Effective flotation separation of dolomite and apatite utilizing baicalin as a green depressant: a mechanistic and experimental study

To address the challenge of separating dolomite from apatite via flotation, this research firstly employed Baicalin (BA) as an environment-friendly depressant and examined the underlying depression mechanism on apatite and dolomite in a sodium oleate (NaOL) collector system. Micro-flotation findings demonstrated effective separation of apatite and dolomite under conditions of 50 mg/L BA and 120 mg/L NaOL at pH 11.0. Zeta potential, adsorption capacity, FT-IR, and SEM-EDS analyses indicated that the dolomite surface exhibited a greater affinity for BA adsorption. Contact angle measurements showed that BA prominently reduced the surface hydrophobicity of dolomite while having a minimal impact on apatite’s surface hydrophobicity. XPS analysis confirmed that BA adsorption on the dolomite surface mainly involved chemisorption between –COO − groups and Ca and Mg sites, whereas a weaker physical adsorption occurred on the apatite surface. Molecular dynamics simulations (MDS) analysis showed that BA exhibited a greater affinity on the dolomite surface relative to apatite, thereby rendering the dolomite surface more hydrophilic than apatite. This study presents a novel methodology for the efficient and sustainable removal of dolomite from apatite, thereby advancing the theoretical understanding of flotation separation in apatite-dolomite systems.