Intensifying fine-grained fluorite flotation process with a combination of in-situ modification and liquid-gas microdispersion

Abstract With the depletion of rich fluorite ore, flotation process suitable for fine-grained fluorite is of great necessity. In this study, such method was preliminarily developed with a combination of in-situ surface modification and gas-liquid microdispersion. By introducing additives into ball-milling, the interaction between reagents and particles was improved. Through exploitation of selective sedimentation of undesired minerals via pH adjustment, the flotation of fine-grained fluorite was achieved with little or even no depressant in this study. Using a well-designed membrane dispersion device, effective interaction between the particles and bubbles was achieved, with massive expansion of the surface area in a limited space, enabling continuous flotation in a miniaturized device. Satisfactory product grade and recovery were obtained while reducing the use of additives, along with significantly decreased costs related to energy consumption, wastewater and flue gas treatment, and facility investments. The mechanism of this flotation separation strategy was summarized on the basis of empirical data. The strategy was effectively and flexibly applied to fluorite ores with different particle sizes and surface properties.