In this study, a novel decyl-salicyl hydroxamic acid (DSHA) collector was synthesized and applied to a malachite flotation. Subsequently, its flotation performance on malachite was studied through micro- and batch-flotation tests, as well as through zeta-potential and X-ray photoelectron spectroscopy (XPS) analyses. The results of micro-flotation tests indicate that DSHA exhibits a powerful ability to collect malachite and a satisfactory selectivity against quartz. The batch-flotation tests also prove that DSHA is an effective collector for copper oxide ore. Furthermore, mixed collectors of DSHA and sodium isobutyl xanthate (SIBX) achieved a better selective separation of CuO than individual DSHA, SIBX, or salicyl hydroxamic add (SHA). The results of a zeta-potential analysis infers that DSHA may chemisorb on malachite.The XPS analysis results provide clear evidence that DSHA adsorbs on malachite through the co-adsorption mode. (C) 2020 Elsevier B.V. All rights reserved.