Selective flotation of quartz and feldspar based on steric hindrance-enhanced electrostatic interaction under neutral pH conditions

Flotation of quartz under neutral conditions (pH 7) achieved using a mixed-reagent system (BDAB and SDBS). • Proposal of a novel mechanism: Surface Steric Hindrance Effects. • High flotation separation purity: quartz (92.06%) and feldspar(85.66%). • Excellent water solubility and extremely low reagent concentration (7.14 μM). The separation of quartz and feldspar from silicate tailings is a critical challenge in solid waste resource recovery. Addressing the challenge of separating quartz from feldspar, this work investigates a flotation process operating under neutral conditions. Based on flotation reagent molecular engineering, an innovative mixed flotation system comprising Benzyldodecyldimethylammonium Bromide (BDAB) and Sodium Dodecylbenzenesulfonate (SDBS) with benzene ring steric hindrance groups was employed. Under condition of pH 7 and an SDBS:BDAB ratio of 1:1.2, high-grade mineral concentrates were achieved, with quartz purity at 92.06% and feldspar purity at 85.66%. The mechanism is governed by specific steric hindrance-enhanced electrostatic interaction, as revealed through FTIR, XPS, and MD simulations. By proposing a novel treatment approach for silicate tailings, this work offers a new perspective for the development of flotation agents and the design of flotation systems. Download: Download high-res image (118KB) Download: Download full-size image