Selective Flotation of Copper Oxide Minerals with A Novel Amino-Triazole-Thione Surfactant: A Comparison to Hydroxamic Acid Collector

ABSTRACT

Developing specific flotation collectors to improve the separation and enrichment of copper oxide minerals from their ores is still a challenging job. In this article, a novel chelating collector, 5-(2,4,4-trimethylpentyl)-4-amino-1,2,4-triazolidine-3-thione (TMATT), was designed to separate and recover copper oxide minerals, and its flotation response to malachite, calcite, and quartz was compared with that of the traditional collector n-octyl hydroxamic acid (OHA). The findings of contact angle and micro-flotation indicated that TMATT exhibited stronger hydrophobization and better flotation performances to malachite than OHA, and also held the high flotation selectivity against quartz and calcite. The bench-scale flotation outcomes showed that TMATT achieved the high-efficient flotation separation and enrichment of copper oxide minerals from the mixed sulfide-oxide copper ore. XPS, FTIR, AFM, and zeta potential deduced that the adsorption of malachite toward TMATT was related to the reduction of surface Cu(Ⅱ) to Cu(Ⅰ) and the formation of TMATT-Cu(Ⅰ) surface complexes in which the exocyclic N and S atoms of TMATT bonded with the surface Cu(Ⅰ) on malachite. The superior hydrophobicity of TMATT-Cu(I) surface complexes in comparison to that of OHA-Cu(Ⅱ) surface complexes, the favorable five-membered ring bonding mode on malachite surfaces and the preferable chelating selectivity to soft acid Cu(Ⅰ) rather than to hard acid Ca(Ⅱ), deserved TMATT to possess better flotation response to malachite against calcite than OHA.

KEYWORDS:

• Amino-triazole-thione collector
• n-octyl hydroxamic acid
• malachite
• flotation
• adsorption

Article highlights

• TMATT was first used as a flotation collector to separate Cu oxide minerals.

• TMATT held better flotation selectivity to malachite against calcite than OHA.

• The exocyclic N and S atoms of TMATT bonded to the surface Cu(Ⅰ) of malachite.

• TMATT preferred to bond with soft acid Cu(Ⅰ) rather than hard acid Ca(Ⅱ).

• TMATT-Cu(I) complexes own stronger hydrophobicity than OHA-Cu(Ⅱ) complexes.

Disclosure statement

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the article.

Supporting information

The XRD (X-ray Diffraction) and XRF (X-ray fluorescence) for malachite, quartz and calcite, and the flowsheet of the locked-cycle flotation experiment were listed in the Supporting Information.

Supplemental data

Supplemental data for this article can be accessed here.

Additional information

Funding

The authors would like to thank the National Natural Science Foundation of China [51474253], the National Basic Research Program of China (973 program) [2014CB643403], and the National High Technology Research and Development Program of China (863 program)[2013AA064101] for the financial support.