Formation of Calcium Ferrite Containing Aluminum (CFA) in Sintering of Iron Ore Fines
Abstract
:1. Introduction
2. Materials and Methods
2.1. Reactions of CFA Formation
2.2. Minerals Determination
2.3. Calculations of Formation Energy for Products
3. Results and Discussion
3.1. Effect of Temperature on CFA Formation
3.2. Effect of Different Types of Al-Containing Materials on CFA Formation
3.3. Reaction of CF with Fe2O3
3.4. Reaction of CF with Al2O3
3.5. Stability of Products Generated in Reactions
4. Conclusions
- (1)
- It was observed in the Fe2O3-CaO-Al2O3 sample sintered below 1200 °C that CF appeared at 1000 °C, while Ca2Fe15.5O25 and CFA appeared at 1100 °C.
- (2)
- It was found that CF and Ca2Fe15.5O25 are the precursors for CFA formation, and the chemical composition of Ca2Fe15.5O25 phase was determined to be CaFe3.96O6.94 (CF1.98), similar to CaFe4O7.
- (3)
- It was revealed that the appearance of CA or CA2 is a main reason to decrease the rate of CFA formation in Fe2O3-CaO-Al2O3 samples.
Author Contributions
Funding
Data Availability Statement
Conflicts of Interest
References
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Materials | Fe2O3 | CaCO3 | Al2O3 | Sintering Time | Sintering Temperature |
---|---|---|---|---|---|
CF | 61.5 | 38.5 | 480 min | 1200 °C | |
Hss | 96.0 | 4.0 | 240 min | 1250 °C |
Reaction | Fe2O3 | CaCO3 | Al2O3 | Hss | CF |
---|---|---|---|---|---|
Fe2O3-CaCO3-Al2O3 | 79.42 | 16.58 | 4 | ||
CF-Fe2O3-Al2O3 | 57.3 | 4 | 38.7 | ||
Hss-CF | 59.7 | 40.3 |
Modules | Functional Used | Plane Wave Basis Set Cut-Off | k-Point | Relativistic Treatment | Pseudopotentials |
---|---|---|---|---|---|
CASTEP | Perdew–Burke–Ernzerhof | 489.8000 eV | 1 × 1 × 1 | Koelling–Harmon | OTFG ultrasoft |
Position | Fe | Ca | Al | O | Minerals |
---|---|---|---|---|---|
Figure 4(a1) | 48.51 | 0.61 | 3.48 | 47.40 | Hss |
Figure 4(a2) | 37.58 | 17.82 | 0.08 | 44.52 | CF |
Figure 4(a3) | 41.10 | 7.59 | 6.22 | 46.08 | CFA |
Figure 4(a4) | 40.70 | 11.79 | 1.61 | 45.89 | CFA |
Figure 4(b1) | 47.06 | 52.94 | Fe2O3 | ||
Figure 4(b2) | 35.40 | 8.12 | 4.50 | 51.97 | Ca2Fe15.50O25 |
Figure 4(b3) | 30.14 | 7.28 | 9.22 | 53.36 | CFA |
Figure 4(b4) | 8.20 | 36.16 | 55.64 | CA2 |
CF | CF1.98 | CFA | CA | C2F | CA2 |
---|---|---|---|---|---|
53,777 | 52,281 | 49,546 | 35,963 | 23,753 | 9092 |
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Du, Y.; Guo, H.; Guo, X.-M. Formation of Calcium Ferrite Containing Aluminum (CFA) in Sintering of Iron Ore Fines. Minerals 2024, 14, 400. https://doi.org/10.3390/min14040400
Du Y, Guo H, Guo X-M. Formation of Calcium Ferrite Containing Aluminum (CFA) in Sintering of Iron Ore Fines. Minerals. 2024; 14(4):400. https://doi.org/10.3390/min14040400
Chicago/Turabian StyleDu, Yu, Hui Guo, and Xing-Min Guo. 2024. "Formation of Calcium Ferrite Containing Aluminum (CFA) in Sintering of Iron Ore Fines" Minerals 14, no. 4: 400. https://doi.org/10.3390/min14040400