Improving xanthate flotation of fine pyrite using SPAM and the mechanism

ABSTRACT

This paper focuses on the promotion mechanism of sulfonated polyacrylamide (SPAM) on SBX flotation performance on fine pyrite, and verifies the positive effect for a gold ore with pyrite as the main Au-bearing mineral. Micro flotation showed that fine pyrite (−26 + 15 μm) floated poorly compared with coarser ones (−74 + 38 μm), and this cannot be completely filled through increasing the SBX dosage; however, by adding moderate SPAM into the pulp after SBX the flotation of fine pyrite was obviously improved. The real ore flotation revealed that SPAM decreased total reagent dosage and improvement on the concentrate indexes. SBX/SPAM system enabled faster settlement of fine pyrite compared with only SBX or SPAM system, indicating that larger particle size was obtained through hydrophobic and bridging flocculation. Zeta potential results showed that the pre-adsorbed SBX had little effect on the further adsorption of SPAM. Contact angle measurements suggested that the addition of moderate SPAM (50 μg/L) had almost no effect on pyrite surface hydrophobicity, illustrating that SPAM just bridged different fine particles adsorbed SBX rather that covered them. FTIR results showed that the amount of SPAM participating in bridging action was few.

KEYWORDS:

• Sulfonated polyacrylamide
• flocculation
• pyrite
• particles
• flotation
• gold

Acknowledgments

The authors acknowledge the support of the Sichuan Science and Technology Program of China (No. 2022YFQ0074; 2022YFS0453), the National Key Research and Development Program ‘Intergovernmental Cooperation in International Science and Technology Innovation’ Key Special Project (No. 2023YFE0104100), the Doctoral Foundation of Southwest University of Science and Technology, China (No. 20ZX7149).

Disclosure statement

No potential conflict of interest was reported by the author(s).

Statement of novelty

Pyrite is an important carrier mineral in many precious metal mines. Recovery of fine particle of pyrite is one of the key challenge to efficient recover precious metals. Xanthate (SBX) alone cannot efficiently float fine pyrite.

In the present study, sulfonated polyacrylamide (SPAM), as an inhibitor of pyrite in the past, was added after SBX to improve SBX’s performance. The total dosage has gone down and the indexes are better. This is an innovative attempt.

Additional information

Funding

The work was supported by the Department of Science and Technology of Sichuan Province [2021YFG0269; 2022YFQ0074; 2022YFS0453]; Southwest University of Science and Technology [20ZX7149]