Journal ArticleDOI
Kinetics of manganese ore reduction by carbon monoxide
K. L. Berg,S. E. Olsen +1 more
TLDR
In this paper, the reduction of higher manganese oxides to MnO by carbon monoxide has been studied in the temperature range 700 °C to 1100 °C, and a topochemical pattern with a single shrinking core inside the ore particles has been observed in most cases.Abstract:
A step has been made in the direction of understanding the fundamental chemical processes taking place inside electric are furnaces producing manganese alloys. The reduction of higher manganese oxides to MnO by carbon monoxide has been studied in the temperature range 700 °C to 1100 °C. A topochemical pattern with a single shrinking core inside the ore particles has been observed in most cases. It has been found that the reduction of some manganese silicates (braunite minerals) is influenced by reaction interface kinetics, whereas the reduction rate of manganese oxides (bixbyite and hausmannite) is mostly determined by product shell pore diffusion. Sintering kinetics and the extent of natural porosity determine the product shell pore diffusivity. As the melting point of the reaction product is approached, rapid sintering leads to a decrease in diffusivity.read more
Citations
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Foaming of flat glass cullet using Si3N4 and MnO2 powders
Alejandro Saburit Llaudis,María José Orts Tari,Francisco Javier García Ten,Enrico Bernardo,Paolo Colombo +4 more
TL;DR: In this article, the authors found that at the highest level of porosity, the strength of foams is negatively affected by a coarse microstructure, determined by cell coalescence.
Journal ArticleDOI
Recycling of waste glasses into partially crystallized glass foams
TL;DR: In this article, a soda-lime glass, alone or mixed with wastes from the manufacturing of glass fibers, was successfully converted into partially crystallized glass foams by a particularly simple and economic processing, consisting of a direct heating of glass powders at temperatures from 900 to 1050°C.
Journal ArticleDOI
Activation of the carbothermic reduction of manganese ore
TL;DR: In this paper, the effect of extended milling on the carbothermic reduction of a manganese ore has been examined using a combination of thermal analysis and X-ray diffraction (XRD).
Journal ArticleDOI
Kinetics of Mn2O3–Mn3O4 and Mn3O4–MnO Redox Reactions Performed under Concentrated Thermal Radiative Flux
Elisa Alonso,Christian Hutter,Manuel Romero,Aldo Steinfeld,Aldo Steinfeld,José Gonzalez-Aguilar +5 more
TL;DR: In this paper, the authors considered the thermochemical cycle for splitting water using concentrated solar energy and derived the overall kinetic rate laws under similar heat and mass-transfer characteristics existing in highly concentrating solar systems, such as solar towers or parabolic dishes.
Journal ArticleDOI
Simulation of direct reduction reactor by the grain model
TL;DR: In this paper, a mathematical model is developed for simulating the behavior of a direct reduction moving bed reactor for the production of sponge iron, which is modeled through a nonisothermal, steady state, heterogeneous model.
References
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Book
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TL;DR: In this article, the authors present the following principles: Momentum Transfer and Overall Balances, Steady State Heat Transfer, Unsteady State and Convective Mass Transfer, and Mass Transfer.
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TL;DR: In this article, the authors present an integrated view of gas-solid reaction systems, where full account is taken of these new developments and where structural models of single particle systems, experimental techniques, interpretation of measurements, the design of gas solids contacting systems, and practical applications are treated in a unified manner.
Journal ArticleDOI
The mechanism of the thermal decomposition of calcium carbonate
TL;DR: In this article, the authors used a modified thermo-balance to measure the diffusion coefficient and thermal conductivity of the porous lime layer, and the mass and heat transfer coefficients to the surface of the compact.
Journal ArticleDOI
The role of natural convection in ladles as affecting tundish temperature control in continuous casting
J. Szekely,J. H. Chen +1 more
TL;DR: In this paper, an approximate analysis is presented to describe the flow field in molten steel held in a ladle, as caused by natural convection, and it is shown that a thick slag layer is required to suppress extensive vertical mixing within the ladle.
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