scholarly journals Influence of MgO on Low Temperature Reduction and Mineralogical Changes of Sinter in Simulated COREX Shaft Furnace Reducing Conditions

Minerals ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 272 ◽  
Author(s):  
Deqing Zhu ◽  
Jianlei Chou ◽  
Benjing Shi ◽  
Jian Pan
Keyword(s):  
Low Temperature ◽  
Shaft Furnace ◽  
Reduction Rate ◽  
Reduction Process ◽  
Smelting Reduction ◽  
Temperature Reduction ◽  
Corex Shaft Furnace ◽  
Reducing Conditions ◽  
Before And After ◽  
Low Temperature Reduction

COREX (Coal-Reduction-Extreme) smelting reduction process provides a sustainable developing way for ironmaking industry, but the sources of iron ore materials restrict its development in China. Meanwhile, the application of sinter, which is marked by low manufacture cost and overcapacity in China, to COREX furnace faced proportion limitation due to its worse low temperature reduction degradation performance. This work explored the influence of MgO content on the low-temperature (550 °C) reduction of sinter in reducing conditions simulating COREX shaft furnace. The mineralogical change of sinter containing different content of MgO before and after reduction was analyzed by X-ray diffraction (XRD), optical microscopy, and scanning electron microscopy for revealing the action mechanism of MgO on the low-temperature-reduction of sinter. The results show that increasing MgO (1.36–3.10%) improved the low temperature reduction degradation performance of sinter, and decreased its reduction degree and reduction rate at low temperature. More MgO the sinter contained, less Fe2O3 and SFCA was observed in sinter. Meantime, less Fe2O3 was reduced and the generation of innerstress was restrained during reduction process. The improved RDI (reduction degradation index) in COREX process of sinter by increasing MgO content is a comprehensive result of lowering strength and inhibiting probable reduction of sinter.

Ultralow-temperature synthesis of small Ag-doped carbon nitride for nitrogen photofixation

2020 ◽  
Vol 10 (22) ◽  
pp. 7652-7660
Author(s):  
Yingzhi Wang ◽  
Rui Zhao ◽  
Fan Wang ◽  
Yong Liu ◽  
Xiaohu Yu ◽  
...  
Keyword(s):  
Low Temperature ◽  
Carbon Nitride ◽  
Deposition Method ◽  
Temperature Synthesis ◽  
Temperature Reduction ◽  
Ultralow Temperature ◽  
Low Temperature Reduction

A low-temperature-reduction–deposition method is used to prepare homogeneously dispersed Ag0/g-C3N4 for efficient N2 photofixation.

Solid Flow in a Shaft Furnace in Smelting Reduction Process under Circumferential Imbalance Conditions

2017 ◽  
Vol 88 (12) ◽  
pp. 1700212 ◽  
Author(s):  
Heng Zhou ◽  
Shengli Wu ◽  
Mingyin Kou ◽  
Biao Tang ◽  
Hanchi Cheng ◽  
...  
Keyword(s):  
Shaft Furnace ◽  
Reduction Process ◽  
Smelting Reduction ◽  
Solid Flow

Low-Temperature Reduction of Magnetite Ore

1936 ◽  
Vol 28 (1) ◽  
pp. 130-133 ◽  
Author(s):  
G. C. Williams ◽  
R. A. Ragatz
Keyword(s):  
Low Temperature ◽  
Magnetite Ore ◽  
Temperature Reduction ◽  
Low Temperature Reduction

Facile Preparation of Ni2 P with a Sulfur-Containing Surface Layer by Low-Temperature Reduction of Ni2 P2 S6

2016 ◽  
Vol 128 (12) ◽  
pp. 4098-4102 ◽  
Author(s):  
Song Tian ◽  
Xiang Li ◽  
Anjie Wang ◽  
Roel Prins ◽  
Yongying Chen ◽  
...  
Keyword(s):  
Surface Layer ◽  
Low Temperature ◽  
Temperature Reduction ◽  
Facile Preparation ◽  
Sulfur Containing ◽  
Low Temperature Reduction

Microstructure of Porous V2O-CeO2-SiO2 Catalyst for SCR of NO with NH3 at Low Temperature

2014 ◽  
Vol 875-877 ◽  
pp. 213-217 ◽  
Author(s):  
Mohd Razali Sohot ◽  
Umi Sarah Jais ◽  
Muhd Rosli Sulaiman
Keyword(s):  
Catalytic Activity ◽  
Low Temperature ◽  
Catalytic Reduction ◽  
Sol Gel ◽  
Reduction Process ◽  
No Emission ◽  
Scr Of No ◽  
Before And After ◽  
The Right ◽  
Proven Method

Selective catalytic reduction (SCR) is a well-proven method to reduce NO emission. However, to choose the right catalyst that provides a surface for reaction between NO and ammonia at low temperatures is a challenging task for a catalysts developers. In an earlier study, we prepared V2O5-CeO2-SiO2 catalyst with increasing V2O5 content by sol-gel route and found that the catalytic activity improved with increasing the V2O5 loading up to 0.5%. The catalytic activity, however, dropped when V2O5 loading was about 1% and increased back when the loading of V2O5 was about 5%. In this study, we looked into the microstructural relationship to explain these findings. The microstructures of the catalysts before and after exposure to NO gas revealed that the catalysts with 0.2% and 0.5% V2O5 were more porous after the reduction process possibly due to improved breakdown of (NH4)HCO3 to NH3 by the possible interaction with the V2O5 and CeO2-containing catalysts which consequently resulted in a more efficient NO reduction to N2 and H2O at low temperature. The microstructure of the catalyst with 1% V2O5 content to 5%, improved back the efficiency although clogging by CeVO4 phase still possible due to its presence based on XRD. The well-ordered micropores before exposure to NO and the more efficient breakdown of (NH4)HCO3 could have contributed to increase back the catalytic activity at low temperature.

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