. 2. Ref. 7. Tab. 8.

scholarly journals Thermodynamic simulation of the V-Al-N-C master alloy aluminothermic smelting

2019 ◽  
Vol 59 (9) ◽  
pp. 132-139
Author(s):  
Alexey V. Larionov ◽  
◽  
Denis V. Taranov ◽  
Vladimir M. Chumarev ◽  
Leonid A. Smirnov ◽  
...  
Keyword(s):  
Master Alloy ◽  
Elemental Carbon ◽  
Thermodynamic Simulation ◽  
Equilibrium Temperature ◽  
Point Of View ◽  
Temperature Dependences ◽  
C Complex ◽  
Vanadium Carbides ◽  
Hsc Chemistry ◽  
Good Agreement

For microalloying of titanium with nitrogen and carbon, the V-Al-N-C complex master alloy is used. One of the main requirements presented by consumers of this ligature to its composition is oxygen content of less than 0.1 % mass. The use of elemental carbon (graphite) in the mixture for out-of-furnace aluminothermic smelting of the V-Al-N-C master alloy promotes the formation of aluminum oxonitrides in the melt, which, in the process of forming the metal and slag phases, can be stored in the alloy as separate inclusions. Since carbon in the master alloy is present in the form of V2Al0.96C1.1 carbide, it is advisable to replace graphite in the composition of the smelting mixture with an alternative precursor containing carbide of this composition. The paper presents the results of thermodynamic simulation of phase formation occurring in the process of V-Al-N-C master alloy smelting using various carbidizers. The equilibrium temperature dependences were obtained using the HSC Chemistry 6.12 software, the database of which was supplemented by the missing thermochemical characteristics of vanadium aluminides (VAl3, V5Al8, V3Al2) and V2AlC carbide borrowed from published sources. Thermodynamic models that take into account the formation of these intermetallic compounds adequately describe the processes that occur during the interaction of mixture components for the aluminothermic smelting of V-Al-N-C alloys. The predicted elemental and phase compositions of the V-Al-N-C model alloys are in a good agreement with the data of chemical, XRD and EMPA analyzes of samples of real alloys. Models that take into account the formation of V2AlC carbide and vanadium aluminides are applicable for calculating the compositions and thermality of mixtures, as well as for predicting the V-Al-N-C alloys smelting products. From the point of view of thermodynamics, replacing graphite in a mixture of the V-Al-N-C master alloy smelting with a precursor alloy V(70)-Al(23)-C(7), carbon in which is represented as V2AlC carbide and vanadium carbides V2C and VC, will not affect the carbon distribution over it phase component and will not adversely affect the technological performance of the smelting.

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