A review of Pb-Sb(As)-S, Cu(Ag)-Fe(Zn)-Sb(As)-S, Ag(Pb)-Bi(Sb)-S and Pb-Bi-S(Te) sulfosalt systems from the Boranja orefield, West Serbia

Recent mineralogical, chemical, physical, and crystallographic investigations of the Boranja orefield showed very complex mineral associations and assemblages where sulfosalts have significant role. The sulfosalts of the Boranja orefield can be divided in four main groups: (i) Pb-Sb(As)-S system with ±Fe and ±Cu; (ii) Cu(Ag)-Fe(Zn)-Sb(As)-S system; (iii) Ag(Pb)-Bi(Sb)-S; (iv) and Pb-Bi-S(Te) system. Spatially, these sulfosalts are widely spread, however, they are the most abundant in the following polymetallic deposits and ore zones: Cu(Bi)-FeS Kram-Mlakva; Pb(Ag)-Zn-FeS2 Veliki Majdan (Kolarica-Centralni revir-Kojići); Sb-Zn-Pb-As Rujevac; and Pb-Zn-FeS2-BaSO4 Bobija. The multi stage formation of minerals, from skarnhydrothermal to complex hydrothermal with various stages and sub-stages has been determined. All hydrothermal stages and sub-stages of various polymetallic deposits and ore zones within the Boranja orefield are followed by a variety of sulfosalts. [Projekat Ministarstva nauke Republike Srbije, br. OI-176016: Magmatism and geodynamics of the Balkan Peninsula from Mesozoic to present day: Significance for the formation of metallic and non-metallic mineral deposits

Rujevac Sb-Pb-Zn-As polymetallic deposit, Boranja orefield, Western Serbia: native arsenic and arsenic mineralization

Rujevac is a low-temperature hydrothermal polymetallic Sb-Pb-Zn-As vein-type ore deposit, hosted within a volcanogenic-sedimentary zone situated in the Rujevac-Crvene Stene-Brezovica Diabase-Chert Formation (DCF) of the Podrinje Metallogenic District (PMD), Serbia. It is located several kilometers SE from the Boranja contact aureole, which is an integral part of the PMD in Western Serbia. Genetically related to the Tertiary granodioritic magma, the mineral assemblages are characterized by specific features. The mineral association of this deposit consists of sulfides, Pb-Sb(As) sulfosalts, native metals, oxides, hydroxides and gangue minerals. Chemical composition of the ore is very complex, where contents of valuable metals range as follows: Sb (0.17-24.31 wt.%), Zn (0.21-6.29 wt.%), Pb (0.15-6.33 wt.%), As (0.06-1.28 wt.%), Cd (25-747 ppm), Ag (7-408 ppm), Hg (13-473 ppm), and Tl ( LT 1-29 ppm). Electron Probe Microanalyses (EPMA) of native arsenic from both the Rujevac and Stragari deposits showed contents of As up to 98.8 and 97.1 wt.%, with impurity contents of Sb up to 1.3 and 6.6 wt.%, and Tl up to 2 and 1.3 wt.%, respectively. Rhombohedral unit-cell parameters for native arsenic from Rujevac and Stragari deposits amount to: a=3.760(2), c=10.555(3) angstrom, V=129.23(7) angstrom(3) and a=3.763(1), c=10.560(5) angstrom, V=129.48(8) angstrom(3), respectively. Mineral assemblages, deposition order and genesis of the Rujevac polymetallic deposit were also discussed in detail. Native arsenic mineralization here has been additionally compared with similar well-known global deposits

Rare Pb-Bi sulfosalt mineralization from the Boranja orefield (Podrinje district, Serbia)

Pb-Bi sulfosalts are uncommon minerals in the deposits and mineralization of Boranja orefield (West Serbia), one of the less-known Serbian ore deposits. In the Kram locality the Pb-Bi sulfosalts occur typically in skarns associated with garnet, epidote, calcite and magnetite. Pyrrhotite, chalcopyrite, chalcopyrrhotite, valerite, tetradymite, native bismuth, native gold are associated with sulfide phases. Furthermore, the electron microprobe analyses of the Pb-Bi sulfosalts yielded empirical formulae: bursaite (Pb4.81Fe0.03CU0.08Ag0.16)(Sigma 5.08)Bi-3.87(S10.99Te0.06)(Sigma 11.05), Cannizzarite (Pb3.05Ag0.02)(Sigma 3.07)Bi4.00S8.93 cosalite (Pb-1.95,Cu-0.08)(Sigma 2.03)(Bi1.92Sb0.01) S-Sigma 1.93(5.05); aikinite (Cu-0.97,Fe-0.02)(Sigma 0.99)(Pb0.9Ag0.05)(Sigma 1.03)Bi0.95S3.03, All of the Pb-Bi sulfosalts have Bi/Pb atomic ratio in the range 0.8-1.3. Unit-cell parameters were calculated for bursaite and cannizzarite. Orthorhombic unit-cell parameters for bursaite amount to: a = 4.106(5); b = 13.42(2); c = 20.50(3) angstrom; V = 1129.7(2) angstrom(3). The strongest reflections in the X-ray powder diffraction pattern are [d(in angstrom)(I)]: 3.456(100), 3.407(90), and 3.550(56). Monoclinic unit-cell parameters for cannizzarite (Q-subcell) amount to: a = 15.560(6); b = 4.105(2); c = 4.125(1) angstrom; beta = 100.78(2); V = 258.8(1) angstrom(3); and for the H-subcell to: a = 15.470(9); b = 4.096(2); c = 7.000(5) angstrom; beta= 98.53(5); V = 438.3(3) angstrom(3). The strongest reflections in the X-ray powder diffraction pattern are: 3.821(88), 3.337(62), and 3.009(61)

Polymetallic mineralization of the Boranja orefield, Podrinje Metallogenic District, Serbia: zonality, mineral associations and genetic features

The Serbo-Macedonian Metallogenetic Province, part of the Alpine metallogenic belt, hosts several ore deposits in mainly three geotectonic units: the Vardar Zone, the Serbo-Macedonian massif, and to a lesser extend the Dinarides. This metallogenic province includes the most significant Pb-Zn and Sb deposits in Serbia, as well as smaller Bi, Mo, Cu, Fe, Sn, Au and minor U, Wand Hg deposits, which are genetically related to emplacement of granitoids. The Podrinje Metallogenic District belongs to the Serbo-Macedonian Metallogenetic Province and incorporates several smaller orefields: Cer (Northwest Serbia), Boranja (West Serbia), and Srebrenica (East Bosnia and Herzegovina). Polymetallic deposits in the Boranja orefield are genetically related to the emplacement of the Tertiary Boranja granodiorite complex. The orefield contains a large number of sulfide deposits with Pb-Zn, and Sb with subordinate Cu, As, Bi and Ag. Small magnetite deposits connected to pyrometasomatic (skarn) stage are also significant. Skarns are of calcic type, and were formed along contacts of Triassic limestones and quartz diorites. Ore minerals are similar among the various types of orebodies in the Boranja orefield and consist of sulfides, sulfosalts [Pb-Bi-(Ag)-Te-Cu, Pb-Sb-(As), Sb-Cu-(Ag, Fe, Zn)], tellurides, native metals and alloys, oxides and complex-oxides, and gangue minerals. Minerals of the Boranja orefield were formed in several successive stages, which together correspond to a single regional-scale mineralization event that is genetically related to the subvulcanic-plutonic intrusion of the Neogene-aged magmatic Boranja complex. This can be best demonstrated by the zonal arrangement of several metallic mineral associations [Fe-Cu(Bi) - GT Pb(Ag)-Zn - GT Sb(As) - GT CaF2(Pb-Zn)], with increasing distance from the Boranja granodiorite. Silver occurs as a minor metal principally as Ag-tetrahedrite, with subordinate native silver, Ag-bearing gold and pyrargyrite. Significant quantities of Ag can also be accommodated in galena as it is found to contain varied amounts of Ag, Bi and Sb (0.001-0.936, 0-3.345, and 0.012-0.510 wt%, respectively). The presence of both Ag and Bi in significant amounts in a Pb-rich sulfide system is essential for development of galena [solid solution alpha-(Pb-2, AgSb, AgBi)S-2]. This study demonstrates that silver, the most economic metal in Boranja orefield, is mainly accommodated in the galena structure, with lesser amounts present in the form of visible and/or invisible Pb-Bi-(Ag) sulfosalts

Low-temperature Ni-As-Sb-S mineralization of the Pb(Ag)-Zn deposits within the Rogozna ore field, Serbo-Macedonian Metallogenic Province: Ore mineralogy, crystal chemistry and paragenetic relationships

The Rogozna ore field (ROF) belongs to the Serbo-Macedonian Metallogenic Province (SMMP), and covers a part of the western Dinarides rim and the Vardar ophiolite zone, situated within the Neogene volcanogenic-intrusive complex of calc-alkaline and shoshonitic rocks within the territories of Serbia and Kosovo. It is well-known for its Cu(Au, Pb, Zn) skarn mineralization and Pb(Ag)-Zn hydrothermal deposits and occurences. Mineral associations, deposition order and genesis of the ROF were discussed in detail. Complex ore parageneses were determined in the Crnac, Plalcaonica, and Kaludjer Pb(Ag)-Zn deposits and are composed of the following minerals: sulfides (pyrrhotite, chalcopyrrhotite, chalcopyrite, sphalerite, galena, pyrite, marcasite, millerite, bravoite), sulfosalts (arsenopolybasite, tetrahedrite, Ag-bearing tetrahedrite, Zn-bearing tetrahedrite, semseyite, heteromorphite, jamesonite, ferrokesterite), arsenides (nickeline), sulfarsenides and sulfantimonides (gersdorffite, Sb-bearing gersdorffite, Fe-bearing gersdorffite, As-bearing ullmannite, arsenopyrite), native metals (native Au, native Ag), oxides (Cr-spinel, rutile, anatase, leucoxene, magnetite, hematite) and gangue minerals (quartz, silicates, chalcedony, carbonates, monazite(Ce), barite, gypsum, anglesite, cerussite, smithsonite, zaratite, limonite). The high-, medium-, and low-temperature hydrothermal mineral assemblage occur throughout the Pb(Ag)-Zn deposits at Kaludjer-Crnac-Plakaonica ore system, in which the whole ore field as high- to medium-temperature hydrothermal formed at shallow to moderate depth. The following stages of ore mineral formation are recognized in the Pb-Zn mineral assemblage at the ROF: i) pre-ore; ii) high-temperature hydrothermal; iii) hypogene; iv) medium-temperature hydrothermal; v) low-temperature hydrothermal; and vi) supergene. Generally, there are two types of mineralization, brecciated ore veins with ribbon-like textures deposited in amphibolites or in contact with quarz latites, and impregnations within columnar ore bodies hosted in silicified and carbonated serpentinites (listwaenites). Ni-mineralization is represented by significant sulphide, arsenide, sulfarsenide, and sulfantimonide occurrences, but the most significant consists of gersdorffite-ullmannite series (GUS) minerals. It is the most developed in the Kaludjer deposit, much lesser at Plakaonica, whereas in the Crnac deposit it was not noted. The importance of the Ni mineralization is of scientific interest for now, as the attention has been directed only to the exploration of lead and zinc. However, it is believed that plans for the future will be focused on a detailed study of nickel. (C) 2014 Elsevier B.V. All rights reserved

Degradation of azithromycin using Ti/RuO2 anode as catalyst followed by DPV, HPLC-UV and MS analysis

The electrodegradation of azithromycin was studied by its indirect oxidation using dimensionally stable Ti/RuO2 anode as catalyst in the electrolyte containing methanol, 0.05 M NaHCO3, sodium chloride and deionized water. The optimal conditions for galvanostatic electrodegradation for the azithromycin concentration of 0.472 mg cm(-3) were found to be NaCl concentration of 7 mg cm(-3) and the applied current of 300 mA. The differential pulse voltammetry using glassy carbon electrode was performed for the first time in the above-mentioned content of electrolyte for the nine concentration of azithromycin (0.075-0.675 mg cm(-3)) giving the limits of azithromycin detection and of quantification as: LOD 0.044 mg cm(-3) and LOQ 0.145 mg cm(-3). The calibration curve was constructed enabling the electrolyte analysis during its electrodegradation process. The electrolyte was analyzed by high-performance liquid chromatography and electrospray ionization time-of-flight mass spectrometry. The electrooxidation products were identified and after 180 min there was no azithromycin in the electrolyte while TOC analysis showed that 79% of azithromycin was mineralized. The proposed degradation scheme is presented