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1

Comparison study of crystal and electronic structures for chalcopyrite (CuFeS2) and pyrite (FeS2)

100%

Li Y. , Liu Y. , Chen J. , Zhao C. , Cui W.

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tom Vol. 57, iss. 1

100--111

EN

Chalcopyrite (CuFeS2) and pyrite (FeS2) are commonly associated with each other, and they both belong to semiconductor minerals. The difference in crystal and electronic structures is an important factor for their flotation separation. Using the density functional method (DFT) combined with Hubbard U correction, their crystal and electronic properties are comparatively studied. The calculated results suggest that the use of antiferromagnetic calculations and Hubbard U correction are very important to the accuracy of the chalcopyrite results. Antiferromagnetic calculations combined with a U value of 2.0 eV on chalcopyrite show a band gap of 0.53 eV, which is very consistent with the experimental results of ~0.5 eV. The density of states (DOS) and Mulliken bond population results indicate that stronger hybridization between Fe 3d and S 3p states in chalcopyrite than in pyrite leads to a stronger covalency of Fe-S bonds in chalcopyrite, causing a reduction in the spin magnetic moment (3.5 μB) from the ideal value. In addition, the greater covalency of bonds in chalcopyrite results in greater hydrophobicity of chalcopyrite than pyrite. The DOS results suggest that S has similar electronic properties in pyrite and chalcopyrite. The oxidation states of Fe and Cu ions in chalcopyrite are discussed based on the coordination field theory according to the calculation results, which confirms an oxidation state of Fe3+Cu1+S2.

2

Fabrication of thin film polycrystalline CIS photovoltaic heterostructure

100%

Pisarkiewicz T. , Jankowski H. , Schabowska-Osiowska E. , Maksymowicz L. J.

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2003

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tom Vol. 11, No. 4

297--304

EN

Manufacturing processes and investigation of properties of thin film materials forming the CulnSe2 (CIS) solar cell have been described. The cell consisted of the following layers: glassl Mol p-CulnSe2/n-CdS/n⁺-ZnO/. CIS absorbers were obtained by pulse magnetron sputtering of metallic targets in argon yielding the multilayer precursors structures which were successively chalcogenised in selenium vapours. Cadmium sulfide buffer layer was manufactured by chemical bath deposition (CBD) method which offers the films with optimal properties. Window zinc oxide layers were obtained by RF magnetron sputtering of metallic Zn:Al target in oxygen reactive atmosphere. Thin film CIS solar cells with the efficiencies of the order of 6% have been produced. Further improvement in technology leading to CIS cells with better parameters have been discussed.

3

Effect of food-grade guar gum on flotation separation of chalcopyrite and monoclinic pyrrhotite in low-alkali systems

100%

Chen X. , Gu G. , Li L. , Chen Z.

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2019

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tom Vol. 55, iss. 2

437--447

EN

The flotation separation of chalcopyrite from monoclinic pyrrhotite using food-grade guar gum (FGG) as a depressant was studied through micro flotation and flotation kinetics experiments, zeta potential, adsorption measurements and scanning electron microscope (SEM) analysis as well as infrared spectroscopy analysis. The flotation tests showed that the reagent scheme of depressant FGG 40 mg/dm3, collector PAX (potassium amyl xanthate) 10 mg/dm3 and frother MIBC (Methyl isobutyl carbinol) 10 mg/dm3 at pH 8.0 could achieve selective flotation separation of chalcopyrite from monoclinic pyrrhotite (a concentrate with Cu grade of 22.35% and recovery of 82.52% was achieved from the mixed minerals flotation), which indicated that FGG exhibited a selective depression effect on monoclinic pyrrhotite The kinetics, zeta potential, adsorption, SEM and infrared studies revealed that the depressant FGG could absorb more strongly on the surface of monoclinic pyrrhotite than chalcopyrite. Additionally, the results revealed that the interaction of FGG with the monoclinic pyrrhotite surface was governed primarily by strong chemisorption, whereas FGG mainly bonded to chalcopyrite through hydrogen bonding bonding. This property was the reason why FGG had excellent depression selectivity toward monoclinic pyrrhotite and weak depression effect on chalcopyrite flotation.

4

Flotation separation of chalcopyrite from talc using carboxymethyl chitosan as depressant

88%

Qian G. , Bo F. , Danping Z. , Jujie G.

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2017

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tom Vol. 53, iss. 2

1255--1263

EN

Flotation separation of chalcopyrite from talc using carboxymethyl chitosan as a depressant was studied. Flotation tests indicated that carboxymethyl chitosan had a selective depression effect on talc and the use of carboxymethyl chitosan as the depressant could achieve flotation separation of chalcopyrite from talc at pH 7. Adsorption studies showed that carboxymethyl chitosan only adsorbed on the surface of talc. This was the reason why carboxymethyl chitosan had high depression selectivity for talc. The zeta potential measurements and XPS analysis indicated that carboxymethyl chitosan adsorbed on the talc surface mainly through physical interaction and hydrophobic interaction may be the main driving force.

5

A case study on the recovery of unevenly embedded particle size in high-carbon chalcopyrite using an alkyne-based thioester collector: Flotation processing and adsorption mechanism

88%

Qi Y. , Luo Y. , Qiu X. , Wei D. , Zhang F. , Wang C.

Physicochemical Problems of Mineral Processing

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2024

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tom Vol. 60, iss. 2

art. no. 188154

EN

Abstract: The difference in chalcopyrite's primary ore-hosting rocks (dolomite and carbonaceous slate) in the Democratic Republic of the Congo results in an extremely uneven grain size distribution. Additionally, the presence of 2.21% organic carbon in the gangue impacts flotation efficiency. To address these challenges, ore properties were analyzed using the Mineral Liberation Analyzer (MLA), X-Ray Diffractometer (XRD), and microscopy. Flotation process was modified to incorporate a "middlings regrinding" processing, utilizing PDEC (an alkyne-based thioester collector, prop-2-yn-1-yl diethylcarbamodithioate) as the collector for experimental studies. Density Functional Theory (DFT) calculations elucidated the interaction mechanism of PDEC on chalcopyrite's surface. The MLA analysis indicates that chalcopyrite is mainly found in medium to fine grains, with the presence of fine-grained copper minerals smaller than 0.04mm accounting for 16.29% of the sample. This implies that these minerals require fine grinding for effective separation. Despite interference from organic carbon, PDEC demonstrates remarkable selectivity and efficiency in chalcopyrite flotation. By employing the "middlings regrinding" flotation method, a concentrate with a Cu content of 26.79% and a recovery of 87.88% was achieved, representing an increase of 0.17% in Cu grade and 4.09% in recovery rate compared to the conventional flotation process. DFT analysis demonstrates that the S 3p orbitals in carbon-sulfur double bond of PDEC and the C 2p orbitals in its acetylene group significantly affect its collection efficiency, engaging in hybridization with the Fe 3d orbitals on the surface of chalcopyrite, thereby facilitating a robust bonding interaction.

6

Comparative investigation on capture characteristics of chalcopyrite and hematite in PHGMS process

88%

Tao M. , Chen L. , Dai P. , Xue Z. , Chen H.

Physicochemical Problems of Mineral Processing

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2024

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tom Vol. 60, iss. 1

art. no. 185334

EN

Pulsating high-gradient magnetic separation (PHGMS) is a promising method of separating chalcopyrite from other minerals with similar floatability. However, the capture characteristics of chalcopyrite in the PHGMS process remain poorly understood. In this study, the difference in the capture capacity of chalcopyrite and hematite, a typical weak magnetic mineral, was theoretically compared. The effects of the key operating parameters, i.e., magnetic induction, slurry flow rate, and magnetic wire diameter, on the capture difference between chalcopyrite and hematite, were investigated through experimental verification. The comparison results showed that chalcopyrite shared a similar capture trend with hematite. The capture mass weight of the matrix decreased with an increase in the pulsating frequency, slurry flow rate, and magnetic wire diameter, but it increased with improved magnetic induction. However, chalcopyrite exhibited a smaller capture mass weight due to its lower susceptibility, which required a higher magnetic induction (1.4 T), slower flow rate (1.5 cm/s), lower pulsating frequency (150 rpm), and smaller matrix diameter (1 mm) for higher efficient recovery of chalcopyrite. As the magnetic induction increased from 0.8 T to 1.6 T, the chalcopyrite recovery improved from 65.84% to 75.80%. These findings provide valuable information for improving the utilization of chalcopyrite.

7

An investigation into using benzohydroxamic acid as a collector for sulfide minerals

88%

Mohammadi-Jam S. , Li Z. , Rose N. , Waters K. E.

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2023

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tom Vol. 59, iss. 5

art. no. 175662

EN

The mining industry aims to promote responsible chemical use during mineral processing operations to minimize the chemical contamination. Hydroxamic acids, which can form strong chelates with metals, have been shown to have less health and environmental issues when compared to xanthate collectors. In this work, the performance of benzohydroxamic acid (BHA) as a collector for galena, chalcopyrite, and quartz was evaluated. The minerals were conditioned with different concentrations (1.5, 3, and 4.5 kg/t) of collector at pHs 8, 9, and 10. The result showed that the treatment of the mineral surfaces with BHA enhanced the flotation recoveries of the sulfide minerals. High concentrations of benzohydroxamate anion, the protonic dissociation product of BHA, existed at basic pHs, where a chemical reaction between the anion and a metal cation on the mineral surface resulted in the adsorption of the collector onto the mineral surface. The microflotation results showed that the BHA collector was able to successfully recover galena and chalcopyrite. Their flotation recovery was dependent on the conditioning pH. Galena showed a high flotation recovery (up to 86%) at both pH 9 and 10, whereas chalcopyrite became most hydrophobic at pH values of 8 and 9 (up to 88%). None of the BHA concentrations or conditioning pHs was able to enhance quartz recovery beyond 7%. The research results have implications in the application of BHA for the froth flotation of galena and chalcopyrite.

8

Response surface methodology (RSM) for optimization of chalcopyrite concentrate leaching with silver-coated pyrite

88%

Salehi S. , Noaparast M. , Shafaei S. Z.

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tom Vol. 52, iss. 2

1023--1035

EN

This study aims to leach copper from chalcopyrite and optimizing the leaching process, using the response surface methodology (RSM). The RSM, a D-optimal design with four factors in three levels was employed to evaluate the effect of particle size, temperature, silver-coated pyrite to chalcopyrite ratio and redox potential parameters on the copper extraction efficiency. A quadratic model was then proposed by the RSM to correlate leaching variables. The tests results indicated that the model was significant with the experimental data at a correlation coefficient (R2) of 0.96. The most important parameters of copper extraction efficiency were particle size and silver-coated pyrite-to-chalcopyrite ratio, and also the squared term of particle size (A2), temperature (B2) and redox potential (D2). In addition, the interaction between redox potential and silver-coated pyrite-to-chalcopyrite ratio (CD) was significant. It was shown that the finer the particle size the faster the leaching rate of copper. It was also indicated that by increasing silver-coated pyrite to chalcopyrite ratio of 6:1 copper recovery increased. The maximum recovery of copper (71%) was obtained for the particle size of -38 μm, 70 °C, 420 mV of redox potential, silver-coated pyrite-to-chalcopyrite ratio of 6 and leaching time of 8 hours.

9

Study on flotation behavior and mechanism of separating chalcopyrite and Molybdenite with ethyl mercaptoglycolate as inhibitor

88%

Yang X.-F. , Xu-Zhao , Liu Y.-Y.

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tom Vol. 59, iss. 2

art. no. 162824

EN

The effect of ethyl thioglycolate organic small molecule inhibitors on chalcopyrite molybdenite flotation behaviour is investigated via single mineral micro-flotation tests, zeta potential tests, and X-ray photoelectron spectroscopy (XPS) analysis. Results of the flotation test indicate that ethyl thioglycolate organic small-molecule inhibitors can effectively separate Cu and Mo and selectively inhibit chalcopyrite under weak alkaline conditions. Infrared spectroscopy and XPS analysis show that hydrophilic functional groups C=O and -COOH in the ethyl thioglycolate organic small molecules can chemically adsorb onto the chalcopyrite surface. Moreover, ethyl thioglycolate has no obvious effect on zeta potential of molybdenite. Therefore, ethyl thioglycolate can effectively separate chalcopyrite and molybdenite.

10

Leaching of chalcopyrite concentrate in hydrogen peroxide solution

88%

Agacayak T. , Aras A. , Aydogan S. , Erdemoglu M.

Physicochemical Problems of Mineral Processing

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2014

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tom Vol. 50, iss. 2

657--666

EN

The leaching conditions of chalcopyrite (CuFeS2) concentrate in a hydrogen peroxide medium were investigated by studying the effects of its leaching parameters, such as stirring speed, temperature, hydrogen peroxide concentration and the particle size of the concentrate on Cu extraction. It was found that stirring speed has no effect on the leaching. Copper extraction from chalcopyrite is directly proportional to hydrogen peroxide concentration, but the extraction decreases at temperatures above 60°C. The maximum copper extraction was obtained with the following conditions without stirring: 240 min of leaching time, 3.0 M hydrogen peroxide concentration, 40°C leaching temperature and 53-75 m particle size fraction.

11

Role of calcium and magnesium cations in the interactions between kaolinite and chalcopyrite in seawater

75%

Uribe L. , Gutierrez L. , Laskowski J. S. , Castro S.

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2017

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tom Vol. 53, iss. 2

737--749

EN

A number of flotation plants around the world have increased the use of seawater due to limited sources of fresh water. The aim of this research work is to study the role that Mg2+ and Ca2+ ions play in the interactions between kaolinite and chalcopyrite in seawater. In order to achieve this objective, the effect of kaolinite on flotation of chalcopyrite is studied over the pH range from 8 to 11, when flotation is carried out in seawater and in a 0.01M NaCl solution. The influence of calcium, magnesium, sodium, and potassium ions on the extent of depression by kaolinite is evaluated. The micro-flotation results indicate that chalcopyrite is depressed by kaolinite in both 0.01 NaCl solution and seawater. In the 0.01 NaCl solution, the depressing effect of kaolinite decreases as the pH increases from 8 to 11. However, the results obtained using seawater show that the depressing effect of kaolinite is similar to what is observed in a 0.01 NaCl solution only at pH values below 9, but above this pH kaolinite significantly affects the recovery of chalcopyrite. The results from experiments with using solutions containing individual cations show that the depressing action of kaolinite in the presence of Mg2+ and Ca2+ is more obvious at pH values of 9 and 10, respectively, which correlates with the pH values at which the first hydroxy-complexes of these divalent cations start forming. This seems to indicate that depressing effect of kaolinite on chalcopyrite in seawater may be related to formation of hydrolyzed species of calcium and magnesium. These species can induce heterocoagulation between kaolinite and chalcopyrite. The trends observed in the micro-flotation experiments are in good agreement with the results of the induction time measurements and slime coating tests.

12

The use of Thiobacillus ferrooxidans bacteria in the process of chalcopyrite leaching

75%

Nowaczyk K. , Juszczak A. , Domka F. , Siepak J.

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nr 5

EN

The use of Thiobacillus ferrooxidans bacteria in the process of copper and iron leaching from chalcopyrite coming from Kotlina Klodzka was investigated. The influence of the mineral content in the leaching solution the pH value and refinement of chalcopyrite on the subsequent stages of leaching was established. The process was described by the 1st order reaction inhibited by one of the products (Cu2+). Assuming this model, the kinetic parameters of leaching were determined.

13

Raman spectroscopy characterization of some Cu, Fe and Zn sulfides and their relevant surface chemical species for flotation

63%

Vázquez-Sánchez E. E. , Robledo-Cabrera A. , Tong X. , López-Valdivieso A.

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tom Vol. 56, iss. 3

483--492

EN

Raman spectroscopy as a high-resolution characterization technique was used to analyze various pure metal sulfides immersed in water, namely pyrite (FeS2), chalcopyrite (CuFeS2), sphalerite (ZnS), marmatite (Zn1-XFeXS) and galena (PbS). The Raman characterization was undertaken in situ with the minerals immersed in water. Characteristic Raman spectrum that shows the vibrational modes of the atomic bonds in the mineral crystal structure is reported. This spectroscopic technique revealed that marmatite particles are composed of micro-size, perhaps nano-size, zones with different Fe and Zn content. With the intensity of the Fe-S and Zn-S Raman signals, the iron content of the zones was quantified. The copper ion up-take by marmatite particles was studied through this technique. It was found that the up-take of copper ions on the marmatite zones depended on their Fe content. Copper ion up-take occurred more preferentially on the zones of low Fe content than on those of high Fe content. The adsorption of the collector propyl xanthate on pyrite and chalcopyrite was also assessed by Raman spectroscopy. The Raman spectrum revealed that dixanthogen formed on the surface of these sulfides.

14

Wiek izotopowy Re-Os siarczkowej mineralizacji Cu-Ag oraz jej charakterystyka mineralogiczna i geochemiczna z obszaru złożowego Lubin–Polkowice (SW Polska)

63%

Mikulski S. Z. , Stein H. J.

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tom nr 468

79--96

PL

W artykule przedstawiono wyniki badań izotopowych Re-Os oraz charakterystykę mineralogiczno-geochemiczną mineralizacji bornitowej i chalkopirytowej występujących w postaci żyłkowo-impregnacyjnej w czarnych łupkach miedzionośnych formacji cechsztyńskiej z obszaru złożowego Lubin i Polkowice. Zbadane próbki reprezentują rudę siarczkową Cu-Ag o zawartościach miedzi od ok. 2,5 do 14,2% ze zróżnicowaną domieszką Ag (40–900 ppm) oraz zawartością substancji organicznej na poziomie ok. 6%. Wartości stosunków chemicznych, takich jak: Co/Ni = 0,1–0,7, V/Cr = 4–17 czy Fe2O3/Corg. = 0,6–1,9 i in., są w zakresach typowych dla czarnych łupków miedzionośnych z formacji cechsztyńskiej. Oprócz siarczków miedzi, które zawierają stałą domieszkę Ag (np. chalkozyn – 0,44–5,03% wag., bornit – 0,33–0,77% wag., chalkopiryt 0,09–0,20% wag.), obecne są również podrzędnie galena, sfaleryt, minerały Ag oraz powszechnie piryt framboidalny. W zbadanych izotopowo próbkach bornitu i chalkopirytu, występujących w postaci żyłek zgodnych z laminacją w łupku, zmierzone zawartości renu wahają się od 5,7 do 12 ppb, a całkowita zawartość osmu – od 27 do 50 ppt. W siarczkach tych jest wysoki udział zwykłego osmu. Stosunki izotopowe: 187Re/188Os są bardzo wysokie, w zakresie od 2269 do 2942, a 187Os/188Os – od ok. 9,8 do ok. 12,4. Obliczony dla tych wartości wiek modelowy Re-Os krystalizacji siarczków miedzi mieści się w zakresie od 268 do 256 mln lat oraz dla jednej próbki żyłki chalkopirytowej – 217 ±2 mln lat. Biorąc pod uwagę wartości stosunków izotopowych 187Re/188Os, możliwe było wyliczenie czteropunktowej izochrony wieku modelowego Re-Os (wiek modelowy 1), który wyniósł 212 ±7 mln lat przy założeniu stosunku inicjalnego 187Os/188Os = 2,13 ±0,31 (MSWD = 1,3; n = 4). Uzyskany wiek modelowy 1 wskazuje na krystalizację bornitu i chalkopirytu, występujących w czarnych łupkach cechsztyńskich w postaci żyłek równoległych do laminacji, w późnym triasie (noryku).

EN

In the paper we present the results of Re-Os isotopic studies as well as the mineralogical and geochemical characteristic of bornite veinlets with chalcopyrite ± chalcocite margins and chalcopyrite veinlets that are parallel to sub-parallel to bedding in the Kupferschiefer from the underground workings of the Lubin and Polkowice mines in SW Poland. Kupferschiefer samples are of grade from 2.5 to 14.2% Cu and with silver admixtures from 40 to 900 ppm and organic matter contents ca. 6%. The ratios of Co/Ni = 0.1–0.7, V/Cr = 4–17 and Fe2O3/Corg = 0.6–1.9 are in the range of values typical for the Kupferschiefer. Besides, copper sulphides, which commonly contain silver admixtures (e.g., chalcocite – 0.44–5.03 wt.%, bornite – 0.33–0.77 wt.%, chalcopyrite 0.09–0.20 wt.%) are associated with minor galena, sphalerite, Ag-minerals and common pyrite framboids. In the isotopically analysed bornite and chalcopyrite samples Re concentrations ranging from 5.7 to 12 ppb, and total Os concentrations ranging from 27 to 52 ppt. Significant common Os is present in all of the analysed sulphides. The isotopic ratios of 187Re/188Os are very high (range: 2269–2942), and of 187Os/188Os from 9.8 to ca. 12.4. Re-Os model ages calculated for these isotopic ratios are in the range from 256 to 268 Ma and for one of the chalcopyrite veinlet was 217 ±2 Ma. Taking into the account the values of the isotopic ratios of 187Re/188Os, it was possible to construct the Re-Os isochrone age for A Model 1regression based on four different samples. They yields age of 212 ±7 Ma, with an initial 187Os/188Os ratio of 2.13 ±0.31 (MSWD = 1.3). Re-Os isochrone age indicates for bornite and chalcopyrite crystallization event of the Ag-bearing Cu sulphide mineralization within the Kupferschiefer in the Late Triassic (Norian), ca. 212 ±7 Ma.

15

Separation of molybdenite from chalcopyrite, using graphene oxide as a novel depressant

63%

Namiranian A. , Noaparast M. , Tonkaboni S. Z. S.

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tom Vol. 68, no. 1

71--86

EN

In this research, graphene oxide was introduced as an efficient flotation reagent for the selective separation of molybdenite from chalcopyrite. The performance of graphene oxide and its adsorption mechanism on chalcopyrite were investigated by flotation tests, FTIR spectra, and XPS measurements. First, graphene oxide was synthesised, and then its performance was evaluated by SEM, XRD, and EDX. Flotation tests were carried out in a hallimond flotation cell with a volume of 300 ml. Optimum flotation values were achieved at pH = 9 by adding 250 g/t of PAX (Potassium Amyl Xanthate) as a collector and 50 g/t of A65 (Poly Propylene Glycol) as a frother. The results showed high recovery, around 80% for molybdenite, while chalcopyrite was depressed in high amounts by employing 11 kg/t of graphene oxide as a depressant. Compared to common chalcopyrite depressants such as NaHS, Na2S, and C2H3NaO2S, graphene oxide had a higher potency in depressing, which can be applied as a green-depressant in the separation of molybdenite from chalcopyrite by the flotation process. Also, the validity of the depressing effect on chalcopyrite was verified by XPS and FTIR spectra.

16

Possibilities of Obtaining Metals from Polymetallic Ore from Zlate Hory

51%

Vrlikova V. , Cablik V. , Janakova I.

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tom R. 21, nr 1/2

33--37

EN

The study deals with the use of flotation to obtain metals from the polymetallic ore from Zlate Hory, the Czech Republic. X-ray diffraction was performed, on the basis of which the mineralogical composition was determined in the sample. The most abundant was quartz with 87.03%. From ore minerals were detected pyrite 2.30%, sphalerite 3.64% and chalcopyrite 1.59%. Due to the high quartz content in the sample, heavy medium separation was selected to reduce its content. The treated polymetallic ore sample was subjected to flotation. In the flotation, the reagents xanthate was used as a collector, and pine oil as a frother. Different flotation conditions were observed, based on which the most suitable conditions for the flotation of metals were determined.

PL

Badanie dotyczy wykorzystania flotacji do otrzymywania metali z rudy polimetalicznej ze złoża Zlate Hory, Republika Czeska. Przeprowadzono dyfrakcję rentgenowską, na podstawie której określono skład mineralogiczny próbki. Największą zawartość wykazał kwarc z 87,03%. Z minerałów rudnych stwierdzono piryt 2,30%, sfaleryt 3,64% i chalkopiryt 1,59%. Ze względu na wysoką zawartość kwarcu w próbce wybrano rozdział w cieczy ciężkiej w celu zmniejszenia jego zawartości. Badaną próbkę rudy polimetalicznej poddano flotacji. We flotacji zastosowano ksantantogenian jako kolektor, a olej sosnowy jako spieniacz. Zbadano różne warunki flotacji, na podstawie których określono najbardziej odpowiednie warunki flotacji metali.