Fluorspar Beneficiation Process: Overcoming Gangue Interference for Efficient Purification

The core challenge in fluorspar beneficiation lies in achieving effective separation from associated gangue minerals such as barite and calcite. This requires a three-pronged approach focusing on crystal property research, innovative reagent systems, and process optimisation to enhance the grade and recovery rate of fluorspar concentrate.

Crystal structure research provides theoretical underpinnings for separation. Analysis reveals variations in collector adsorption stability across different fluorite crystal faces, enabling enhanced floatability through selective grinding. Colour differences also influence floatability, with colourless fluorite demonstrating superior floatability, thereby informing process design.

Innovation in reagent systems is pivotal for separation. Addressing the poor water solubility of conventional collectors, specific sulfonate-based collectors (e.g., sodium dodecyl sulphate, sodium dodecylbenzenesulfonate) demonstrate superior collection efficiency for fluorite under suitable pH conditions. Certain sulfonates can even separate fluorite from barite at low temperatures. Regarding inhibitors, modified starch selectively suppresses barite, while specific natural extracts combined with chemical reagents efficiently inhibit calcite and barite, respectively, resolving separation challenges in multi-gangue coexistence.

Process implementation must be tailored to local conditions, employing distinct workflows based on fluorite grain size distribution and gangue composition. For fluorite ores with uneven coarse-fine grain distribution, graded flotation yields high-grade concentrates. Low-grade tailings achieve efficient resource recovery through a combined ‘coarse-grain conventional flotation - fine-grain hydrophobic agglomerate flotation’ process. For finely disseminated fluorite ores, a ‘weakly alkaline roughing - weakly acidic scavenging’ process, combined with specialised modified collectors, yields high-grade fluorite concentrates.