Flotation of copper mineral fines and aggregates using novel bio-inspired Vitamin E xanthate collectors

• Novel Vitamin E xanthate collectors were used for the flotation of fine CuFeS 2. • TPGS-X and VitE-X were found to enhance the grade and recovery of the fines. • Flocculation with APAM was applied, aiming to improve fines flotation. • APAM decreases the effectiveness of collectors by reducing CuFeS 2 hydrophobicity. • Aggregates flotation remains challenging due to entrapment & low hydrophobicity. This paper investigates the use of novel bio-based collectors D-α-tocopherol polyethylene glycol 400 succinate xanthate (TPGS-X) and α-tocopherol ethyl xanthate (VitE-X) in the flotation of chalcopyrite fine particles and aggregates, as an alternative replacement for conventional xanthate collectors. Potassium amyl xanthate (PAX) was used as a conventional collector for comparison. Commercial anionic polyacrylamide (APAM) flocculants were applied to selectively aggregate the fines with the aim of improving recovery via the formation of larger aggregates. The performance of all collectors was evaluated through the flotation recovery and grade of both the fines and aggregated particles. Contact angle tests were also performed to analyse the effect of the reagents on the hydrophobicity of the chalcopyrite surface. The experimental results showed that TPGS-X provided the best chalcopyrite recovery and grade amongst all collectors, followed by VitE-X, although quartz was also recovered via entrainment. PAX addition improved the grade of the concentrates but did not significantly affect the recovery of the valuable particles. Increasing TPGS-X dosage enhanced chalcopyrite grade from ∼ 43 % to 54 % and recovery from ∼ 48 % up to 82 %. The addition of APAM for fines aggregation was also found to reduce chalcopyrite flotation recovery and grade due to entrapment effects. Contact angle experiments demonstrated that all collectors increased the hydrophobicity of the chalcopyrite surface, but treatment with APAM reduced the effectiveness of the collectors. This potentially suggests that the surface hydrophobicity has a more dominant effect on the flotation efficiency than the aggregate size for the chalcopyrite-quartz system. Finally, both novel TPGS-X and VitE-X were found to be able to improve the flotation of fine particles, but the flotation of aggregates remains challenging for the investigated system.