scholarly journals Thermodynamic modeling of iron recovery processes

2021 ◽  
Vol 64 (11) ◽  
pp. 825-831
Author(s):  
I. A. Rybenko ◽  
E. V. Protopopov
Keyword(s):  
Equilibrium State ◽  
Thermodynamic Modeling ◽  
Software Package ◽  
Slag System ◽  
Equilibrium Composition ◽  
Reducing Agents ◽  
Optimal Conditions ◽  
Iron Recovery ◽  
Resource Saving ◽  
System Equilibrium

One of the promising directions in metallurgy is the use of iron-containing waste, such as converter production sludge, iron-containing concentrates, rolling scale, iron ore processing waste and others. Development of new resource-saving technologies using such waste requires preliminary research and accumulation of information in the field of iron recovery. The paper considers the processes of iron recovery from oxides under various conditions. The authors used the method of thermodynamic modeling based on the search for the entropy maximum. The thermodynamic modeling tool was TERRA software package created at the Bauman Moscow State Technical University. TERRA complex is designed to calculate the thermodynamic properties and composition of the phases of equilibrium state of arbitrary systems with chemical and phase transformations. Using this software package, studies of the processes of iron recovery by various reducing agents (carbon, manganese, and silicon) in model thermodynamic systems were carried out, and optimal conditions for temperature and consumption of reducing agents were determined. The paper presents the results of a study of processes in the metal-slag system in equilibrium. The analysis of the metal-slag system equilibrium state was carried out for the temperature range of 1773 - 1973 K with different amounts of slag. Boundaries of the areas of redox processes were determined and the influence of metal components on conditions for iron oxides recovery from slag to metal was evaluated. The dependences of the system equilibrium composition on temperature at different ratios of metal and slag were obtained, as well as the optimal conditions for iron recovery.

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 A Bi-Stable von-Mises Truss for Morphing Applications Actuated Using Shape Memory Alloys

2013 ◽  
Author(s):  
Silvestro Barbarino ◽  
Farhan S. Gandhi ◽  
Rodolphe Visdeloup
Keyword(s):  
Equilibrium State ◽  
Shape Memory ◽  
Stable Equilibrium ◽  
The Other ◽  
Stable Equilibrium State ◽  
Actuation Force ◽  
Numerical Predictions ◽  
System Equilibrium ◽  
Governing Differential Equation ◽  
Von Mises

The present study focuses on a bi-stable von-Mises truss (VMT), with integrated Shape Memory Alloy (SMA) wires which are resistively heated to provide the actuation force to transition the VMT from one stable equilibrium condition to the other, and back. This coupled VMT-SMA system can potentially be used in structural morphing applications. The paper considers in detail the design of the system, equilibrium between the VMT and the SMA wires, the initial pre-stress required in the two SMA wires, explains how the active (heated) SMA wire drives the VMT beyond the unstable equilibrium state, and the VMT in moving to the second stable equilibrium state pre-stresses the passive (unheated) SMA wire. The two SMA wires switch roles in moving the VMT back from the second to the first stable equilibrium state. A prototype is designed and fabricated and the transition of the VMT from one equilibrium state to the other, and back, is experimentally demonstrated. The governing differential equation representing the VMT behavior is coupled with equations representing the SMA behavior based on the Brinson thermo-mechanical model. The numerical predictions of system displacements versus temperature and time show good correlation with experimental results.

scholarly journals Thermodynamic modeling of deoxidation products and inclusion chemistry in Mn/Si killed tire-cord steel

2012 ◽  
Vol 48 (1) ◽  
pp. 37-43 ◽  
Author(s):  
A.D. Prasad ◽  
S.R. Sankaranarayanan
Keyword(s):  
Free Energy ◽  
Thermodynamic Modeling ◽  
Slag Phase ◽  
Slag System ◽  
Al2o3 Content ◽  
Tire Cord ◽  
Oxide Systems ◽  
Tire Cord Steel ◽  
Inclusion Chemistry ◽  
The Stability

The present work deals with thermodynamic modeling of oxide systems, in the context of slags and inclusions in steelmaking. The work has emphasis on oxides encountered during the production of tire - cord steel. Control of inclusion chemistry and variation in eutectic temperature and eutectic composition of MnOAl2O3- SiO2 slag system have been studied, using Thermo-CalcR software. Relatively low liquidus temperatures are obtained for ratio of MnO/SiO2 = 0.5 - 1.5 and Al2O3 content from 10 - 20 mass%. It has been observed that the addition of Alumina leads to further increase in the liquidus temperature. The stability of inclusions is analyzed in terms of free energy values of related slag systems; and an appropriate minimum of Gibbs free energy value of slag phase observed at around 50 ppm of Oxygen. The observations could not be verified using thermodynamic experiments, but have been compared with findings in the open literature.

scholarly journals DEVELOPMENT OF RESOURCE-SAVING TECHNOLOGY FOR PROCESSING HEAVY OIL RESIDUES

2021 ◽  
Vol 1 (1) ◽  
pp. 43-44
Author(s):  
Igor' Kuzora ◽  
Elena Simonova ◽  
Stepan Uhanev
Keyword(s):  
Heavy Oil ◽  
Oil Sludge ◽  
Optimal Conditions ◽  
Resource Saving ◽  
Treat Ment ◽  
Heavy Oil Residues

The physicochemical and chemmotological characteristics of oil sludge from treat ment facilities were studied to determine the optimal conditions for their dewatering. The possibility of using them as a component in various fuel compositions is investigated.

scholarly journals Thermodynamical consideration of the synthesis of solid AlN from thermal plasma

2001 ◽  
Vol 66 (8) ◽  
pp. 523-534 ◽  
Author(s):  
Jelena Radic-Peric ◽  
Nikola Pekas
Keyword(s):  
Thermal Plasma ◽  
Equilibrium Composition ◽  
Thermal Plasmas ◽  
Synthesis Process ◽  
Gas Mixture ◽  
Optimal Conditions ◽  
Temperature Range ◽  
Gas System ◽  
Thermodynamical Consideration

The synthesis process of solid AlN in thermal plasmas was investigated theoretically by computing the equilibrium composition of the gas mixture involving nitrogen and various amounts of aluminum, oxygen and hydrogen for the temperature range between 1000 and 5500 K. The results obtained by treating the plasma as a single-gas system were combined with those which take into account the presence of solid AlN and liquid Al, to find the optimal conditions for the deposition of solid AlN. The factors determining the efficiency of this process are discussed.

scholarly journals Flow characteristics of drag-reducing natural bamboo fiber suspensions with minimal environmental load

TAPPI Journal ◽  
2019 ◽  
Vol 18 (9) ◽  
pp. 559-566
Author(s):  
SATOSHI OGATA ◽  
TAKUYA KUBO
Keyword(s):  
Flow Characteristics ◽  
Average Diameter ◽  
Reducing Agents ◽  
Bamboo Fiber ◽  
Pipe Diameter ◽  
Mechanical Degradation ◽  
Environmental Load ◽  
Resource Saving ◽  
Application Range ◽  
Bamboo Fibers

The reduction of pipe friction loss by adding drag-reducing agents has attracted attention as an aid to energy conservation. Drag-reducing agents induce drag reduction (DR) effects and should have a minimal environmental load, with natural resource-saving potential. This study demonstrates bamboo fiber as a drag-reducing agent that saves natural resources and has a low environmental load. Using pressure drop measurements, we report DR with suspensions of bamboo fibers with the average diameter of 13.3 μm and aspect ratio of 98.7. The maximum DR obtained in this experiment is 43% at the concentration of 4000 ppm and pipe diameter of 30 mm; DR is affected by the Reynolds number, suspension concentration, and pipe diameter. In addition, the bamboo fibers can be easily removed from the suspensions by filtration. We found that low-environmental-load bamboo fiber has DR effects like those of other fibers; its effects are greater than those of conventional synthetic fibers and wood pulp. Furthermore, it is resistant to mechanical degradation, recoverable, and recyclable. Therefore, DR effects can be selectively obtained by adding the fibers only when DR is needed; the fibers can then be collected when DR is no longer necessary. This method might greatly expand the application range of DR agents. The results demonstrate the usefulness of bamboo fibers as DR additives.

Thermodynamic modeling of the formation of corundum-bearing rocks within the Belomorian mobile belt using Perple_x software

2020 ◽  
Author(s):  
Ekaterina Akimova ◽  
Alexander Kol’tsov
Keyword(s):  
High Pressure ◽  
Thermodynamic Modeling ◽  
Software Package ◽  
Planetary Science ◽  
Mobile Belt ◽  
Belomorian Mobile Belt ◽  
Biotite Gneiss ◽  
Zone Formation ◽  
Rock Interaction ◽  
Massif Central

<p>More than a dozen deposits of corundum-bearing rocks are known within the Belomorian mobile belt (references in Serebryakov, Rusinov, 2004); their genesis remains debatable. Some authors consider corundum-bearing rocks to be normal metamorphic rocks (for example, Lebedev et al., 1974), others suggest the metasomatic genesis of rocks with corundum: 1 – corundum-bearing rocks were formed as a result of high-temperature high-pressure (600 - 700ºC, 7 - 8 kbar) metasomatism which was accompanied by desilification and the introduction of Ca and Na (Serebryakov, Rusinov, 2004); 2 – these rocks are a product of hydrothermal alteration of gneisses by fluids associated with basic intrusions (Bindeman et al., 2014). All these assumptions were made without a detailed physicochemical analysis of the mineral parageneses of corundum-bearing rocks.<br>The Perple_X software package (Connolly, 2005) is discussed in some recent works as an effective tool for the thermodynamic modeling of the open systems (Goncalves et al., 2012, Manning, 2013). Using the Perple_X software package (version Perple_X 6.8.7, updated 04.07.2019) we constructed P-T, T-μ (SiO<sub>2</sub>), and μ(SiO<sub>2</sub>)-μ(Na<sub>2</sub>O) pseudosections for a given chemical composition of kyanite-garnet-biotite gneiss of the Chupa sequence. The hp02ver.dat thermodynamic database was used, the diagram μ(SiO<sub>2</sub>) - μ(Na<sub>2</sub>O) was calculated for P = 8 kbar, T = 650ºC, in the presence of a carbonic-aqueous fluid with X(CO<sub>2</sub>) = 0.3. Selected solid solution models are Ca-Amph(D) for hornblende, Gt(HP) for garnet, St(HP) for staurolite, Bi(HGP) for biotite, feldspar for feldspar, Sp(HP) for spinel.<br>The results show that the majority of corundum-bearing rocks varieties (amphibole-free corundum-bearing rock, amphibole-bearing rock with corundum, altered quartz-free kyanite-garnet-biotite gneiss, kyanite-garnet amphibolite) could be formed by metasomatic alteration of kyanite-garnet-biotite gneisses of the Chupa sequence. This process was characterized by a significant decrease in µ(SiO<sub>2</sub>) and a slight increase in µ(Na<sub>2</sub>O). Our conclusion is partly consistent with the hypothesis that corundum-bearing rocks were formed as a result of metasomatism, which was accompanied by desilification of Ky-Grt-Bt gneisses and the introduction of Na and Ca (Serebryakov, Rusinov, 2004).</p><p>The study was conducted according to the IPGG project 0153-2019-0004.</p><p>Bindeman I.N., Serebryakov N.S., Schmitt A.K. et al. (2014) Field and microanalytical isotopic investigation of ultradepleted in <sup>18</sup>O Paleoproterozoic “Slushball Earth” rocks from Karelia, Russia. Geosphere. V. 10. P. 308-339.</p><p>Connolly J.A.D. (2005) Computation of phase equilibria by linear programming: A tool for geodynamic modeling and its application to subduction zone decarbonation.  Earth and Planetary Science Letters, 236, p. 524–541.</p><p>Goncalves P., Oliot E., Marquer D., Connolly J.A.D. (2012) Role of chemical processes on shear zone formation: an example from the Grimsel metagranodiorite (Aar massif, Central Alps). J. metamorphic Geol., 30, p. 703–722.</p><p>Lebedev V.I., Kalmykova N.A. & Nagaytsev Yu.V. (1976) Corundum-staurolite-hornblende schists of the Belomorskiy complex, International Geology Review, 18:6, 653-662.</p><p>Manning C.E. (2013) Thermodynamic modeling of fluid-rock interaction at conditions of the earth's middle crust to upper mantle. Reviews in Mineralogy & Geochemistry, 76, p. 135-164.</p><p>Serebryakov, N.S., Rusinov, V.L. (2004) High-T high-pressure Ca, Na metasomatism and formation of corundum in the precambrian Belomorian mobile belt. Dokl. Earth Sci. 395, pp. 549–533.</p>

scholarly journals IGE Model: An Extension of the Ideal Gas Model to Include Chemical Composition as Part of the Equilibrium State

2012 ◽  
Vol 2012 ◽  
pp. 1-18 ◽  
Author(s):  
Christopher P. Paolini ◽  
Subrata Bhattacharjee
Keyword(s):  
Thermodynamic Properties ◽  
Equilibrium State ◽  
Major Change ◽  
Equilibrium Composition ◽  
Ideal Gas ◽  
The State ◽  
State Evaluation ◽  
Pure Substances ◽  
Ideal Gas Model ◽  
The Ideal

The ideal gas (IG) model is probably the most well-known gas models in engineering thermodynamics. In this paper, we extend the IG model into an ideal gas equilibrium (IGE model) mixture model by incorporating chemical equilibrium calculations as part of the state evaluation. Through a simple graphical interface, users can set the atomic composition of a gas mixture. We have integrated this model into a thermodynamic web portal TEST (http://thermofluids.sdsu.edu/) that contains Java applets for various models for properties of pure substances. In the state panel of the IGE model, the known thermodynamic properties are entered. For a given pressure and temperature, the mixture's Gibbs function is minimized subject to atomic constraints and the equilibrium composition along with thermodynamic properties of the mixture are calculated and displayed. What is unique about this approach is that equilibrium computations are performed in the background, without requiring any major change in the familiar user interface used in other state daemons. Properties calculated by this equilibrium state daemon are compared with results from other established applications such as NASA CEA and STANJAN. Also, two different algorithms, an iterative approach and a direct approach based on minimizing different thermodynamic functions in different situation, are compared.

scholarly journals Thermodynamic modeling of reduction of metals from B2O3-CaO-Ni(Zn,Pb,Cu)O melts carbon monoxide

2019 ◽  
Vol 59 (9) ◽  
pp. 125-131
Author(s):  
Alexander S. Vusikhis ◽  
◽  
Evgeny N. Selivanov ◽  
Stanislav N. Tyushnyakov ◽  
Victor P. Chentsov ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
Thermodynamic Modeling ◽  
Equilibrium Composition ◽  
Metal Phase ◽  
Oxide Melt ◽  
Reducing Ability ◽  
Lead And Zinc ◽  
Nickel Copper ◽  
Reducing Gases ◽  
Copper Lead

Thermodynamic modeling technique is used to describe the metal reduction from oxide melt by carbon monoxide. The B2O3-CaO-MeO (Me – Ni, Zn, Pb, Cu) system, was used with periodic output of the metal phase and gases from the working body. The approach originality is that the equilibrium is determined for each single portion of the gas injected into the working body, and the metal oxides content being reduced in each calculation cycle is taken from the previous data. This approach gives qualitative possibility to make simulated processes closer to real ones. The proposed method calculations allow determining, such parameters as the oxide melt and metal phase compositions, degree of elements reduction, oxide and metal phases mass ratio, equilibrium composition of the gas, reducing ability of gas utilization degree, and others, depending on the introduced gas quantities. Reducing process modeling of Nickel, Copper, Lead and Zinc from B2O3-CaO-MeO melts gives opportunity to determine the process for each metal. Copper reducing from CuO, goes with intermediate oxide (CuO → Cu2O → Cu) formation. Reduction of Nickel (NiO → Ni), Lead (PbO → Pbs + Pbg) and Zinc (ZnO → Zng) proceeds in one stage. The temperature dependence of the non-ferrous metals content in the oxide melt, its reduction degree and reducing agent quantity introduced are described by the second-order polynomial equations. The information obtained may be useful for thermo-extraction processes prognosis during the Nickel, Copper, Lead, and Zinc extraction from non-ferrous metallurgy slag in bubbling process of oxide melt by reducing gases.

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