The composition of Bayan Obo iron ore concentrate is complex. If a large proportion is used to prepare pellets, abnormal swelling will occur during blast furnace smelting. This paper studies the swelling behavior of pellets prepared from Bayan Obo iron ore concentrate in stages during the reduction process; XRD and SEM-EDS analysis and calculates the crystal parameters of the reduction products in each stage. The results show that the total RSI of pellets prepared from Bayan Obo iron ore concentrate is as high as 35%, and the third stage of reduction has the maximum swelling rate, which is 24%. The mechanisms of the three stages reduction swelling of pellets are the crystal transformation, the effect of slag phase and the growth of iron whiskers. The results can enrich the reduction swelling theory of pellets prepared from complex intergrowth minerals.
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References
1.
ZhuDHuangWYangCet al.Technical progress in iron ore pelletization. Sinter Pelletizing. 2017;42:42–49.
2.
YeK.Heavily push forward the pelletizing production in Our country. Sinter Pelletizing. 2007;05:1–5.
3.
WeiXWangX.Market analysis on pellet ore. Min Eng. 2019;17:1–4.
4.
LiuW.Knowledge and view on development of pellet production in China. Ironmak. 2006;03:10–13.
5.
ZhangSWangBLanCet al.Prospects and present status of pellets chemical composition control. Iron Steel. 2020;55:19–26.
6.
ShaYGeerdesMSongY.Technical and economic analysis of blast furnace operation with high pellet ratio in China. Ironmak. 2019;38:1–5.
7.
LuoGLiuAWangYet al.Influence of MgO on the reduction swelling performance of alkali pellets. Sinter Pelletizing. 2016;41:31–33.
8.
WangPWangYLuoGet al.Study of the soft drip performance of melting steel form reasonable furnace charging for baotou iron and steel (group). J Inner Mongolia Univ Sci Technol. 2010;29:103–107.
9.
GaoDWangYLuoGet al.Study of crystal stock resistance and comparison of sphericity between the self-produced and Barun ore concentrate. J Inner Mongolia Univ Sci Technol. 2010;29:99–102.
10.
LiuALuoGWangYet al.The influence of K, Na and F on reduction swelling of hematite pellets. J Inner Mongolia Univ Sci Technol. 2016;35:113–116.
11.
FuG.Analysis of affecting factors of oxidized pellet RSI at baotou iron and steel (group) and study on its reasonable controlInner Mongolia Univ Sci Technol. 2019;2–8.
12.
SunZ.Study on the reduction and expansion characteristics of iron ore pellets. Sinter Pelletizing. 1983;03:17–24.
13.
LiangZ.Study on gas-based reduction and accompanying swelling behavior of iron ore pellets. Cent S Univ. 2013;1–9.
14.
FeiH.Experimental study on reduction expansion of synthetic hematite pellets. Sinter Pelletizing. 1986;03:10–16.
15.
LinYFeiHXuCet al.Study on the reduction and swelling performance of panzhihua pellet. Sichuan Metall. 1979: 1–12.
16.
ShojiHYoshiakiI.Abnormal swelling during reduction of binder bonded iron ore pellets with CO-CO2 gas mixtures. ISIJ Int. 2003;43:1370–1375.
17.
UmadeviTKumarAKarthikPet al.Characterisation studies on swelling behaviour of iron ore pellets. Ironmak Steelmak. 2018;45:157–165.
18.
ZhouQGuoC.Study on the mechanism of the influence of alkali metals and fluorine on the reduction and swelling of pellets. Acta Metall Sinica. 1986;06:95–102.
19.
PiXSunQLuoGet al.Research review on reduction expansion mechanism of pellets. Sinter Pelletizing. 2017;42:28–34.
20.
ZhangJ. Roasting characteristics and reduction behaviors of fluxed branzilian hematite oxidized pellets. Cent S Univ. 2012;1–12.
21.
LiuZ.Experimental study on improving the proportion of self produced concentrate for belt type roasting machine in Baotou steel. Sci Technol Baotou Steel. 2018;44:41–44.
22.
LuoGZhaoBLiuJet al.Study on mineralogical structure and metallurgical performance of bao steel MgO-containing pellets. Sinter Pelletizing. 2015;40:25–27.
23.
WeiGFuGLvZet al.Study on substituting bentonite with cobinder for pellet of Baotou steel. Sci Technol Baotou Steel. 2020;46:19–22.
24.
XieH.Design gist about pellet straight grate and relationship between thus and spheric agglomeration’s output and quality. China Metall. 2015;25:28–35.
25.
WangHSohnH.Effect of CaO and SiO2 on swelling and iron whisker formation during reduction of iron oxide compact. Ironmak Steelmak. 2011;38:447–452.
26.
PanB.Expansion and pulverization of iron ore concentrate oxidized pellets in the reduction stage of hematite-magnetite. Iron Steel Van Tit. 1983: 50–55.
27.
MohantyMMishraSMishraBet al.Effect of basicity on the reduction behavior of iron ore pellets. Arab J Sci Eng. 2018;43:5989–5998.
28.
LuoGLiuAWangYet al.Influence of MgO on the reduction swelling performance of alkali pellets. Sinter Pelletizing. 2016;41:31–33.
29.
LuoGLiuAWangYet al.Effect of MgO on reduction swelling index of pellets containing K, Na and F. Iron Steel. 2016;51:14–18.
