Mineralogy and crystallographic properties of heu-type zeolitic tuff from the novakovic deposit, Bosnia and Herzegovina

This paper presents mineralogical and crystallographic characterization of the zeolitic tuff from the Novakovic deposit, Republic of Bosnia and Herzegovina. The zeolitic tuff is of a whitish color composed of Ca-clinoptilolite and an amorphous phase (volcanic glass and amorphous SiO 2 ). The zeolitic tuff was analyzed by X-ray diffraction of the polycrystalline sample (XRPD), scanning electron microscopy and energy dispersive spectroscopy (SEM/EDS), and differential thermal and thermogravimetric (DTA/DTG) methods. According to the results obtained, it can be concluded that the studied zeolitic tuff is composed of Heu-type minerals. Based on the chemical analysis, thermal treatment and XRPD analysis it was determined that this is a mineral Ca-clinoptilolite. Thermal analysis in the temperature range from 300 up to 700°C showed that the examined zeolite minerals from the Novaković deposit are stable up to the temperature of 600°C. The crystal structure of Ca-clinoptilolite has been refined in the centrosymmetric space group C2/m (S.G. 12) with disordered distribution of Al and Si in the tetrahedral framework. The unit-cell parameters are as follows: a = 17.662 Å, b = 17.874 Å, c = 7.402 Å, β = 116.32° and V = 2122.73 Å 3 . The basic structural motif is represented by four channels. Three channels are composed of eight-membered rings, and one of ten-membered rings. The ten-membered (channel A) and one eight-membered channel (B) are parallel to the crystallographic axis c, and the other eight-membered channel is parallel to the a-axis. Ca-clinoptilolite comprises approximately 90 % of the studied zeolite tuff while the rest 10 % is the amorphous phase. The overall cation exchange capacity (CEC) amounts to 187 mmolM + / 100 g, and calcium represents the most abundant cation in the studied sample. The atomic ratios of Si/Al, Na + /(Na + +K + ), and Ca 2+ /(Ca 2+ +Mg 2+ ) are as follows: 4.36, 0.14, and 0.55, respectively. The zeolite tuff is both thermally and structurally stable and has applications in various areas of industry and agriculture. © 2018, Association of Chemists and Chemical Engineers of Serbia. All rights reserved

Mineralogy and crystallochemical characteristics of HEU-type minerals from zeolitic tuff deposits of Serbia

The results of perennial research of several Serbian zeolitic tuffs enriched with HEU-type minerals are presented in this paper. There are several recognized zeolitic tuff deposits containing HEU-type minerals: Zlatokop, Igroš, Beočin, Toponica, Slanci, but their comparative mineralogical and crystallochemical features have not been studied in detail so far. These zeolitic tuff deposits are spatially and genetically connected to volcanic and pyroclastic rocks of marine and lake environments of Senonian and Eocene, and Neogene age, respectively. As a result of devitrification and diagenesis process of volcanic glass within zeolitic tuffs hypocrystalline porphiry and vitroclastic textures occur. The studied zeolitic tuffs are mainly composed of heulandite occuring in a form of needle- to plate-like crystals of 0,1 do 100 μm in length, associated with other silicates. Depending on the type and content of exchangeable cations as well as the thermal stability of these raw materials, 24 clinoptilolite-Ca and heulandite-Ca can be distinguished. The values of cation exchange capacity and surface area capacity range from 96 to 166 meq/100 g, and from 8,0 to 10,5 meq/100 g, respectively. HEU-type minerals can be distinguished either by a Si/Al ratio or arrangement of extra framework cations within the crystal structure of these minerals. [Projekat Ministarstva nauke Republike Srbije, br. TR 34013: Osvajanje tehnoloških postupaka dobijanja ekoloških materijala na bazi nemetaličnih mineralnih sirovina i br. 45012: Sinteza, procesiranje i karakterizacija nano strukturnih materijala za primenu u oblasti energije, mehaničkog inţenjerstva, zaštite životne sredine i biomedicine

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

Badanie możliwości otrzymywania koncentratu poflotacyjnego zawierającego mikę ze skaolinizowanego granitu

This study shows the results of flotation concentration of mica minerals from kaolinised granite taken from the "Bašića bare" deposit – Kobaš, Srbac, The Republic of Srpska (B&H). Mineralogical composition of kaolinised granite is as follows: kaolinite, feldspar, quartz, and mica. After separating >0.630 mm, and 0.630 mm i <0.043 mm, zawierających największe ilości kaolinitu, pozostały produkt stanowi klasa ziaren o wymiarach –0.630+0.043, zawierających kwarc, skaleń oraz mikę. Koncentrat zawierający mikę otrzymano z koncentratu poflotacyjnego, skaleń i kwarc zebrano w produkcie dolnym procesu flotacji. W oparciu o analizy składu mineralogicznego stwierdzono, że minerałami występującymi w największych ilościach są mika oraz chloryty/iły, kwarc oraz skalenie wy-stępują w znacznie mniejszych ilościach podczas gdy pozostałe minerały występują jedynie w ilościach śladowych. Przeprowadzona analiza mineralogiczna koncentratu miki w ujęciu ilościowym w oparciu o wyniki rentgenowskiej dyfraktometrii proszkowej (X-ray powder diffraction – XRPD) ujawniła że skład jego jest następujący: mika ≈55%; chloryty/iły ≈35 %; kwarc ≈5%; skalenie (łącznie plagioklazy i skalenie potasowe) ≈5%