XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3 1329
Influence of Reducing Gas Concentration on Separation
Performances
The effect of reducing gas concentration on the separation
efficiency of HMPT products is also critical and cannot be.
(Zhang et al., 2023b). Too low a concentration may result
in inadequate reduction of weakly magnetic iron miner-
als, thereby affecting recovery, while too high a concen-
tration may result in excessive reduction of magnetite to
weakly magnetic wüstite, which is unfavorable for subse-
quent weak magnetic separation. Therefore, it is necessary
to determine an appropriate reducing gas concentration.
With the HMPT temperature controlled at 500°C, a feed
rate of 120 kg/h and a reducing gas flow rate of 3.5 m3/h,
the effect of the reducing gas concentration on the separa-
tion performance of the transformed products was investi-
gated. The results, as shown in Figure 5, indicate that as the
reducing gas concentration increases, the TFe recovery of
the magnetic product remains relatively stable, fluctuating
between 91.60% and 93.29%. As the reducing gas concen-
tration increases from 15% to 22.5%, the TFe content of
the magnetic product increases from 62.48% to 64.86%.
Further increases in reducing gas concentration result in
only minor changes in TFe grade and magnetic product
recovery. These results indicate that a suitable reducing gas
concentration is approximately 22.5%.
Influence of Feeding Rate on Separation Performances
The magnitude of the feed rate affects not only the through-
put of the HMPT reactor, but also the effectiveness of the
HMPT process. It must be kept within a reasonable range
because significant variations in the feed rate may require
adjustments in other reaction conditions (such as the
amount of natural gas burned in the suspension furnace
and the flow of reducing gas) (Tang et al., 2022b). With the
HMPT temperature controlled at 500°C, a reducing gas
flow rate of 3.5 m3/h and a reducing gas concentration of
22.5%, the effect of the feed rate on the separation perfor-
mance of the transformed products was investigated. The
results, as shown in Figure 6, indicate that there is a slight
downward trend in the recovery of the magnetic product
TFe as the feed rate increases. The TFe recovery is highest
at a feed rate of 120 kg/h, reaching 93.40%, and further
increases in the feed rate cause it to decrease to 91.25%.
This phenomenon can be attributed to the increased accu-
mulation of thermal energy in the reactor as the feed rate
increases, which raises the surface temperature of the iron
minerals and promotes the reduction process. However,
increasing the feed rate also reduces the residence time of
the iron minerals in the reducer, which affects the complete
reduction of some iron minerals. Therefore, the appropriate
feed rate is determined to be 120 kg/h.
Figure 5. Effect of the reducing gas concentration on separation indexes for the
magnetic product
Influence of Reducing Gas Concentration on Separation
Performances
The effect of reducing gas concentration on the separation
efficiency of HMPT products is also critical and cannot be.
(Zhang et al., 2023b). Too low a concentration may result
in inadequate reduction of weakly magnetic iron miner-
als, thereby affecting recovery, while too high a concen-
tration may result in excessive reduction of magnetite to
weakly magnetic wüstite, which is unfavorable for subse-
quent weak magnetic separation. Therefore, it is necessary
to determine an appropriate reducing gas concentration.
With the HMPT temperature controlled at 500°C, a feed
rate of 120 kg/h and a reducing gas flow rate of 3.5 m3/h,
the effect of the reducing gas concentration on the separa-
tion performance of the transformed products was investi-
gated. The results, as shown in Figure 5, indicate that as the
reducing gas concentration increases, the TFe recovery of
the magnetic product remains relatively stable, fluctuating
between 91.60% and 93.29%. As the reducing gas concen-
tration increases from 15% to 22.5%, the TFe content of
the magnetic product increases from 62.48% to 64.86%.
Further increases in reducing gas concentration result in
only minor changes in TFe grade and magnetic product
recovery. These results indicate that a suitable reducing gas
concentration is approximately 22.5%.
Influence of Feeding Rate on Separation Performances
The magnitude of the feed rate affects not only the through-
put of the HMPT reactor, but also the effectiveness of the
HMPT process. It must be kept within a reasonable range
because significant variations in the feed rate may require
adjustments in other reaction conditions (such as the
amount of natural gas burned in the suspension furnace
and the flow of reducing gas) (Tang et al., 2022b). With the
HMPT temperature controlled at 500°C, a reducing gas
flow rate of 3.5 m3/h and a reducing gas concentration of
22.5%, the effect of the feed rate on the separation perfor-
mance of the transformed products was investigated. The
results, as shown in Figure 6, indicate that there is a slight
downward trend in the recovery of the magnetic product
TFe as the feed rate increases. The TFe recovery is highest
at a feed rate of 120 kg/h, reaching 93.40%, and further
increases in the feed rate cause it to decrease to 91.25%.
This phenomenon can be attributed to the increased accu-
mulation of thermal energy in the reactor as the feed rate
increases, which raises the surface temperature of the iron
minerals and promotes the reduction process. However,
increasing the feed rate also reduces the residence time of
the iron minerals in the reducer, which affects the complete
reduction of some iron minerals. Therefore, the appropriate
feed rate is determined to be 120 kg/h.
Figure 5. Effect of the reducing gas concentration on separation indexes for the
magnetic product