An Innovative Process for Extracting Scandium from Nickeliferous Laterite Ore

摘要

Laterite ores contain significant amounts of scandium, a strategic material with versatile applications. In this study, a two-stage process was developed to concentrate and recover scandium from nickeliferous laterite ore. In the first step, carbothermic smelting was performed at 1400-1600 °C using lignite as a reductant and calcia and/or silica as a flux. This process resulted in a slag phase concentrated in Sc and a metallic iron phase enriched with nickel and cobalt. Under the optimum conditions, scandium was successfully concentrated in the slag phase more than 14 times than that in the starting material. In the second step, the slag phase was leached using NaOH cracking to recover Sc. A fractional factorial design methodology was utilized to investigate the effect of various operating parameters during the smelting and the leaching processes and to optimize the processes. After optimization, 88% of scandium was recovered during the NaOH cracking process.