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    Wyświetlanie 1-14 z 14
    Tytuł:
    Adsorption Behavior of Glucuronic Acid on Pyrite Surface: an electrochemical and DFT Study
    Autorzy:
    Ning, Xu Jia
    Ying, Yang Hong
    Lin, Tong-Lin
    Powiązania:
    https://bibliotekanauki.pl/articles/355049.pdf
    Data publikacji:
    2020
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    glucuronic acid
    pyrite
    adsorption
    Opis:
    Bacterial adsorption on mineral surface is one of the key steps in bioleaching process. The bacteria adsorb on the mineral surface via the extracellular polymeric substances (EPS) layer. In this paper, the behavior of glucuronic acid, one of the key substances in EPS layer, adsorbed on the pyrite surface is studied using DFT and electrochemical methods. Adsorption capacity of glucuronic acid is stronger than that of water. Glucuronic acid adsorbs on pyrite surfaces and it follows a mixed type of interactions (physisorption and chemisorption). Adsorption of glucuronic acid on pyrite surface followed Langmuir’s adsorption isotherm with adsorption standard free energy of –27.67kJ mol-1. The structural and electronic parameters were calculated and discussed.
    Źródło:
    Archives of Metallurgy and Materials; 2020, 65, 1; 433-440
    1733-3490
    Pojawia się w:
    Archives of Metallurgy and Materials
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Evaluation of Contact Angle on Pyrite Surface
    Wyznaczanie kąta zwilżania na powierzchni pirytu
    Autorzy:
    Koval, L.
    Matysek, D.
    Powiązania:
    https://bibliotekanauki.pl/articles/318336.pdf
    Data publikacji:
    2014
    Wydawca:
    Polskie Towarzystwo Przeróbki Kopalin
    Tematy:
    contact angle
    pyrites
    potassium and sodium xanthates
    sessile drop method
    kąt zwilżania
    piryt
    ksantogeniany potasu i sodu
    metoda osadzonej kropli
    Opis:
    In the present paper, the contact angle measurements using six different xanthate solutions and distilled water were studied on twelve polished pyrite surfaces using sessile drop method. The 10% solutions of three potassium and three sodium xanthates were used. The pyrite samples from six countries and ten different deposits were utilized. The chemical composition of pyrites was studied using EDX microanalysis which proved that pyrite samples were not heterogenic. No relation or dependence between the contact angle and the chemical composition (i.e., Fe:S ratios) was found. The average values of contact angles measured using potassium and sodium xanthates were lower than the values of contact angle measured using distilled water. From these measurements can be concluded, that the pyrite samples are favourably wetted by either potassium or sodium xanthates than distilled water in flotation environment. The comparison of potassium and sodium xanthates showed better suitability of the potassium xanthates for the possible pyrite flotation (lower contact angle was measured on eight out of twelve samples for potasium xanthates). Pyrite samples Sokolov, Jachymov and Kutna Hora showed the lowest average contact angle values from all xanthates using potassium amyl xanthate (PAX) with average values of 34,80°, 42,94° and 31,01° respectively. The sodium xanthates would be more appropriate for the Navajun 2 and 3, Jachymov Sadon, and Norilsk pyrite samples. Very small differences in average contact angle values were obtained when potassium/sodium ethyl and isobutyl xanthates were compared. The minimum average values of contact angle for six out of twelve samples and for five out of eight samples in hydrothermal deposits were measured using ethyl xanthates what makes them the most suitable collectors for the pyrite samples from hydrothermal deposits and for pyrites in general. Even smaller variation in the results was showed using isobutyl xanthates with the highest average values of contact angle what makes them not suitable as the collectors for pyrite samples used in this study. The average value of contact angle measured using SIBX was 58,50°.
    W pracy tej badano pomiary kąta zwilżania z użyciem trzech różnych roztworów ksantatui wody destylowanej na dwunastu polerowanych powierzchniach pirytu za pomocą metody osadzania kropli. Użyty został 10% roztwór trzech ksantatów potasu i trzech ksantatów sodu. Wykorzystane zostały próbki pirytu z sześciu państw i dziesięciu różnych depozytów. Skład chemiczny pirytów był zbadany za pomocą mikroanalizy EDX, która udowodniła, że próbki pirytu nie były heterogeniczne. Nie znaleziono żadnej relacji lub zależności między kątem zwilżania i składem chemicznym (np. stosunku Fe:S). Średnie wartości kąta zwilżania zmierzone z użyciem ksantatów potasu i sodu były niższe niż wartości kąta zwilżania zmierzone z użyciem wody destylowanej. Z pomiarów tych można wnioskować, że próbki pirytu są łatwiej zwilżane za pomocą ksantatów potasu lub sodu niż za pomocą wody destylowanej w środowisku flotacyjnym. Porównanie ksantatów potasu i sodu wykazało lepszą przydatność ksantatu potasu w możliwej flotacji pirytu (niższy kąt zwilżania został zmierzony w ośmiu z dwunastu próbek dla ksantatu potasu). Próbki pirytu Sokolov, Jachymov i Kutna Hora wykazały najniższe średnie wartości kąta zwilżania ze wszystkich ksantatów z użyciem potasowego amylu ksantatu (PAX) ze średnimi wartościami odpowiednio 34,80°, 42,94° i 1,01°. Ksantaty sodu mogą być bardziej odpowiednie dla próbek pirytu Navajun 2 i 3, JachymovSadon i Norilsk. Bardzo małe różnice w wartościach średnich kąta zwilżania zostały uzyskane gry potasowy lub sodowy etyl i izobutyl ksantatu były porównywane. Minimalne średnie wartości kąta zwilżania dla sześciu z dwunastu próbek i na pięciu z ośmiu próbek z depozytów hydrotermalnych były zmierzone z użyciem etylu ksantatu co czyni je najbardziej odpowiednimi kolektorami dla próbek pirytu z depozytów hydrotermalnych i pirytów w ogóle. Jeszcze mniejsze wahania wyników wykazano używając izobutylu ksantatów lecz uzyskano najwyższe średnie wartości kąta zwilżania co czyni je niewłaściwymi kolektorami dla próbek pirytu użytych w tym badaniu. Średnia wartość kąta zwilżania zmierzonego z użyciem SIBX wynosiła 58,50°.
    Źródło:
    Inżynieria Mineralna; 2014, R. 15, nr 2, 2; 119-125
    1640-4920
    Pojawia się w:
    Inżynieria Mineralna
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Galvanic contacting effect of pyrite on xanthate adsorption on galena surface: DFT simulation and cyclic voltammetric measurements
    Autorzy:
    Ke, B.
    Chen, J.
    Li, Y.
    Chen, Y.
    Powiązania:
    https://bibliotekanauki.pl/articles/110904.pdf
    Data publikacji:
    2018
    Wydawca:
    Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
    Tematy:
    adsorption
    DFT
    galvanic interaction
    pyrite surface
    galena surface
    cyclic voltammetric measurements
    Opis:
    The effect of galvanic interaction between pyrite and galena on xanthate adsorbing on the galena surface has been investigated by means of density functional theory (DFT) and cyclic voltammetric measurements. The calculated results show that differences in the contact site and contact distance between galena and pyrite can affect the intensity of the galvanic interaction, and the relationship between the intensity of galvanic interaction and the adsorption ability of xanthate on galena surface has been studied in detail. In general, the galvanic interaction between pyrite and galena surface can enhance the adsorption of xanthate on the galena surface. The adsorption energies of xanthate on the galena surface decrease with the decrease of contact distance, and when the contact distance is lower than 4 Å, the adsorption energies decrease significantly at Pb-Pb, Pb-S and S-S sites. In particular, at the contact distance of 3 Å, a sharp decrease of adsorption energy is observed at the Pb-Pb contact site; in this case, the negative shift of the Pb-S bonding range and DOS non-locality at Pb-Pb contact site are significantly greater than that of the S-S or Pb-S contact sites. The cyclic voltammetric measurements reveal that the galvanic interaction between galena and pyrite improves the adsorption of xanthate on galena surface, which is in good agreement with the DFT results.
    Źródło:
    Physicochemical Problems of Mineral Processing; 2018, 54, 3; 826-836
    1643-1049
    2084-4735
    Pojawia się w:
    Physicochemical Problems of Mineral Processing
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    First-principles study on the adsorption structure of water molecules on a pyrite (100) surface
    Autorzy:
    Liu, Yingchao
    Chen, Jianhua
    Li, Yuqiong
    Zhang, Junjie
    Kang, Duan
    Powiązania:
    https://bibliotekanauki.pl/articles/1447970.pdf
    Data publikacji:
    2021
    Wydawca:
    Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
    Tematy:
    pyrite
    water molecules
    adsorption
    Opis:
    The hydration structure of water molecule adsorption at different coverages of a monolayer on a pyrite (100) surface were simulated using the density functional theory (DFT) method. The results demonstrate that the Fe-O interaction weakens and the adsorption energy per water molecule decreases with increasing water coverage, except at a monolayer coverage of 12/12 (i.e., full coverage). H-S and H-O hydrogen bonds were formed on the nearest surface layer. When large amounts of water molecules adsorb onto the surface, the adsorbed water molecules can be divided into three layers: the layer nearest to the surface, the second nearest to the surface, and the layer farthest from the surface. The thickness of the former two layers is approximately 5.5 Å. The three layers have water densities of 1.12 g/cm3, 1.08 g/cm3, and 0.95 g/cm3, respectively, suggesting that there is a strong interaction between the pyrite surface and water molecules and the influence of surface structure on water adsorption reaches a distance of more than 10 Å. Dynamics simulations suggest that the water molecules close to the mineral surfaces are in an orderly arrangement while those far from the surface are disordered.
    Źródło:
    Physicochemical Problems of Mineral Processing; 2021, 57, 2; 121-130
    1643-1049
    2084-4735
    Pojawia się w:
    Physicochemical Problems of Mineral Processing
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Adsorption mechanism of copper xanthate on pyrite surfaces
    Autorzy:
    Deng, Zhengbin
    Cheng, Wanli
    Tang, Yun
    Tong, Xiong
    Liu, Zhihong
    Powiązania:
    https://bibliotekanauki.pl/articles/1447276.pdf
    Data publikacji:
    2021
    Wydawca:
    Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
    Tematy:
    pyrite
    cupric xanthate
    cuprous xanthate
    adsorption
    surface
    Opis:
    The ratio of the hydrophobic to hydrophilic species and their distribution on mineral surfaces significantly influences the floatability of sulfide minerals. Through the flotation test, the influence of different reagents on pyrite flotation was examined. The interaction mechanisms between copper xanthate and pyrite were evaluated using advanced analysis technologies, including contact angle measurements, zeta potential analysis, scanning electron microscopy, energy dispersive spectroscopy, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy. The results show that the butyl xanthate in solution reacts with copper sulfate to form cupric xanthate, increasing the consumption of the collector butyl xanthate and resulting in lower floatability of pyrite. Cupric xanthate can be adsorbed on the pyrite surface through bonding with the sulfur sites. The adsorbed cupric xanthate on the pyrite surface undergoes redox reaction. The cupric xanthate is reduced to cuprous xanthate, and the sulfur on the surface will be oxidized. The adsorption products on the pyrite surface contain both cuprous xanthate and cupric xanthate. As the pH of a solution increases, the absolute value of the zeta potential of pyrite surface increased and the surface contact angle increased. Iron xanthate is also formed on the pyrite surface through a chemical reaction between the xanthate ions and pyrite, oxidation of xanthate ions to dixanthogen also takes place. Cuprous xanthate is the main hydrophobic substance on the pyrite surface, which can change the surface electrical properties and wettability of pyrite, and improve hydrophobicity of pyrite.
    Źródło:
    Physicochemical Problems of Mineral Processing; 2021, 57, 3; 46-60
    1643-1049
    2084-4735
    Pojawia się w:
    Physicochemical Problems of Mineral Processing
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Interaction between sphalerite and pyrite and its effect on surface oxidation of sphalerite
    Autorzy:
    Yang, B.
    Xie, X.
    Tong, X.
    Lan, Z.
    Cui, Y.
    Powiązania:
    https://bibliotekanauki.pl/articles/109553.pdf
    Data publikacji:
    2018
    Wydawca:
    Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
    Tematy:
    sphalerite
    surface oxidation
    minerals interaction
    DFT
    Opis:
    The interaction between sphalerite and pyrite was investigated by dissolution test, X-ray photoelectron spectroscopy (XPS), zeta potential measurement and density functional theory (DFT) calculation. Dissolution tests indicated that sphalerite dissolution was promoted due to the galvanic interaction between sphalerite and pyrite. The Zn2+ ion concentration increased with increasing pyrite content and dissolved time. XPS analysis results demonstrated that a new oxidation product was formed on the sphalerite surface in the presence of pyrite in a pulp. Zeta potential measurements showed that the isoelectric point of sphalerite increased from 3.3 to 5.4 due to galvanic interaction. DFT calculation results suggested that electron transfer from sphalerite to pyrite occurred when they contacted. The Zn 4s and S 3p states of sphalerite lost electrons. The Fe 4p and 4s of pyrite states obtained electrons, and Fe 3d and S 3s states lost a small number of electrons. The surface oxidation of sphalerite was promoted due to the interaction with pyrite, and the collectorless floatability of sphalerite decreased.
    Źródło:
    Physicochemical Problems of Mineral Processing; 2018, 54, 2; 311-320
    1643-1049
    2084-4735
    Pojawia się w:
    Physicochemical Problems of Mineral Processing
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Insight into the effect of galvanic interactions between sulfide minerals on the floatability and surface characteristics of pyrite
    Autorzy:
    Yang, Bo
    Tong, Xiong
    Xie, Xian
    Huang, Lingyun
    Powiązania:
    https://bibliotekanauki.pl/articles/1448232.pdf
    Data publikacji:
    2021
    Wydawca:
    Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
    Tematy:
    galvanic interaction
    floatability
    pyrite
    sulfide minerals
    Opis:
    Complex sulfide ores are usually found as a mixture of various sulfide and gangue minerals, and froth flotation is the predominant method for the selective separation of sulfide minerals. Adherence and contact between sulfide minerals are inevitable during froth flotation, and galvanic interactions between sulfide minerals will occur because of differences in rest potentials. However, the effect of these galvanic interactions on the selective flotation of sulfide minerals have been rarely studied. In this work, the effect of the galvanic interaction between pyrite and sphalerite on the flotation behavior and surface characteristics of pyrite was investigated by micro-flotation tests, collector adsorption tests, electrochemical techniques and XPS (X-ray photoelectron spectroscopy) surface analysis. The micro-flotation tests indicated that the floatability of pyrite decreased in the pH range of 4.0 to 9.5 and increased under strongly alkaline pH conditions (pH > 10) due to the galvanic interaction. The collector adsorption results demonstrated that the adsorption capacity of the collector on the pyrite surface was significantly reduced because of the galvanic interaction between pyrite and sphalerite. The electrochemical measurements revealed that the decrease in the oxidation current of xanthates to dixanthogen was responsible for the decreasing adsorption capacity of the collector on the pyrite surface. The XPS results indicated that the formation of the $S_O_3^{2-}$ oxidation product on the pyrite surface decreased at a strongly alkaline pH due to the galvanic interaction. Therefore, pyrite floatability improved at an alkaline pH. These results consistently showed that the galvanic interaction between pyrite and sphalerite had an important influence on the floatability and surface characteristics of pyrite.
    Źródło:
    Physicochemical Problems of Mineral Processing; 2021, 57, 2; 24-33
    1643-1049
    2084-4735
    Pojawia się w:
    Physicochemical Problems of Mineral Processing
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Ammonium chloride’s weakening effect on the copper activation of pyrite in flotation and the surface regulation mechanism behind it
    Autorzy:
    Zhang, Shengdong
    Chen, Yumeng
    Tong, Xiong
    Xie, Xian
    Lu, Yalin
    Powiązania:
    https://bibliotekanauki.pl/articles/110323.pdf
    Data publikacji:
    2019
    Wydawca:
    Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
    Tematy:
    pyrite
    depression
    cuprammonium solution
    pH buffering property
    flotation
    Opis:
    The traditional separation process of pyrite and marmatite is carried out under highly alkaline conditions. Therefore, a large amount of lime is demanded and the zinc recovery cannot be guaranteed. However, under weakly alkaline conditions, copper-activated pyrite has good floatability, which is difficult to separate from marmatite. In this paper, ammonium chloride (NH4Cl) is used for depressing the flotation of copper-activated pyrite to achieve the separation of these two minerals under weakly alkaline environment. The flotation tests show that NH4Cl can significantly reduce the floatability of pyrite in weakly alkaline conditions. The results of adsorption tests and X-ray photoelectron spectroscopy (XPS) analyses indicate that NH4Cl can obviously change the composition of pyrite surface by increasing the content of iron/copper hydroxide and reducing the content of copper sulfides. Calculation of the solution composition demonstrates that the addition of NH4Cl results in the occurrence of Cu(NH3)n2+ and the pH buffering property. Based on these results, it can be concluded that the depression of NH4Cl on copper activated pyrite is mainly derived from two aspects: 1) the pH buffering property of the conjugated acid-base pair (NH4+/NH3) can impede the decline of OH- concentration, which results in more hydroxide adsorbed on pyrite; 2) NH3 (aq) competes with the pyrite surface to consume Cu2+through complexation, which causes a reduction in the amount of copper sulfides formed on the pyrite surface.
    Źródło:
    Physicochemical Problems of Mineral Processing; 2019, 55, 5; 1070-1081
    1643-1049
    2084-4735
    Pojawia się w:
    Physicochemical Problems of Mineral Processing
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Dispersive effect of low molecular weight sodium polyacrylate on pyrite-serpentine flotation system
    Autorzy:
    Zhao, K.
    Yan, W.
    Wang, X.
    Gu, G.
    Deng, J.
    Zhou, X.
    Hui, B.
    Powiązania:
    https://bibliotekanauki.pl/articles/110158.pdf
    Data publikacji:
    2017
    Wydawca:
    Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
    Tematy:
    dispersant
    serpentine
    flotation
    surface potential
    dispersion mechanism
    Opis:
    In this work, the dispersive effect of low molecular weight sodium polyacrylate (PAAS) on serpentine, and its dispersion mechanism were systematically investigated through zeta potential measurements, micro and batch flotation as well as adsorption tests. At pH 5, where flotation of iron sulphide was routinely performed, pyrite and serpentine minerals were oppositely charged, and therefore they were attracted to each other. Slime coatings of serpentine adhered to the surface of pyrite, decreasing the adsorption density of a collector on the pyrite surface, but also reducing the flotation recovery. PAAS increased the flotation recovery of pyrite by promoting dispersion between pyrite and serpentine. The effective flotation separation of pyrite from the refractory iron sulphide ore was possible by using PAAS as a dispersant. Anionic PAAS adjusted the surface potential of serpentine through adsorption on the serpentine surface and changed the interaction between pyrite and serpentine particles from attractive to repulsive, and then dispersed pyrite and serpentine.
    Źródło:
    Physicochemical Problems of Mineral Processing; 2017, 53, 2; 1200-1213
    1643-1049
    2084-4735
    Pojawia się w:
    Physicochemical Problems of Mineral Processing
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Adsorption of yeast dextran on clinochlore surface and the implications for pyrite/clinochlore separation
    Autorzy:
    Wang, Zhen
    Zou, Dan
    Zhao, Kaile
    Safarov, Sayfidin
    Xu, Ying
    Powiązania:
    https://bibliotekanauki.pl/articles/2146917.pdf
    Data publikacji:
    2022
    Wydawca:
    Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
    Tematy:
    clinochlore
    pyrite
    flotation
    yeast dextran
    adsorption
    Opis:
    Silicate minerals with a certain degree of flotability are often easy to mix into sulfide ore concentrate in mineral processing industry. In this paper, the adsorption of yeast dextran on clinochlore and its application in pyrite/clinochlore separation were investigated. The adsorbed amount and micro polarity measurement results displayed that the yeast dextran molecules selectively adsorbed onto clinochlore surface compared with pyrite. The adsorbed yeast dextran resulted in the increase in the surface polarity of clinochlore surface, and inhibited the further adsorption of xanthate, thus keep it hydrophilic and depressed. Quantum chemical computation results indicated that yeast dextran was mainly adsorbed on mineral surface by the chelation with the surface metal active sites, and the chelating strength of yeast dextran with three ions was in the sequence of Fe3+ > Mg2+ > Fe2+. While Mg2+, Fe2+ and Fe3+ are the main metal ions on the surface of clinochlore, and Fe2+ is the unique metal ions on pyrite surface. This is the reason of the selectivity of the yeast dextran depressant for pyrite/clinochlore flotation system. The flotation results demonstrated that yeast dextran was qualified to selectively depress clinochlore in pyrite flotation.
    Źródło:
    Physicochemical Problems of Mineral Processing; 2022, 58, 4; art. no. 151635
    1643-1049
    2084-4735
    Pojawia się w:
    Physicochemical Problems of Mineral Processing
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Effect of pyrite type on the electrochemistry of chalcopyrite/pyrite interactions
    Autorzy:
    Forbes, E.
    Smith, L.
    Vepsalainen, M.
    Powiązania:
    https://bibliotekanauki.pl/articles/110218.pdf
    Data publikacji:
    2018
    Wydawca:
    Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
    Tematy:
    flotation
    arsenic
    pyrite
    galvanic interaction
    Surface oxidation
    Opis:
    Pyrite is the most common sulphide gangue mineral occurring in base metal sulphide ores around the world. Pyrite is known to galvanically interact with valuable minerals such as chalcopyrite, altering their electrochemical and flotation behaviour. Different types of pyrite are known to vary in texture, chemical composition and electrochemical activity. However, the effect that these differences have on the degree of pyrite interaction with chalcopyrite are not well studied. This work examines two distinct types of pyrite from different deposits that have a similar chemical composition, but vary greatly in texture. It investigates the way in which these pyrites interact with chalcopyrite surfaces, affecting both its electrochemical behaviour and floatability. It was found that the Renison pyrite was characterised by a much higher level of surface activity than the Huanzala pyrite. This was attributed to the elevated levels of arsenic within the mineral’s crystalline matrix.
    Źródło:
    Physicochemical Problems of Mineral Processing; 2018, 54, 4; 1117-1129
    1643-1049
    2084-4735
    Pojawia się w:
    Physicochemical Problems of Mineral Processing
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Response surface methodology (RSM) for optimization of chalcopyrite concentrate leaching with silver-coated pyrite
    Autorzy:
    Salehi, S.
    Noaparast, M.
    Shafaei, S. Z.
    Powiązania:
    https://bibliotekanauki.pl/articles/110894.pdf
    Data publikacji:
    2016
    Wydawca:
    Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
    Tematy:
    chalcopyrite
    copper extraction
    silver-coated pyrite
    optimization
    response surface methodology
    Opis:
    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.
    Źródło:
    Physicochemical Problems of Mineral Processing; 2016, 52, 2; 1023-1035
    1643-1049
    2084-4735
    Pojawia się w:
    Physicochemical Problems of Mineral Processing
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Study on surface modification of cerussite by thermochemical processing with pyrite
    Autorzy:
    Zheng, Yong-Xing
    Ning, Ji-Lai
    Xie, Haiyun
    Lv, Jin-Fang
    Hu, Pan-Jin
    Pang, Jie
    Powiązania:
    https://bibliotekanauki.pl/articles/1448573.pdf
    Data publikacji:
    2021
    Wydawca:
    Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
    Tematy:
    cerussite
    pyrite
    surface modification
    thermochemical processing
    flotation
    Opis:
    In this paper, surface modification of cerussite by thermochemical processing with pyrite was studied based on microflotation tests, X-ray powder diffractometry (XRD), X-ray photoelectron spectroscopy (XPS) and electron probe microanalysis (EPMA). Microflotation test results showed that the surface modification facilitated flotation of the treated cerussite and improved the flotation recovery to approximately 90%. The results of XRD analyses confirmed that cerussite was transformed into massicot, which then interacted with pyrite to form $PbS$, $PbSO_4$, $PbO•PbSO_4$ and $4PbO•PbSO_4$. XPS analyses results revealed that both $PbS$ and $PbS_2$ were formed on the mineral surface, and the percentage of $PbS$ increased with increasing $FeS_2$/$PbCO_3$ (F/P) mole ratio, which was advantageous for the flotation of the modified cerussite. EPMA analyses showed that particles with layered configurations were obviously formed after thermochemical processing. The thickness of the products at the outer layer of the particles increased when the F/P mole ratio increased. Moreover, the S and O contents in the products increased and decreased, respectively.
    Źródło:
    Physicochemical Problems of Mineral Processing; 2021, 57, 1; 156-167
    1643-1049
    2084-4735
    Pojawia się w:
    Physicochemical Problems of Mineral Processing
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Surface chemistry and flotation properties of galena and pyrite particles in the presence of xanthate- monothiophosphate- thiocarbamate collectors
    Autorzy:
    Ercelik, Gokhan
    Terzi, Mert
    Kursun, Ilgin
    Ozdemir, Orhan
    Powiązania:
    https://bibliotekanauki.pl/articles/24148622.pdf
    Data publikacji:
    2023
    Wydawca:
    Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
    Tematy:
    pyrite
    galena
    zeta potential
    bubble-particle attachment time
    micro-flotation
    Opis:
    In this study, surface chemistry and flotation properties of the gold-bearing galena and pyrite minerals of Menderes region, Izmir, Turkey were investigated with the use of xanthate-thiocarbamate-monothiophosphate collectors. In this context, the micro-flotation experiments, the zeta potential, and bubble-particle attachment time measurements were conducted in the presence of Thiophosphate (Aero S-8045), Xanthate (SIBX), and Thiocarbamate (Aero float MX-505) collectors. In the case of micro-flotation experiments, the MX-505 exhibited higher flotation efficiency for both minerals compared to SIBX and S-8045 collectors. In the micro-flotation tests conducted on galena and pyrite, while the flotation recovery of 99.82% and 81.96% were obtained with MX-505, the flotation recovery of 89.64% and 62.50% were reached in the case of using SIBX. Furthermore, the S-8045 resulted in the flotation recovery s of 75.09% and 25.45% for galena and pyrite, respectively. In the case of zeta potential experiments as a function of pH, the galena mineral showed a negative charge between -17.22 to -41.42 mV at pH 5 – 11, no point of zero charge (pzc) was determined, and the pzc of pyrite was determined as pH≈8. The bubble-particle attachment time experiments performed in the presence of S-8045, SIBX, and MX-505 collectors indicated that the attachment efficiency was 100% in the presence of MX-505 at 12.5-75 g/Mg dosages and 1-1000 ms contact times. These results revealed that there was an extraordinarily strong interaction between the galena/pyrite and the air bubbles in the presence of MX-505. The results obtained within this study indicated that galena and pyrite minerals showed inherently less than 25% natural floatability which can only be enhanced under specific conditions. The results obtained within this study indicated that galena and pyrite minerals showed inherently low natural floatability which can only be enhanced under specific conditions. In the tests conducted on these minerals, galena mineral showed higher than %20 natural floatability compared to pyrite mineral, and collectors produced from thiocarbamates have shown greater effectiveness compared to xanthate and thiophosphate.
    Źródło:
    Physicochemical Problems of Mineral Processing; 2023, 59, 5; art. no. 167947
    1643-1049
    2084-4735
    Pojawia się w:
    Physicochemical Problems of Mineral Processing
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
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