<p>Oleic acid is a commonly used fatty acid collector in fluorite flotation, known for its effective collecting performance and cost-effectiveness, but with a limited selectivity. In this study, a novel collector, <i>α</i>-sulfonate group mixed acid (<i>α</i>-SMA), is introduced. The flotation test results demonstrate that the <i>α</i>-SMA collector provides significantly better selectivity in fluorite flotation. Specifically, the <i>α</i>-SMA collector exhibits a similar collecting ability to oleic acid for fluorite; however, its capacity to collect calcite is substantially lower. Zeta potential tests indicate that, under identical dosage conditions, <i>α</i>-SMA adsorbs in greater quantities on fluorite than on calcite. As a result, fluorite exhibits substantially higher flotation recoveries versus calcite with <i>α</i>-SMA collector. X-ray photoelectron spectroscopic analysis suggests that <i>α</i>-SMA facilitates a higher electron donation to Ca²⁺ ions on fluorite compared to calcite surface, forming stronger chemical bonds with fluorite surface. This enhanced interaction leads to stronger adsorption of <i>α</i>-SMA on fluorite. Furthermore, when <i>α</i>-SMA adsorbs solely through its sulfonic group, its carbon chain is positioned almost parallel to calcite surface. This configuration significantly reduces the hydrophobicity of the calcite surface, leading to very low calcite recovery rates with <i>α</i>-SMA collector.</p>