Measurement and Modeling of Thermal Conductivity for Dense Iron Oxide and Porous Iron Ore Agglomerates in Stepwise Reduction
TLDR
In this paper, Li et al. measured the thermal conductivities of pure hematite, magnetite, and wustite using the laser flash method as reference value and summarized them in the form of an empirical equation k = 1/(AT+B).Abstract:
Thermal conductivities of dense pure hematite, magnetite and wustite measured using the laser flash method as reference value have been summarized in the form of an empirical equation k=1/(AT+B). Wustite shows an almost constant and the relatively low thermal conductivity due to the lattice imperfection. Thermal resistivities, 1/k, of three iron oxides appear to change linearly as a function of temperature up to the Tammann temperature.Effective thermal conductivities of fired, nonfired pellets and sinter, reduced into magnetite, wustite and metallic iron by CO-CO2 or H2 gas, have also been systematically measured in the temperature range from room temperature to 1273 K. The porosity of samples was found to change from 20 to 62% by the reduction from hematite to metallic iron. Measured effective thermal conductivity values of these iron ore agglomerates are remarkably smaller than those of dense materials due to the existence of pore. Effective thermal conductivities of metallic iron and hematite strongly depend on temperature. There is no significant difference in the effective thermal conductivities of reduced samples at the same reduction degree.The measured effective thermal conductivity values have been well-explained by the modified unit cell model originally proposed by Luikov when considering the structure composed of core part and connecting part in the solid phase. This model also clearly identify the distinction of solid structure in samples originated from the difference in preparation and reduction degree.read more
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Estimation and modeling of parameters for direct reduction in iron ore/coal composites: Part II. Kinetic parameters
TL;DR: In this paper, a review of the mathematical modeling of rates of reduction, of coal gasification, and of coal devolatilization of coal in iron/ore coal composites is presented.
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Thermal conductivity of ferropericlase in the Earth's lower mantle
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Rate-determining steps for reduction in magnetite-coal pellets
TL;DR: In this paper, a comprehensive modelling approach and experimental results were used to test possible rate-determining steps for direct reduction in pellets containing fine magnetite and coal, and a survey of rate constants from the literature was presented.
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Thermal and magnetic properties of nanostructured densified ferrimagnetic composites with graphene - graphite fillers
S. Ramirez,K. Chan,K. Chan,R. Hernandez,E. Recinos,E. Recinos,E. Hernandez,Ruben Salgado,Alexander Khitun,Javier E. Garay,Javier E. Garay,Alexander A. Balandin +11 more
TL;DR: In this paper, an experimental study of thermal and magnetic properties of nanostructured ferrimagnetic iron oxide composites with graphene and graphite fillers synthesized via the current activated pressure assisted densification was conducted.
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Biotar ironmaking using wooden biomass and nanoporous iron ore
Yuichi Hata,Hadi Purwanto,Sou Hosokai,Jun Ichiro Hayashi,Yoshiaki Kashiwaya,Tomohiro Akiyama +5 more
TL;DR: In this paper, a new biomass iron-making method was proposed, which employs low-grade iron ore and woody biomass for promoting the direct reduction, FeO + C = Fe + CO, in which dehydrated, porous limonite iron ore was filled with carbon deposited from the biomass tar, biotar.
References
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Gas-solid reactions
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.