Vanadium–titanium magnetite ore blend optimization for sinter strength based on iron ore basic sintering characteristics

doi:10.1016/j.minpro.2015.04.019

International Journal of Mineral Processing

Volume 142, 10 September 2015, Pages 125-133

https://doi.org/10.1016/j.minpro.2015.04.019 Get rights and content

Highlights

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The method for improving V–Ti sinter strength based on the basic sintering characteristics (BSCs) was proposed.
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The application of the method on V–Ti sinter was verified useful.
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The key factor influencing the V–Ti sinter strength was revealed.
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The principle of choosing matching ore for V–Ti sinter strength was proposed.
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The mechanism of the key factors influencing the sinter strength was analyzed.

Abstract

Vanadium titanium magnetite (V–Ti) ore is one kind of important polymetallic minerals in China and the mainstream route of comprehensive utilization process is blast furnace (BF) → basic oxygen furnace (BOF). V–Ti sinter is one of the main burdens employed for BF and poor tumbler strength (TI) limits its efficiency. In order to optimize the V–Ti blends for sinter TI, the basic sintering characteristics (BSCs) of 5 kinds of V–Ti ores, 2 ordinary ores and 3 groups of optimization V–Ti blends were studied. In addition, the sinter pot tests were conducted to obtain the TI of the produced sinter. The influencing factors on assimilation temperature (AT), the relations between the 4 characteristics of BSCs, and the factors influencing the V–Ti sinter TI were analyzed. The results showed that the BSCs of 5 kinds of V–Ti ores DB, HW, YT, JL and FH were good except liquid phase fluidity characteristic index (LF). The key reason why V–Ti sinter had a poor TI was the low LF, which caused the sinter with a large-pore structure. Therefore, the matching ores for optimization V–Ti blends should have a high LF. In addition, self-strength of the bonding phase (BS) and crystal intensity (CI) had an important impact on TI when the melt formed was sufficient and meanwhile the melt had a high LF. Moreover, the proper AT was the prior factor for the melt generation. In addition, the optimization V–Ti blends had good BSCs. The sinter TI with 7% NF ore addition could meet the production requirements for its TI was higher than 65%. Totally, the method of V–Ti magnetite ore blend optimization for sinter strength based on iron ore basic sintering characteristics was useful.

Introduction

Vanadium and titanium magnetite (V–Ti) ore has a very high comprehensive utilization value due to its high-content vanadium, titanium, iron, etc. In addition, V–Ti ore as a major source of vanadium is found in various countries, such as Australia, China, Russia, and South Africa (Moskalyk and Alfantazi, 2003, Deng et al., 2012, Yu, 2004). But because of its complicated phase structure, and numerous mineral components (Hu et al., 2013), V–Ti ore is classified as a typical polymetallic paragenic resource that is difficult to treat and utilize (Si et al., 2012). Currently, the mainstream route of the comprehensive utilization of V–Ti ore is blast furnace (BF) → basic oxygen furnace (BOF). However, it is found that the smelting operation and the comprehensive utilization of V–Ti burden in BF affected seriously for its poor tumbler strength (TI) compared with that of ordinary sinter.

Thus, the researches on the improvement of V–Ti sinter quality especially TI are valuable. The research on the properties of raw materials, especially the characteristics of iron ores is fundamental and important. In addition to the traditional room temperature characteristics of iron ores, generally including physical structure (Ono et al., 2009, Formoso et al., 2003, Ellis et al., 2007), chemical composition (Hsieh, 2005, Wu et al., 2011, Wu et al., 2011), and basic sintering characteristics (BSCs) of iron ores proposed by Wu et al., 2002a, Wu et al., 2002b get more and more attention of the researchers. BSCs including 4 kinds of high temperature characteristics of iron ores, such as assimilation characteristic, liquid phase fluidity characteristic, self-strength of bonding phase, and crystal intensity characteristic, could reflect the behavior and exhibit some physical and chemical characteristic of iron ores in the sintering process. Extensive work (Zhang et al., 2012, Zhang et al., 2013, Zhang et al., 2014, Wu et al., 2010) on BSCs has been conducted to optimize the iron ore blends and the results confirm that there is great significance in mastering the BSCs of iron ores, which will be beneficial to improving sinter properties and productivity. Though, the previous work almost focuses on the ordinary iron ores and the ordinary ore blends, there are limited studies on the BSCs of V–Ti ores and their blends. In addition, the previous work on the optimization of iron ore blends usually is based on one of the BSCs such as assimilation characteristic. Furthermore, the relations between the BSCs and the produced sinter's properties such as TI were not revealed.

Therefore, in the present research, firstly, the BSCs of 5 kinds of V–Ti ores FH, DB, HW, YT, JL, and 2 kinds of ordinary ores YD and NF were studied. Secondly, 3 groups of optimization V–Ti blends YH, NH-1, and NH-2, mixed with ordinary iron ores, were designed and determined based on the results of the first research. Thirdly, sinter pot tests were carried out to verify the method's usefulness and to aiming to achieve the sinter TI. Fourthly, the relations between the 4 characteristics of BSCs and the produced sinter's TI were obtained. Finally, the rules of V–Ti ore blend optimization for the sinter TI were proposed and it would be useful to the V–Ti iron ore optimization for achieving a high value of sinter TI.

Section snippets

Experimental materials

The 5 kinds of vanadium–titanium magnetite ores DB, HW, YT, JL, and FH (mixed by DB, HW, YT and JL) and 2 ordinary ores (hematite) YD, and NF used in this study are supplied by Chengde Jianlong Iron and Steel Group Company, China. The chemical composition of iron ores and coke breeze for experimental work are listed in Table 1, Table 2.

It can be seen from Table 1 that the total iron content of 5 kinds of V–Ti ores is higher than that of ores NF and YD especially YD, and the TiO₂ content of V–Ti

Assimilation characteristic

Fig. 5 shows the results of assimilation reaction tests of 5 kinds of V–Ti ores DB, HW, YT, JL, and FH and 2 ordinary ores YD, and NF. Among 5 kinds of V–Ti ores, JL has the lowest AT (1240 °C), then DB (1250 °C), YT and FH (1255 °C), HW has the highest AT (1270 °C). AT of FH is in the range of the min and max ATs of DB, HW, YT, and JL. The 2 ordinary ores YD, and NF all have relatively high ATs 1275 °C and 1260 °C, respectively. On the whole, ATs of 5 kinds of V–Ti ores and 2 ordinary ores are all

Conclusions

In order to optimize the V–Ti blends for sinter TI, the BSCs of 5 kinds of V–Ti ores, 2 ordinary ores and 3 groups of optimization V–Ti blends were studied. In addition, the sinter pot tests were conducted to obtain the TI of the produced sinter. The influencing factors on AT, the relations between the 4 characteristics of BSCs, and the key factor influencing the V–Ti sinter TI were analyzed. The conclusions were as follows.

(1)
The method of V–Ti iron ore blend optimization for sinter strength

Acknowledgments

The authors are grateful to the National High Technology Research and Development Program of China (863 Program) (Nos. 2012AA062302 and 2012AA062304), Program of the National Natural Science Foundation of China (Nos. 51090384 and 51174051), and The International Cooperation of Ministry of Science and Technology Major of China (No. 2012DFR60210) for support of this research.

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Vanadium–titanium magnetite ore blend optimization for sinter strength based on iron ore basic sintering characteristics

Highlights

Abstract

Introduction

Section snippets

Experimental materials

Assimilation characteristic

Conclusions

Acknowledgments

Powder Technol.

Miner. Eng.

Int. J. Miner. Process.

J. Iron. Steel Res. Int.

Leaching vanadium from extracted vanadium residue of vanadium titanomagnetite

Chin. J. Nonferrous Met.

Effect of ore properties on sinter bed permeability and strength

Ironmak. Steelmak.

Influence of nature and particle size distribution on granulation of iron ore mixtures used in a sinter strand

Ironmak. Steelmak.

Effect of raw material composition on the sintering properties

ISIJ Int.

Reduction behavior of Panzhihua titanomagnetite concentrates with coal

Metall. Mater. Trans. B

Differential thermal analysis of assimilation and melting-formation phenomena in the sintering process of iron ores

ISIJ Int.

Effect of mineral composition and pore structure on reducibility of composite iron ore sinter

ISIJ Int.