Enhanced flotation of Pb(II)-activated wolframite using a novel collector

ABSTRACT

The flotation enrichment of fine-particle wolframite played a crucial role in production of strategic key metal tungsten. In this paper, N-[(3-hydroxyamino)-propoxy]-N-hexyl dithiocarbamate (HAHD) was designed to strengthen the flotation recovery of wolframite. The in situ AFM images clearly exhibited that the pre-activation of wolframite with Pb²⁺ ions significantly enhanced the self-assemble and aggregation of HAHD on its surface, and its surface hydrophobicity and floatability dramatically improved. The FTIR and XPS results recommended a chemisorption of HAHD to the Pb(II)-activated wolframite, and in the surface HAHD-Pb(II) complexes, both dithiocarbamate and hydroxamate groups chelated Pb(II) to deliver the four-membered and five-membered ring configurations. The double-site adsorption rendered a closed loop anchor of HAHD on the Pb(II)-activated wolframite surface, which essentially weakened the hydration of OH- ions toward Pb²⁺, Fe²⁺ or Mn²⁺ ions in/on wolframite interface. In addition, the hexyl group exhibits a strong hydrophobization, and the dithiocarbamate displays a selective affinity against alkaline earth metal minerals. These encouraged HAHD to be a strong-power and selective collector for wolframite versus calcite at its low dose.

Highlights

• N-[(3-hydroxyamino)-propoxy]-N-hexyl dithiocarbamate promotes wolframite flotation.

• In situ AFM showed the self-assemble of HAHD on Pb(II)-activated wolframite surface.

• Both dithiocarbamate and hydroxamate reacted with the Pb(II)-activated wolframite.

• The double-site adsorption rendered a closed loop anchor to weaken surface hydration.

• HAHD is a strong-power collector for selective flotation of wolframite against calcite.

KEYWORDS:

• Wolframite
• dithiocarbamate
• hydroxamate
• in situ AFM
• flotation

Acknowledgement

The authors sincerely appreciate the support of the National Natural Science Foundation of China (51925406).

Author’s contributions

Jing Qi: Investigation, Methodology, Data curation, Writing-original draft. Sheng Liu: Methodology, Investigation. Xianyang Qiu: Methodology, Supervision. Guangyi Liu: Conceptualization, Supervision, Methodology, Writing-review & editing, Funding acquisition.

Disclosure statement

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

Supplementary material

Supplemental data for this article can be accessed online at https://doi.org/10.1080/08827508.2022.2108420

Additional information

Funding

The work was supported by the National Natural Science Foundation of China [51925406]