Selective adsorption mechanism of a new combined collector on the surfaces of quartz and potassium feldspar.

This article focuses on a novel flotation methodology for the selective separation of quartz and potassium feldspar using a combined collector system of ethyl-bis(dodecyl dimethyl ammonium bromide) (Gemini) and sodium oleate (NaOL) under neutral to weakly alkaline conditions. Experimental results demonstrate that while single collectors (Gemini or NaOL) show limited selectivity, their combination significantly enhances quartz recovery relative to feldspar, achieving up to a 46.51% higher flotation recovery of quartz at pH 7 with a Gemini/NaOL molar ratio of 1:1. Analytical techniques including zeta potential measurements, Fourier transform infrared spectroscopy, x-ray photoelectron spectroscopy, and molecular dynamics simulations reveal that Gemini primarily adsorbs on both mineral surfaces via physicochemical interactions, whereas NaOL preferentially adsorbs on feldspar’s aluminum and silicon sites, competitively reducing Gemini adsorption on feldspar and thus enabling effective separation. This study provides insights into the adsorption mechanisms of combined collectors and suggests an environmentally friendly, cost-effective approach for improving quartz purity in mineral processing.