Carbothermic reduction characteristics of ludwigite and boron-iron magnetic separation

Guang Wang; Qing-guo Xue; Jing-song Wang

doi:10.1007/s12613-018-1650-3

Volume 25 Issue 9

Sep. 2018

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Article Navigation > International Journal of Minerals, Metallurgy and Materials > 2018 > 25(9): 1000-1009

Guang Wang, Qing-guo Xue, and Jing-song Wang, Carbothermic reduction characteristics of ludwigite and boron-iron magnetic separation, Int. J. Miner. Metall. Mater., 25(2018), No. 9, pp. 1000-1009. https://doi.org/10.1007/s12613-018-1650-3

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Guang Wang, Qing-guo Xue, and Jing-song Wang, Carbothermic reduction characteristics of ludwigite and boron-iron magnetic separation, Int. J. Miner. Metall. Mater., 25(2018), No. 9, pp. 1000-1009. https://doi.org/10.1007/s12613-018-1650-3

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Research Article

Carbothermic reduction characteristics of ludwigite and boron-iron magnetic separation

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Corresponding author:
Guang Wang E-mail: wangguang@ustb.edu.cn
Received: 22 January 2018; Revised: 29 March 2018; Accepted: 24 April 2018

Abstract

Abstract

Ludwigite is a kind of complex iron ore containing boron, iron, and magnesium, and it is the most promising boron resource in China. Selective reduction of iron oxide is the key step for the comprehensive utilization of ludwigite. In the present work, the reduction mechanism of ludwigite was investigated. The thermogravimetry and differential scanning calorimetry analysis and isothermal reduction of ludwigite/coal composite pellet were performed. Ludwigite yielded a lower reduction starting temperature and a higher final reduction degree compared with the traditional iron concentrates. Higher specific surface area and more fine cracks might be the main reasons for the better reducibility of ludwigite. Reducing temperature highly affected the reaction fraction and microstructure of the reduced pellets, which are closely related to the separation degree of boron and iron. Increasing reducing temperature benefited the boron and iron magnetic separation. Optimum magnetic separation results could be obtained when the pellet was reduced at 1300℃. The separated boron-rich non-magnetic concentrate presented poor crystalline structure, and its extraction efficiency for boron reached 64.3%. The obtained experimental results can provide reference for the determination of the comprehensive utilization flow sheet of ludwigite.
- complex iron ore;
- boron resource;
- carbothermic reduction;
- magnetic separation

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References

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