Thermal Conductivity and Diffusivity of Iron Ore Pellet Having Low Porosity.

A comprehensive characterization on the structural and thermophysical properties of sintered ore particles toward waste heat recovery applications

“…8, the thermal conductivity data of SOPs and other closely-related materials documented in available literature are involved for comparison. As measured by Akiyama et al [17] at a temperature as high as 123 C, the thermal conductivity of fired pellets of iron oxide (Fe 2 O 3 ) lies between 1.10 and 1.57 W/mK at a porosity of~0.235, which is in fairly good agreement with the present results that were obtained at a much lower temperature of 15 C. The thermal conductivity slightly increases to 1.44e1.57 W/ mK when the iron oxide was reduced to magnetite (Fe 3 O 4 ) having a porosity around 0.32 [17], which was measured at 16 C. As reported by Sundarmurti and Rao [18,19], the thermal conductivity of pure iron oxide and pelletized iron ores at a porosity above 0.24 seems to be consistent with the decreasing porosity dependence of the present data for a porosity ranging from 0.22 to 0.24, although their data were obtained as the average values over a wide temperature range up to 700 C. Despite a lack of temperaturedependent data in the present work, it is agreed by other studies…”

“…In addition to the pelletized iron ores, the thermal conductivity of pressed iron ores was also measured by Sundarmurti and Rao [19]. However, such data are excluded intentionally in Fig.…”

“…The thermal conductivity of dense pure and reduced iron ore agglomerates and nonfired pellets were measured using the laser flash method (LFM) [17]. Sundarmutri and Rao [18,19] determined the thermal diffusivity and conductivity of fired spherical hematite pellets and dried pellets using transient conduction for radial heat flow. Nishioka et al [20] also estimated the effective thermal diffusivity of porous solids by LFM, and revealed that the pore sizes have a great influence on the effective thermal diffusivity as well as porosity.…”

Heat Transfer in a Bed of Dry Iron Ore Pellets

“…This value is close to the value of diffusivity within individual pellets, 3) which could either be coincidence or the result of a significant contact area between pellets. Diffusivity of wet pellets is expected to be lower, and heat exchange would be retarded even further if a phase transition from ice to water were to be observed.…”

“…3) This study focuses on heat transfer over a temperature range commonly observed during transport of iron ore pellets. Specifically, KPBO pellets of Luossavaara Kiirunavaara Aktiebolag (LKAB) are commonly shipped shortly after production, i.e.…”