Temat: sphalerite - Prolib Integro

Skocz do pozycji: 1.

Tytuł:: Selective flotation separation of chalcopyrite and sphalerite by thermal pretreatment under air atmosphere
Autorzy:: Zhou, Hepeng
Geng, Liang
Zhang, Yongbing
Yang, Zhizhao
He, Kunzhong
Xie, Fanxin
Tematy:: thermal pretreatment
chalcopyrite
sphalerite
flotation
oxidation; Pokaż więcej
Wydawca:: Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Powiązania:: https://bibliotekanauki.pl/articles/1448899.pdf Link otwiera się w nowym oknie
Opis:: Thermal pretreatment was performed to enhance the flotation separation of chalcopyrite and sphalerite under the air atmosphere for the first time. Microflotation experiment showed that the floatability of chalcopyrite vanished after thermal pretreatment at above 170℃. By contrast, the floatability of sphalerite was well maintained with a flotation recovery of 90%. In artificial mixed mineral flotation experiments, the separation of sphalerite and chalcopyrite was successfully realized by thermal pretreatment. Results of Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy analyses indicated that the chalcopyrite surface was oxidized dramatically at 170℃, and hydrophilic species such as sulfate ($SO_4^{2-}$), oxides ($CuO$ and $Fe_2O_3$), and hydroxyl species ($Fe(OH)_3$) were formed on the surface. Hence, the adsorption of potassium butyl xanthate on chalcopyrite decreased significantly after thermal pretreatment. The reason for the higher oxidation speed of chalcopyrite than that of sphalerite was also analyzed.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 2.

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.
Tematy:: sphalerite
surface oxidation
minerals interaction
DFT; Pokaż więcej
Wydawca:: Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Powiązania:: https://bibliotekanauki.pl/articles/109553.pdf Link otwiera się w nowym oknie
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.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 3.

Tytuł:: Density functional theory study of H2O adsorption on different sphalerite surfaces
Autorzy:: Deng, Zheng-bin
Tong, Xiong
Huang, Ling-yun
Xie, Xian
Tematy:: density functional theory
sphalerite
water adsorption
hydrophobicity; Pokaż więcej
Wydawca:: Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Powiązania:: https://bibliotekanauki.pl/articles/110593.pdf Link otwiera się w nowym oknie
Opis:: Effects of In, Ge, Fe substitution in the lattice of sphalerite on wettability were usually ignored, therefore the optimal flotation condition could be difficult to find due to lacking of sufficient theoretical study on water adsorption, resulting lower recoveries of different sphalerites. Adsorption of H2O on different sphalerite surfaces was studied using density functional theory (DFT) method. All computational models were built in a vacuum environment to eliminate the effects of oxygen and other factors. H2O molecule prefers to stay with ideal sphalerite, indium-beard sphalerite, germanium-beard sphalerite and marmatite surfaces rather than water. Compared with ideal sphalerite surface, Fe atom improves the hydrophilicity of surface, while In and Ge atoms reduce the hydrophilicity.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 4.

Tytuł:: Potential ZnS fossilization of gastropods (Middle Jurassic claystones from Central Poland)
Autorzy:: Sawłowicz, Zbigniew
Szczepanik, Patrycja
Dostawca treści:: Repozytorium Uniwersytetu Jagiellońskiego

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Skocz do pozycji: 5.

Tytuł:: Quantifying the spreading factor to compare the wetting properties of minerals at molecular level – case study: sphalerite surface
Autorzy:: Mohseni, M.
Abdollahy, M.
Poursalehi, R.
Khalesi, M. R.
Tematy:: wettability
contact angle
molecular simulation
sphalerite
spreading factor; Pokaż więcej
Wydawca:: Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Powiązania:: https://bibliotekanauki.pl/articles/109377.pdf Link otwiera się w nowym oknie
Opis:: Spreading of water droplet on sphalerite surface was quantified at molecular level and was utilized for comparison of the wetting properties of sphalerite protonated and hydroxylated surfaces. Molecular dynamic simulations were used to characterize the wetting of sphalerite (110) plane. Experimental contact angles of water droplet on sphalerite surfaces were measured and the results were compared with simulated contact angles to ensure that the simulations are accurate enough for calculation of spreading factors. Shape descriptors such as perimeter, area, Feret’s diameters and circularity were used to characterize the shape of droplet-sphalerite interface at molecular level. Using the shape descriptors, different spreading factors were defined and calculated spreading factors were correlated with simulated contact angle. It was shown that spreading factors which were defined as the volume of water droplet divided by the area and Feret’s diameters, with correlation coefficient of 0.98 and 0.97, can be used as accurate tools for wetting comparison of functionalized sphalerite surface at molecular scale. Proposed approach also can be used for investigations on the effect of surface chemical and physical anisotropies on preferred wetting in specific direction at molecular scales.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 6.

Tytuł:: Zinc extraction from Ghazouat leach residues by using jarosite method
Autorzy:: Begar, Abdelhakim
Djeghlal, Mohamed El Amine
Ould Hamou, Malek
Tematy:: sphalerite
Zn
zinc
acid leaching
leaching residue
extraction; Pokaż więcej
Wydawca:: Politechnika Wrocławska. Wydział Geoinżynierii, Górnictwa i Geologii. Instytut Górnictwa
Powiązania:: https://bibliotekanauki.pl/articles/2016450.pdf Link otwiera się w nowym oknie
Opis:: In this paper, it was aimed to select and propose a feasible as well as an applicable method, for the extraction of zinc that was present in the disposed GHAZOUAT leach residues having 17.82 wt. % Zn and 20.82 wt. % Fe. After the determination of the components of the residue, the acid leaching was performed to reclaim Zn sequentially. The acid leaching experiments were carried out for Zn extraction by controlling acid concentration, reaction duration and temperature. At the optimum conditions, 240 g/L H2SO4 at 90 °C for 210 min, 80% of initial iron content was removed, and the resultant overall zinc extraction was usually superior than 96%.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 7.

Tytuł:: Copper adsorption reaction rate and ion exchange ratio during the copper activation of sphalerite
Autorzy:: Liu, J.
Luo, D.
Huang, L.
Wang, Y.
Wen, S.
Tematy:: sphalerite
copper activation
solution chemistry
ion exchange ratio
reaction rate; Pokaż więcej
Wydawca:: Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Powiązania:: https://bibliotekanauki.pl/articles/110651.pdf Link otwiera się w nowym oknie
Opis:: A theoretical analysis method of the solution chemistry characteristic of Cu(II) at various pH values was developed. Using such method, the existence form of Cu species and their proportions in aqueous solution can be clearly determined. After that, the copper adsorption and ion exchange ratio (E) during the copper activation of sphalerite were investigated. The results indicated that the copper activation of sphalerite can be divided into two stages, i.e., the fast activation stage (t ≤4 min) and slow activation stage (t >4 min). The general form of the copper adsorption rate was determined as ΓCu=K1ln(t) +Γ1, which is confirmed by the data fitting of the fast activation stage. The lower activation pH results in higher ion exchange efficiency for Cu substituting Zn. For a strong acid pH of 4.1, the E maintains about 1:1 in the entire activation time range and is not dependent on the activation time. However, the value of E is greater than 1 under weak acidic (pH=6.2) and alkaline (pH=9.1) pH conditions and it significantly depends on the activation time. For such conditions, E decreases with increase in the activation time, which supports the ion exchange mechanism, but within short activation time, it is not a 1:1 ion exchange process.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 8.

Tytuł:: Study of process water effect on the activation of sphalerite during differential flotation of Pb-Cu-Zn
Autorzy:: Gutiérrez Pérez, Victor Hugo
Olvera Vázquez, Seydy Lizbeth
Santos Madrid, Rocio
Regino Piña, Rafael
Cruz Ramírez, Alejandro
Rivera Salinas, Jorge Enrique
Alaniz Hernández, Daniel Israel
Tematy:: sphalerite activation
process water
differential flotation
copper ions
lead ions; Pokaż więcej
Wydawca:: Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Powiązania:: https://bibliotekanauki.pl/articles/2146897.pdf Link otwiera się w nowym oknie
Opis:: This work was aimed to analyze the effect of concentration of Cu.2+ and Pb.2+ ions in flotation process water with sphalerite activation, the analysis was performed at Cozamin Mining flotation circuit. This analysis demonstrated that (i) it was possible to determine the relationship between Sodium Cyanide and Ammonium Bisulfite used as depressants and Cu.2+ and Pb.2+ contents in the process water. (ii) It also proved the relationship between lead and iron content in the head with the Pb.2+ ions in process water. According to the data gathered and analysis performed, (iii) it was also determined that it was possible to reuse process water as long as the use of Ammonium Bisulfite was reduced and recommended replacing the use of Sodium Cyanide with Zinc Sulfate (ZnSO4) as a depressant of Sphalerite. Additionally, the concentration of Cu.2+ and Pb.2+ ions in the water should be controlled in a range of 10 to 20 ppm and 0.10 to 0.20 ppm, respectively.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 9.

Tytuł:: Pressure acid leaching of sphalerite concentrate. Modeling and optimization by response surface methodology
Autorzy:: Guler, E.
Tematy:: pressure leaching
sphalerite concentrate
optimization
response surface methodology
central composite rotatable design; Pokaż więcej
Wydawca:: Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Powiązania:: https://bibliotekanauki.pl/articles/110475.pdf Link otwiera się w nowym oknie
Opis:: The zinc leaching from sphalerite concentrate using oxygen under pressure in sulfuric acid solution was primarily studied and evaluated. The effects of important leaching parameters such as oxygen partial pressure, temperature, solid/liquid ratio and leaching time on leaching efficiency, Zn concentration and Fe extraction were investigated. Response surface methodology based on central composite rotatable design technique was used to optimize the leaching process parameters in order to obtain a suitable leach solution with high Zn leaching efficiency considering further processes such as precipitation of contaminating metal ions and electrolysis. The optimum leaching condition for maximum Zn leaching efficiency and Zn concentration with minimum Fe extraction was determined as follows: oxygen partial pressure of 12 bars, temperature of 150 °C, solid/liquid ratio of 0.20 and leaching time of 89.16 minutes. The achieved experimental results for Zn leaching efficiency, Zn concentration and Fe extraction under the optimum conditions were as 94%, 80 g/dm3 and 8.1% respectively. The experimental results corresponded well with the predicted results of quadratic polynomial models.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 10.

Tytuł:: Effect of organic matter on the color of sphalerite from the Silesia-Cracow lead-zinc deposits, Poland
Autorzy:: Rybicki, M.
Tematy:: chromatografia gazowa
barwa
próbka
organic matter
color
sphalerite
Silesia
Cracow
GC-MS method; Pokaż więcej
Wydawca:: Uniwersytet Śląski. Wydział Nauk o Ziemi
Powiązania:: https://bibliotekanauki.pl/articles/100769.pdf Link otwiera się w nowym oknie
Opis:: Using gas chromatography-mass spectrometry (GC-MS) sphalerite samples from lead and zinc mines of the Silesian-Cracow region were studied in terms of the effect of organic matter on their coloration. The results indicate no correlation between the abundance and chemical composition of organic matter and sphalerite coloration. TOC values for investigated samples are in the range of 0.5-1.28%. A basic feature characterizing all samples is very similar distribution of n-alkanes, with a predominance of short-chain n-alkanes (from n-C13 to n-C21) over long-chain n-alkanes (from n-C25 to n-C35). Among the isoprenoids pristane dominates over phytane (Pr/Ph ratio in one sample is even 8.95), which does not correspond to previous studies (Karwowski et al. 2001) and may be due to the multi-source nature of organic matter present in sphalerite inclusions from the Silesian-Cracow Zn-Pb deposits. The occurrence of hopanes with 17β,21β(H) stereochemistry indicates a low maturity of test samples.
Przy zastosowaniu chromatografii gazowej sprzężonej ze spektrometrią mas (GC-MS) zbadano próbki sfalerytu z kopalń cynku i ołowiu regionu śląsko-krakowskiego pod kątem wpływu materii organicznej na ich barwę. Otrzymane wyniki wskazują na brak korelacji między ilością oraz składem chemicznym materii organicznej a barwą sfalerytu. Wartości TOC dla badanych próbek mieszczą się w przedziale 0.5-1.28%. Charakterystyczną cechą wszystkich próbek jest bardzo zbliżona dystrybucja nalkanów, z wyraźną przewagą n-alkanów krótkołańcuchowych (od n-C13 do n-C21) nad długołańcuchowymi. Wśród izoprenoidów pristan dominuje nad fitanem (stosunek Pr/Ph w jednej próbce wynosi nawet 8.95), co nie odpowiada wynikom poprzednich badań (Karwowski et al. 2001) i może być spowodowane wieloźródłowym charakterem inkluzji materii organicznej w sfalerytach ze śląsko-krakowskich złóż Zn-Pb. Obecność hopanów o strukturze 17β,21β(H) wskazuje na bardzo niską dojrzałość termiczną badanych próbek.
Dostawca treści:: Biblioteka Nauki

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