Flotation Of Sphalerite Research Articles

Influence of surface oxidation rate on the flotation of sphalerite and galena inhibited by gum arabic

Differences in the flotation behavior of galena and sphalerite using potassium permanganate (KMnO4) and gum arabic (GA) alone and using a mixture of KMnO4 and GA were investigated. The single mineral flotation tests revealed that when KMnO4 and GA were used individually, galena and sphalerite flotation were inhibited, but the reagent dosages required were large. Sphalerite was strongly inhibited by the addition of a tiny amount of GA after oxidation with KMnO4 while galena was not inhibited under the same conditions. Following oxidation by KMnO4, galena and sphalerite exhibited a significant 83 % difference in flotation recovery when 10 mg/L GA was used, which clearly showed the potential for the combined use of KMnO4 and GA to achieve flotation separation of galena from mixed lead-zinc ores. The inhibitory effect of GA on sphalerite was investigated through a combination of analytical techniques, including Microcalorimetry, Fourier Transform Infrared (FTIR) Spectroscopy, contact angle measurements, X-ray Photoelectron Spectroscopy (XPS), and Scanning Electron Microscopy (SEM) coupled with Energy Dispersive X-ray (EDS) analysis. The results displayed that sphalerite had a much higher oxidation rate than galena, resulting in more oxides and hydroxides. As a result, the sphalerite surface exhibits an increased availability of active sites favorable to GA adsorption, thereby impeding Butyl xanthate (PBX) adsorption. However, the galena surface was able to absorb PBX, resulting in mineral separation.

Совершенствование реагентных режимов флотации руд сложного вещественного состава

Pyrite copper-zinc (sulfide) and polymetallic ores in Russia are complex and rebellious mineral raw materials. The main processing technology for such ores is flotation. Enhancement of the flotation technology for such mineral raw materials is currently performed in several directions. The practice of copper-zinc ore processing proves that obtaining highquality zinc and pyrite concentrates is impossible without the use of various modifiers in the sphalerite and pyrite flotation process. Such reagents are copper (II), zinc and iron (II) sulfates in the alkali-calcic medium. Therefore, research was carried out to study floatation properties of sphalerite and pyrite in the alkali-calcic medium with addition of one of the indicated sulfates to the mineral flotation process. The effect of each of the sulfates of copper (II), zinc and iron (II) on the flotation properties of sphalerite and pyrite was studied during flotation of the mineral with butyl xanthate and dithiophosphate at pH equal to 8, 10, and 12. The aim of this work was to study the effect of the sulfhydryl collectors in presence of copper sulfates, zinc and iron for flotation of sphalerite and pyrite with the grain-size class of 0.074 + 0.044 mm from one of the Russian deposits.

The depression mechanism of magnesium on the flotation of sphalerite with different iron contents: DFT and experimental studies

Previous studies have not examined the effect of iron content in sphalerite on magnesium depressing sphalerite. Herein, the impact of magnesium on the sphalerite flotation with different iron contents was investigated through experiments and various analytical techniques in this work. Flotation trials showed that the depression of magnesium on the flotation of sphalerite could be significantly improved with the increasing iron contents. Solution chemical calculations indicated that MgOH+ was the dominant group in solution under high-alkalinity environment. Zeta potential measurements demonstated that substitution of iron in sphalerite promoted adsorption of MgOH+ on the mineral surface. FTIR analysis indicated that Mg(OH)2 was more likely to adsorb on the surface of high iron marmatite. Surface properties investigations corroborated that Mg could produce Mg(OH)2 on the high-iron marmatite surface, improving the hydrophilicity of the surface. DFT calculations confirmed that the surface of iron-substituted sphalerite was more likely to interact with Mg(OH)2 than MgOH+. The present work provides new mechanistic sight for the depression of magnesium on the flotation of sphalerite with different iron contents.

Flotation separation of chalcopyrite from pyrite and sphalerite using a novel collector: An experimental and mechanism investigation

In this paper, a new collector, named O-isobutyl-N-allyl thionocarbamate (IBATC), was synthesized, and the structure was characterized by Fourier Transform Infrared Spectrometer (FTIR) and 1H NMR, 13C NMR analysis. The collection performance of IBATC was evaluated by flotation tests and interaction mechanism was investigated by means of adsorption amount, zeta potential measurements, FTIR, X-ray photoelectron spectroscopy (XPS) and density functional theory (DFT) calculation. The flotation tests results proved that IBATC was inclined to collect chalcopyrite compared with pyrite and sphalerite. Especially in the pH range of 9.5–10 and IBATC concentrate of 30–40 mg/L, the recovery of chalcopyrite exhibited more than 80 %. The adsorption amount and zeta potential measurements showed that IBATC had a greater orientation to chalcopyrite. FTIR and XPS analysis demonstrated IBATC chemically adsorbed on chalcopyrite surface, whereas physically adsorbed on pyrite and sphalerite. Further, DFT calculation of the interaction between IBATC and chalcopyrite proved that S atom of IBATC donated electrons to Cu sites on chalcopyrite surface and the adsorption energy was −19.45 kcal/mol, referring to an exothermic reaction. As a result, IBATC showed great capacity for the separation flotation of chalcopyrite, pyrite and sphalerite.

Effects of seawater on the adsorption of xanthate onto galena and sphalerite

Seawater contains divalent calcium and magnesium cations. Under alkaline conditions, calcium and magnesium ions react with hydroxide ions to form insoluble hydroxyl complexes or hydroxide precipitates. The hydrophilic substances that may be adsorbed on the mineral surface during the flotation process hinder the adsorption of the collector, affecting mineral hydrophobicity, and thus reducing the floatability of the mineral. In this study, the effects of seawater on the adsorption of xanthate onto galena and sphalerite were investigated. The results show that under strong alkaline conditions, seawater has significant and slight adverse effects on sphalerite and galena, respectively. Flotation regulators such as ethylenediamine tetraacetic acid, sodium hexametaphosphate, and sodium silicate can eliminate the adverse effect on galena and sphalerite flotation to a certain extent. The mechanisms were revealed through microflotation experiments, contact angle measurements, bubble-particle attachment tests, zeta potential measurements, and XPS analysis.

Selective flotation of galena and sphalerite using N-(phosphonomethyl) iminodiacetic acid as an eco-friendly depressant

This study explored the use of N-(phosphonomethyl) iminodiacetic acid (PMIDA) as an eco-friendly depressant for the selective flotation of galena and sphalerite. Microflotation tests were performed to assess the effectiveness of PMIDA. Moreover, the depression mechanism of PMIDA was analyzed through solution chemistry calculations, zeta potential measurements, contact angle determination, X-ray photoelectron spectroscopy, and density-functional theory calculations. Solution chemistry calculations revealed that the presence of PMIDA as PMIDA3− ions in the pulp optimized the depressive effect on sphalerite. Additionally, contact angle results indicated a significant improvement in the surface hydrophilic of sphalerite after PMIDA treatment. Zeta potential measurements revealed that the adsorption capacity of xanthate on the sphalerite surface after PMIDA treatment significantly decreased. X-ray photoelectron spectroscopy analyses indicated that the adsorption of PMIDA on the sphalerite surface was associated with the phosphate functional groups of PMIDA. Density-functional theory simulation data indicated preferential adsorption of PMIDA on the sphalerite surface. These results indicate the potential of PMIDA as a promising depressant to inhibit the flotation of sphalerite and facilitate the selective flotation of galena.

The Effect of Novel Submicronic Solid Activators on Sphalerite Flotability

In this study, we examine the effect of novel submicronic activators made from copper minerals and copper-rich concentrate on sphalerite flotability. The copper minerals and copper concentrate are ground in a vibratory micromill and ultrasonically treated to obtain submicronic sphalerite activators. Histograms show that the concentration of copper particles in the activator after treatment is 92%–94%, with particle sizes of 105–115 nm. The results concerning monomineral flotation showed that sphalerite flotation is possible with the use of submicronic copper particles as an activator. At the same time, the consumption of mineral copper is much lower (by 10 times) than that of copper sulfate. The best results are achieved when submicronic particles of covellite and bornite (with a 60% concentration of particles 300–500 nm in size) were used. Sphalerite recovery amounted to 80%, which is higher than the recovery obtained with the use of copper sulfate by 2% but is 2% lower compared to the use of copper oxyhydroxide. The flotation effect of the submicronic activators on sphalerite was tested in laboratory conditions using polymetallic ore from one of Kazakhstan’s deposits. It is shown that the novel submicron activators based on bornite and copper concentrate exhibit much lower consumption rates and can replace the more expensive copper sulfate at the same Zn content (54.8%–54.9%), obtaining recovery rates of 95.69%–96.57%.

Effect of content and spin state of iron on electronic properties and floatability of iron-bearing sphalerite: A DFT+U study

Iron is an impurity widely occurred in sphalerite, and its effect on sphalerite flotation is complex. In this work, the effects of iron content and spin state on electronic properties and floatability of iron-bearing sphalerite are comprehensively studied using density functional theory Hubbard U (DFT+U) calculations combined with coordination chemistry flotation. The band gap of ideal sphalerite is 3.723 eV, and thus electron transition is difficult to occur, resulting in poor floatability. The results suggest the band gap of sphalerite decreases with increasing iron content. For low iron content, the decreased band gap facilitates electron transition; at this case, Fe2+ in a high-spin state possesses one π electron pair, which can form a weak π-backbonding with xanthate, causing increasing floatability. However, for medium and high iron-bearing sphalerite, with the further decrease of band gap, Fe2+ is oxidized to Fe3+ due to electrochemical interaction, and hence π-backbonding is eliminated, leading to lower floatability of iron-bearing sphalerite, which is consistent with the flotation experimental results. This work could give a deeper understanding of how sphalerite flotation behaviors are affected by iron content.

Optimization of shape factor by the response surface method, and the effect on sphalerite flotation recovery

Various morphological parameters that affect the flotation recovery of sphalerite were modelled and optimized using the response surface method (RSM). The effects of roughness value, shape factor, and collector concentration were investigated using the central composite full design method. The results were evaluated by analysis of variance. The optimum roughening time was found to be 25 minutes, the optimum roughness value was 2.9071 um, and the optimum collector concentration was 0.001 M. Using these values, a flotation recovery of 98.01% was obtained. Similarly, in shape factor studies, the optimum grinding time was 15 seconds, the optimum roundness value 0.7421, and the optimum collector concentration 0.0009 M, which resulted in a flotation recovery of 94.30%. The average error between the optimization results and the experimental results was estimated to be less than 6%, and the R2 values were greater than 90%. The study shows that RSM can be effectively applied in finding the economic optimum condition for obtaining maximum flotation recovery with minimum reagent consumption.

Evaluation of the effects of L-cysteine addition on the bioleaching of zinc and cadmium from sphalerite flotation concentrate

The primary zinc ore in the world is sphalerite, and roasting-leaching-electrowinning (RLE) is the most typical method of processing. This method has different disadvantages, and bioleaching is an alternative and eco-friendly method for sphalerite treatment. The major drawback of bioleaching is its slow kinetics. In this study, an evaluation of the effects of L-cysteine addition on the bioleaching of zinc and cadmium from a concentrate of sphalerite was investigated in the presence of mixed cultures of mesophilic and moderately thermophilic microorganisms. The results showed that L-cysteine addition increased the dissolution rates of zinc and cadmium while reducing them at higher concentrations. The optimal conditions were achieved by using 0.1 g/L of L-cysteine in mesophilic cultures with zinc recovery of 73.92% and cadmium recovery of 81.45%, respectively. Similarly, zinc recovery was 92.54% in thermophilic cultures, while cadmium recovery was 88.66%. Field emission scanning electron microscopy (FE-SEM) and X-ray diffraction (XRD) analyses have detected the formation of jarosite and elemental sulfur on sphalerite surfaces in mesophilic conditions, as well as ammoniojarosite and elemental sulfur in moderately thermophilic conditions. Fourier transform infrared (FTIR) spectroscopy was employed to identify molecular structures and functional groups on the surface of bioleached residues in mesophilic and moderately thermophilic conditions. To assess the environmental risk of residues, a combination of synthetic precipitation leaching procedure (SPLP) and toxicology characteristic leaching procedure (TCLP) methods were used.

Using ML8 to achieve the lime-free separation of sphalerite-pyrrhotite under the copper activation system

Sphalerite flotation is conducted under Cu2+ activation system, whereas the selective separation of pyrrhotite is difficult due to the inevitable activation effect of Cu2+, which requires a large amount of lime to depress pyrrhotite flotation. In this study, the conventional collector butyl xanthate and a novel collector ML8 were compared to the selectivity of the flotation separation of sphalerite and pyrrhotite. The ML8 was investigated as an effective sphalerite collector to achieve the lime-free separation of sphalerite and pyrrhotite. Single mineral flotation indicated that sphalerite exhibited good floatability under low-alkaline conditions, whereas pyrrhotite was almost non-floatable, and their selective separation could be achieved using a low dosage of ML8. Mixed mineral flotation further confirmed that the ZnS separation could be achieved under low-alkaline conditions (pH = 9) using ML8 as a sphalerite collector. Reagents adsorption measurements demonstrated that ML8 possessed greater affinity to sphalerite than pyrrhotite, thus the contact angle of sphalerite increased from 51° to 76° after treatment with ML8 while that of pyrrhotite only increased from 67° to 70°. XPS detection results illustrated that the adsorption sites of ML8 on sphalerite were the adsorbed Cu site on the mineral surface rather than the Zn site of sphalerite crystal. The amount of Cu sites located on sphalerite was much greater than on pyrrhotite after the activation with copper sulfate.

Flotation Mechanism of Sphalerite by Sulfuration–Amine Method

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.

INFLUENCES OF GRINDING CONDITIONS ON GALENITE-SPHALERITE FLOTATION KINETICS

Grinding is more than just crushing, it is also a process that causes a chemical reaction on the surface of the mineral. Water used in the grinding process significantly affects the galvanic interaction. 
 Different grinding conditions result in different pulp chemistries. This becomes especially important in sulfide flotation in terms of recovery and selectivity. There are limited studies examining the effects of dry and wet grinding prior to the flotation of sulfide minerals. This study compared the effects of wet and dry grinding on the flotation kinetics of complex Pb-Zn sulfide ore at P80 of 20 and 50 µm grind sizes. Results showed that dry grinding positively affected the sphalerite ore flotation compared to wet grinding in terms of recovery and grade in both galenite and sphalerite rougher flotation stages. Considering that the effect of dry grinding was due to the difference in pulp chemistry, the reasons were explored based on particle morphology, and pulp potentials. 
 The results showed that grinding the same ore under dry and wet conditions significantly affected the flotation performance. In light of the pulp potential measurements, it was determined that the reducing environment obtained in the wet grinding negatively affected the flotation performance, while the oxidizing environment formed during the dry grinding affected the flotation performance positively. This was attributed to the fact that galvanic interactions that occurred during wet grinding were significantly reduced during dry grinding. Hence, better galenite and sphalerite flotation was obtained following dry grinding.

Investigations of Monomineralic Flotation of Galena, Sphalerite, and Pyrite at Different Temperatures

Temperature variations could potentially impact flotation performance, leading to operational and economic issues. Several historical and currently operating plants across Canada have reported seasonal metal losses as one of their major challenges. Improvements in flotation efficiency at cold temperatures are important for the sustainable development of the industry, especially in view of expanding mining operations to the north and the increasing impact of climate change-originated weather extremes on mining operations. To better understand the driving mechanisms of the seasonal metallurgical variation, the degree of vulnerability of froth flotation to fluctuations in temperature, and to develop recommendations addressing seasonally driven losses, a series of mono-mineral flotation tests were conducted. The observed variations in yield and recovery kinetics for different sulfide minerals follow a similar pattern: higher recovery and slower kinetics at lower temperatures, and lower recoveries and faster kinetics at higher temperature conditions. Following the results of the flotation tests, foam height and stability were investigated at different temperatures to explain the observed variations. A high correlation between changes in mono-mineral flotation behavior and foam properties with temperature was revealed.

Flotation Recovery of Sphalerite in Sea Water: A Feasibility Study

Mining and mineral processing industry adversely affects ecosystems and communities in nearby areas, including high freshwater consumption and scarcity. That is why the emerging global trend is to use sea water in flotation to recover valuable minerals from finely disseminated base metals ores. Recent studies investigate sea water flotation of copper, molybdenum, nickel sulphides and pyrite, while flotation of sphalerite, the main valuable mineral for zinc production, remains uncovered. This paper examines the feasibility of sphalerite flotation by conventional collectors in artificial sea water using a bubble-particles technique and frothless flotation tests. Potassium isopropyl xanthate (PIPX) and sodium isopropyl dithiophosphate (SIDTP) were used as collectors, and copper sulphate was introduced as the activator, while zinc sulphate and sodium sulphide were used as depressants. We examined the most common size fractions of sphalerite: medium (−74 + 44 μm) and fines (−44 μm). The findings showed the feasibility of sphalerite flotation in artificial sea water. We also established correlations between the rate of bubble-particle attachment and the sphalerite flotation recovery resulting in the growth of flotation recovery with the increase of the bubble-particle attachment rate. The results can be used as guidelines in choosing flotation reagents for sphalerite flotation in sea water. Another practical application of the results is the potential for sustainable development of the industrial sector, ecosystems and societies due to the replacement of fresh water by sea water, although further technological and environmental studies are required.

Влияние сульфата железа, сернистого натрия и их смеси на флотацию сфалерита в щелочной среде

Introduction. The quality of the enrichment process is affected by many factors, ranging from the characteristics of the raw materials supplied to the enrichment plant to the enrichment technology and the agents used. Strict process control is required at all stages from mining to concentrate extraction. Copper-zinc ores of Russian deposits are difficult for enrichment due to high mass fraction of pyrite in ore and fine irregular intergrowth of sulfide minerals between themselves and with rock minerals. The practice of enrichment of copper-zinc ores has established that it is impossible to obtain high-quality zinc and pyrite concentrates without adding sphalerite flotation modifier agents to various flotation operations. To improve the flotation activity of sphalerite, copper sulphate is used as an activation additive in the enrichment process chain. Purpose of work. To study the effect of sulfhydryl collectors on flotation of sulfide minerals, and development of innovative technologies of flotation of copper-zinc and polymetallic ores considering the acidity of the environment. Materials and methods. In the experimental part of the work, several methods of materials and agents preparing were used, a variety of equipment was used, as well as methods of analysis and processing of results. The material composition and grain size distribution of sphalerite was studied using the MLA System Quanta. X-ray phase analysis of sphalerite was carried out at the University of science and technology "MISIS" in Research Laboratory of ultra-hard materials on Rigaku Geigerflex device using monochromatized CuKα-radiation. Thermographic studies were carried out using a Q -1500D derivatograph. The following flotation agents were used in the work: collector - butyl potassium xanthate, foam agent MIBC, medium regulator - lime, modifiers - iron sulfate, sodium sulphide and mixture of iron sulfate and sodium sulphide. Flotation experiments were carried out on the laboratory flotation machine FL-189 G. Results. The kinetics of sphalerite flotation is characterized not by a single value of the flotation kinetics constant for all flotation mineral grains, but by a set of such values corresponding to quite certain fractions of sphalerite extracted in the foams product. It has been found that in the initial period of flotation the mineral grains with a high value of the flotation velocity constant are flotated, and in the final period of flotation the grains of the same mineral with a low value of the same flotation velocity constant are flotated. Discussion. The introduction of iron (II) sulphate into the mineral slurry leads to a redistribution of the flocculated mineral between medium and lightly flocculated fractions. This indicates that iron (II) sulphate acts as an activator for sphalerite flotation. At a low flow rate of this agent, the proportion of medium flotable fractions increases and the proportion of easily and hardly flotable fractions decreases. With increase in the agent consumption up to 400 g/t and more, the opposite picture is observed - the proportion of medium flotable fraction decreases and the proportion of easily flotable fraction increases in flocculated sphalerite. The replacement of iron (II) sulphate by sodium sulphate has the opposite effect on the flotation spectrum of sphalerite. The introduction of a mineral suspension of a solution of sodium sulfide and iron (II) sulfate into the liquid phase at a consumption of 200 g/t of each agent leads to a decrease in the proportion of easily and especially medium floatable fractions of the mineral and an increase in the proportion of difficultly floatable fractions. Conclusions: 1. An increase in the pH of pulp liquid phase leads to a decrease in the extraction of zinc concentrate in the foam product during flotation with butyl xanthate. 2. The introduction of a solution of sodium sulfide with ferrous sulfate reduces the floatability of the mineral, which is reflected in a decrease in the extraction of zinc concentrate. 3. Sodium sulfide and iron sulphate, while simultaneously dosing them into the flotation pulp, act as depressants in the sphalerite flotation process. 4. Sodium sulfide depresses sphalerite at all studied pH concentrations. Resume. The results of the research can be useful in improving the methods for processing sulfide ores (lead-zinc and copper-zinc) which are included in the group of polymetallic ores. The developed methods of flotation processing make it possible to improve the quality of enrichment and increase the extraction of a valuable component.

Hotspots and trends of sphalerite flotation: Bibliometric analysis

Flotation is the most important method for recovering sphalerite, and it has attracted significant research attention worldwide. In this study to clarify the hotspots for phased research frontiers and research progress of sphalerite flotation technology in the last 20 years, 720 pieces of relevant academic literature were selected by using “flotation” and “sphalerite, marmatite, and zinc sulfide” as keywords from the web of science database. The authors, institutions, and literature keywords were clustered by the visualization software VOSviewer and CiteSpace. The results show that, the number of papers published on sphalerite flotation has increased significantly since 2008, and China has made important contributions, various fund and zinc resource reserves have an important impact on sphalerite research. Universities are the main body of sphalerite research, and most of the foreign countries have independent research groups with little exchange and cooperation, whereas Chinese universities have more cooperation and many representative research teams. This paper systematically expounds on the research hotspots in this field, including the improvement of flotation separation technology, the progress of research methods, and the progress of reagents, provides a comprehensive overview for the future flotation research of sphalerite, and determines the further research fields.

Separation of sphalerite and dolomite using sodium alginate as an environmentally friendly depressant in a carbonate-hosted Pb-Zn ore system

Magnesium in zinc concentrate causes serious environment problems during hydrometallurgical processes. In the flotation of carbonate-hosted Pb-Zn ore, the separation of dolomite is critical to obtain high-quality zinc concentrate. In this study, fine-grained dolomite was found to be more floatable than coarse-grained dolomite, and it was the main cause of magnesium contamination. Entrainment dominated the flotation of fine-grained dolomite. The environmentally friendly sodium alginate (SA) was successfully used to depress dolomite, and the adsorption mechanism was found to be SA molecules chelating with Ca sites on the surface of the dolomite. The adsorption of SA enhanced dolomite hydrophilicity and increased the particle size due to flocculation, which reduced the entrainment. SA depressed sphalerite during flotation, but the Cu2+ ions enhanced butyl xanthate (BX) adhesion and inhibited the depressive effect of SA. Thus, sphalerite maintained good floatability. Overall, dolomite was selectively depressed by SA during the flotation of sphalerite, and the content of magnesium in the zinc concentrate decreased significantly from 3.65% to 2.37%. This study used SA as a dolomite depressant and obtained a higher quality zinc concentrate when floating a carbonate-hosted Pb-Zn ore, indicating its potential for commercialization and widespread industrial application.

Flotation separation of galena from sphalerite using hyaluronic acid (HA) as an environmental-friendly sphalerite depressant

A disaccharide unit glycosaminoglycan named hyaluronic acid (HA) was exploited as a novel sphalerite depressant in the flotation separation of Pb-Zn sulfides in this study. The effect of HA on the flotation of galena and sphalerite were evaluated by micro-flotation tests. The depression mechanisms were investigated by adsorption capacity, Zeta potential and X-ray photoelectron spectroscopy (XPS) analysis. The results of micro-flotation tests proved that HA was an efficient and selective sphalerite depressant, which could depress sphalerite but hardly influence the flotation of galena to achieve desirable separation results using sodium isobutyl xanthate as collector. The results of adsorption capacity and Zeta potential tests suggested that HA was more inclined to adsorb on sphalerite surface than that of galena, which hindered the adsorption of SIBX on sphalerite surface but insignificantly affected the interaction of SIBX with galena surface. XPS results indicated that HA chemisorbed on sphalerite through the coordination of carboxyl and N-acetyl groups with Zn sites, whereas it physically adsorbed on galena surface by means of hydrophobic interaction.

Research on the flotation of sphalerite and germanium-bearing sphalerite activated by copper ion and its mechanism difference

Although numerous studies on the flotation activation of sphalerite by copper ion have been reported, but there are still some important problems to be studied further. Previous research works did not comprehensively investigate the effect of germanium content on the floatability of germanium-bearing sphalerite, and did not obtain direct evidence of the activation difference of copper ions on sphalerite and germanium-bearing sphalerite. In this paper, the effect of germanium content in sphalerite on the floatability of sphalerite was studied using micro flotation test. The difference mechanism between copper ion activated sphalerite and germanium-bearing sphalerite was studied using surface adsorption amount measurements, Zeta potential measurements, local electrochemical impedance spectroscopy analysis, and time-of-flight secondary ion mass spectrometry. The results show that the increase of germanium content reduces the floatability of sphalerite and reduces the adsorption of copper and xanthate. Especially after activation by copper ions, the downward trend is more obvious. The reason for the less adsorption of copper and xanthate on the surface of germanium-bearing sphalerite is that Ge occupies the exchange site of Cu and Zn.