• NaOL significantly enhances flotation recovery of brucite over diaspore and limonite at pH 11 with 40 mg/L collector.
• Surface analysis (contact angle, zeta potential, XPS) confirms stronger adsorption of NaOL on brucite due to exposed Mg2+ sites from weak interlayer bonding.
• DFT calculations reveal higher adsorption energy and stable chemical adsorption via covalent O–metal bonds on brucite surface.
• Molecular-level insights guide the design of selective collectors for efficient separation of hydroxide minerals.