Reductive roasting of nickel laterite ore with sodium sulphate for Fe-Ni production. Part II: Phase transformation and grain growth

ABSTRACT

In Part II, the correlation between Fe–Ni grain growth and characteristic fusion temperatures of the Na₂SO₄–laterite mixtures, and phase transformations of the reduced pellets were investigated. For the mechanism of sodium sulphate, Na⁺ is able to liberate the hosted nickel and iron within lizardite, while SO₄^2– is the sulphur source for the formation of Fe–FeS eutectic compound which can decrease the characteristic fusion temperatures to promote the growth of ferronickel grains. The mean particle size of ferronickel increased from 7.4 μm to 48.6 μm with the addition of 20 wt% Na₂SO₄.

KEYWORDS:

• Laterite ore
• ferronickel
• grain growth
• FeS
• sodium sulphate

Funding

The authors thank the National Natural Science Foundation of China (Grant Nos. 51174230 and 51234008), and the Program for New Century Excellent Talents in University (Grant No. NCET–11–0515) for the financial support of this research. This work was also financially supported by the Co-Innovation Center for Clean and Efficient Utilization of Strategic Metal Mineral Resources.

Additional information

Funding

The authors thank the National Natural Science Foundation of China (Grant Nos. 51174230 and 51234008), and the Program for New Century Excellent Talents in University (Grant No. NCET–11–0515) for the financial support of this research. This work was also financially supported by the Co-Innovation Center for Clean and Efficient Utilization of Strategic Metal Mineral Resources.