Determination of three stages for molybdenite flotation kinetics in seawater

ABSTRACT

This research mainly investigated the flotation kinetics of molybdenite in seawater based on four flotation models. Molybdenite flotation presented an excellent agreement with the first-order model with rectangular distribution. The ultimate cumulative recovery (R_∞) and flotation rate constant (k) of molybdenite decreased in seawater, mainly due to the divalent cations, with the impact of Mg²⁺ being significantly greater than that of Ca²⁺. The addition of sodium silicate (SS) and sodium hexametaphosphate (SH) increased the flotation recovery and rate, probably due to the positive role of dispersants on preventing the attachment of seawater precipitates onto molybdenite surface. In addition, three different stages of flotation kinetics were proposed to reveal the molybdenite flotation for the first time, with the highest flotation recovery and rate being found at Stage I. However, seawater showed a negative role on Stage I, i.e. resulting in a longer duration and lower recovery, as compared to that in pure water. The addition of both SS and SH improved the flotation kinetics at Stage I, with SH being more significant. Therefore, it is more feasible to eliminate the negative effects of seawater on molybdenite flotation at the initial stage (Stage I).

KEYWORDS:

• Flotation kinetics
• molybdenite
• seawater
• dispersants

Acknowledgments

The authors acknowledged financial supports from the National Natural Science Foundation of China under the projects of 51974215, 51774223 and Hubei Key Laboratory of Mineral Resources Processing & Environment (ZHJJ202001).

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

The work was supported by the National Natural Science Foundation of China [51974215, 51774223].