Extended Data Fig. 6: Microstructure and composition of the metallic phase after 4 minutes of processing.
From: Sustainable nickel enabled by hydrogen-based reduction
(a) Microstructure of the metallic nodules. (b) Enlarged view of the metallic region (highlighted in pink, A) showing micron-sized inclusions within the metal. (c) Elemental mapping of an inclusion (highlighted in orange, B), showing a Si-rich core surrounded by Fe oxides. (d) Overall composition of the region highlighted in red (Area 1) shows 44 wt.% Ni, with minimal impurities (Si ~0.08 wt.%, P ~ 0.00 wt.%, Ca ~0.09 wt.%). Spot analysis of an inclusion-free region (spot 1, (b)) reveals a dissolved Si content of less than 0.04 wt.%, significantly lower than typical commercial ferronickel alloys (Si up to 0.3 wt.%). Scale bar: (a) 300 µm, (b) 5 µm, (c) 1 µm.
