Influence of Coating Oxide and Sulfur Pressure on Sticking during Fluidized Bed Reduction of Iron Ores.

Abstract

Showa-ku, Nagoya, Process TechnologyIn order to avoid sticking during a fluidized bed reduction of iron ores and elucidate its mechanism,their reduction tests using two types of easily sticked ores coated by a water-slurry consisting of each submicron reagent of gangue species were carried out at 900"C by N.

Characterization of Precipitated Carbon by XPS and Its Prevention Mechanism of Sticking during Reduction of Fe2O3 Particles in the Fluidized Bed

“…Otherwise, the iron ore fines with additions of CaO, MgO and Al2O3 showed the sticking could be avoided or decreased. [8][9][10] While, the coating methods of powder, solution and slurry were by means of mechanical mixing, leading to the non-uniform distribution of additives on the surface of iron ore fines that lowered the prevention efficiency for sticking. Moreover, the method was more or less difficult in operation.…”

“…[1][2][3][4] However, the industrialized development of the fluidized bed in iron-making was limited, [5][6][7] which was mainly attributed to the defluidization resulted from sticking among iron ore particles. [8][9][10][11] To prevent sticking problem during reduction of iron ores in the fluidized bed, some methods were proposed by previous researchers. Low reduction temperature that led to small adhesive force among iron ore fines and high gas velocity that produced high momentum of particles were useful for suppressing sticking.…”

Parameters Optimization, Sticking Mechanism and Kinetics Analysis of Fine Iron Ore in Fluidized-Reduction Process

“…7,8,[13][14][15] The five factors are denoted by letters A, B, C, D, and E, where A represents the reduction temperature, A 1 represents 923 K temperature, A 2 is 1 023 K, and A 3 is 1 123 K; B represents the linear velocity of the reducing gas, B 1 is 0.4 m/s, B 2 is 0.6 m/s, and B 3 is 0.8 m/s; C represents the coating oxide that accounts for 2 mass% of the total fine iron ore, C 1 represents ORD-S fine iron ore without coating, C 2 represents coating CaO that accounts for 2 mass% of the total fine iron ore, and C 3 is coating MgO which accounts for 2 mass% of the total fine iron ore; D represents the diameter particles size of ORD-S fine iron ore, D 1 denotes < 0.15 mm, D 2 denotes 0.15-0.63 mm, and D 3 denotes 0.63-1.0 mm; E represents the hydrogen volume content in reducing gas mixture, E 1 is 60 vol.%, E 2 is 80 vol.%, and E 3 is 100 vol.%. Tables 3 and 4 show The weight of 150 g of fine iron ore is taken in each experiment.…”

“…These residues significantly advance to the peripheral, which makes sticking among the particles easier. 8,13) A minimum rate of metallization ratio is set. For the metallization rate, MgO additive accounting for 2 mass% of the total amount of iron ore is selected.…”

Effect of Coating Mg(OH)₂ with Heterogeneous Deposition Method on Sticking during Fluidized Bed Reduction of Iron Ore

“…Furthermore, MgO was proved to be the best coating agent compared with other oxides. 11,[26][27][28] In the previous investigations, the total adding amount of coating agent was selected as the reference for measuring the coating degree. In fact, the actual coating amount on the particle surface was usually much less than the total adding amount of coating agent.…”