Operation of Pilot Plant for Fluidized Bed Reduction at High Temperatures and Pressures

Abstract

In order to develo/l a direct reduction /11'OCeSS by fluidized bed, experimental operations of a. 11ilot plant were carried Ollt. The plant comprised multi/lie fluidized bed with both counter current and cross current contacting of ore and gas in a reactor of 25 cm inner diameter. Th e results are summarized as follows ,' (I) Stable and sintering-free continllolls operation at a maxim lim tem-/lerature q[ 900°C was carried out, using coarse partieies of H amersley iron ore (16-1 15 mesh) under a pressure q[ 7 kg /cm', C; the /lroduct of above 95°o reduction was obtained, the utilization of hy drogen gas was 17° 0 and tlze /lroductivity was 55 t/m'. d. (2) T he distribution of fractional reduction in a fluidized bed was survl!J'ed by magnetic se/laration of samples obtained from the bed. R eduction rate of Ilartieies in tlze bed was obtained directly from the distribution Cl/rve. An operation analysis was 1//{Ide on the basis of the ill[ormation obtained for /Jartieie reduction. (3) Opera tioll s using a /Jartition /Jlate designed b)' the allthors were sllccessful and dJectiue to increase the reduction degree of /noc/ucts and the

The sticking problem during direct reduction of fine iron ore in the fluidized bed

“…With lower reduction temperatures occurs diffusion slowly, and one homogeneous structure with dense participation formed, low reduction degree and longer reduction time could be achieved. At higher temperatures occurs higher reduction degree [1,2,10,[26][27][28][29]. If the temperature increases the iron ore will start to soften and to smelt.…”

Preliminary investigation into direct reduction of iron in low temperature hydrogen plasma

“…In other words, in the plasma state both H and H z can coexist and for these reasons studies are underway to produce iron using hydrogen plasma in a manner similar to the hydrogen plasma smelting reduction process. 2,5,17,18 It is clear that there could be different possible routes for the reduction of iron ore in hydrogen plasma, as the plasma itself contain different species, namely, excited hydrogen molecules, hydrogen atoms, and ionic hydrogen and other gaseous species. Figure 2a presents equilibrium partial pressure of molecular hydrogen versus temperature for the reactions (4)- (7).…”

“…In other words, in the plasma state both H and H + can coexist and for these reasons studies are underway to produce iron using hydrogen plasma in a manner similar to the hydrogen plasma smelting reduction process 2,5, 17, 18…”