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Chalcopyrite and galena are primary raw materials for producing Cu and Pb metals, respectively. Flotation is still the main method to recover these two minerals. So far, lots of work has been done to recover them from low-grade refractory ores, whereas the efficient separation of these two minerals remains a major challenge. In this review, the crystal, surface, floatability and needed reagents were discussed. Firstly, the crystalline structures were introduced, including physical and chemical properties, and followed by surface properties from a density functional theory simulation perspective. As reviewed, the surface properties were closely related to their floatability, such as the degree of surface oxidization, particle size, galvanic interactions, metal ions, and so on. Moreover, the floatability of minerals could be influenced by flotation reagents, and therefore a range of new collectors and depressants were described. The review aimed to provide a deep understanding on the factors affecting Cu/Pb flotation separation as well as to develop new depressants helping to guide the flotation separation of Cu/Pb/Zn polymetallic sulfide ores for researchers. [ABSTRACT FROM AUTHOR]

The demand for non-ferrous copper metals has increased dramatically with the development of the global economy; accordingly, some refractory copper sulfide ores with low grade and their associated minerals are beginning to be utilized, making the flotation separation of copper concentrates exceptionally difficult, especially the separation of chalcopyrite and pyrite. In this paper, S-allyl-O, O′-dibutyl phosphorodithioate (ADTP) was synthesized by a one-pot method and used as a chalcopyrite collector in the flotation separation of chalcopyrite and pyrite. Flotation experiments results have shown that ADTP exhibits better selectivity and greater collecting power for chalcopyrite under neutral or weak base conditions. The 95% recovery of chalcopyrite can be achieved at pH 8.0 and 8.0 mg/L ADTP. From the analysis results of the contact angle, the SEM-EDS spectrogram, and elemental mapping, it was found that ADTP adsorbed uniformly on a chalcopyrite surface and made a significant contribution to the hydrophobicity of the surface. Confirmed by FTIR and XPS analysis, ADTP was able to form P–S–Cu bonds on a chalcopyrite surface, proving that it was adsorbed on the chalcopyrite surface in the form of chemisorption. [ABSTRACT FROM AUTHOR]

To address the issue of mediocre separation efficiency of depressants in the copper-lead separation process, this article synthesized a macromolecular organic depressant, polymaleic anhydride-ethylenediaminetetraacetic acid (PMA–EDTC), using a polycarboxylic macromolecule as the backbone and also introducing –N–(C=S)–S– as the solidophilic group and employed as a galena depressant. The structure of PMA–EDTC was characterized using Fourier transform infrared (FT-IR). The effect of PMA–EDTC on the floatability of galena and chalcopyrite was investigated through micro-flotation and Contact angle measurements. The experimental results demonstrated that PMA–EDTC exhibited selectivity inhibition towards galena rather than chalcopyrite across a wide pH range. At a dose of 8 mg/L, there was effective separation between galena and chalcopyrite with a separation coefficient of 24.17, effectively altering the floatability of galena while having little impact on the floatability of chalcopyrite. The selective inhibition behavior and adsorption mechanism of PMA–EDTC on galena and chalcopyrite were investigated using FT-IR, Zeta potential, and X-ray photoelectron spectroscopy (XPS). FT-IR and Zeta potential studies indicated that PMA–EDTC formed chemical adsorption on the surface of galena. XPS confirmed the model of chemical adsorption of PMA–EDTC on lead atoms in the galena surface. The results indicate that PMA–EDTC adsorbs on the surface of galena via its –(C=S)–S–group, forming a hydrophilic complex and achieving selective depression of lead and the cleaning flotation of copper. [ABSTRACT FROM AUTHOR]

Sphalerite is a common sulfide mineral, and xanthate is usually used as the collector of sphalerite flotation. In order to realize the simultaneous flotation of sphalerite- and zinc-containing oxide ores, in this paper, dodecylamine was used as the collector and sodium sulfide as the regulator to explore the flotation behavior of sphalerite in a sulfuration–amine system through single mineral flotation tests, and several analytical methods, including contact angle measurement, adsorption capacity test, FT-IR, and XPS, were employed to discuss the interaction mechanism of dodecylamine on the surface of sphalerite. The results confirm that dodecylamine had a strong collecting effect on sphalerite throughout almost the entire pH range, and the flotation recovery increased with the increase in pH, reaching 86.81% at pH 12. It was found that the effect of sodium sulfide on the floatability of sphalerite was relatively weak, and a weak activation effect, of about 2% improved recovery, was achieved. The results of the mechanism analysis further show that dodecylamine underwent both physical adsorption and chemical adsorption on the surface of sphalerite, and the physical adsorption was enhanced with the increase in pH. The above findings provide evidence for the simultaneous flotation of zinc-containing sulfide-oxide mixed minerals. [ABSTRACT FROM AUTHOR]

In present research, a new chelating collector S -carboxymethyl- O , O ′-dibutyl dithiophosphate (CMDT) was used in the flotation separation of malachite from quartz. The flotation performances of CMDT on malachite (Cu 2 CO 3 (OH) 2 and quartz (SiO 2) were evaluated by micro-flotation tests. The flotation results demonstrated that CMDT exhibited a stronger adsorption and a better selectivity on malachite against quartz. A good separation efficiency for artificially mixed minerals was obtained at pH around 9.0 with Na 2 S as a regulator together. The CMDT adsorption mechanism was investigated and analysed by Fourier transform infrared spectroscopy (FT-IR), zeta potential and X-ray Photoelectron Spectroscopy (XPS) analysis. The FT-IR spectra showed that CMDT could react with Cu2+ ions and might adsorb on malachite surface by strong chemisorption. On the other hand, zeta potential and XPS analysis results provided enough evidences that CMDT possessed a stronger affinity on malachite than quartz. Unlabelled Image • CMDT is innovatively used as malachite collector. • CMDT shows excellent flotation performance for malachite against quartz. • Cu2+ ions released by malachite could promote the recovery of quartz with CMDT. • Adsorption mechanism of CMDT on malachite surface is revealed by FT-IR and XPS. [ABSTRACT FROM AUTHOR]

[Display omitted] • ATT heterocyclic surfactant could adsorb on chalcopyrite interface and make it hydrophilic. • ATT can selectively and strongly depress chalcopyrite and has no obvious negative effect on molybdenite. • A four-coordination structure was formed through S-Cu and N -Cu bonds confirmed by XPS and DFT. • Water could strengthen the adsorption of ATT on chalcopyrite interface via DFTB+ method. Flotation is an interfacial chemical reaction in essence. The selective adsorption of flotation reagents on mineral surfaces leads to the transition of hydrophilicity/hydrophobicity of mineral particles, and then to regulate the floatability differences between various minerals. 5-amino-1,3,4-thiadiazole-2-thiol (ATT) is a heterocyclic ring compound, which can chelate copper ions easily and usually used as a copper corrosion inhibitor. Based on those good chelating properties with copper ions, this paper attempted to apply ATT as a chalcopyrite depressant in the flotation separation of Cu/Mo ores. The adsorption mechanism of ATT on chalcopyrite surface was explored by means of UV–vis, FTIR, contact angle and XPS analysis, and it revealed the possibility of ATT using as a selective chalcopyrite depressant in the flotation separation of Cu/Mo ores by micro-flotation tests. Finally, the adsorption morphology of ATT depressant on chalcopyrite surface was unveiled by DFT method from a microscopic level. Through these FTIR and XPS analysis, combined with DFT simulation results, it was inferred that ATT was mainly chemically adsorbed on chalcopyrite surface by S Cu and N Cu bonds. These studies confirmed that ATT was very likely to be an excellent chalcopyrite depressant in Cu/Mo flotation separation. [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel polymer depressant DTC-PAA was synthesized and used as galena depressant. • DTC-PAA showed excellent depressing performance on galena at pH 8.5. • Chalcopyrite was separated effectively from galena in the presence of DTC-PAA. • DTC-PAA chemisorbed on galena surface via dithiocarbamate groups and Pb sites. In this research, to achieve green effective separation of chalcopyrite and galena, a novel synthetic depressant, dithiocarbamated poly(acrylamide-allyamine) (DTC-PAA), was prepared and innovatively employed as a galena depressant. The flotation behaviours of chalcopyrite and galena were investigated by micro-flotation experiments in the absence and presence of DTC-PAA depressant comparing with potassium dichromate with O-isopropyl-N-ethyl thiocarbamate (IPETC) as the collector. The micro-flotation results showed that DTC-PAA was an effective depressant for galena in the flotation separation from chalcopyrite when using IPETC collector. Their adsorption mechanisms were unravelled by FT-IR, zeta potential, adsorption capacity measurement, XPS and DFT calculations. The results of adsorption capacity tests showed that DTC-PAA prevented the adsorption of IPETC collector on galena surface. However, DTC-PAA could not prevent IPETC from adsorbing on chalcopyrite surface. It was found that DTC-PAA depressant could chemisorb onto Pb sites of galena surface through dithiocarbamate groups in DTC-PAA. These findings were also supported by FT-IR, zeta potential, XPS analysis and DFT calculations results. It implied that DTC-PAA might be a promising alternative of the potassium dichromate depressant in the flotation separation of Cu-Pb ores. [ABSTRACT FROM AUTHOR]

In this study, a novel organic depressant maleyl 5-amino-1,3,4-thiadiazole-2-thiol (MATT) was synthesized and utilized as a galena depressant in the flotation separation of molybdenite and galena. The results of the flotation test indicated that MATT exhibited an excellent depression ability on galena but barely influenced the flotation of molybdenite in the pH range of 6.0–11.0. Zeta potential results suggested that MATT preferentially adsorbed on galena surface. UV-visible spectroscopy analysis indicated that the stoichiometric ratio of lead ion and reagent in the complex compound. XPS analysis demonstrated that the S (-SH) atom and N (1,3,4-thiadiazole group) atom of MATT coordinated with the Pb atom on galena surface. [ABSTRACT FROM AUTHOR]

• A macromolecule PAM-ATU was employed as a galena depressant. • PAM-ATU could realize the separation of molybdenite from galena at pH around 10.5. • PAM-ATU could adsorb on galena surface via chemisorption by FT-IR and XPS analysis. In the present research, a macromolecular depressant poly(acrylamide-allylthiourea) (PAM-ATU) was explored to depress galena in the flotation separation from molybdenite. Its flotation behavior was evaluated by micro-flotation tests. The micro-flotation results revealed that PAM-ATU could depress galena strongly at 4.0 mg/L within pH 6.0–12.0, while molybdenite was found sensitive to the pH. At pH around 10.5, molybdenite showed a relatively good floatability with a nearly 80.0% recovery in the presence of 4.0 mg/L PAM-ATU. The flotation separation results for artificially mixed minerals proved that 1.0 mg/L PAM-ATU could selectively depress galena well. FT-IR and XPS analysis results demonstrated that PAM-ATU was likely to adsorb on galena surface by chemisorption. This study indicated that the synthesized PAM-ATU with low molecular weight might be a promising galena depressant in the flotation separation of Mo/Pb ores. [ABSTRACT FROM AUTHOR]

• A PAM-ATU polymer was introduced as the chalcopyrite depressant. • PAM-ATU showed a stronger depressing power to chalcopyrite than TGA. • A good separation efficiency was achieved when using diesel collector. • PAM-ATU chemisorbed on chalcopyrite surface via Cu sites and thiourea groups. In the present study, the poly(acrylamide-allyl thiourea) (PAM-ATU) with an average molecular weight of approximately 1.66 × 104 g/mol was introduced as the chalcopyrite depressant in the flotation separation of molybdenite and chalcopyrite. The effects of PAM-ATU on their flotation performances were evaluated by micro-flotation and bench-scale experiments, and its adsorption mechanism to chalcopyrite was investigated by Fourier transform infrared spectroscopy (FT-IR), zeta potential tests and X-ray Photoelectron Spectroscopy (XPS) measurements. The flotation experiments results demonstrated that PAM-ATU had a stronger depressing ability than the conventional depressant thioglycolic acid (TGA) for chalcopyrite. At pH around 10.5, a good separation efficiency for artificially mixed minerals could be achieved with a 78.2% Mo recovery and a 58.9% Mo grade in the froth products, in which, the Cu grade was only 1.68%. It was also found that nearly 80.0% of Cu was depressed effectively with 150 g/t PAM-ATU after one rougher flotation in bench-scale experiments with a Mo recovery of almost 80.0%. FT-IR, zeta potential tests and XPS analysis results provided strong evidence that PAM-ATU could adsorb on chalcopyrite surface. Further, FT-IR and XPS analysis suggested that PAM-ATU might mainly chemisorb on chalcopyrite via Cu sites on surface through S and N atoms in PAM-ATU polymer. This study indicated that the synthesized PAM-ATU polymer with low molecular weight could be a promising depressant for chalcopyrite in the flotation separation of Cu-Mo ores. [ABSTRACT FROM AUTHOR]

[Display omitted] • TMA was first explored as a chalcopyrite depressant in Cu-Mo flotation separation. • TMA could realize the effective separation of Cu-Mo artificially mixed minerals. • TMA could effectively reduce the contact angle of chalcopyrite. • TMA was likely to chemisorb on chalcopyrite by FT-IR and XPS analysis. In this study, N-thiourea-maleamic acid (TMA) was first introduced as a chalcopyrite depressant in flotation separation of Cu-Mo sulfide ores. The effects of TMA on the separation of Cu-Mo were investigated by micro-flotation tests. The results indicated that TMA was beneficial to separate chalcopyrite and molybdenite in the flotation separation of artificially mixed minerals at pH around 9.0 with a Mo recovery of 95.56% and depressing 94.64% of Cu. Its adsorption mechanism was revealed by contact angle, UV–Vis spectra, FT-IR and XPS measurements, in which, the contact angle and UV–Vis spectra measurements further proved that TMA did adsorb on chalcopyrite surface. Moreover, FT-IR and XPS measurements demonstrated that S atoms in the thiourea group of TMA interacted with Cu sites on chalcopyrite surface. All these findings confirmed that TMA would be a highly effective chalcopyrite depressant. TMA could adsorb onto chalcopyrite surface thereby increase its hydrophilicity without significant influence on molybdenite. [ABSTRACT FROM AUTHOR]

[Display omitted] • BDTP was synthesized via a simple one-pot reaction. • BDTP was innovatively used for Pb-Zn flotation separation under low alkali conditions. • BDTP could adsorb on galena surface by chemisorption confirmed by FTIR, SEM-EDS and XPS. • A six-membered ring and a "bullet" shape complex were formed by P-S-Pb and C-O-Pb bonds. In this paper, a novel selective galena collector, called S-benzoyl-O, O'-dibutyl dithiophosphate (BDTP), was synthesized via an one-pot reaction with ammonium dibutyl dithiophosphate (DTP) and benzoyl chloride as initial raw materials, and was innovatively used in Pb-Zn flotation separation. Its flotation performances and adsorption mechanism on galena surface were detailly studied. The micro-flotation results illustrated that BDTP exhibited superior selectivity and collecting power over the conventional collectors (sodium isobutyl xanthate (SIBX) and sodium diethyldithiocarbamate (DTC)), realizing the effective flotation separation of galena and sphalerite at pH around 9.0 with ZnSO 4 and Na 2 SO 3 as modifiers. The contact angle (CA) results demonstrated that the treated galena surface by BDTP was more hydrophobic than that of sphalerite. Scanning electron microscope-Energy dispersive X-ray spectroscopy (SEM-EDS) results also told us BDTP had been adsorbed on galena surface successfully. In addition, FTIR and X-ray Photoelectron Spectroscopy (XPS) analysis results suggested that the interaction of BDTP with galena may be dominated by the chemisorption. The BDTP may act as a bidentate ligand, bonding with Pb atoms on galena surface via S atoms in the P=S group or O atoms in the C=O group to form two different adsorption geometries, which are a six-membered ring structure with one Pb atom and a "bullet"-shape complex with two different Pb atoms. [ABSTRACT FROM AUTHOR]

• Galena and sphalerite floated well using diethyldithiocarbamate (DTC) as collector. • Cationic guar gum (CGG) exhibited selective depressant effect on sphalerite. • Only adding CGG after DTC could realize the separation of galena from sphalerite. • Addition order of CGG and DTC could lead to remarkable adsorption difference. In this study, the effect of cationic guar gum in the flotation separation of galena from sphalerite when diethyldithiocarbamate acted as galena collector was investigated, mainly through flotation tests and ToF-SIMS analysis. The flotation results showed that the cationic guar gum could selectively depress the sphalerite flotation and enhance the preferential flotation of galena only when it was added after collector diethyldithiocarbamate. The ToF-SIMS analysis found that addition of cationic guar gum after diethyldithiocarbamate exhibited no effect on the collector adsorption on galena surface but could selectively inhibit the collector coverage on sphalerite surface, and further result in the floatability difference. [ABSTRACT FROM AUTHOR]