Effects of Na2SO4 on iron and nickel reduction in a high-iron and low-nickel laterite ore
- 18 Downloads
This study investigates the reactions of Na2SO4 and its effects on iron and nickel reduction in the roasting of a high-iron and low-nickel laterite ore through gas composition, X-ray diffraction, and scanning electron microscope analyses. Results showed that a reduction reaction of Na2SO4 to SO2 was performed with roasting up to 600°C. However, no clear influence on iron and nickel reductions appeared, because only a small amount of Na2SO4 reacted to produce SO2. Na2SO4 reacted completely at 1000°C, mainly producing troilite and nepheline, which remarkably improves selective reduction of nickel. Furthermore, the production of low-melting-point minerals, including troilite and nepheline, accelerated nickel reduction and delayed iron reduction, which is attributed to the concurrent production of magnesium magnetite, whose structure is more stable than the structure of magnetite. Reduction reactions of Na2SO4 resulted in weakening of the reduction atmosphere, and the main product of Na2SO4 changed and delayed the reduction of iron. Eventually, iron metallization was effectively controlled during laterite ore reduction roasting, leading to iron mainly being found in wustite and high iron-containing olivine.
Keywordslaterite ore ferronickel reduction magnetic separation
Unable to display preview. Download preview PDF.
This work was financially supported by the National Natural Science Foundation of China (Nos. 51474018 and 51674018).
- R. Elliott, A Study on the Role of Sulphur in the Thermal Upgrading of Nickeliferous Laterite Ores [Dissertation], Queen’s University, Kingston, 2015.Google Scholar
- D.Q. Zhu, Y. Cui, K. Vining, S. Hapugoda, J. Douglas, J. Pan, and G.L. Zheng, Upgrading low nickel content laterite ores using selective reduction followed by magnetic separation, Int. J. Miner. Process., 106(2012), p. 1.Google Scholar
- E.X. Gao, Z.G. Liu, T.C. Sun, and X.P. Wang, Inhibition mechanism of iron mineral reduction in high iron type laterite nickel ore with the addition of sodium sulfate, Chin. J. Eng., 38(2016), No. 6, p. 754.Google Scholar
- S.W. Zhou, B. Li, Y.G. Wei, H. Wang, C.Y. Wang, and B.Z. Ma, Effect of additives on phase transformation of nickel laterite ore during low-temperature reduction roasting process using carbon monoxide, [in] Drying, Roasting, and Calcining of Minerals, Florida, 2015, p. 177.Google Scholar
- Y.F. Ren, L.Y. Jiang, S.T. Wang, and L. Feng, Studies of the occurrence state and the mineral composition of MgO in dolomite sintered ore as well as its effect on the metallurgical performance, Sintering Pelletizing, 1984, No. 3, p. 1.Google Scholar
- Y.F. Ren, L.Y. Jiang, and S.T. Wang, The occurrence state and function of magnesia on the artificial enriched ore, J. Beijing Univ. Iron. Steel. Technol., 1983, No. 4, p. 1.Google Scholar
- G.H. Li, M.J. Rao, T. Jiang, T.M. Shi, and Q.Q. Huang, Reduction roasting-magnetic separation mechanisms of nickelferous laterite ore in presence of sodium salts, Chin. J. Nonferrous Met., 22(2012), No. 1, p. 274.Google Scholar