1. A process for reducing iron ore, the process comprising:
inputting a powder comprising iron ore such that said powder falls
downwards in a reactor tube;
5 inputting a reducing gas into the reactor tube whereby the downwardly
falling powder and the reducing gas assume a dilute flow regime;
indirectly heating the reactor tube so as to heat the falling powder and the
reducing gas to a temperature at which the falling powder is caused to be reduced.
2. A process as claimed in claim 1, comprising inputting the powder at a flux in
the range of 0.5-1.0 kg m-2
s
-1
10 .
3. A process as claimed in claim 1 or 2, wherein an average velocity of the
downwardly falling powder is less than 3.0 m/s and greater than 0.2 m/s.
4. A process as claimed in any one of the preceding claims, wherein a particle size
distribution of the powder comprising iron ore is within the range of 25 µm to 250
15 µm.
5. A process as claimed in any one of the preceding claims, wherein a residence
time of the downward falling powder is about 10 to 50 s.
6. A process as claimed in any one of the preceding claims, further comprising
collecting a resultant reduced iron powder product from a base of the reactor tube.
20 (DELETED)
7. A process as claimed in any one of the preceding claims, further comprising
collecting an exhaust gas. (DELETED)
8. A process as claimed in claim 7, wherein the exhaust gas comprises entrained
input powder particles, the process further comprising extracting the particles from
25 the gas stream and re-inputting the particles into the reactor tube. (DELETED)
43
9. A process as claimed in claim 7 or 8, further comprising scrubbing the exhaust
gas so as to remove gas reaction products therefrom and re-inputting the scrubbed
gas into the reactor tube. (DELETED)
10. A process as claimed in any one of the preceding claims, wherein the reactor
5 tube is heated so that a temperature of between 700 °C and 900 °C is reached
within the reactor tube.