Distinct Difference in High-temperature Characteristics between Limonitic Nickel Laterite and Ordinary Limonite

Abstract

In order to achieve the effective utilization of limonitic nickel laterite for stainless steel production at lower cost, the distinct difference in high-temperature characteristics between limonitic nickel laterite and ordinary limonite has been systematically expounded via compact sintering method and the comparative analysis of the relevant sintering performance at the suitable basicity has also been conducted through sinter pot tests. The results indicate that limonitic nickel laterite possesses much poorer assimilability and liquid phase fluidity due to the abundant high-smelting minerals compared with ordinary limonite. The strength of bonding matrix of limonitic nickel laterite is relatively better as the basicity is not exceed 1.4 while that of ordinary limonite is maintained at a higher level with the basicity of no less than 1.8. Meanwhile, the former is far weaker than the latter due to the much less amount of liquid phase, rather higher porosity and looser microstructure of the bonding matrix. Limonitic nickel laterite is identified as a far more refractory ore for sintering compared with ordinary limonite, further supported by sinter pot tests. It is essential to strengthen limonitic nickel laterite sintering from the standpoints of how to promote the liquid phase formation and densification of the sinter.