Experimental study on recovering barite from lead-zinc tailings by gravity-flotation combined process

The Panlong Lead-zinc Mine in Guangxi contains major minerals such as galena, sphalerite, pyrite, barite, and dolomite. Among these, barite resources have been consistently underutilized, leading to significant wastage of resources. Conventional barite flotation is expensive and its return water complicates lead-zinc recovery, while shaking table-based gravity-flotation combined processes suffer from large space requirements and challenges in industrial scaling. To address these challenges, this study develops a novel process focused on gravity separation for recovering barite from lead-zinc flotation tailings, consisting of “coarse and fine fractions classification - pre-discarding by reflux classifier - flotation desulfurization - shaking table cleaning”. The process begins with classifying the tailings, followed by pre-concentration using a reflux classifier （RC） for both coarse and fine fractions, effectively removing calcium-bearing gangue minerals such as dolomite and producing a pre-concentrate rich in barite and pyrite. Flotation desulfurization is then carried out using oxalic acid as an activator and butyl xanthate as a collector, efficiently removing pyrite whose density is close to that of barite. The desulfurized concentrate is further purified by shaking table cleaning to obtain a high-grade barite concentrate. Experimental results show that this process achieves a barite concentrate with a BaSO₄ grade of 92.61% and a BaSO₄ recovery of 42.47%, enabling efficient comprehensive recovery of barite resources. The introduction of pre-discarding technology using the reflux classifier （RC） significantly improves recovery efficiency and shortens the separation process, offering a new approach for recovering barite from tailings.