Flotation of Li Pegmatite with a Soybean Oil-Based Collector: Fundamental Studies

Abstract

ABSTRACT In this work, the effect of a soybean oil-based collector on the surface properties of spodumene, feldspar, quartz, and muscovite was characterized and evaluated. By means of gas chromatography, it was determined that the reagent was composed of a mixture of carboxylic acids: linoleic (48%), oleic (28%), palmitic (13.3%), stearic (3.6%), α-linolenic (3.4%), and elaidic (3.2%). The reagent contained ~14 ppm Ca (determined by inductively coupled plasma optical emission spectroscopy – ICP-OES) and a critical micellar concentration (CMC) of 100 mg/L. At pH 6, the spodumene recovery was 50–60% higher than the other mineral recoveries, ascribed to chemical adsorption of the collector ionic-molecular species, which has high hydrophobicity power, on Al3+ sites on the spodumene surface. For pH values >10, the recoveries of feldspar and quartz were higher than spodumene, due to their activation by hydroxyl and hydroxide of Ca and subsequent adsorption of ionic specimen of the collector. The electrokinetic potential curves of spodumene, feldspar, and muscovite with collector were shifted toward more negative values compared to their electrokinetic potential curves without reagent. Fourier transform infrared spectroscopy (FT-IR) showed chemical adsorption of the anionic species of the collector at pH 6 with the Al3+, Fe3+, and Ca sites on the surface of aluminosilicates and Ca for quartz.