scholarly journals Thermodynamic modeling of nickel and iron reduction from B2O3 – CaO – Fe2O3 – NiO melt by СО – СО2 and Н2 – Н2О mixtures

2021 ◽  
Vol 64 (5) ◽  
pp. 353-359
Author(s):  
A. S. Vusikhis ◽  
L. I. Leont’ev ◽  
E. N. Selivanov
Keyword(s):  
Thermodynamic Modeling ◽  
Iron Reduction ◽  
Selective Reduction ◽  
Gas Composition ◽  
Oxide Melt ◽  
Second Stage ◽  
Maximum Value ◽  
Working Medium ◽  
Third Stage ◽  
Successive Calculation

To predict the conditions for metals reduction from an oxide melt by gas in bubbling processes, a thermodynamic modeling technique has been developed that provides an approximation to real systems. The main difference between the accepted method and the well-known one is in conducting successive calculation cycles with withdrawal of the generated gases and the metal phase from the working medium. This paper presents the results of thermodynamic modeling of nickel and iron reduction processes from B2O3 – CaO– Fe2O3 – NiO melts by mixtures of CO– CO2 and H2 – H2O containing 0 – 60 % CO2 (H2O) in the temperature range of 1273 – 1673 K. The calculations evaluated the content of nickel and iron oxides in the melt and the degree of their reduction. It is shown that, regardless of the gas composition, this process proceeds in several stages. At the first stage, Fe2O3 is reduced to Fe3O4 and FeO. СFe2O3 values decrease to almost zero, while СFe3O4 and CFeO increase simultaneously. By the end of the phase, СFeO reaches its maximum value. At the second stage, the Fe3O4 → FeO transition occurs, when СFe3O4 values reach maximum, nickel and iron begin to reduce to metal. At reduction by CO– CO2 mixture, an increase in temperature reduces the metallization of both nickel and iron. Similarly, an increase in the CO2 content of the introduced gas affects. During interaction of the oxide melt with a gas containing 60 % CO2 , the third stage is absent. At reduction by H2 – H2O mixture, an increase in temperature reduces the metallization of nickel, but increases metallization of iron. With increasing water vapor content in the introduced gas, the degree of metallization of both nickel and iron decreases. The obtained data are useful for creating technologies for selective reduction of metals and formation of ferronickel of the required composition.

scholarly journals Modeling of metals reducing from B2O3-CaO-Fe2O3-ZnO melts by CO-CO2 mixtures

2020 ◽  
Vol 62 (4) ◽  
pp. 94-98
Author(s):  
Alexander S. Vusikhis ◽  
◽  
Evgeny N. Selivanov ◽  
Stanislav N. Tyushnyakov ◽  
Victor P. Chentsov ◽  
...  
Keyword(s):  
Thermodynamic Modeling ◽  
Iron Reduction ◽  
Selective Reduction ◽  
Distillation Process ◽  
Oxide Melt ◽  
Second Stage ◽  
Reduction Processes ◽  
Gas Consumption ◽  
Three Stages ◽  
The Given

Thermodynamic modeling technique has been developed to predict the conditions of metals reduction from oxide melt by gas during bubbling processes. The technique provides approximation to real systems with periodic removal of metal phase and gases from the working body. The given work presents thermodynamic modeling results of Zinc and Iron reduction processes from B2O3-CaO-Fe2O3-ZnО melts by СО-СО2 different composition mixtures in the 1273-1673 K temperature range. Approximation to real processes is used. Zinc and Iron oxides content in the melt and its reducing degree have been estimated during the calculations. Three stages of the process have been obtained by the calculations. Reducing of Fe2O3 to Fe3O4 and FeO is realized in the first stage. Concentration of Fe2O3 (СFe2O3) decreases almost to zero while СFe3O4 и СFeO have been increased simultaneously. Concentration of СFe3O4 reaches its maximum to the end of process. Transition of Fe3O4 → FeO takes place in second stage when СFeO reaches its maximum, and Zinc and Fe begin its reducing. Temperature increase promotes metallization by Zinc, but decreases by Iron. An increase of input gas CO/CO2 ratio leads to Fe reducing degree. It thereby ensures required indicators of the Zinc selective reduction achievement but requires more gas consumption. The relationships between CZnO and φZn depending on temperature and amount of reducing input gas consumption have been obtained. Given work results may be useful for precut estimation of the probable parameters of Zinc distillation process from the melt. Besides, these results may be useful as the basis for the experimental results analysis.

scholarly journals Thermodynamic modeling of iron and zinc reduction from B2O3 ‒ CaO ‒ Fe2O3 ‒ ZnО melt by СО ‒ CO2 and H2 ‒ Н2О mixtures

2021 ◽  
Vol 64 (7) ◽  
pp. 488-497
Author(s):  
A. S. Vusikhis ◽  
L. I. Leont’ev ◽  
E. N. Selivanov
Keyword(s):  
Thermodynamic Modeling ◽  
Iron Reduction ◽  
Working Fluid ◽  
Oxide Melt ◽  
Second Stage ◽  
Third Stage ◽  
Iron And Zinc ◽  
Gas Consumption ◽  
Three Stages ◽  
Zinc Reduction

The paper presents the thermodynamic modeling results of zinc and iron reduction from B2O3 ‒ CaO ‒ Fe2O3 ‒ ZnО melts by CO ‒ CO2 and H2 ‒ H2O mixtures containing 0 – 60 % CO2 (H2O) at 1273 – 1673 K using a technique describing the reduction of metals from an oxide melt by gas in bubbling processes, under conditions that provide an approximation to real systems. Its originality is equilibrium determination for each individual portion of gas supplied into the working fluid. The reducible metals oxides content in each calculation cycle is taken from the previous data. During the calculations, changes in the content of zinc (СZnO ) and iron (СFe2O3 , СFe3O4 and СFeO ) oxides in the melt and the degree of their reduction were estimated. When using CO or H2 as a reducing agent, this process proceeds in three stages. In the first stage, Fe2O3 is reduced to Fe3O4 and FeO. CFe2O3 values decrease to almost zero, while CFe3O4 and CFeO increase simultaneously. By the end of the stage, СFe3O4 reaches its maximum value. At the second stage, the Fe3O4 → FeO transition occurs, when СFeO values reach its maximum. At these stages, there is a slight increase in the CZnO . At the third stage, the values CFeO and CZnO decrease, and iron and zinc are reduced. An increase in temperature dramatically reduces the gas consumption for zinc reduction by 2 – 3 times, and the replacement of CO with H2 reduces it by less than 20 %. In the presence of oxidizing agents (CO or H2O), only zinc is reduced. The process ends when the final content of zinc oxide in the melt corresponds to the equilibrium with the initial gas composition. The higher the temperature, the less CZnO is. The obtained data are useful for the development of technologies for the selective recovery of metals.

scholarly journals Plasmachemical Process of Destruction of Sulphide Polymers

2016 ◽  
Vol 5 (4) ◽  
pp. 249
Author(s):  
S.H. Aknazarov
Keyword(s):  
Ordered Structure ◽  
Mechanism Of Formation ◽  
Plasma Dynamic ◽  
Second Stage ◽  
The Third ◽  
Dynamic Movement ◽  
Maximum Value ◽  
Third Stage ◽  
Three Stages ◽  
Air Medium

The process of destruction of sulphidic polymers is investigated and mechanism of formation of laser erosive plasma is offered. The using of modulator of good quality allows obtaining of ordered structure of laser plasma, which is formed as a toroid and kept by own magnetic field. The process of plasma formation and movement over the surface of the sample proceeds in three stages. At the first stage the dense hot nucleus of a torch absorbing laser radiation is formed. At the second stage there is a transition of thermal energy of plasma into kinetic energy of the directed dynamic movement. At the third stage – the plasmoid, having reached the maximum value of rate, is sharply hindered owing to interaction with the air medium, reorganization of the plasma dynamic movement itself takes place. Processes of plasma states under different conditions are separated both in space and in time.

scholarly journals Thermodynamic modeling of nickel and iron reduction from multicomponent silicate melt in bubbling process. Report 2. Reducing agent – a mixture OF Н2 – Н2О

2018 ◽  
Vol 61 (10) ◽  
pp. 794-799 ◽  
Author(s):  
A. S. Vusikhis ◽  
L. I. Leont’ev ◽  
D. Z. Kudinov ◽  
E. N. Selivanov
Keyword(s):  
Carbon Monoxide ◽  
Iron Oxide ◽  
Nickel Oxide ◽  
Thermodynamic Modeling ◽  
Iron Reduction ◽  
Nickel Content ◽  
Reduction Process ◽  
Gas Mixture ◽  
Degree Of Reduction ◽  
Oxide Melt

A number of technologies in ferrous and non-ferrous metallurgy  are based on bubbling processes. For prediction of melting parameters  including the reduction of metals from oxide melt by a reducing gas  in a bubbling layer in industrial aggregates, a thermodynamic modeling technique is proposed based on calculation of the equilibrium in  oxide-melt-metal-gas system. Originality of the technique is that equilibrium is determined for each unit dose of gas introduced into the  working body, with the contents of oxides of metals being reduced in  each subsequent design cycle equal to the equilibrium in the previous  one. For the analysis NiO (1.8  %) – FeO (17.4  %) – CaO (13.5  %)  –  MgO  (1.9  %) – SiO2 (58.0  %) – Al2O3 (7.4  %) oxide system was  taken, closely corresponding to composition of oxidized nickel ore.  The ratio of Н2О/Н2 in gas mixture varies between 0 and 1.0. (1823  K),  amount and composition of formed metal (ferronickel), as well as the  indices (the ratio of slag and metal, the degree of reduction of metals)  are important in implementation of the process under commodity conditions. The increase in hydrogen consumption monotonously reduces  the content of nickel oxide in the melt, while the content of iron oxide  initially increases, and then decreases.  When H2 is introduced in an  amount of about 50 m3 per ton of the melt, the content of nickel oxide  in it is reduced to 0.017  %, and of iron oxide to 16.7  %. Resulting ferronickel contains 61  % Ni, ratio of slag and metal – 42  units. Further  increase in H2 consumption leads to preferential iron reduction. An increase in H2O/H2 ratio worsens the results of reduction of metals from  the melt: decrease in degree of reduction of nickel and iron, increase  in nickel content in the alloy, and the ratio of slag and metal. However,  even with a H2 / H2O ratio of 1.0, which corresponds to 50  % of H2O  in the gas mixture, reduction process does not stop. For comparison,  the work presents data on change in content of nickel and iron oxides,  when metals are restored from similar melts with carbon monoxide.  At a nickel recovery rate of 98  %, indicators are close in case of using  both H2 and CO. However, to achieve them, it is required 2.5  times less hydrogen, and 1.36 times less mixture in which H2O/H2  =  0.11  (H2  –  90  %) than carbon monoxide.

scholarly journals Thermodynamic Modeling of Iron and Nickel Reduction from B2O3-CaO-FeO-NiO Melts

2020 ◽  
Author(s):  
A.S. Vusikhis ◽  
L.I. Leontiev ◽  
E.N. Selivanov ◽  
V.P. Chentsov
Keyword(s):  
Carbon Monoxide ◽  
Thermodynamic Modeling ◽  
Open System ◽  
Iron Reduction ◽  
Nickel Extraction ◽  
Residual Content ◽  
Oxide Melt ◽  
Closed Systems ◽  
Joint Reduction ◽  
Gas Bubbling

At present, during solving theoretical and applied problems of metallurgical technologies improving, thermodynamic modeling (TDM) methods are widely used to calculate multicomponent and multiphase systems. However, existing methodology TДM are intended for the balance analysis in the ”closed” systems. The authors of [9] proposed a technique that allows, using TDMs, to describe metal reduction processes during gas bubbling of multicomponent oxide melts in approximation to “open” real systems. The applicability of the methods is estimated using the example of joint Nickel and Iron reduction modeling in the B2O3-CaO-FeO-NiO system by Carbon monoxide for ”open” and ”closed” systems. The data obtained comparison for ”open” and ”closed” systems show that the consecutive output of products (gas and metal) from working medium promotes achievement of the best parameters for Nickel extraction to alloy and to its residual content in oxide melt. Using this technique, the TДM process of joint reduction of Nickel and Iron in system B2O3-CaO-FeO-NiO by Carbon monoxide in ”open” system was undertaken at various temperatures in the 1273-1773K interval. Keywords: thermodynamic modeling, ”closed” system, ”open” system, joint reduction, Carbon monoxide, oxide melt, gas bubbling

scholarly journals The impact of the temperature of rapeseed oil methyl esters on nitrogen oxides emissions

2020 ◽  
Vol 171 ◽  
pp. 01002
Author(s):  
Weronika Gracz ◽  
Mirosław Czechlowski ◽  
Damian Marcinkowski ◽  
Wojciech Golimowski ◽  
Patrycja Pochwatka
Keyword(s):  
Nitrogen Oxides ◽  
Rapeseed Oil ◽  
Power Grid ◽  
Methyl Esters ◽  
Second Stage ◽  
The Third ◽  
Maximum Value ◽  
Third Stage ◽  
The Impact ◽  
Rapeseed Oil Methyl Esters

The purpose of the tests described in this publication was to examine the effect of the temperature of the biodiesel burned, resulting from the transesterification of rapeseed oil with methanol, on the level of nitrogen oxides emissions. The tests were carried out on a test stand equipped with a 9.5 kW engine. Electricity was transffered directly to the power grid. The measurements were started after the engine has warmed up, when the oil temperature exceeded 85°C. In the first stage, the engine was loaded with the maximum achievable torque (100%), in the second stage the torque was set at 75% of the maximum value, and for measurements in the third stage the torque was 50% of the maximum value. Three tests were carried out, one for each of the three fuel temperatures: 20, 40 and 55°C.

The Coherence of Mary Barton: Romance, Realism, and Utopia

2015 ◽  
Vol 5 (3) ◽  
pp. 185-200
Author(s):  
Robert Z. Birdwell
Keyword(s):  
Thomas Carlyle ◽  
The Novel ◽  
Second Stage ◽  
The Third ◽  
Third Stage ◽  
Three Stages ◽  
Mode Of Production

Critics have argued that Elizabeth Gaskell's first novel, Mary Barton (1848), is split by a conflict between the modes of realism and romance. But the conflict does not render the novel incoherent, because Gaskell surpasses both modes through a utopian narrative that breaks with the conflict of form and gives coherence to the whole novel. Gaskell not only depicts what Thomas Carlyle called the ‘Condition of England’ in her work but also develops, through three stages, the utopia that will redeem this condition. The first stage is romantic nostalgia, a backward glance at Eden from the countryside surrounding Manchester. The second stage occurs in Manchester, as Gaskell mixes romance with a realistic mode, tracing a utopian drive toward death. The third stage is the utopian break with romantic and realistic accounts of the Condition of England and with the inadequate preceding conceptions of utopia. This third stage transforms narrative modes and figures a new mode of production.

How well do voice-hearing assessment measures capture the positive experiences of individuals?

2019 ◽  
Author(s):  
Lucy Armstrong ◽  
Lorna Hogg ◽  
Pamela Charlotte Jacobsen
Keyword(s):  
Systematic Review ◽  
Lived Experience ◽  
Second Stage ◽  
The Third ◽  
Third Stage ◽  
Hearing Assessment ◽  
Positive Experiences ◽  
Assessment Measures ◽  
Stage 1 ◽  
The Voice

The first stage of this project aims to identify assessment measures which include items on voice-hearing by way of a systematic review. The second stage is the development of a brief framework of categories of positive experiences of voice hearing, using a triangulated approach, drawing on views from both professionals and people with lived experience. The third stage will involve using the framework to identify any positve aspects of voice-hearing included in the voice hearing assessments identified in stage 1.

scholarly journals When the World Breaks Down: A 3-Stage Existential Model of Nihilism in Schizophrenia

2021 ◽  
pp. 1-24
Author(s):  
Philipp Klar ◽  
Georg Northoff
Keyword(s):  
The Self ◽  
First Person ◽  
Second Stage ◽  
Existential Crisis ◽  
Third Stage ◽  
The World ◽  
Third Person ◽  
Pathological Development ◽  
Sense Of Reality ◽  
Intentional Structure

The existential crisis of nihilism in schizophrenia has been reported since the early days of psychiatry. Taking first-person accounts concerning nihilistic experiences of both the self and the world as vantage point, we aim to develop a dynamic existential model of the pathological development of existential nihilism. Since the phenomenology of such a crisis is intrinsically subjective, we especially take the immediate and pre-reflective first-person perspective’s (FPP) experience (instead of objectified symptoms and diagnoses) of schizophrenia into consideration. The hereby developed existential model consists of 3 conceptualized stages that are nested into each other, which defines what we mean by existential. At the same time, the model intrinsically converges with the phenomenological concept of the self-world structure notable inside our existential framework. Regarding the 3 individual stages, we suggest that the onset or first stage of nihilistic pathogenesis is reflected by phenomenological solipsism, that is, a general disruption of the FPP experience. Paradigmatically, this initial disruption contains the well-known crisis of common sense in schizophrenia. The following second stage of epistemological solipsism negatively affects all possible perspectives of experience, that is, the first-, second-, and third-person perspectives of subjectivity. Therefore, within the second stage, solipsism expands from a disruption of immediate and pre-reflective experience (first stage) to a disruption of reflective experience and principal knowledge (second stage), as mirrored in abnormal epistemological limitations of principal knowledge. Finally, the experience of the annihilation of healthy self-consciousness into the ultimate collapse of the individual’s existence defines the third stage. The schizophrenic individual consequently loses her/his vital experience since the intentional structure of consciousness including any sense of reality breaks down. Such a descriptive-interpretative existential model of nihilism in schizophrenia may ultimately serve as input for future psychopathological investigations of nihilism in general, including, for instance, its manifestation in depression.

The Origins of the Village Revisited: From Nuclear to Extended Households

2002 ◽  
Vol 67 (3) ◽  
pp. 417-433 ◽  
Author(s):  
Kent V. Flannery
Keyword(s):  
Nuclear Family ◽  
Extended Family ◽  
Near East ◽  
Shared Storage ◽  
Nuclear Families ◽  
Second Stage ◽  
Third Stage ◽  
Two Stages ◽  
Extended Households ◽  
The Village

In Mesoamerica and the Near East, the emergence of the village seems to have involved two stages. In the first stage, individuals were distributed through a series of small circular-to-oval structures, accompanied by communal or “shared” storage features. In the second stage, nuclear families occupied substantial rectangular houses with private storage rooms. Over the last 30 years a wealth of data from the Near East, Egypt, the Trans-Caucasus, India, Africa, and the Southwest U.S. have enriched our understanding of this phenomenon. And in Mesoamerica and the Near East, evidence suggests that nuclear family households eventually gave way to a third stage, one featuring extended family households whose greater labor force made possible extensive multifaceted economies.

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