Extended Data Fig. 1: Weight loss of Ni-ore due to thermal decomposition.
From: Sustainable nickel enabled by hydrogen-based reduction
Weight loss experienced by Ni-Ore upon heating in an inert atmosphere (Ar) as determined by TGA-DSC. The weight loss is broadly categorized into three stages: Stage 1 - weight loss due to the removal of moisture present in the ore. Stage 2 - weight loss attributed to the transformation of goethite into haematite (2FeO(OH) → Fe2O3 + H2O) and the removal of crystalline water from pimelite (Ni3Si4O10(OH)2·4H2O). Stage 3 - Dehydroxylation of serpentine minerals such as lizardite to forsterite, fayalite, entstantite type species (2Mg3Si2O5(OH)4 → 3Mg2SiO4 + SiO2 + 4H2O; (Mg,Fe,Ni)3Si2O5(OH)4 → 3(Mg,Fe,Ni)2SiO4 + SiO2 + 4H2O; (Mg,Fe,Ni)3Si2O5(OH)4 → (Mg,Fe,Ni)SiO3 + (Mg,Fe,Ni)2SiO4 + 2H2O) – and transformation from olivines to pyroxenes (Mg2SiO4 + SiO2 → 2MgSiO3). Endothermic peaks are related with dehydroxylation reactions and decomposition of serpentines to simpler species. The exothermic peak at 814 °C is related to the formation of pyroxene from olivine species, such as enstantite.
