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A novel flotation depressant with selective adsorption properties based on orbital matching was used to replace cyanide for the flotation separation of jamesonite and marmatite. The presence of characteristic groups, such as the sulfhydryl and amino groups, enhanced the adsorption of DL-cysteine on the metal ions (Zn2+ and Fe2+) on marmatite surface. The adsorption of DL-cysteine on the marmatite surface significantly enhanced the surface hydrophilicity and decreased the flotation recovery. [Display omitted] • DL-cysteine is a potential green depressant for marmatite flotation. • DL selectively depressants marmatite but has little effect on jamesonite floatability. • The adsorption between DL and marmatite hinders DDTC adsorption. • Coordination theory analysis confirmed the complexation between DL and Fe2+/Zn2+. Flotation is an effective separation technique for removing marmatite, a harmful impurity, from jamesonite. In this study, DL-cysteine (DL) was used as an eco-friendly flotation agent for the targeted separation of jamesonite from marmatite. Micro-flotation experiments, zeta potential measurement, Fourier transform infrared, and X-ray photoelectron spectroscopies show that DL can combine with metal ions on the surface of marmatite through chemical complexation, thereby selectively hindering the flotation of marmatite. The competitive adsorption of DL and sodium diethyldithiocarbamate on marmatite surface is the main factor leading to the change in marmatite floatability. The flotation coordination theory confirms that Fe2+ is the main active site on marmatite surface. π-back-bonding and σ-bonding are the main driving forces for the adsorption of DL on marmatite surface. Importantly, DL can be produced using animal hair as a raw material. It is, thus, a low-cost material with good environmental compatibility and high selectivity and a potential green depressant for marmatite flotation. [ABSTRACT FROM AUTHOR]

[Display omitted] • SA selectively depressed marmatite and achieves excellent Pb-Zn separation. • SA strongly chemically complexes with metal ions on the surface of marmatite. • Fe2+ easily forms π-backbonding with SA and dominates the adsorption of SA. • SA is a low toxicity and effective alternative to traditional marmatite depressants. In this study, sodium alginate (SA) is proposed as a flotation depressant for the selective separation of galena and marmatite. The effect of SA on the flotation performance of galena and marmatite was investigated using sodium butyl xanthate (SBX) as the collector. The adsorption behavior of SA on the mineral surface was theoretically analyzed. The micro-flotation results demonstrated that the flotation of marmatite could be selectively depressed through the addition of SA before SBX at pH = 11. The contact angle, FTIR, XPS, and zeta potential results demonstrated that SA could be selectively adsorbed on the marmatite surface, thereby hindering the subsequent adsorption of the collector and affecting its flotation. A coordination theory analysis further confirmed that Fe2+ was the active site on the marmatite surface. SA can form π-backbonding with Fe2+ on the surface of the marmatite, resulting in strong adsorption but weaker interactions with Zn2+ and Pb2+. Overall, the high selectivity and environmental compatibility of SA make it an effective green depressant for the flotation separation of marmatite. [ABSTRACT FROM AUTHOR]

[Display omitted] • Study on adsorption difference of sodium alginate on galena and marmatite. • Iron atom is the main active site on the surface of marmatite. • The existence of iron enhances the bonding strength between SA and marmatite. • Fe2+ can form π-backbonding with SA by providing a pair of π electrons. • vdW, steric effects and weak covalent interactions dominate the adsorption of SA. In this study, density functional theory (DFT) was used to simulate the adsorption of sodium alginate (SA) on the surface of sphalerite, marmatite (1 1 0), and galena (1 0 0). The results showed that SA was mainly adsorbed on the surface of sphalerite by van der Waals interaction and steric hindrance without iron substitution. However, the substitution of iron on the surface of sphalerite significantly increased the adsorption energy of SA. In particular, the substitution of a large amount of iron significantly changed the surface properties of sphalerite, and the adsorption of SA on the surface of sphalerite changed from physical to chemical adsorption. The results of a density of states comparative analysis, charge transfer, and coordination theory analysis also confirmed that the adsorption of SA on a marmatite surface was easier and more stable than that on galena or sphalerite. Overall, the high selectivity of SA is expected to make it a green depressant of marmatite. [ABSTRACT FROM AUTHOR]

[Display omitted] • Sodium alginate (SA) was introduced as an arsenopyrite depressant. • KMnO 4 promoted the adsorption of SA on arsenopyrite. • Covalent hydrogen bonding and chemical complexation dominated SA adsorption. • SA selectively adsorbed on arsenopyrite and reduced its floatability. In this study, sodium alginate (SA) was used as a selective depressant, combined with potassium permanganate oxidizing pretreatment, which will benefit the separation of chalcopyrite and arsenopyrite. Flotation experiments were conducted with chalcopyrite and arsenopyrite after treatment with SA and/or potassium permanganate, and the possible complexes formed by SA on the mineral surface were theoretically analyzed. SA was more easily adsorbed on the arsenopyrite surface after potassium permanganate pretreatment. The maximum depressant effect of arsenopyrite was observed following treatment with 62.5 mg/L of potassium permanganate and 1000 mg/L of SA with flotation at pH 11. Fourier-transform infrared spectroscopy and X-ray photoelectron spectroscopy indicated that the adsorption of SA on the chalcopyrite and arsenopyrite surfaces was dominated by chemisorption. Theoretical analyses confirmed that the adsorption strength of SA on the arsenopyrite surface was higher than that on chalcopyrite. Furthermore, the intermolecular interactions between SA and the possible complexes formed were investigated using interaction region indicator function tools. The results of this investigation revealed that SA adsorption on chalcopyrite and arsenopyrite surfaces is controlled by partial covalent hydrogen bonds and other weak interactions. Therefore, SA can be used as a promising green depressant for the separation of arsenopyrite during chalcopyrite flotation. [ABSTRACT FROM AUTHOR]