The selective flotation behavior and mechanism of malachite with a double coordination structure amino-triazole-thione collector

Malachite is considered to be the most desirable copper-bearing mineral to develop in response to the increased costs of mining copper sulfide ores such as chalcopyrite. The surface of malachite readily forms a water film, resulting in poor floatability. Additionally, its association with calcite and quartz makes achieving selective flotation challenging. Therefore, the design and optimization of collector structure play a crucial role in effectively floating malachite. In this article, a double coordination structure amino-triazole-thione collector, 3-isobutylxanthic acid methyl ester-4-amino-1,2,4-triazole-5-thione (MiBuXATT), was first synthesized and used in malachite flotation separation from calcite and quartz. The flotation separation mechanism was studied by a series of surface and interface characterization analysis methods. Micro-flotation experiments, contact angle measurement, ζ-potential analysis, UV, FTIR and XPS spectra analyses show that MiBuXATT can selectively adsorb the copper active site on the surface of malachite by forming MiBuXATT-Cu(I) surface compound, and achieve selective hydrophobic enrichment. Concurrently, the theoretical calculations further substantiated that MiBuXATT exhibits enhanced adsorption on the malachite surface in its negative ion form.