Flotation performance and adsorption mechanism of 5-hydroxyoctan-4-one oxime to malachite
(1. Institute of Resources Utilization and Rare Earth Development, Guangdong Academy of Sciences, Guangzhou 510650, China;
2. State Key Laboratory of Rare Metals Separation and Comprehensive Utilization, Guangzhou 510650, China;
3. Guangdong Provincial Key Laboratory of Development and Comprehensive Utilization of Mineral Resources, Guangzhou 510650, China;
4. School of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China)
2. State Key Laboratory of Rare Metals Separation and Comprehensive Utilization, Guangzhou 510650, China;
3. Guangdong Provincial Key Laboratory of Development and Comprehensive Utilization of Mineral Resources, Guangzhou 510650, China;
4. School of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China)
Abstract: In order to improve the utilization efficiency of copper oxide mineral resources, a novel collector, 5-hydroxyoctan-4-one oxime (HOO), was synthesized from a commodity chemical butyraldehyde and hydroxylamine hydrochloride. Its flotation performance and adsorption mechanism to malachite were investigated by flotation tests, Fourier transform infrared spectrum (FTIR), X-ray photoelectron spectroscopy (XPS) analysis and density functional theory (DFT) calculation. Flotation results of malachite showed that HOO exhibited better collecting ability and less dosage compared to benzohydroxamic acid (BHA). FTIR and XPS data gave clear evidence for the formation of Cu-oxime complex (five-membered and six-membered ring chelates) on malachite surfaces after HOO adsorption through the linkage among C—OH, C=NOH and Cu species. Moreover, DFT results showed that HOO coordinated with Cu atoms preferably through the oxime and hydroxyl groups to form bidentate chelates.
Key words: flotation; adsorption; oxime collector; copper oxide ore; malachite