Selective Flotation Of Chalcopyrite Research Articles

Selective flotation of chalcopyrite from pyrite via seawater oxidation pretreatment

The flotation separation of chalcopyrite from pyrite has attracted increasing attention due to the consumption of vast water resources and depressants. This study proposed the seawater oxidation pretreatment for non-depressant flotation separation of chalcopyrite from pyrite, as an effective and environmentally friendly strategy. Without the addition of depressants, seawater oxidation for 3 d effectively depressed pyrite flotation, with the highest recovery difference greater than 70% and a selectivity index greater than 6 between chalcopyrite and pyrite. The surface investigation showed that pyrite surface was more readily oxidized to form hydrophilic Fe oxidants/oxyhydroxides, as compared to that of chalcopyrite. Further UV-visible spectrophotometer and Fourier transform infrared spectrum (FTIR) results indicated that xanthate was less adsorbed onto the treated pyrite surface, resulting in un-floatable particles. Chalcopyrite surface was changed slightly due to seawater oxidation, thereby insignificantly affecting its flotation. The coordination theory was further used to reveal the combination mechanisms between xanthate and pyrite or chalcopyrite. This study therefore provides a promising strategy to effectively separate chalcopyrite from pyrite, especially in the freshwater-deficient area.

Selective flotation of chalcopyrite from galena using a novel collector benzoic diethylcarbamothioic thioanhydride: An experimental and theoretical investigation

The flotation separation of chalcopyrite and galena has always been the focus of production. Benzoic diethylcarbamothioic thioanhydride (BDT) is a novel chelating collector that has shown a certain application strength in the field of sulfide ore flotation. In this research, micro-flotation tests, zeta potential tests, Fourier transform infrared spectroscopy measurements, X-ray photoelectron spectroscopy measurements, and density functional theory (DFT) calculations were used to investigate the selective recovery and selective adsorption of BDT on chalcopyrite and galena. The flotation results showed that BDT had good flotation selectivity for chalcopyrite and galena, which achieved up to 96.67 % and 50.26 %, respectively, at pH 6 using a collector dosage of 100 g/t. The analysis of the adsorption mechanism showed that CS and CO in BDT are mainly involved in the adsorption process. On the surface of chalcopyrite, CS and CO can form a six-membered chelating ring with Fe or Cu sites. BDT can also be adsorbed on the surface of galena in the same way, but the adsorption strength is weaker than that on the surface of chalcopyrite.

Pulsating high-gradient magnetic separation of chalcopyrite and talc

The selective flotation of chalcopyrite from talc in practice is currently difficult and consumes a large amount of depressors, resulting in high production and environmental costs. The pulsating high-gradient magnetic separation (PHGMS) method has a strong potential for the effective separation of chalcopyrite and talc, based on their difference in magnetic susceptibility. In this work, the effects of magnetic induction, pulsating frequency and feed velocity of a pliot-scale PHGMS separator on the separation performance for pure chalcopyrite and talc minerals were investigated. The results indicate that the PHGMS achieves a selective separation of chalcopyrite from talc; and under the optimized conditions, a chalcopyrite concentrate of 30.22% Cu grade with 75.79% chalcopyrite recovery at talc content as low as 5.77% was produced from a chalcopyrite-talc mixture assaying 10.69% Cu and 66.67% talc. It was found that the chalcopyrite recovery for the ultra-fine particles fraction below 30 µm is lower than those of coarser fractions, as a result of the increased hydrodynamic drag over the magnetic force acting upon the ultra-fine particle. Entrainment may also occur between ultra-fine talc and chalcopyrite particles, which reduces the Cu grade for such ultra-fine particles in the copper concentrate. The PHGMS method may provide an environment-friendly and low-cost technology for the separation of chalcopyrite and talc.

Pulsating HGMS for industrial separation of chalcopyrite from fine copper-molybdenun co-flotation concentrate

Chalcopyrite occurring in porphyry copper deposits accounts for nearly 70% of the total copper reserve in the world, and in China more than 50% of the molybdenum concentrate was produced from this copper ore, in the form of molybeinite. Chalcopyrite (CuFeS2) and molybdenite (MoS2) are both sulphide minerals and may be easily co-floated, due to their similar floatability. However, the selective flotation of chalcopyrite from molybdenite is difficult and consumes a large amount of chemical reagents for chalcopyrite depression, which results in the high productive and environmental costs. In this investigation, pulsating HGMS with new matrix was industrially attempted for the separation of chalcopyrite from a fine copper-molybdenun co-flotation concentrate assaying 25–26% Cu and 0.35–0.36% Mo, in a super-large porphyry copper ore processing plant. It produced a copper concentrate at high weight around 30%, assaying around 31.50% Cu and 0.080–0.100% Mo, at 30–40% Cu and 6–10% Mo recoveries respectively; the non-magnetic product from the pulsating HGMS process assays 22–24% Cu and 0.45–0.50% Mo, at 60–70% Cu and 90–94% Mo recoveries respectively. The pulsating HGMS technology significantly reduces the use for flotation reagents and the productive and environmental costs for copper-molybdenun separation, and may provide a valuable reference for the copper-zinc, copper-lead and copper-talc separations, etc.

Investigations on the selective flotation of chalcopyrite from talc using gum Arabic as depressant

ABSTRACT The flotation separation of chalcopyrite from talc is difficult due to their good natural floatability. To solve this problem, the effect of gum Arabic (GA) on the flotation separation of chalcopyrite from talc was systematically investigated and its selective depression mechanism was discussed. Single mineral flotation test results showed the addition of GA could effectively depress the flotation of talc across the whole pH tested, while had a negligible effect on chalcopyrite in the pH range of 6–8. The mixed minerals flotation tests demonstrated that the effective separation of chalcopyrite from talc could be achieved with a concentrate of 31.36% Cu grade at 87.15% Cu recovery in the presence of GA. This was attributed to the greater adsorption density of GA on talc surface than that on chalcopyrite surface. In addition, compared to the concentrate (Cu grade: 27.01%, Cu recovery: 87.03%) with guar gum as the depressant, an increase of 4.35% of Gu grade was obtained with the use of GA. The results of X-ray photoelectron spectroscopy (XPS) measurements and zeta potential tests indicated that GA adsorbed on talc surface mainly via hydrophobic interaction and hydrogen bond may also play a role.

Selective separation of chalcopyrite and pyrite with a novel and non-hazardous depressant reagent scheme

Pyrite depression in xanthate flotation of multiple sulphide minerals has become a serious problem in every mineral industry. The present study introduces a novel and non-hazardous depressant reagent scheme in selective flotation of chalcopyrite from pyrite with sodium butyl xanthate (SBX) as the collector. The combined inhibitory effect of an organic polymer, tricarboxylate sodium starch (TCSS), and calcium oxide (CaO) depressed the flotation of pyrite more strongly than that of the chalcopyrite in a wide pH range of 7–12. The synergistic effect of CaO and TCSS achieved an improved selective flotation separation of chalcopyrite from pyrite at low alkaline pH of 9, for which the recovery of chalcopyrite was over 80% and that of pyrite was less than 19%. The IR spectral, XPS spectral, UV–vis spectral and zeta potential measurements indicated that the surface of pyrite adsorbed significantly more amount of CaO and TCSS than that of the chalcopyrite. The dissolved calcium species preferentially adsorbed on the pyrite surface decreasing its negative charge and promoting TCSS adsorption. The findings of this research are of great significance in reducing the consumption of larger doses of lime in conventional Cu–Fe flotation circuits of the copper industry.

Selective flotation of chalcopyrite from pyrite using diphosphonic acid as collector

Ethyl xanthate (EX) is a widely used collector in the flotation of sulfide minerals. However, it also has the disadvantages of low selectivity and harm to human health. Screening and/or designing more selective and green collectors is a ‘hot topic’ in mineral processing field. In this work, 1-Hydroxyethylidene-1, 1-diphosphonic acid (HEDP), a cheap green reagent widely used in water treatment, was for the first time, applied in the flotation separation of chalcopyrite from pyrite. In addition, a comparative test of the traditional EX collector was also carried out. Flotation results of single mineral and binary mineral mixture showed that HEDP possessed a better selectivity for the separation of chalcopyrite from pyrite than EX. Zeta potential measurement results indicated that HEDP exhibited a stronger adsorption on chalcopyrite and a weaker interaction with pyrite. Hence, HEDP is a promising collector that possesses the potential to replace EX in future chalcopyrite flotation practice.

The selective flotation of chalcopyrite against galena using alginate as a depressant

In this paper, sodium alginate was put forward as a flotation depressant for selectively separating the chalcopyrite from galena. The effects of the sodium alginate on the flotation performance of chalcopyrite and galena were studied using ammonium dibutyl dithiophosphate as the collector. The adsorption behaviors of sodium alginate on the mineral surfaces were investigated through surface analysis including zeta potential, FTIR spectra and XPS spectra analysis. The micro-flotation results showed that sodium alginate exhibited selective and strong depressant effect on the galena flotation while had little influence on the chalcopyrite flotation, whether it was added before or after the collector. The surface analysis results demonstrated that sodium alginate could selectively adsorb on the galena surface and then hinder the subsequent collector adsorption thus resulting in the hydrophilic galena surface. The selective adsorption mainly consisted of the interactions between the Pb2+ on the galena surface and the functional groups in sodium alginate. Sodium alginate did not adsorb on chalcopyrite surface or interfere with the collector coverage on chalcopyrite surface. Based on these findings, a possible adsorption model of the sodium alginate on the water-solid interface of the two minerals was proposed. The paper shows that sodium alginate has the potential to act as an effective, non-toxic depressant in the flotation of Cu-Pb polymetallic sulphide ores.

Selective separation of chalcopyrite from pyrite with a novel non-hazardous biodegradable depressant

Pyrite depression in copper ore flotation often requires large doses of inorganic depressants that lead to high toxicity, high costs, and low selectivity. Thus, this study offers a novel pyrite depressant, polyglutamic acid (PGA), in the selective flotation of chalcopyrite with xanthate as a collector. The flotation and adsorption mechanism on chalcopyrite and pyrite were systematically studied using a series of flotation tests, zeta potential measurements, adsorption analysis, infrared spectral (IR) analysis, and X-ray photoelectron spectroscopy (XPS) analysis. The addition of PGA depressed the flotation of pyrite more strongly than chalcopyrite in the wide pH range of 8–12. In the presence of PGA, selective separation between the two minerals was achieved at pH 9, and the recovery of chalcopyrite was over 85% and that of pyrite was less than 20%. All of the surface analysis techniques indicated that PGA interacted differently with the two minerals and the surface of pyrite adsorbed a much greater amount of PGA than that of chalcopyrite. Prior addition of PGA significantly reduced the adsorption of the collector on the pyrite surface and thus depressed its flotation. However, the significant adsorption of the collector and its oxidation to dixanthogen on the chalcopyrite surface caused its improved flotation even in the presence of PGA. Therefore, PGA, which is a non-hazardous, biodegradable, and renewable reagent, could be used as an alternative pyrite depressant in Cu–Fe conventional flotation circuits.

Selective flotation of chalcopyrite and molybdenite using H2O2 oxidation method with the addition of ferrous sulfate

Hydrogen peroxide (H2O2) has been used as an oxidizing agent in the selective flotation of chalcopyrite and molybdenite. However, this method required relatively high concentration of H2O2 to deliver flotation results (i.e., mineral grades and recoveries) comparable to those obtained by the conventional copper-molybdenum (Cu-Mo) ores flotation using sodium hydrosulfide (NaHS). Therefore, further improvements are needed to reduce the consumption of H2O2 reagent. In this study, ferrous sulfate (FeSO4) was used to enhance the oxidation performance of H2O2 through Fenton-like reactions. Flotation results showed that the consumption of H2O2 reagent could be reduced by the addition of FeSO4 without losing the flotation selectivity. The reason might be caused by increasing of oxidation performance as indicated by the increasing concentration of dissolved oxygen after the addition of FeSO4 into the H2O2 aqueous solution. Surface analysis using X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM) images showed that the surface of chalcopyrite was covered by more hydrophilic precipitates after the oxidation treatment using H2O2 aqueous solution with the addition of FeSO4, thus more hydrophilic surface and lower floatability. On the other hand, the surface of molybdenite was slightly oxidized and its surface remained hydrophobic as confirmed from contact angle results. Flotation tests using Cu-Mo bulk concentrate demonstrated that selective flotation might be possible using a mixture of FeSO4 and H2O2 aqueous solution. Moreover, this new method could be used as an alternative to copper depressant in Cu-Mo selective flotation, replacing the NaHS reagent.

Electrolysis Oxidation of Chalcopyrite and Molybdenite for Selective Flotation

Electrolysis oxidation of chalcopyrite and molybdenite was investigated, via various electrochemical methods, with the aim of realizing selective flotation of these minerals. Result of potential polarization indicated that oxidation via electrolysis affected only the chalcopyrite surface, owing mainly to the difference in conductivity of these minerals. Also measurements of contact angle after electrolysis indicated that contact angle of chalcopyrite selectively decreased whereas that of molybdenite did not decrease drastically. XPS analyses after electrolysis indicated that chalcopyrite peak decreased whereas iron oxyhydroxide (goethite) and iron sulfate increased, it suggests that these oxidation products covered on the surface of chalcopyrite. On the other hand, molybdenite peak is similar after electrolysis except for molybdenum oxide/oxygen with molybdenite can be seen for oxygen peak. From these results and general knowledge that sulfide hydrophobicity and sulfate/oxyhydroxide hydrophilicity, it can be explained that with electrolysis oxidation, hydrophilic oxihydroxide and sulfate covered on the surface of hydrophobic chalcopyrite then chalcopyrite surface became hydrophilic. On the other hand, molybdenite surface keep hydrophobic since its difficulty of oxidation and it is difficult to stay molybdenum oxide on the surface due to its soluble property. These results revealed that chalcopyrite was selectively oxidized and, hence, selective flotation of chalcopyrite and molybdenite was possible. This electrolysis oxidation methods were compared with those governing other oxidation treatments.

Selective flotation of chalcopyrite and molybdenite with H2O2 oxidation

The selective flotation of chalcopyrite (CuFeS2) and molybdenite (MoS2) was studied using surface oxidation treatments (i.e., ozone (O3) and hydrogen peroxide (H2O2)). The results indicated that the oxidation treatments had different effects on the wettability of chalcopyrite and molybdenite. Single mineral flotation results showed that the H2O2 treatment had higher separation selectivity for molybdenite and chalcopyrite compared with that of the ozone treatment. The contact angle measurement and X-ray photoelectron spectroscopy (XPS) analysis results showed that the chalcopyrite surface became hydrophilic owing to the surface deposition of oxidized iron and copper after the H2O2 treatment. On the other hand, the contact angle of molybdenite slightly increased following the H2O2 treatment at high concentrations. Possible mechanisms of this phenomenon were proposed in this work. Moreover, the separation selectivity of each oxidation method was discussed. Flotation tests using bulk Cu-Mo concentrate showed that H2O2 could deliver a flotation result comparable to conventional Cu-Mo flotation using NaHS.

Complexing collecting agent for selective flotation of chalcopyrite

Under analysis is interaction between 1-phenyl-2,3-dimethylaminopyrazolone-5 (AMD) and copper in solution and on the surface of chalcopyrite. It is found that AMD experiences chemical adsorption on the surface of chalcopyrite as a compound with copper. Effect exerted on adsorption of AMD agent on copper sulfide by ammonium rhodanate (NH4CNS), introduced as an additional ligand, or its mixture with acetic acid is defined. Based on the analytical research and the analytical chemistry data, the type of adsorption on the surface of chalcopyrite is determined. The flotation tests on monomineral fraction of chalcopyrite and pyrite, and copper sulfide ore prove selectivity of AMD in separation of chalcopyrite and pyrite.

Selective flotation of chalcopyrite and molybdenite with plasma pre-treatment

For pretreatment of selective flotation, plasma treatment of chalcopyrite and molybdenite was applied then the minerals were washed by solution at pH 9 with oxygen bubbling. Surface characteristics of these minerals were investigated with AFM, XPS, zeta potential and contact angle measurements. Contact angle of chalcopyrite and molybdenite decreased a lot by plasma treatment. When they were washed with pH 9 solution with oxygen bubbling, contact angle of molybdenite increased whereas chalcopyrite one kept low. Adhesion force measurements indicated similar behavior. Result of flotation experiments indicated low recovery of both chalcopyrite and molybdenite after plasma treatment and only molybdenite recovery became higher after washing. Selective flotation of chalcopyrite and molybdenite could be achieved with this process. However, flotation of mixture of chalcopyrite and molybdenite after these treatments indicated both chalcopyrite and molybdenite were depressed. Addition of emulsified kerosene changed the flotation results where molybdenite was floated and chalcopyrite was depressed. Possible mechanism of selective flotation was proposed from the results of XPS, AFM, etc.

Selective Flotation of Chalcopyrite and Marmatite by MBT and Electrochemical Analysis

Various collectors were compared in the selective flotation of copper–zinc ore by using isopropyl ethylthionocarbamate (Z-200), buthl xanthate, ammonium dibutyl dithiophosphate, and mercapto benzothiazole (MBT). The latter showed effective selectivity in the flotation of chalcopyrite and marmatite and was selected for a detailed study by using cyclic voltammetry and Tafel. The results of microflotation pointed out that the flotation of marmatite was significantly affected by CuSO4 activation. At weakly alkaline pH, marmatite activated by Cu2+ is dependent on Cu2+ concentration shown in electrochemical tests, and the activation products were Cu2S and CuS. The increasing addition of Cu2+ may remove the hydroxides and S0, resulting in considerable activation. The corrosion of marmatite is accelerated with the addition of CuSO4. Mechanisms are suggested for the selectivity of chalcopyrite/marmatite by MBT: the hydrophilic hydroxides (Zn(OH)2 and Fe(OH)3) are formed on the marmatite surface, which renders the marmatite surface hydrophilic and hampers the reaction between MBT and marmatite-activated products, while the hydrophobic compounds (MBT)2 and Cu(MBT)2 formed on the chalcopyrite surface improve the flotability of chalcopyrite.

Dextrin as a Regulator for the Selective Flotation of Chalcopyrite, Galena and Pyrite

Dextrin as a Regulator for the Selective Flotation of Chalcopyrite, Galena and Pyrite

THE ROLE OF NA2S2O5 AND ACTIVATED CARBON ON THE SELECTIVE FLOTATION OF CHALCOPYRITE FROM A COPPER ORE USING A DITHIOPHOSPHINE-TYPE COLLECTOR

This article presents the results of an investigation into the effects of sodium meta bi-sulphite (Na2S2O5) and activated carbon on the selective flotation of chalcopyrite from pyrite. In Küre Copper Concentrator, a chalcopyrite concentrate is produced with around 17.5% Cu content using lime as a depressant. Flotation tests conducted in this investigation employ Na2S2O5 and activated carbon as regulating reagents and reveal that Cu grades up to 28% could easily be achieved. The deactivation mechanism of S2O5 2− may be similar to that of SO3 2− such that the decomposition of the collector and/or oxidized surface species may be effective on selectivity. Activated carbon removes collector species from the pulp, creating collectorless flotation conditions. Conditioning time is an important parameter on selectivity and decreases the dosage of Na2S2O5 used.

Influence of sodium thiosulphate on oxidation of sulphide minerals during selective flotation of copper-nickel ores

The studies of sulphur distribution in oxidation products of pyrrhotite and chalcopyrite being components of Cu-Ni ores showed that the elementary sulphur — sulphoxide ion ratio on the mineral surface and in the liquid phase of mineral suspensions changes in the presence of sodium thiosulphate. Sodium thiosulphate exhibits properties of a reducing agent and prevents formation of hydrophobic elementary sulphur on pyrrhotite surface due to oxygen absorption and oxidation of thiosulphate-ions to sulphates. The decrease in pyrrhotite floatability is observed, and more favorable conditions are provided for selective flotation of chalcopyrite on copper-nickel ore processing.

Consideration on the Selective Flotation of Chalcopyrite and Pyrite

Consideration on the Selective Flotation of Chalcopyrite and Pyrite