입도분포가 넓은 분철광석의 분화특성

목차

1. Introduction

2. Experimental
2.1 Experiment Instrumental System

2.2 Materials

2.3 Methods and Conditions of Experiment

3. Analysis Method of Degradation and Reduction Degree

4. Results

5. Discussion

6. Conclusions

본문내용

, Butterworth -Heinemann, Boston, (1991), 68
(18) Daizo Kunii and Octave Levenspiel : Fluidization Engineering, John Wiley & Sons, New York, (1962), 74
Table 1. Chemical compositions and physical properties of iron ore fines used.
Table 2. Size distribution of 1∼5 mm iron ore fines used as sample.
Table 3. Experimental conditions.
Fig. 1. Schematic diagram of a fluidized-bed apparatus.
Fig. 2. Size distributions of iron ore fines before and after the cold fluidization.
Fig. 3. Effect of ore type on the size distribution of iron ore fines.
Fig. 4. Variation of the size distribution of iron ore fines with reaction time.
Fig. 5. Variation of reduction degree with time during the fluidized-bed reduction.
Fig. 6. Effect of temperature on the size distribution of iron ore fines.
Fig. 7. Effect of superficial gas velocity on the size distribution of iron ore fines.
Fig. 8. Effect of superficial gas velocity on the elutriation loss of iron ore fines.
Fig. 9. Effect of gas composition on the size distribution of iron ore fines.
Fig. 10. Size distributions of iron ore fines before and after the hot fluidization
under nitrogen atmosphere.
Fig. 11. Size distributions of iron ore fines before and after the cold fluidization
under nitrogen atmosphere.
Fig. 12. Comparison of size distributions for the cold and hot fluidization of Ore-A.
Fig. 13. Comparison of size distributions for the cold and hot fluidization of Ore-B.
Fig. 14. Variation in solid holdup in vertical direction of reactor during
the fluidized-bed reduction of iron ore fines.
Fig. 15. Variation in total weight and pressure drop in reactor during
the fluidized-bed reduction of iron ore fines.
Fig. 16. Size distributions of iron ore fines in reactor, cyclone, collector and filter before and after reduction.
Table 1. Chemical compositions and physical properties of iron ore fines used.
Chemical
compositions
(
wt``%``
)
T. Fe
FeO
SiO2
Al2O3
TiO2
CaO, Mn, P, S
Combined
water
Ore-A
63.49
0.37
4.32
2.33
0.11
bal.
3.55
Ore-B
59.10
0.51
4.63
1.21
0.05
bal.
8.46
Ore-C
65.20
0.49
4.18
1.54
0.46
bal.
2.83
Physical
properties of
1∼5 mm ores
True density
(
g/cm^3`
)
Bulk density
(
g/cm^3`
)
Sphericity
(
varphi _p
)
Harmonic mean
size ( m)
Ore-A
4.50
2.37
0.73
2260
Ore-B
4.43
2.21
0.61
Ore-C
4.62
2.03
0.45
Table 2. Size distribution of 1∼5 mm iron ore fines used
as sample.
Size range
(mm)
Mean size
(mm)
Weight
(mass %)
Cumulative weight
(mass %)
1.00-2.00
2.00-2.86
2.86-3.36
3.36-4.00
4.00-4.75
1.50
2.43
3.11
3.68
4.38
36.5
18.8
11.7
19.3
13.7
36.5
55.3
67.0
86.3
100.0
Table 3. Experimental conditions.
Variables
Conditions
Ore type
Ore-A(Fe2O3), Ore-B(Fe2O3·H2O)
Ore-C(Fe2O3)
Particle size
1∼5 mm
Temperature
Room temperature, 710∼890 ℃
Gas atmosphere and
composition
N2(100)
Mixing gas, (vol. %)
MG1 : CO(50), CO2(20), H2(25), Ar(5)
MG2 : CO(65), CO2(5), H2(25), Ar(5)
Fluidization time
5∼50 min
Superficial gas velocity
2.5 Nm/s (cold), 3.5∼4.9 m/s (hot)
Ore weight
1000∼6000 g
Pressure
1.15 atm

키워드

분철광석,   분화특성