A mixed collector system for columbite-tantalite flotation

Effective collector is essential in columbite-tantalite flotation from gravity tailings, as well as in the sustainable utilisation of Ta-Nb resources. In this study, benzohydroxamic acid (BHA) and sodium isobutyl xanthate (SIBX) were introduced as a mixed collector system to improve the flotation of columbite-tantalite at reduced cost. An increase in columbite-tantalite recovery was observed in the presence of BHA-SIBX mixtures relative to those with BHA alone. The 3:1 BHA-SIBX mixture exhibited the highest columbite-tantalite recovery. The synergistic enhancement of the flotation performance was attributed to the improved adsorption of the BHA-SIBX mixture on the columbite-tantalite surface compared to that on BHA alone. Batch flotation tests of real ore showed that, compared with BHA (600 g/t), a smaller amount of the BHA-SIBX mixture (400 g/t) was needed to achieve better Ta2O5 recovery. Additionally, an economic evaluation confirmed the economic efficiency of recovering fine columbite-tantalite from gravity tailings using the mixed BHA-SIBX collector.