scholarly journals Efecto de la descomposición de gas de amoniaco (NH3) sobre el hinchamiento de óxidos de hierro durante reducción

Athenea ◽  
2020 ◽  
Vol 1 (2) ◽  
pp. 5-11
Author(s):  
Oscar Dam
Keyword(s):  
Structural Changes ◽  
Metallurgical Society ◽  
Swelling Behavior ◽  
Ore Pellets ◽  
Materials Engineering ◽  
Swelling Mechanism ◽  
Magnetite Pellets ◽  
Reduction Swelling ◽  
Institute Of Technology ◽  
American Society

Con el objeto de estudiar la relación y efecto del gas nitrógeno en los gases reductores utilizados en los ensayos de reducibilidad de óxidos de hierro, en condiciones isotérmicas, se ejecutó un esquema de ensayos utilizando gas amoniaco, tal que la descomposición del gas en el reactor produjera un gas de H2 y N2. Además, se planifico la adición de 6% de NH3 en una corriente de gas 28% H2 y 68% N2 para obtener una composición de gas de 70% N2 y 30% H2. Esto permitiría la reinterpretación de los datos de laboratorio para comparar las curvas d reducibilidad entre ambas condiciones, asumiendo que la posible diferencia entre ambas condiciones a comparar los cambios de volumen de las muestras reducidas. La diferencia a estudiar se basará en la estimación y comparación de la velocidad de formación de hierro metálico en las etapas de reducción de hematita/magnetita/wustita (FeO), así como los efectos del nitrógeno absorbido por el hierro metálico fresco producido, partir de la mezcla de gas reductor, sobre el cambio de volumen de las muestras. Así mismo se comparan empíricamente los cambios catastróficos de volumen causados por el nitrógeno comparando fuentes de este gas en reductores carbonosos sólidos. Palabras clave: reducción gaseosa, hierro de reducción directa (HRD), catálisis, catalizador de hierro, amoniaco, hinchamiento, absorción, nitruración. ensayos isotérmicos, nitrógeno en carbón. Referencias [1]O.G. Dam . The Influence of Nitrogen on the Swelling Mechanism of Iron Oxides During Reduction. Univ. of London. PhD Thesis 1983. [2]J.D Bogde.- Thermoelectric Power Measurements in Wustite. Univ. of Michigan. 1976. [3]O.G. Dam  y J. Jeffes. Model for the Assessment of Chemical Composition of reduced iron ores from single measurements. Ironmaking and Steelmaking. 1987. Vol. 14, N`5. [4]M. Yang. Nitriding-Fundamentals, modelling and process optimization. Tesis PhD. Worcester PolytechInstitute. 2012. [5]T. EL Kasabgy y W-K. LU. (1980). The Influence of Calcia and Magnesia in Wustite on the Kinetics of Metallization and Iron Whisker Formation. Metallurgical 1980 American Society for Metals and the Metallurgical Society of AIME Volume 11b, September 1980, pp. 410-414. [6]Srikar Potnuru Studies nn the Physical Properties and Reduction Swelling Behavior of Fired Haematite Iton ore Pellets. MSc Thesis. Department of Metallurgical and Materials Engineering National Institute Of Technology, Rourkela May 2012. [7]R.S Agarwal y S.S. Hembram. To Study the Reduction and Swelling Behavior Iron Ore Pellets. BSc. Department of Metallurgical and Materials Engineering National Institute Of Technology, Rourkela May 2013. [8]C.E. Seaton y J.S. Foster. and Velasco. Structural Changes Occurring during Reduction of Hematite and Magnetite Pellets Containing Coal Char. Transactions ISIJ, Vol. 23, 1983, pp. [10]C. Bozco. et.al. Interaction of Nitrogen with Iron Surfaces. Journal of Catalysis 49. 1977. [11]L.S. Darken y R.W. Gurry, Physical Chemistry of Metals. Mc Graw hIll . 1953. [12]H. A. Weirdt, y Z .Zwell. Trans. AIME. 229. 142. 1969. [13]J.J.S.Schulten. et al. Trans. Soc. Faraday. 53, 1363, 1957. [14]E.G.Barret y C.F. Wood. Bureau of Mines R-I 3229. 1934.

scholarly journals Effect of the reaction of ammonia gas on the swelling of metallic iron and its oxides during nitriding processes

Athenea ◽  
2021 ◽  
Vol 2 (4) ◽  
pp. 38-45
Author(s):  
Oscar Dam G. ◽  
Luis Azocar
Keyword(s):  
Iron Oxides ◽  
Metallic Iron ◽  
Swelling Behavior ◽  
Test Scheme ◽  
Volume Changes ◽  
Ammonia Gas ◽  
Ore Pellets ◽  
Materials Engineering ◽  
Magnetite Pellets ◽  
Institute Of Technology

In order to study the relationship and effect of nitrogen gas in the reducing gases used in the reducibility tests of iron oxides, under isothermal conditions, a test scheme was executed using ammonia gas, such that its decomposition of the gas in the reactor produced a mixture of H2 and N2 gases. Furthermore, the addition of 6% NH3 in a 28% H2 and 68% N2 gas stream was planned to obtain a gas composition of 70% N2 and 30% H2. This would allow comparing the reducibility curves between both conditions, assuming that the possible difference between both conditions to compare the volume changes of the reduced samples. The difference to be studied will be based on the estimation and comparison of the rate of formation of metallic iron in the stages of reduction of Hematite / Magnetite / Wustite (FeO), as well as the effects of nitrogen absorbed by the fresh metallic iron produced, or present. in iron catalysts to produce ammonia, from the reducing gas mixture, on the volume change of the samples. Likewise, the catastrophic volume changes caused by nitrogen are compared by comparing sources of this gas in solid carbonaceous reducers. Keywords: Gaseous Reduction, Direct Reduced Iron, isothermal tests. References [1]O. Dam G. “The Influence of Nitrogen on the Swelling Mechanism of Iron Oxides During Reduction”. Univ. of London. PhD Thesis 1983. [2]J. Bogde. “Thermoelectric Power Measurements in Wustite. Univ. of Michigan”. 1976. [3]O. Dam G. y J. Jeffes. “Model for the Assessment of Chemical Composition of reduced iron ores from single measurements. Ironmaking and Steelmaking”. Vol. 14, N`5. 1987. [4]M. Yang. “Nitriding-Fundamentals, modelling and process optimization”. Tesis PhD. Worcester Polytech Institute. 2012. [5]EL Kasabgy. T and W-K. LU. “The Influence of Calcia and Magnesia in Wustite on the Kinetics of Metallization and Iron Whisker Formation”. Metallurgical 1980 American Society for Metals and the Metallurgical Society of AIME Volume 11b, pp. 410-414. 1980. [6]“Srikar Potnuru Studies nn the Physical Properties and Reduction Swelling Behavior of Fired Haematite Iton ore Pellets”. MSc Thesis. Department of Metallurgical and Materials Engineering National Institute Of Technology, Rourkela May 2012. [7]R. Agarwal, S. Hembram. “To Study the Reduction and Swelling Behavior Iron Ore Pellets”. BSc. Department of Metallurgical and Materials Engineering National Institute Of Technology, Rourkela May 2013. [8]C. Seaton., J. Foster. and J. Velasco. “Structural Changes Occurring during Reduction of Hematite and Magnetite Pellets Containing Coal Char”. Transactions ISIJ, Vol. 23, 1983, pp. [10]C. Bozco. “Interaction of Nitrogen with Iron Surfaces”. Journal of Catalysis 49. pp16-41. 1977. [11]L. Darken y R. Gurry. “Physical Chemistry of Metals”. Mc Graw hIll . 1953. [12]H. Weirdt and Z. Zwell, Trans. AIME. 229. 142. 1969. [13]J. Schulten. Trans. Soc. Faraday. 53, 1363, 1957. [14]E. Barret y C. Wood. Bureau of Mines R-I 3229. 1934

Effect of basicity on the reduction swelling behavior and mechanism of limestone fluxed iron ore pellets

2021 ◽  
Author(s):  
Yufeng Guo ◽  
Kuo Liu ◽  
Feng Chen ◽  
Shuai Wang ◽  
Fuqiang Zheng ◽  
...  
Keyword(s):  
Iron Ore ◽  
Swelling Behavior ◽  
Iron Ore Pellets ◽  
Ore Pellets ◽  
Reduction Swelling

scholarly journals Century-Long Dynamics of the Land Use Structure in the United States

2020 ◽  
pp. 220-231
Author(s):  
Valerij Minat
Keyword(s):  
United States ◽  
Land Use ◽  
Structural Changes ◽  
The United States ◽  
Structural Features ◽  
Summary Table ◽  
Land Use Structure ◽  
Periodic Dynamics ◽  
Space Dynamics ◽  
American Society

The paper studies the experience of American land use in the twentieth century on the territory of 48 contiguous continental states. Changes in time and space (dynamics) of the main indicators of distribution and use of land resources that form the structural appearance of the U.S. land fund are shown. Based on the analysis of the countrys land use structure, the resulting part of which is a summary table, the periodic dynamics of the land use structure (in twenty-year time intervals) is considered, and the dependence of structural changes in land use on the level and nature of the socio-economic development of American society is shown. The study of the age-old dynamics of structural features of American land use conducted on the basis of scientific materials of American scientists and data from official American statistics makes it possible to draw generalizing conclusions about the nature of land use in the United States, both in the whole country and in the regional aspect. As a result, the author has obtained a generalized scientific picture of how the structure of land use in the continental part of the country (without Alaska) has changed over the course of a century in the direction from maximum to optimal use of natural resources.

scholarly journals Complete Proceedings - Single PDF Download

2000 ◽  
Vol 1 (3) ◽  
pp. 0
Author(s):  
J. W. Johnson
Keyword(s):  
New England ◽  
Massachusetts Institute ◽  
Massachusetts Institute Of Technology ◽  
Corps Of Engineers ◽  
Wave Research ◽  
Institute Of Technology ◽  
American Society ◽  
Civil Engineers

This conference was sponsored jointly by the Council on Wave Research and the Massachusetts Institute of Technology, with support also being given by the Northeastern Section of the American Society of Civil Engineers, the Boston Society of Civil Engineers and the Boston Section of the American Society of Mechanical Engineers. Appreciation is expressed to the New England Division of the Corps of Engineers for photographs supplied to illustrate the cover and the section titles of this publication.

Environmentalists abide: Listening to whale music – 1965–1985

2017 ◽  
Vol 35 (6) ◽  
pp. 1096-1114 ◽  
Author(s):  
Max Ritts
Keyword(s):  
Predominantly White ◽  
Lived Experience ◽  
Instrumental Music ◽  
Structural Changes ◽  
Antonio Gramsci ◽  
North American Society ◽  
Bay Area ◽  
White Middle Class ◽  
History Of ◽  
American Society

Music can enrich geographical efforts to understand ideology as a lived experience. This paper explores the history of whale music – instrumental music that samples or thematizes whale sound. For environmentalists who came of age in the late 1960s, whale music fostered new interrogations about the identity of nature and the nature of identity, interrogations that reflected structural changes in North American society. To understand whale music’s surprising ideological power, I draw on Althusser’s formative idea of interpellation, and refine it with insights from Antonio Gramsci, John Mowitt, and Neil Smith. As examples from British Columbia’s Lower Mainland and California’s Bay Area reveal, whale music interpellated environmentalists, capturing the energies of predominantly white middle-class subjects eager to develop new relationships with nature. Whale music was not discovered, as its devotees proposed it was, but invented, through a combination of animal sounds, recording techniques, consumer trends, and ideologies of nature. It reveals environmentalism as a sonorous formation – a system that recruits listeners into sonically-mediated realms of thought, action, and subjectivity.

scholarly journals Dynamic and Isothermal Reduction Swelling Behaviour of Olivine and Acid Iron Ore Pellets under Simulated Blast Furnace Shaft Conditions

2012 ◽  
Vol 52 (7) ◽  
pp. 1257-1265 ◽  
Author(s):  
Mikko Iljana ◽  
Olli Mattila ◽  
Tuomas Alatarvas ◽  
Ville-Valtteri Visuri ◽  
Jari Kurikkala ◽  
...  
Keyword(s):  
Blast Furnace ◽  
Iron Ore ◽  
Swelling Behaviour ◽  
Iron Ore Pellets ◽  
Furnace Shaft ◽  
Ore Pellets ◽  
Isothermal Reduction ◽  
Reduction Swelling

scholarly journals Molecular Dynamics Simulation in the Interlayer of Mixed-Layer Clays Due to Hydration and Swelling Mechanism

Crystals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 586
Author(s):  
Yu Yang ◽  
Sanjeev Adhikari ◽  
Guoyuan Xu
Keyword(s):  
Molecular Dynamics ◽  
Hydrogen Bonds ◽  
Interaction Energy ◽  
Mixed Layer ◽  
Bound Water ◽  
Swelling Behavior ◽  
Dynamics Simulation ◽  
Basal Spacing ◽  
Water Interaction ◽  
Swelling Mechanism

The swelling behavior of clay minerals is widely known for its importance in soil and environmental sciences and its detrimental effects in engineering fields. Although more than 70 percent of all clays are of mixed-layer types, the vast majority of the previous experiments and simulations are focused on pure clays, which cause the swelling mechanism of the widespread mixed-layer clay (MLC) and its role in soils are little understood, especially the most common illite-montmorillonite (I-M) mixed-layer clay (MLC). This paper reports on a molecular dynamics (MD) study of the differences in swelling behavior between I-M MLCs containing K+ and Na+ and Na-montmorillonite (MMT). It captures the evolution of quantitative properties such as basal spacing d, interaction energy, and many hydrogen bonds in the clay interlayer, increasing hydration for the first time through the scripts. It is found that MLCs have smaller swellings than Na-MMT due to the asymmetric interlayer charges and mixed counterions in the I-M interlayer. However, in terms of the interaction energy for the in-depth reason of swelling, it is found that the clay-clay interaction energy and the clay-ion interaction energy drop, while the clay-water interaction energy increases with increasing hydration. In addition, the attractive interaction of clay-bound water seriously promotes swelling, and it is mainly composed of Coulomb interaction and Van der Waals interaction. The higher the K+ concentration, the more noticeable these phenomena are. Besides, it is also reported that the number and distribution mechanism of hydrogen bonds in MLCs are very different from that of pure clay. This work provides insight into the molecular mechanism for initial swelling and clay-bound water interaction in widespread MLCs. This will help to decipher its specific role in soils and minimize clay swelling.

Sign in / Sign up

Export Citation Format

Share Document