Two-stage reduction for the preparation of ferronickel alloy from nickel laterite ore with low Co and high MgO contents

Abstract

The preparation of ferronickel alloy from the nickel laterite ore with low Co and high MgO contents was studied by using a pre-reduction–smelting method. The effects of reduction time, calcination temperature, quantity of reductant and calcium oxide (CaO), and pellet diameter on the reduction ratio of Fe and on the pellet strength were investigated. The results show that, for a roasting temperature >800 °C, a roasting time >30 min, 1.5wt% added anthracite coal, 5wt% added CaO, and a pellet size of ~10 mm, the reduction ratio of Fe exceeds 70% and the compressive strength of the pellets exceeds 10 kg per pellet. Reduction smelting experiments were performed by varying the smelting time, temperature, quantity of reductant and CaO, and reduction ratio of Fe in the pellets. Optimal conditions for the reduction smelting process are as follows: smelting time, 30–45 min; smelting temperature, 1550°C; quantity of reductant, 4wt%–5wt%; and quantity of CaO, 5wt%; leading to an Fe reduction ratio of 75% in the pellets. In addition, the mineral composition of the raw ore and that during the reduction process were investigated by process mineralogy.

Keywords

pre-reduction / smelting / ferronickel alloy / nickel laterite ore

References

[1] Ma X.D., Cui Z.X., Zhao B.J. Efficient utilization of nickel laterite to produce master alloy. JOM, 2016, 68(12): 3006.

[2] Liu Z.G., Sun T.C., Wang X.P., Liu Z.G., Sun T.C., Wang X.P., Gao E.X. Generation process of FeS and its inhibition mechanism on iron mineral reduction in selective direct reduction of laterite nickel ore. Int. J. Miner. Metall. Mater., 2015, 22(9): 901.

[3] Tang X.H., Liu R.Z., Yao L., Ji Z.J., Zhang Y.T., Li S.Q. Ferronickel enrichment by fine particle reduction and magnetic separation from nickel laterite ore. Int. J. Miner. Metall. Mater., 2014, 21(10): 955.

[4] Liu M., Lv X.W., Guo E.G., Chen P., Yuan Q.G. Novel process of ferronickel nugget production from nickel laterite by semi-molten state reduction. ISIJ Int., 2014, 54(8): 1749.

[5] Cao C., Xue Z.L., Duan H.J. Making ferronickel from laterite nickel ore by coal-based self-reduction and high temperature melting process. Int. J. Nonferrous Metall., 2016, 5(2): 9.

[6] Senanayake G., Senaputra A., Nicol M.J. Effect of thiosulfate, sulfide, copper(II), cobalt(II)/(III) and iron oxides on the ammoniacal carbonate leaching of nickel and ferronickel in the Caron process. Hydrometallurgy, 2010, 105(1–2): 60.

[7] Chander S., Sharma V.N. Reduction roasting/ammonia leaching of nickeliferous laterites. Hydrometallurgy, 1981, 7(4): 315.

[8] Guo X.Y., Li D., Wu Z., Tian Q.H. Application of response surface methodology in optimizing the sulfation-roasting-leaching process of nickel laterite. Int. J. Miner. Metall. Mater., 2012, 19(3): 199.

[9] McDonald R.G., Whittington B.I. Atmospheric acid leaching of nickel laterites review: Part I. Sulphuric acid technologies. Hydrometallurgy, 2008, 91(1–4): 35.

[10] Das G.K., de Lange J.A.B. Reductive atmospheric acid leaching of west Australian smectitic nickel laterite in the presence of sulphur dioxide and copper(II). Hydrometallurgy, 2011, 105(3–4): 264.

[11] Whittington B.I., Muir D. Pressure acid leaching of nickel laterites: a review. Miner. Process. Extr. Metall. Rev., 2000, 21(6): 527.

[12] Zhai X.J., Fu Y., Zhang X., Ma L.Z., Xie F. Intensification of sulphation and pressure acid leaching of nickel laterite by microwave radiation. Hydrometallurgy, 2009, 99(3–4): 189.

[13] Harris B., Magee J. Atmospheric chloride leaching: the way forward for nickel laterites. Hydrometallurgy 2003: 5th International Symposium Honoring Professor Ian M. Ritchie, 2003 501.

[14] Norgate T., Jahanshahi S. Low grade ores — Smelt. leach or concentrate? Miner. Eng., 2010, 23(2): 65.

[15] Li B., Wang H., Wei Y.G. The reduction of nickel from low-grade nickel laterite ore using a solid-state deoxidisation method. Miner. Eng., 2011, 24(14): 1556.

[16] Jiang M., Sun T.C., Liu Z.G., Kou J., Liu N., Zhang S.Y. Mechanism of sodium sulfate in promoting selective reduction of nickel laterite ore during reduction roasting process. Int. J. Miner. Process., 2013, 123(10): 32.

[17] Valix M., Usai F., Malik R. Fungal bio-leaching of low grade laterite ores. Miner. Eng., 2001, 14(2): 197.

[18] Lee H.Y., Kim S.G., Oh J.K. Electrochemical leaching of nickel from low-grade laterites. Hydrometallurgy, 2005, 77(3–4): 263.

[19] Warner A.E.M., Dalvi A.D., Mackey P.J., Tarasov A.V. JOM world nonferrous smelter survey: Part III. Nickel: laterite. JOM, 2006, 58(4): 11.

[20] Rao M.J., Li G.H., Jiang T., Luo J., Zhang Y.B., Fan X.H. Carbothermic reduction of nickeliferous laterite ores for nickel pig iron production in China: a review. JOM, 2013, 65(11): 1573.