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Wyszukujesz frazę "molybdenite" wg kryterium: Wszystkie pola

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    Wyświetlanie 1-15 z 15
    Tytuł:
    Flotation of molybdenite in the presence of microemulsified collector
    Autorzy:
    You, X.
    Li, L.
    Lyu, X.
    Powiązania:
    https://bibliotekanauki.pl/articles/109765.pdf
    Data publikacji:
    2017
    Wydawca:
    Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
    Tematy:
    molybdenite
    flotation
    microemulsified collector
    diesel
    Opis:
    In this paper molybdenite flotation using microemulsified collector was reported. The flotation performance of microemulsified collector and conventional diesel was compared. This study is a prelimi-nary investigation which uses pure molybdenite mineral in a modified Hallimond tube. The pH tests showed that the highest recovery of molybdenite in the presence of diesel and microemulsion was ob-tained at pH=6, reaching the recoveries of 93% and 90%, respectively. In the case of obtaining similar results, it was observed that the microemulsion consumption was lower in comparison to diesel. In the flotation tests with microemulsified collector the recovery slightly decreased because too large collector amount caused formation of more unstable bubbles. The contact angle measurements showed that the microemulsified collector was more effective for increasing the hydrophobicity of molybdenite surface. An adsorption model was proposed and it was suggested that the non-ionic surfactant present in the mi-croemulsified collector formed a continuous bimolecular layer, resulting in the increased surface hydro-phobicity. The accomplishment of this research demonstrated the viability of the use of microemulsified collector in molybdenite flotation, attempting to simplify the molybdenite flotation process, especially replace the conventional emulsified collector with high energy consumption and difficult storage.
    Źródło:
    Physicochemical Problems of Mineral Processing; 2017, 53, 1; 333-341
    1643-1049
    2084-4735
    Pojawia się w:
    Physicochemical Problems of Mineral Processing
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Kinetics of hydrophobic agglomeration of molybdenite fines in aqueous suspensions
    Autorzy:
    Yang, B.
    Song, S.
    Lopez-Valdivieso, A.
    Powiązania:
    https://bibliotekanauki.pl/articles/110890.pdf
    Data publikacji:
    2015
    Wydawca:
    Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
    Tematy:
    agglomeration rate
    molybdenite fines
    hydrophobic agglomeration
    Opis:
    The kinetics of hydrophobic agglomeration of molybdenite fines in aqueous suspensions has been studied in this work. This study was performed on minus 5 μm molybdenite particles through turbid-ity measurements and imaging. The results have showed that stirring strength and kerosene addition greatly affected the agglomeration rate of molybdenite fines in aqueous suspensions. The higher was the stirring strength, the larger the agglomeration rate was. Kerosene addition enhanced not only the agglom-eration rate, but also the agglomerates structure. It was recommended to use radial impeller for the for-mation of hydrophobic agglomeration, because it produced a stronger shear field in impeller zone.
    Źródło:
    Physicochemical Problems of Mineral Processing; 2015, 51, 1; 181-189
    1643-1049
    2084-4735
    Pojawia się w:
    Physicochemical Problems of Mineral Processing
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Influencing mechanisms of sodium hexametaphosphate on molybdenite flotation using sea water
    Autorzy:
    Wang, Lizhangzheng
    Li, Yubiao
    Fan, Ruihua
    Fan, Rong
    Powiązania:
    https://bibliotekanauki.pl/articles/109351.pdf
    Data publikacji:
    2019
    Wydawca:
    Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
    Tematy:
    sodium hexametaphosphate
    flotation
    molybdenite
    sea water
    mechanism
    Opis:
    Flotation using sea water has been considered as a promising alternative to concentrate molybdenite (MoS2) under alkaline conditions due to scarcity of fresh water and increasingly strict regulations on the quality of discharged water. However, the MoS2 recovery with sea water during flotation has not been satisfactory, owing to the depressing effects from the hydrophilic metallic species onto MoS2 surface. This study combines experimental and theoretical studies of MoS2 flotation to investigate how the physicochemical properties of MoS2 vary with the addition of a dispersant, sodium hexametaphosphate (SHMP), and in sea and fresh water. Our experimental results show that the addition of SHMP during flotation has increased the recovery of MoS2, via reducing the adsorption of the hydrophilic metallic precipitation onto MoS2 surface. The DLVO calculation confirms that the addition of SHMP increases the floatability of MoS2 by dispersing the formed hydrophilic metallic precipitation (Mg(OH)2 colloids) from the MoS2 surface, via reversing attraction force to repulsion force, thereby improving MoS2 flotation recovery.
    Źródło:
    Physicochemical Problems of Mineral Processing; 2019, 55, 5; 1091-1098
    1643-1049
    2084-4735
    Pojawia się w:
    Physicochemical Problems of Mineral Processing
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Mechanism and leaching kinetics of molybdenite concentrate in a hydrogen peroxide-acid system
    Autorzy:
    Aracena, Alvaro
    Azocar, Alan
    Ibáñez, Juan Patricio
    Jerez, Oscar
    Powiązania:
    https://bibliotekanauki.pl/articles/110193.pdf
    Data publikacji:
    2019
    Wydawca:
    Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
    Tematy:
    molybdenite concentrate
    hydrogen peroxide
    kinetics
    mechanism of reaction
    Opis:
    The mechanism and leaching kinetics of a molybdenite concentrate in a H2O2-H2SO4 system were studied. The experimental work was performed in a batch reactor equipped with a condenser, a mechanical agitator and a temperature control system. The effects of the temperature, H2O2 and H2SO4 concentrations, particle size, liquid/solid ratio and agitation speed on the Mo recovery were investigated. The thermodynamic results showed that the leaching mechanism it was governed by several intermediate reactions; however, the influences of sulfuric acid and passivation were not observed in the reaction. The most predominant experimental result was the maximum Mo recovery of 81.3% by leaching 64 μm particles at 333 K (60 °C) for 5400 s (90 min). The molybdenum recovery was generally enhanced by increasing the H2O2 and H2SO4 concentrations. However, at H2SO4 concentrations higher than 1.0 mol/dm3, the Mo recovery decreased. Although the agitation speed affected the Mo recovery considerably, high recoveries could be still obtained without mixing. The experimental results and XRD analysis confirmed the reaction mechanisms. The leaching kinetics were analyzed using a shrinking core model in which the rate was controlled by diffusion through a porous layer with radius ro. The reaction rate orders were 1.0 and 0.2 for the H2O2 and H2SO4 concentrations, respectively, and the rate was inversely proportional to the square of the initial particle radius. The calculated activation energy was 75.2 kJ/mol in the temperature range of 278-333 K (5-60 °C).
    Źródło:
    Physicochemical Problems of Mineral Processing; 2019, 55, 1; 140-152
    1643-1049
    2084-4735
    Pojawia się w:
    Physicochemical Problems of Mineral Processing
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Study on flotation behavior and mechanism of separating chalcopyrite and Molybdenite with ethyl mercaptoglycolate as inhibitor
    Autorzy:
    Yang, Xiao-Feng
    Xu-Zhao
    Liu, Yao-Yao
    Powiązania:
    https://bibliotekanauki.pl/articles/24085868.pdf
    Data publikacji:
    2023
    Wydawca:
    Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
    Tematy:
    ethyl thioglycolate
    chalcopyrite
    molybdenite
    inhibitor
    separation
    Opis:
    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.
    Źródło:
    Physicochemical Problems of Mineral Processing; 2023, 59, 2; art. no. 162824
    1643-1049
    2084-4735
    Pojawia się w:
    Physicochemical Problems of Mineral Processing
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Application of superconducting magnetic separation to an artificial mixture of chalcopyrite and molybdenite
    Autorzy:
    Li, Daokui
    Kou, Jue
    Sun, Chunbao
    Yu, Baoqiang
    Wang, Chao
    Powiązania:
    https://bibliotekanauki.pl/articles/110786.pdf
    Data publikacji:
    2019
    Wydawca:
    Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
    Tematy:
    magnetic matrices
    superconducting magnetic separation
    buildup behavior
    chalcopyrite and molybdenite separation
    Opis:
    Superconducting magnetic separation of chalcopyrite and molybdenite was studied, along with the effects of the magnetic flux density, slurry concentration, and pulsation amplitude on the separation. According to the force equilibrium model of magnetic particles that accumulated on magnetic matrices during the superconducting magnetic separation, the saturated buildup of magnetic particles was calculated. The saturated buildup of magnetic particles was an approximate fan ring and had a positive correlation with the background magnetic flux density. Superconducting magnetic separation tests results showed that a Mo concentrate with a Mo grade of 31.86% and recovery of 87.24% and a Cu concentrate with a Cu grade of 30.57% and recovery of 94.76% could be obtained. This verified the feasibility of separating mixed Cu and Mo minerals via superconducting magnetic separation.
    Źródło:
    Physicochemical Problems of Mineral Processing; 2019, 55, 3; 597-604
    1643-1049
    2084-4735
    Pojawia się w:
    Physicochemical Problems of Mineral Processing
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Research on optimization method of flotation kinetic model based on molybdenite particle size effect
    Autorzy:
    Wan, He
    An, Yanni
    Qu, Juanping
    Zhang, Chonghui
    Xue, Jiwei
    Wang, Sen
    Bu, Xianzhong
    Powiązania:
    https://bibliotekanauki.pl/articles/24085892.pdf
    Data publikacji:
    2023
    Wydawca:
    Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
    Tematy:
    particle size effect
    molybdenite
    mathematical model
    method of correction
    Opis:
    Flotation kinetic models can be applied to describe the flotation process and to predict mineral recoveries. However, the size composition of the target minerals in the feed ore fluctuates considerably, resulting in insufficient accuracy with flotation kinetic models. There have been many studies that focus on the investigation of flotation kinetics with different particle sizes, while the optimization methods for flotation kinetic models based on particle size effects have not been reported. In this paper, flotation tests, optical microscope observations, and particle size analysis were used to identify the reasons for the decrease in accuracy of the flotation kinetic model due to changes in the composition of molybdenite particle size. Additionally, an optimization method for the flotation kinetic model was developed based on the particle size effect. The test results show that the accuracy of the flotation kinetic model for fixed particle size minerals is very high, but the predicted results for flotation recoveries of different particle size mineral mixtures have large deviations. The poor accuracy might be due to the autogenous carrier effect caused by the particle size composition fluctuating considerably. The optimization method for the flotation kinetic model is based on the particle size effect. The model can accurately describe the flotation process of molybdenite with different size compositions of molybdenite and predict the flotation recovery of molybdenite.
    Źródło:
    Physicochemical Problems of Mineral Processing; 2023, 59, 2; art. no. 163004
    1643-1049
    2084-4735
    Pojawia się w:
    Physicochemical Problems of Mineral Processing
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Physico-chemical factors in flotation of Cu-Mo-Fe ores with seawater: a critical review
    Autorzy:
    Castro, S.
    Powiązania:
    https://bibliotekanauki.pl/articles/109447.pdf
    Data publikacji:
    2018
    Wydawca:
    Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
    Tematy:
    pyrite
    chalcopyrite
    molybdenite
    Seawater flotation
    Metabisulfite
    Opis:
    This paper aims to provide a comprehensive review on the physico-chemical factors governing the flotation of Cu-Mo-Fe sulfide ores in seawater, which is different from NaCl or KCl solutions because it contains hydrolysable ions such as Mg2+, Ca2+, HCO3-, CO32-, etc., which can precipitate with lime as hydroxides, Ca, and Mg insoluble salts. Under pH 9.0 Mg2+ ions do not depress molybdenite. However, over the critical pH of precipitation of Mg(OH)2 (pH>10.0), molybdenite is strongly depressed in seawater. This detrimental effect on molybdenite discards the use of lime to depress pyrite in Cu-Mo-Fe ores floated in seawater. In plant practice, the use of sodium metabisulfite (MBS) has replaced lime as a pyrite depressant. It works at pH 6.5-7.0 where the natural floatability of molybdenite is enhanced. Consequently, pH control in rougher and cleaning circuits, and the use of MBS to depress pyrite, have allowed the successful use of non-desalinated seawater in flotation of Cu-Mo-Fe sulfide ores at industrial scale.
    Źródło:
    Physicochemical Problems of Mineral Processing; 2018, 54, 4; 1223-1236
    1643-1049
    2084-4735
    Pojawia się w:
    Physicochemical Problems of Mineral Processing
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Investigation of effective parameters for molybdenite recovery from porphyry copper ores in industrial flotation circuit
    Autorzy:
    Nakhaei, F.
    Irannajad, M.
    Powiązania:
    https://bibliotekanauki.pl/articles/110240.pdf
    Data publikacji:
    2014
    Wydawca:
    Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
    Tematy:
    flotation
    copper
    molybdenum
    recovery
    Opis:
    The Sarcheshmeh copper mine is a significant copper and molybdenum producer. Sampling of the Sarcheshmeh flotation circuit (in a six-month period) showed that a large share of waste of molybdenite took place in rougher cells. Since the rougher cells tailing is transferred to tailing thickener, the main focus of this paper was on this section. In the current study, the factors which influence the recovery of molybdenite and copper were investigated. Molybdenite recovery in the bulk flotation circuit was consistently lower than that of the copper sulphides as well as being far more variable. This paper describes the methodically use of size by size recovery data, quantitative mineralogy, and liberation degree analysis to identify the factors contributing to molybdenite recovery relative to copper in industrial rougher circuit. The results showed that the size by size recovery for both metals in the ultrafine and coarse fractions recovery was reduced. On the other hand, the highest recovery occurred in the intermediate sizes from 27 μm to 55 μm. Molybdenum recovery in the fine and ultrafine and coarse fractions drops off to a greater extent than the recovery of copper. The investigations of degree liberation showed that the recovery of copper sulphides is more dependent on the liberation state of valuable minerals while for molybdenite some other factor splay a significant role.
    Źródło:
    Physicochemical Problems of Mineral Processing; 2014, 50, 2; 477-491
    1643-1049
    2084-4735
    Pojawia się w:
    Physicochemical Problems of Mineral Processing
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Effect of sodium sulfide waste water recycling on the separation of chalcopyrite and molybdenite
    Autorzy:
    Wu, D.
    Peng, H.
    Abdalla, M.
    Powiązania:
    https://bibliotekanauki.pl/articles/110657.pdf
    Data publikacji:
    2018
    Wydawca:
    Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
    Tematy:
    vanadium slag
    low pressure leaching
    liquid phase oxidation
    kinetics
    Opis:
    The effect of sodium sulfide waste water recycling on the separation of chalcopyrite and molybdenite was investigated in this work. The waste water, which was separated from the slurry after selective flotation, was recycled in the flotation system. This operation significantly improved the subsequent flotation of chalcopyrite and saved the reagent. The results showed that the depression efficiency of sodium sulfide gradually disappeared in the recycling tests due to the consumption. The consumption of sodium sulfide in the separation was not only caused by the adsorption on mineral surfaces but also resulted from the precipitation of metal ions which released from minerals. These effects decreased the solution reducibility and the adsorption of hydrosulfide ions, finally resulting in the less depression for chalcopyrite flotation. After adding a certain amount of sodium sulfide to the recycling, the depression of chalcopyrite performed well and the pulp potential maintained at a relatively lower level. Moreover, the pulp potential was an available parameter to control the flotation separation of chalcopyrite and molybdenite, which made the method easily applied to industry.
    Źródło:
    Physicochemical Problems of Mineral Processing; 2018, 54, 3; 629-638
    1643-1049
    2084-4735
    Pojawia się w:
    Physicochemical Problems of Mineral Processing
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Insights into the depression effect and adsorption mechanism of HACC on chalcopyrite surface in Cu-Mo flotation separation
    Autorzy:
    Li, Mingyang
    Zhang, Pengpeng
    Xiangpeng, Gao
    Huang, Lingyun
    Powiązania:
    https://bibliotekanauki.pl/articles/27323662.pdf
    Data publikacji:
    2023
    Wydawca:
    Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
    Tematy:
    chalcopyrite
    molybdenite
    flotation
    adsorption
    depressant
    Opis:
    In this study, hydroxypropyltrimethyl ammonium chloride chitosan (HACC) was first introduced as a depressant during separating chalcopyrite from molybdenite (Cu-Mo). The selective effects of HACC on the separation of Cu-Mo were conducted by single-mineral flotation experiments. The findings from this study revealed that HACC helped separate Cu and Mo efficiently at pH 6 with 8 mg/dm3 of HACC, resulting in 76.22% and 5.38% of Mo and Cu flotation recovery, respectively. The adsorption mechanism of HACC was investigated via zeta potential, adsorption density, and contact angle measurement along with FT-IR and XPS analyses. The contact angle and adsorption density measurements offer indisputable proof that HACC can adsorb on the surface of chalcopyrite. Furthermore, FT-IR and XPS analyses confirm that N atoms in quaternary ammonium groups of HACC interact with Cu sites on the surface of chalcopyrite. The findings also suggest that HACC adsorbs on the surface without significantly impacting molybdenite. All these results confirm that HACC can be an effective chalcopyrite depressant.
    Źródło:
    Physicochemical Problems of Mineral Processing; 2023, 59, 6; art. no. 172481
    1643-1049
    2084-4735
    Pojawia się w:
    Physicochemical Problems of Mineral Processing
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Effect of seawater main components on frothability in the flotation of Cu-Mo sulfide ore
    Autorzy:
    Laskowski, J. S.
    Castro, S.
    Ramos, O.
    Powiązania:
    https://bibliotekanauki.pl/articles/109747.pdf
    Data publikacji:
    2014
    Wydawca:
    Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
    Tematy:
    seawater
    froth stability
    Cu-Mo flotation
    magnesium ions
    molybdenite flotation
    Opis:
    The main problem in the flotation of Cu-Mo sulfide ores in seawater is poor floatability of molybdenite at pH>9.5. Froth stability plays a very important role in determining concentrate grade and recovery in flotation operations and in this paper both floatability and frothability have been tested. The frothability have been studied by measuring froth equilibrium layer thickness in a modified laboratory flotation cell. Two chemical aspects of seawater need to be considered: the content of NaCl (around 87% of salinity), and the concentration of secondary ions (around 13%) (sulfate, magnesium, calcium, bicarbonate ions, etc.). Seawater, NaCl solutions, and seawater’s ions were found to depress frothability. The effect of pH on frothability over the pH range from 9.5 to 11, which is very strong in freshwater, becomes negligible in seawater and the tested electrolyte solutions. The analysis of the relationship between the mechanisms of molybdenite depression and the loss of frothability in seawater implies that the effects of the studied ions on molybdenite floatability and on pulp frothability are different. While depression of molybdenite floatability could be tracked down to magnesium hydroxide precipitation as a main culprit, the depression of frothability is a much more complicated issue.
    Źródło:
    Physicochemical Problems of Mineral Processing; 2014, 50, 1; 17-29
    1643-1049
    2084-4735
    Pojawia się w:
    Physicochemical Problems of Mineral Processing
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Isotopic Re-Os age of molybdenite from the Szklarska Poręba Huta Quarry (Karkonosze, SW Poland)
    Autorzy:
    Mayer, W.
    Creaser, R. A.
    Mochnacka, K.
    Oberc-Dziedzic, T.
    Pieczka, A.
    Powiązania:
    https://bibliotekanauki.pl/articles/2059392.pdf
    Data publikacji:
    2012
    Wydawca:
    Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
    Tematy:
    Karkonosze granite
    hydrothermal mineralisation
    Re/Os isotopic age
    Opis:
    New Re/Os isotopic data for molybdenite from the Szklarska Poręba Huta Quarry provide ages of 307 ± 2 Ma and 309 ± 2 Ma, respectively. The quarry is dominated by the porphyritic (“central”) and equigranular (“ridge”) varieties of the Karkonosze granite. Ore mineralisation hosted in aplogranite includes an assemblage of sulphides, sulphosalts, oxides and various rare phases. The molybdenite ages obtained are consistent with a previously published isotopic age of leucogranite (aplogranite?) from the same quarry and are only slightly older than a recently published, refined 2 6Pb/238U age of untreated zircons from the Szklarska Poręba Huta porphyritic granite. The age of the molybdenite corresponds moderately well to the younger stage of post-magmatic, pneumatolitic/hydrothermal activity of the Karkonosze granite (about 312 Ma).
    Źródło:
    Geological Quarterly; 2012, 56, 3; 505--512
    1641-7291
    Pojawia się w:
    Geological Quarterly
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Rhenium abundance in molybdenites : a case study on vein-type Cu-Mo-Au mineralisation in the Qarachilar area, Sungun porphyry Cu and Siah Kamar porphyry Mo deposits, NW Iran
    Autorzy:
    Simmonds, Vartan
    Mathur, Ryan
    Selby, David
    Powiązania:
    https://bibliotekanauki.pl/articles/2058578.pdf
    Data publikacji:
    2019
    Wydawca:
    Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
    Tematy:
    Qarachilar
    Sungun
    Siah Kamar
    Qaradagh Batholith
    molybdenite
    Re content
    Opis:
    The vein-type Cu-Mo-Au mineralisation in Qarachilar, the Sungun porphyry Cu deposit (PCD) and the Siah Kamar porphyry Mo deposit (PMD) are all located at the northwestern end of the Neo Tethys-related Urumieh-Dokhtar volcano-plutonic belt of Iran. Re contents of moIybdenite samples from the Qarachilar, Sungun and Siah Kamar deposits are about 112.67-462 ppm, 53.24-252.29 ppm, and 10.44-41.05 ppm, respectively. Re contents of the first two deposits fall in the range of PCDs, while those of the latter are lower and correspond to PMDs. The relatively high Re content of the Qarachilar and Sungun molybdenites can be explained considering the low abundance of molybdenite, a mantle-dominated source for ore materials and the incorporation of oxidized and acidic hydrothermal fluids with high fCl. The high abundance of molybdenite in the Siah Kamar PMD has resulted in volume dilution of Re. Furthermore, occurrence of the main ore within the potassic alteration zone and, hence, the alkaline nature of the responsible fluids in this zone have also affected the Re content of molybdenites. Variations of the Re content in different veins/veinlets showed a negative relationship with the formation temperature of these veins, and a positive/negative relationship with the acidity/alkalinity of the hydrothermal fluids, while the grain size of molybdenites showed a positive relationship.
    Źródło:
    Geological Quarterly; 2019, 63, 3; 478--492
    1641-7291
    Pojawia się w:
    Geological Quarterly
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Wiek molibdenitów w Polsce w świetle badań izotopowych Re-Os
    The age of molybdenites in Poland in the light of Re-Os isotopic studies
    Autorzy:
    Mikulski, S.Z.
    Stein, H.J.
    Powiązania:
    https://bibliotekanauki.pl/articles/2062033.pdf
    Data publikacji:
    2012
    Wydawca:
    Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
    Tematy:
    wiek izotopowy Re–Os
    molibdenit
    procesy pomagmowe
    granitoidy
    waryscydy
    Karkonosze
    masyw Strzegom-Sobótka
    Sudety
    blok przedsudecki
    blok małopolski
    blok górnośląski
    Tatry
    Re-Os isotope age
    molybdenite
    post-magmatic processes
    Variscides
    granitoids
    Karkonosze Massif
    Strzegom-Sobótka Massif
    Sudetes
    Fore-Sudetic Block
    Małopolska Block
    Upper Silesian Block
    Tatra Mts.
    Opis:
    W artykule przedstawiono wyniki datowań metodą Re–Os wieku molibdenitów związanych z waryscyjskimi intruzjami granitoidowymi w Polsce. W masywie karkonoskim oraz w jego wschodniej osłonie metamorficznej stwierdzono dwa etapy krystalizacji molibdenitów (od 326 ±1 do 310 ±1 mln lat), które odzwierciedlają aktywność pneumatolityczną i hydrotermalną w okresie karbońskim od wizenu/ serpuchowu do moskowu. W masywie Strzegom–Sobótka zarówno molibdenity rozetkowe występujące w formie impregnacji w granitach, jak i molibdenity w przecinających je żyłkach kwarcowych wykazują zbliżony wiek (od 309 ±1 do 296 ±2 mln lat). Krystalizacja molibdenitów w tym masywie była pochodną procesów pomagmowych związanych z powolnym stygnięciem magm odpowiedzialnych za powstanie monzogranitów hornblendowo-biotytowych. Zakres wiekowy krystalizacji molibdenitów ze strefy kontaktu bloku małopolskiego z blokiem górnośląskim mieści się w czasie od 301 ±2 do 296,3 ±1,4 mln lat. Najstarszy wiek izotopowy Re–Os krystalizacji wśród zbadanych dotychczas molibdenitów uzyskano dla próbki molibdenitu pochodzącej z Tatr – 350,5 ±1,2 mln lat. Z kolei najmłodsze wieki krystalizacji molibdenitów stwierdzono w próbkach z kamieniołomu w Siedlimowicach (257 ±1 mln lat) oraz w Miedziance (213 ±1 mln lat). Wieki te wskazują na procesy kataklazy i remobilizacji roztworów hydrotermalnych w młodszych okresach, tj. w późnym permie i triasie. Wyniki badań izotopowych molibdenitów pozwoliły określić relacje czasowe pomiędzy poszczególnymi hydrotermalnymi etapami krystalizacji kruszców i procesami magmowo-tektonicznymi w czasie ok. 140 mln lat, tj. od missisipu (karbon) do noryku (późny trias) w różnych obszarach wystąpień waryscyjskich intruzji granitoidowych w Polsce.
    The paper presents the results of molybdenites that closely correlate with the Variscan granite intrusions in Poland. In the Karkonosze Massif and its eastern metamorphic cover, there are two separate stages of Re-Os ages of molybdenite crystallization (326 ±1 to 310 ±1 Ma), which reflect pneumatolitic and hydrothermal activity in the Carboniferous (from the Visean/Serpukhovian to the Moscovian). In the Strzegom–Sobótka Massif, both rosette-like molybdenites disseminated in granitoids and those from the quartz veinlets reveal similar Re-Os ages that range from 309 ±1 to 296 ±2 Ma. Molybdenite crystallization in the Strzegom–Sobótka Massif was related to the post-magmatic processes associated with a slow cooling of magma responsible for the formation of hornblende-biotite monzogranites. The time range of molybdenites crystallization form the contact zone between the Małopolska and Upper Silesian blocks is from 301 ±2 to 296.3 ±1.4 Ma. The oldest Re-Os isotopic age of molybdenite (350.5 ±1.2 Ma) was received for a molybdenite sample from the Polish part of the Tatra Mountains. The molybdenites from the eastern part of the Strzegom–Sobótka Massif (Siedlimowice quarry, 257 ±1 Ma) and from the Miedzianka abandoned Cu (-U) mine (213 ±1 Ma) yielded the youngest Re-Os ages. These ages indicate tectonic reactivation and remobilization of hydrothermal fluids in the Late Permian and Late Triassic. The Re-Os isotopic studies of molybdenites allowed defining the time relation between successive hydrothermal stages of ore precipitation and tectonic-magmatic processes during ca. 140 million years e.g. from the Mississippian (Carboniferous) to the Norian (Late Triassic) in different areas of the occurrence of Variscan granitoid intrusions in Poland.
    Źródło:
    Biuletyn Państwowego Instytutu Geologicznego; 2012, 452; 199--216
    0867-6143
    Pojawia się w:
    Biuletyn Państwowego Instytutu Geologicznego
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
      Wyświetlanie 1-15 z 15

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