Selective Carbon Enrichment from Micro/Nano Silicon–Carbon Ores via Sodium Hexametaphosphate: Mechanistic Insights and Structural Characterization

Ultrafine nano-grinding of silicon–carbon ores combined with sodium hexametaphosphate (SHMP) treatment enhanced silica dispersion and effectively separated silica and carbon particles. The hydrophobic nature of carbon promoted its re-agglomeration and sedimentation, achieving selective carbon enrichment. Characterization via FTIR, Raman spectroscopy, and TEM revealed two types of amorphous carbon with distinct structural features. BET analysis indicated a specific surface area of 92 m2/g for the carbon-rich fraction, suggesting potential applications in catalysis and energy storage after further activation.