Reductive Conditioning-Driven Proanthocyanidin Adsorption: A Green Strategy for Pyrite Depression in Copper Sulfide...

Area of Science:

• Mineral Processing
• Surface Chemistry
• Computational Chemistry

Background:

• Efficient separation of chalcopyrite and pyrite is difficult in mineral processing due to similar floatability.
• Existing methods face challenges under weak alkaline conditions.

Purpose of the Study:

• To develop an innovative depressant system for enhanced flotation separation of chalcopyrite and pyrite.
• To leverage differences in iron valence states for selective mineral depression.

Main Methods:

• Utilized a combined depressant system of sodium sulfide (Na2S) and proanthocyanidins (PC).
• Conducted artificial mixed ore tests to evaluate separation efficiency.
• Employed surface characterization techniques and density functional theory (DFT) calculations.
• Investigated the adsorption mechanisms of collectors on mineral surfaces.

Main Results:

• The combined Na2S and PC depressant system significantly improved separation efficiency compared to PC alone.
• Achieved a copper concentrate grade of 30.61% and a copper recovery of 90.31%.
• Na2S pretreatment enhanced PC's depression of pyrite by increasing Fe2+ active sites, hindering collector adsorption on pyrite.

Conclusions:

• The synergistic effect of Na2S and PC offers an effective strategy for chalcopyrite-pyrite separation.
• Understanding mineral surface chemistry and DFT calculations are crucial for designing effective flotation reagents.
• This approach provides a foundation for developing novel pyrite depressants in mineral processing.