Mechanisms for the selective separation of spodumene from feldspar by sodium N-oleoylsarcosinate as an efficient collector

Abstract

The primary source of lithium is spodumene, a mineral commonly associated with aluminosilicate minerals like feldspar. Flotation is widely regarded as the most effective method for separating spodumene from feldspar. The efficiency of this separation process is largely dependent on the choice of flotation reagents. In this work, an efficient collector, sodium N-oleoylsarcosinate (SNOS), was employed to achieve the separation of spodumene and feldspar. To investigate the flotation behavior and underlying mechanism, comprehensive approaches involving flotation tests, solution chemical calculation, Fourier transform infrared spectroscopy (FTIR), contact angle measurements, atomic force microscope (AFM), and density functional theory (DFT) calculations were launched. Operating under optimal conditions, Li2O demonstrated a recovery of 88.59% and a concentrate grade of 7.12% in the mixed minerals flotation. Due to more O and Al active sites on spodumene, SNOS exhibited strong chemisorption and multilayer adsorption on Ca(II)-activated spodumene. Remarkably, SNOS, with its three oxygen sites, displayed a robust reaction with Ca(Ⅱ)-activated spodumene, boasting an adsorption energy as substantial as −789.41 kJ/mol. In contrast, the interaction of SNOS with Ca(Ⅱ)-activated feldspar was negligible. Therefore, the proficient SNOS collector with notable selectivity, holds immense potential for practical application in the flotation of real spodumene ores.