scholarly journals Rare-Metal (In, Bi, Te, Se, Be) Mineralization of Skarn Ores in the Pitkäranta Mining District, Ladoga Karelia, Russia

Minerals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 124
Author(s):  
Vasily I. Ivashchenko
Keyword(s):  
Solid Solution ◽  
Low Temperatures ◽  
Rare Metal ◽  
Mining District ◽  
Hydrothermal Solutions ◽  
Rapakivi Granite ◽  
Ore Mineralization ◽  
Skarn Deposits ◽  
Electron Microanalysis ◽  
End Members

The results of the study of rare-metal (Bi, Te, Se. Be, In) mineralization of skarn deposits (Sn, Zn) in the Pitkäranta Mining District, genetically related to the Salmi anorthosite-rapakivi granite batholiths of Early Riphean age are reported. Minerals and their chemical composition were identified on the base of optical microscopy as well as electron microanalysis. The diversity of rare-metal ore mineralization (native metals, oxides, and hydroxides, carbonates, tellurides, selenides, sulfides, sulphosalts, borates, and silicates) in Pitkäranta Mining District ores is indicative of considerable variations in the physicochemical conditions of their formation controlled by the discrete-pulse-like supply of fluids. Bismuth, wittichenite, and matildite are the most common rare-metal minerals. Sulfosalts of the bismuthinite-aikinite series are represented only by its end-members. The absence of solid solution exsolution structures in sulfobismuthides suggests that they crystallized from hydrothermal solutions at low temperatures. Be (>10 minerals) and In (roquesite) minerals occur mainly in aposkarn greisens. Roquesite in Pitkäranta Mining District ores formed upon greisen alteration of skarns with In released upon the alteration of In-bearing solid sphalerite (Cu1+ In3+) ↔ (Zn2+, Fe2+) and chalcopyrite In3+ ↔ Fe3+ and 2Fe3+ ↔ (Fe2+, Zn2+) Sn4+ solutions. Sphalerite with an average In concentration of 2001 ppm, is a major In-bearing mineral in the ores.

scholarly journals REE-bearing minerals in the Rapakavi Grante, Southern Finland

2015 ◽  
Vol 7 (1) ◽  
Author(s):  
Thair Al-Ani
Keyword(s):  
Solid Solution ◽  
Electron Probe ◽  
Granitic Magma ◽  
Accessory Mineral ◽  
Hydrothermal Solutions ◽  
Rapakivi Granite ◽  
Solid Solution Series ◽  
Ree Mineralization ◽  
Geochemical Studies ◽  
Primary Minerals

AbstractThe studied rock samples belong to the classic 1615–1645 Ma Wiborg Rapakivi granite terrane of southeastern Finland. Geochemical studies show that the rapakivi granites and associated rocks form metaluminous to peraluminous A-type granites and plot in the "within plate granites (WPG)" field on the tectonic discriminate diagrams from the Onkamaa, Suomenniemi and Luumäki. The rapakivi granite displays enrichment of light over heavy REE (LREE/HREE = 2-34) and usually negative Eu anomalies (Eu/Eu* = 0.01 - 1.4). Enrichment in REE in some studied samples is confined to highly fractionated portions of the Rapakivi granite. Fractional crystallization of the evolving fluorite-rich peraluminous granitic magma was accompanied, particularly at later stages by fluid fractionation, which plays an important role in the genesis of the REE-mineralization. The studied rapakivi granites host REE-minerals including monazite-(Ce), allanite (Ce), bastnäsite (Ce), xenotime, thorite and REE-bearing mineral apatite. Monazite and allanite are the most important REE carriers in the studied granites and these minerals are strongly enriched in the LREE.Monazites are hosted in apatite, quartz, plagioclase, K-feldspar, and biotite. Grain size of monazite is variable ranging from 50 to >100 μm.Monazite contains 48-68 wt% REE2O3, 24.3-29.3 wt% P2O5 and low Th<1.5 wt%ThO2. The Y, REE, U, Th-bearing minerals are not commonly associated with the primary minerals except for Th-bearing minerals, which occur as silicates (e.g. thorite, ThSiO4); and/or replace other elements in the structure of some accessory mineral, especially xenotime, brabantite, zircon, and apatite. Electron probe microanalysis (EPMA) provides an indication of solid solution series between thorite-xenotimezircon, which are related to hydrothermal solutions enriched in REE, Y, P, U, F, and Zr.

scholarly journals Structural and spectroscopic study of the kieserite-dwornikite solid-solution series, (Mg,Ni)SO4·H2O, at ambient and low temperatures, with cosmochemical implications for icy moons and Mars

2020 ◽  
Vol 105 (10) ◽  
pp. 1472-1489 ◽  
Author(s):  
Dominik Talla ◽  
Madeleine Balla ◽  
Claudia Aicher ◽  
Christian L. Lengauer ◽  
Manfred Wildner
Keyword(s):  
Solid Solution ◽  
Ir Spectra ◽  
Raman Spectra ◽  
Low Temperatures ◽  
Lattice Parameters ◽  
Solid Solution Series ◽  
Icy Moons ◽  
Solution Series ◽  
Ni Content ◽  
End Members

Abstract The investigation of the presence and role of sulfates in our solar system receives growing attention because these compounds play a crucial role in the water budget of planets such as Mars and significantly influence melting equilibria on the icy moons of Saturn and Jupiter, leading to the formation of subsurface oceans and even cryovolcanism. Despite the dominant presence of higher sulfate hydrates such as epsomite, MgSO4·7H2O, and mirabilite, Na2SO4·10H2O, on these moons' surfaces, it is not excluded that lower-hydrated sulfates, such as kieserite, MgSO4·H2O, are also present, forming from higher hydrates under pressures relevant to the mantle of the icy moons. Given the composition of the soluble fraction in C1 and C2 chondritic meteorites, which are high in Ni content and also considered to represent the composition of the rocky cores of the Jovian icy moons, the actual compositions of potentially present monohydrate sulfates likely lie at intermediate values along the solid-solution series between kieserite and transition-metal kieserite-group end-members, incorporating Ni in particular. Moderate Ni contents are also probable in kieserite on Mars due to the planet's long-term accumulation of meteoritic nickel, although likely to a much lesser extent than Fe. Structural and spectroscopic differences between the pure Mg- and Ni-end-members have been previously documented in the literature, but no detailed crystal chemical and spectroscopic investigation along the Mg-Ni solid solution has been done yet. The present work proves the existence of a continuous (Mg,Ni)SO4·H2O solid-solution series for the first time. It provides a detailed insight into the changes in lattice parameters, structural details, and positions of prominent bands in infrared (transmission, attenuated total reflectance, diffuse reflectance) and Raman spectra in synthetic samples as the Ni/Mg ratio progresses, at both ambient as well as low temperatures relevant for the icy moons and Mars. UV-Vis-NIR crystal field spectra of the Ni end-member also help to elucidate the influence of Ni2+-related bands on the overtone- and combination modes. The (Mg,Ni)SO4·H2O solid-solution series shows Vegard-type behavior, i.e., lattice parameters as well as spectral band positions, change along linear trends with increasing Ni content. Infrared spectra reveal significant changes in the wavenumber positions of prominent bands, depending on the Ni/Mg ratio. We show that the temperature during measurement also has an influence on band position, mainly in the case of H2O-related bands. The changes observed for several absorption features in the IR spectra enable rough estimation of the Ni/Mg ratio in the monohydrate sulfate, which is applicable to present and future remote sensing data, as well as in situ measurements on Mars or the icy moons. The spectral features most diagnostic of composition are the vibrational stretching modes of the H2O molecule and a band unique to kieserite-group compounds at around 900 cm–1 in the IR spectra, as well as the pronounced ν3 and ν1 sulfate stretching modes visible in Raman spectra.

scholarly journals Mobility and Bioavailability of Metal(loid)s in a Fluvial System Affected by the Mining and Industrial Processing of Pb

Geosciences ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 167
Author(s):  
Unai Cortada ◽  
María Carmen Hidalgo ◽  
Julián Martínez ◽  
María José de la Torre
Keyword(s):  
Total Concentration ◽  
Rare Metal ◽  
Mining District ◽  
X Ray ◽  
Industrial Processing ◽  
Solids Concentration ◽  
Mobile Fraction ◽  
Type Water ◽  
The Impact

The abandoned mining district of Linares (South Spain) is marked with waste from the mining and the processing of metal ores that pose an environmental hazard to watercourses. A combined analysis of waste, sediments and water was carried out to analyse the impact of a smelter on Baños Creek. The composition of the facility waste was determined using X-ray diffractometry and scanning electron microscopy. The total contents of the metal(loid)s in the waters and sediments of the watercourse were analysed, and sequential metal(loid) extraction of solid samples was carried out. The facility wastes consisted mainly of secondary minerals, such as natropharmacosiderite and spertiniite, as well as rare metal salts, such as mopungite and NaPb2(CO3)2(OH). The leachates generated by these wastes were highly alkaline, with a pH of 10 and a total dissolved solids concentration of approximately 9 g L−1. This Na-bicarbonate-type water had an As concentration above 200 mg L−1 and elevated levels of Pb, Sb and Zn (5029 µg L−1, 841 µg L−1 and 525 µg L−1, respectively). This highly contaminated lixiviate had a significant effect on the chemical quality of the waters and the bioavailability of metal(loid)s in the creek sediments, especially in the headwaters. In this zone, the As, Pb, Sb and Zn concentrations in the most mobile fraction of the sediments reached 1035 mg kg−1, 261 mg kg−1, 45 mg kg−1 and 30 mg kg−1, respectively. By comparison, smelter slag and mining waste have a much lower impact on the waters and the mobile fraction of the sediments, while significantly increasing the total concentration of these potentially toxic elements in creek sediments.

Timing of fluorite mineralization and exhumation events in the east Central Alborz Mountains, northern Iran: constraints from fluorite (U–Th)/He thermochronometry

2021 ◽  
pp. 1-17
Author(s):  
Behnam Shafiei Bafti ◽  
István Dunkl ◽  
Saeed Madanipour
Keyword(s):  
Thermal Relaxation ◽  
Geothermal Gradient ◽  
Source Rocks ◽  
Lower Amount ◽  
Mining District ◽  
Northern Iran ◽  
East Central ◽  
Central Alborz ◽  
Ore Mineralization ◽  
History Of

Abstract The recently developed fluorite (U–Th)/He thermochronology (FHe) technique was applied to date fluorite mineralization and elucidate the exhumation history of the Mazandaran Fluorspar Mining District (MFMD) located in the east Central Alborz Mountains, Iran. A total of 32 fluorite single-crystal samples from four Middle Triassic carbonate-hosted fluorite deposits were dated. The presented FHe ages range between c. 85 Ma (age of fluorite mineralization) and c. 20 Ma (erosional cooling during the exhumation of the Alborz Mountains). The Late Cretaceous FHe ages (i.e. 84.5 ± 3.6, 78.8 ± 4.4 and 72.3 ± 3.5 Ma) are interpreted as the age of mineralization and confirm an epigenetic origin for ore mineralization in the MFMD, likely a result of prolonged hydrothermal circulation of basinal brines through potential source rocks. Most FHe ages scatter around the Eocene Epoch (55.4 ± 3.9 to 33.1 ± 1.7 Ma), recording an important cooling event after heating by regional magmatism in an extensional tectonic regime. Cooling of the heated fluorites, as a result of thermal relaxation in response to geothermal gradient re-equilibration after the end of magmatism, or exhumation cooling during extensional tectonics characterized by lower amount of erosion are most probably the causes of the recorded Eocene FHe cooling ages. Oligocene–Miocene FHe ages (i.e. 27.6 ± 1.4 to 19.5 ± 1.1 Ma) are related to the accelerated uplift of the whole Alborz Mountains, possibly as a result of the initial collision between the Afro-Arabian and Eurasian plates further to the south.

scholarly journals GRANITOIDS, RARE-METAL PEGMATITES AND Ta-Nb MINERALIZATION OF SHPOLIANO-TASHLYK ORE AREA (INGUL MEGABLOCK, UKRAINIAN SHIELD)

2018 ◽  
pp. 24-29
Author(s):  
O. Hrinchenko ◽  
S. Bondarenko ◽  
T. Mironchuk
Keyword(s):  
Rare Metal ◽  
Ukrainian Shield ◽  
Wide Range ◽  
Ore Minerals ◽  
Ore Mineralization ◽  
Isomorphic Series ◽  
Single Complex ◽  
Complex Features ◽  
First Time ◽  
Range Of Values

Composition of granites, genetically associated pegmatites and superimposed metasomatites distributed within Shpoliano-Tashlyk ore area (Ingul megablock) is considered. It is established, that on the basis of similarity in their petrographic and petrochemical features granitoids of the area can be related to single complex. Features of ore mineralization are defined by both composition of granitoids (Sgranites) after which rare-metal pegmatites are formed and intensity of superimposed metasomatic alterations. Main minerals-concentrators of Ta and Nb mineralization in granitic pegmatites and metasomatites are represented by minerals of three isomorphic series – columbite-tantalite (Fe,Mn)(Nb,Ta,Ti)2O6, ilmenorutile-struverite (Ti,Nb,Ta)O2 and pyrochlore-microlite (Ca,Na)2Ta2O6(O,B,OH,F). Depending on geological setting such ore minerals as tapiolite, ixiolite, cassiterite, uraninite, nigerite, gahnite are commonly found in association with these minerals. Chemical composion of tantalo-niobates sampled from ore-bearing pegmatites and metasomatites is investigated by microprobe analysis. Most minerals of columbite-tantalite series are characterized by distinct and rhythmic internal zonality and contrasting mosaic structure which are related to considerable heterogeneities of their chemical composition. Within one aggregate mineral phases with wide range of values – from 9,80 to 71,0 % for Ta2O5 and from 10,6 to 70,1 % for Nb2O5 – are established. Among minerals ferruginous varieties which composition relates to Fe-columbite-tantalites (Nb2O5/Ta2O5 = 1–1,2; FeO/MnO = 2,5–6) prevail. Columbite-tantalites are characterised by high contents of admixture elements present (%): TiO2 – to 5,88; WO3 – to 3,70; SnO2 – to 9,20; Sc2O3 – to 5,40. Scandium ores occur as scandium-rich minerals that are mostly confined to the minerals of columbite-tantalite series found in Polohivka ore field. On the Ukrainian Shield high contents of Sc2O3 in tantalo-niobates are established for the first time. Minerals of ilmenorutile-struverite series do not quantitatively yield to minerals of columbite-tantalite series. For minerals of this series Nb2O5/Ta2O5 ratio varies in the range of 0,6-1,4. Among characteristic admixture-elements are prevailed (%): SnO2 – to 3,1, V2O5 – to 5,05; FeO – to 11,51, Cr2O3 – to 1,20. Minerals of pyrochlore-microlite series are of subordinate importance. For the first time by results of U-Pb dating of columbite-tantalites from Mostove ore manifestation (Shpoliano-Tashlyk area) the age of Ta-Nb mineralization is established to be about 1965 ± 25 million years.

An Approach to the Solid Solution Problem Using a Computerized Identification Technique

1969 ◽  
Vol 13 ◽  
pp. 539-549
Author(s):  
Gerald G. Johnson ◽  
Frank L. Chan
Keyword(s):  
Solid Solution ◽  
Powder Diffraction ◽  
Lattice Parameter ◽  
Powder Diffraction File ◽  
X Ray ◽  
Complete Solid Solution ◽  
Vegard’S Law ◽  
Identification Technique ◽  
Approximate Composition ◽  
End Members

Since for most real systems, solid solution effects influence the position and intensity of the x-ray powder diffraction pattern, it is desirable and necessary to have an automatic system which will identify standard reference phases regardless of the amount of solid solution. Using the system CdS-ZnS, where the lattice parameter a0 changes from 4.136 to 3.820Å, with complete solid solution over the entire range of composition, an illustrative study was made. This work presents the results obtained from a computer analysis of the powder pattern obtained. It has been found that if the starting chemistry is known and the end members of the series are in the ASTM Powder Diffraction File, that the solid solution can be identified. Once the phases present are identified, a plot following Vegard's law yields the approximate composition of the sample under consideration. These two methods of compositional determination agree quite well. Examples of the computer system and description of the program input and output with interpretation of the results will be discussed.

Relations between single mineral equilibrium models and equilibrium models with a solid-solution of q end-members

Clay Minerals ◽  
1988 ◽  
Vol 23 (1) ◽  
pp. 69-80 ◽  
Author(s):  
J. Pages ◽  
P. Aurousseau
Keyword(s):  
Solid Solution ◽  
Aqueous Solutions ◽  
Equilibrium Model ◽  
Equilibrium Models ◽  
Mineral Equilibrium ◽  
Solution Models ◽  
Homogeneous Set ◽  
End Members ◽  
Mathematical Relations

AbstractMinerals studied by an equilibrium model with a single mineral are similar to those studied in solid-solution models with q end-members. After discussing solid-solution models with q end-members where the limits of this kind of models are specified, the mathematical relations between the two kinds of models are developed. These relations show that the equilibrium model with a single mineral is compatible with the geochemical assumption of solid-solution. A method for estimation of equilibrium between a single mineral and a homogeneous set of aqueous solutions is proposed.

scholarly journals The Formation of Barite and Celestite through the Replacement of Gypsum

Minerals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 189 ◽  
Author(s):  
Pablo Forjanes ◽  
José Astilleros ◽  
Lurdes Fernández-Díaz
Keyword(s):  
Solid Solution ◽  
Fluid Phase ◽  
Secondary Phase ◽  
Crystal Habit ◽  
Replacement Reaction ◽  
Random Orientation ◽  
End Members ◽  
Kinetics Of ◽  
Oriented Layer ◽  
Orientational Relationship

Barite (BaSO4) and celestite (SrSO4) are the end-members of a nearly ideal solid solution. Most of the exploitable deposits of celestite occur associated with evaporitic sediments which consist of gypsum (CaSO4·2H2O) or anhydrite (CaSO4). Barite, despite having a broader geological distribution is rarely present in these deposits. In this work, we present an experimental study of the interaction between gypsum crystals and aqueous solutions that bear Sr or Ba. This interaction leads to the development of dissolution-crystallization reactions that result in the pseudomorphic replacement of the gypsum crystals by aggregates of celestite or barite, respectively. The monitoring of both replacement reactions shows that they take place at very different rates. Millimeter-sized gypsum crystals in contact with a 0.5 M SrCl2 solution are completely replaced by celestite aggregates in less than 1 day. In contrast, only a thin barite rim replaces gypsum after seven days of interaction of the latter with a 0.5 M BaCl2 solution. We interpret that this marked difference in the kinetics of the two replacement reactions relates the different orientational relationship that exists between the crystals of the two replacing phases and the gypsum substrate. This influence is further modulated by the specific crystal habit of each secondary phase. Thus, the formation of a thin oriented layer of platy barite crystals effectively armors the gypsum surface and prevents its interaction with the Ba-bearing solution, thereby strongly hindering the progress of the replacement reaction. In contrast, the random orientation of celestite crystals with respect to gypsum guarantees that a significant volume of porosity contained in the celestite layer is interconnected, facilitating the continuous communication between the gypsum surface and the fluid phase and guaranteeing the progress of the gypsum-by-celestite replacement.

scholarly journals Ag-Pb-Sb Sulfosalts and Se-rich Mineralization of Anthony of Padua Mine near Poličany—Model Example of the Mineralization of Silver Lodes in the Historic Kutná Hora Ag-Pb Ore District, Czech Republic

Minerals ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 430 ◽  
Author(s):  
Pažout ◽  
Sejkora ◽  
Šrein
Keyword(s):  
Solid Solution ◽  
Czech Republic ◽  
Chemical Element ◽  
Hydrothermal Fluids ◽  
Tectonic Events ◽  
Mineral Phases ◽  
Ore Mineralization ◽  
Ore Mineralogy ◽  
Low Sulfidation ◽  
Ore District

Significant selenium enrichment associated with selenides and previously unknown Ag-Pb-Sb, Ag-Sb and Pb-Sb sulfosalts has been discovered in hydrothermal ore veins in the Anthony of Padua mine near Poličany, Kutná Hora ore district, central Bohemia, Czech Republic. The ore mineralogy and crystal chemistry of more than twenty silver minerals are studied here. Selenium mineralization is evidenced by a) the occurrence of selenium minerals, and b) significantly increased selenium contents in sulfosalts. Identified selenium minerals include aguilarite and selenides naumannite and clausthalite. The previously unknown sulfosalts from Kutná Hora are identified: Ag-excess fizélyite, fizélyite, andorite IV, andorite VI, unnamed Ag-poor Ag-Pb-Sb sulfosalts, semseyite, stephanite, polybasite, unnamed Ag-Cu-S mineral phases and uytenbogaardtite. Among the newly identified sulfides is argyrodite; germanium is a new chemical element in geochemistry of Kutná Hora. Three types of ore were recognized in the vein assemblage: the Pb-rich black ore (i) in quartz; the Ag-rich red ore (ii) in kutnohorite-quartz gangue; and the Ag-rich ore (iii) in milky quartz without sulfides. The general succession scheme runs for the Pb-rich black ore (i) as follows: galena – boulangerite (– jamesonite) – owyheeite – fizélyite – Ag-exces fizélyite – andorite IV – andorite VI – freieslebenite – diaphorite – miargyrite – freibergite. For the Ag-rich red ore (ii) and ore (iii) the most prominent pattern is: galena – diaphorite – freibergite – miargyrite – pyragyrite – stephanite – polybasite – acanthite. The parallel succession scheme progresses from Se-poor to Se-rich phases, i.e., galena – members of galena – clausthalite solid solution – clausthalite; miargyrite – Se-rich miargyrite; acanthite – aguilarite – naumannite. A likely source of selenium is in the serpentinized ultrabasic bodies, known in the area of “silver” lodes in the South of the ore district, which may enable to pre-concentrate selenium, released into hydrothermal fluids during tectonic events. The origin of the studied ore mineralization is primarily bound to the youngest stage of mineralization of the whole ore district, corresponding to the Ag-Sb sequence of the ´eb´ ore type of the Freiberg ore district in Saxony (Germany) and shows mineralogical and geochemical similarities to low-sulfidation epithermal-style Ag-Au mineralization.

Crystalline Thin and/or Thick Film of Perovskite-Type Oxides by Hydrothermal Electrochemical Techniques

1992 ◽  
Vol 271 ◽  
Author(s):  
Masahiro Yoshimura
Keyword(s):  
Vapor Pressure ◽  
Low Temperatures ◽  
Electrochemical Techniques ◽  
Electrical Current ◽  
Hydrothermal Solutions ◽  
Saturation Vapor Pressure ◽  
Glass Substrates ◽  
Perovskite Type Oxide ◽  
Perovskite Type ◽  
Saturation Vapor

ABSTRACTWell crystallized polycrystalline perovskite-type oxide thin and/or thick films were prepared at sufficiently low temperatures by newly developed “hydrothermal electrochemical techniques” where metals were electrochemically oxidized and reacted with some components in hydrothermal solutions. BaTiO3 films 70 to 300 nm thick were formed in Ba(OH)2 solution at 100–200°C under saturation vapor pressure on the Ti substrate and Ti deposited glass substrates. The electrical current enhanced to thicken their films. SrTiO3, BaFeO3 and LiNbO3 films were also prepared.

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