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CULTURAL HERITAGE AND PROTECTION OF HAND-WHEELED POTTERY MANUFACTURE IN WESTERN SERBIA: CHARACTERISTICS OF ZLAKUSA POTTERY BASED ON SEM-EDS AND OPTICAL MICROSCOPY
No full textTraditional coiling and hand-wheel manufacture of pottery from the locally sourced raw clay is characteristic for Western Serbia (DJORDJEVIĆ, 2013) and especially well known in Zlakusa. Pottery from Zlakusa is on the UNESCO Representative List of the Intangible Cultural Heritage of Humanity. In technological terms, it is a unique phenomenon that actively coexists with discovery of new techniques and production processes. This brings to a rise in imitations of this pottery manufacture due to its enlarged popularity. The main goal of this work was to show characteristics of the pottery manufacture based on mineralogy [scanning electron microscopy (SEM-EDS) and optical microscopy] and applying the obtained knowledge in the preservation of this type of cultural heritage in Serbia
Postupak solidifikacije i stabilizacije teških metala iz otpadnih rudničkih voda adsorbovanih na paletama letećeg pepela u ekološki prihvatljiv građevinski materijal
No full textPostupak implementacije apsorbovanih teških metala, posebno bakra, iz kiselih rudničkih voda procesom stabilizacije/solidifikacije u ekološki prihvatljiv i primenjiv građevinski materijal bezbedan za životnu sredinu, dobija se tako što se u jednom reakcionom sudu zagreva 33 mass % elementarnog sumpora koji je nus-proizvod procesa rafinerije nafte i modifikovanog sumpora diciklopentadienom, na temperaturu od 132°-141 ºC (tako da je njihov maseni odnos 98,2% sumpora i 1,8% modifikovanog sumpora). U drugom reakcionom sudu u količini od 56 mass % zagreva agregat na temperaturu do 160 ºC, a njemu se dodaje 5 mass % letećeg pepela iz termoelektrane kao filera. Ovoj smesi se dodaje 6 mass % peleta letećeg pepela na kojima je izvršena apsorpcija teških metala, posebno bakra iz rudničkih voda, tako što se sve komponente homogenizuju tokom 2 do 5 minuta, a dobijena smesa izliva u kalupe prethodno zagrejane na 120 ºC i vibrira 10 sekundi. Površina ovako dobijene sumpor-polimerne betonske mešavine se izravna i ostavi da očvrsne u kalupu na sobnoj temperaturi, a dobijeni sumpor-polimerni beton očvrsne u vremenskom intervalu od 15 minuta do nekoliko časova u zavisnosti od veličine i oblika uzorka. Nakon 3 časa očvršćavanja uzorci se izvade iz kalupa i neguju na sobnoj temperaturi od 20 ºC tokom 24 časa, pri čemu oblik kalupa zavisi od potreba potrošača. Ovim postupkom i upotrebom otpadnog materijala iz rudničkih voda, letećeg pepela i elementarnog sumpora se ne stvaraju deponije otpadnog materijala već se korisno i ekološki prihvatljivo koristi kao građevinski materijal
Analiza rasta, trendova i prognoze stanja tržišta krečnjaka i kreča u svetu
No full textZa funkcionisanje industrijskih grana koje koriste krečnjak i kreč izuzetno je važna analiza potreba i
zahteva tržišta. Kako bi se predviđanja o stanju tržišta u praksi pokazala kao tačna, neophodno je
obuhvatiti veliki broj parametara relevantnih za datu prognozu i naći uzročno posledičnu vezu
između njih. Takođe, pristup podacima i njihova obrada nije ograničena samo na jednu državu ili
jednu regiju, već se radi o globalnom umrežavanju i razmeni informacija kako bi predviđanja bila
što preciznija. Za predviđanje procentualnog rasta tržišta određene mineralne sirovine ili
proizvoda, najčešće za period tri do pet godina, koristi se CAGR (Compound Annual Growth Rate).
Prema analizi CAGR u periodu 2019.-2024. godine očekivani rast tržišta krečnjaka biće do 6%. U
periodu 2014.-2019. godine svetska potrošnja kreča je porasla sa prosečnom godišnjom stopom od
4-5 %. Prognozirana potrošnja gašenog (hidratisanog) kreča u periodu 2017.-2025. godine od 3 %
vezuje se za njegovu upotrebu u oblasti zaštite životne sredine, poljoprivrede i građevinarstva
The clay preliminary testing from municipality area of Rekovac
No full textOn the territory of Rekovac municipality, geological research has discovered clay deposit ""Oparić"". The sample was taken from the well core with 9 m depth, then stirred with water and sifted by wet process on a sieve with 0.063mm opening. It was obtained 71 % of reflections (class + 0.063 mm) and 29 % of sieves (class -0.063 mm). The chemical and X-ray analysis of the class -0.063mm was done. The results showed there is increased content of iron in the form of Fe2O3, which reduces the clay quality. Further research should focus on finding the iron removing possibility by magnetic concentration
Lead Removal from Water Solutions Using Alginate-Immobilized Peach Stone Particles
No full textFruit processing industries generate millions of tons of
organic waste annually, often improperly disposed of at
open landfills. Based on the circular economy and waste
management concepts, reusing these bio-waste materials
is one of the future sustainable demands. Furthermore,
recent investigations have shown that this material type
can be reused as high-quality sorbents, with certain
modifications that should be applied. Considering this,
we have investigated the possible application of lignocellulosic
waste-peach stones (Prunus Persica L.),
immobilized in sodium alginate, as heavy metals sorbent.
The immobilized particles (IPS) were utilized to
remove metals from synthetic water solutions. Among
all metals (Pb, Cu, Cd, and Zn), IPS has shown superior
performance in Pb removal, governing further investigations.
Dried IPS spheres were characterized by FTIR,
SEM/EDX, and TG techniques. The batch reaction system
investigated the effects of the contact time, initial
Pb concentration, and mass-to-volume ratio. Optimized
operational parameters were used in kinetic and isotherm
studies. Obtained data were modeled using a
nonlinear form of pseudo-first, pseudo-second, Elovich,
Freundlich, and Langmuir equations. The results showed
pseudo-second-order kinetics with Freundlich isotherm
fitting Pb removal, indicating a heterogeneous IPS surface
with the multilayer adsorption and adsorbed molecule
interaction. As obtained from Langmuir isotherm,
IPS particles have removed Pb by saturation capacity of80.40 mg Pb/g. These preliminary results indicate that
IPS can be applied to purify waters contaminated with
lead metal
Improvement of at-welding technology of railway rails with different cross sections
No full textU radu je prikazana nova tehnologija aluminotermijskog zavarivanja (AT) prelaznih šina 49E1 na 60E1(EN 13674-1:2005.), oslonjena na potpuno nove materijale. Ona se odnosi na pešćane kalupe kod kojih su oblik i dimenzije ulivnog sistema projektovani tako da mogu odgovoriti svim zahtevima za postizanje zavarenih spojeva zadatog kvaliteta. Da bi ovaj zahtev bio u potpunosti ispunjen, projektovana je, takođe, AT smeša, čijom se aktivacijom dobija termitni čelik za ispunu, sa temperaturom izlivanja koja obezbeđuje optimalnu livkost metala, kao i viskoznost troske. U radu su zatim prikazani rezultati ispitivanja probnih prelaznih zavarenih spojeva, shodno standardima JŽS.Z2.610 i EN 14730-1:2012, a odnose se na utvrđivanje mehaničkih svojstava zavarenih spojeva, makrostruktirnih i mikrostrukturnih karakteristika, homogenosti i hemijskog sastava termitnog čelika za ispunu. Dobijeni rezultati pokazuju da je primenjena tehnologija optimalna, jer obezbeđuje upotrebu ove tehnologije u industrijskim uslovima na železnici.The paper presents a new aluminothermic (AT) welding technology of 49E1 transition rails on 60E1 (EN 13674-1: 2005), based on entirely new materials. It refers to sand molds in which the shape and dimensions of the inflow system are designed to meet all requirements for achieving welded joints of a given quality. The AT mixture was also designed to fulfill those requests; resulting liquid steel has a casting temperature that ensures optimal castability of the metal and slag viscosity. The paper presents the test results of the transients welded joints, following the standards JŽS.Z2.610 and EN 14730-1: 2012, and relates to the determination of mechanical properties of welded joints macrostructural and microstructural characteristics, homogeneity, and chemical composition of thermite steel. The obtained results show that the applied technology is optimal because it ensures the use of this technology in industrial conditions on the railway
Removal of non-steroidal anti-inflammatory drugs from water by zeolite-rich composites: The interference of inorganic anions on the ibuprofen and naproxen adsorption
No full textComposites of two natural zeolites ? clinoptilolite and phillipsite, and cationic surfactants (cetylpyridinium chloride and Arquad? 2HT-75) were tested for the removal of two emerging contaminants ? ibuprofen and naproxen. For each zeolite-rich rock, two different modifications of the zeolitic surfaces were prepared (monolayer and bilayer surfactant coverage). The influence of the initial drug concentrations and contact time on adsorption of these drugs was followed in buffer solution. The Langmuir model showed the highest adsorption capacity for the composite characterized by a bilayered surfactant at the clinoptilolite surface: 19.7 mg/g and 16.1 mg/g for ibuprofen and naproxen, respectively. Also, to simulate real systems, drug adsorption isotherms were conducted in natural water (Grindstone creek water ? Columbia, Missouri, USA) by using the best performing adsorbent; in this case, a slight decrease of drug adsorption was recorded. Kinetic runs were performed in distilled water as well as in the presence of ions such as sulfates and bicarbonates; also, in this case, the interfering agents defined an adsorption decrease for bilayer composites
Thermally Induced Phase Transformation of Mn - LTA and Mn-FAU Zeolite to Anorthite Phases
No full textData on thermally induced transformations of Mn exchanged zeolites LTA and FAU topology are presented in this paper. Thermally induced phase transformation of Mn-exchange zeolites are followed in the range from 700 to 1300 degrees C. Both frameworks collapse into amorphous intermediate products after heating between 600 and 650 degrees C. Prolonged heating of the intermediate product above 1100 degrees C results directly in formation of a disorder Mn-anorthite LTA and Mn-anorthite(FAU). The parameter of unit cell of Mn-anorthite(LTA) and Mn-anorthite(FAU), in temperature range between 700 and 1300 degrees C, was observed in space group C1. The phase conversions in the temperature range investigated were followed by thermal, Xray powder diffraction and FT-IR analyses
Geological and mineral characteristics of zeolithic tuff “Toponica” deposits near Kosovska Kamenica
No full textZeolites are a group of natural and artificial inorganic compounds, which have specific physicochemical properties appropriate for industrial application. These minerals make a specific group of alumosilicates within tectosilicates because of their origin, chemical compositions, structural characteristics and application. This paper presents the results of mineralogical and crystallographic examination of zeolite tuff samples from the Toponica deposit. The deposit of zeolite tuff ""Toponica"" is located in the extreme eastern part of Kosmet near Kosovska Kamenica. The immediate geological structure of the zeolite tuff deposit consists of the Lower Miocene (M) clayey sandstone, the horizon of the white zeolite tuff and the reclassified Miocene clays, clays and gravel. The basic mineral composition is the mineral clinoptilolite-Ca from the heylandite series
The influence of the particle size on crystallization of glass powders from the system Li2O-Al2O3-GeO2-P2O5
No full textThe glass was prepared by standard melt-quenching technique. The crystallization of powder glass from the system Li2O-Al2O3-GeO2-P2O5 was studied. The investigations were performed under non-isothermal and isothermal conditions using DTA and XRD methods. The results showed that the glass crystallize by primary crystallization. As a primary phase the LiGe2(PO4)3 is formed. The influence of particle size of the glass powder samples in the range 0-1 mm on the temperature of the DTA crystallization peak, Tp, the peak height (δT)p and the parameter Tp2/(ΔT)p was studied. It was indicated that for the particle size in the range 0.05-0.4 mm, surface and volume crystallization are significant, while for the particle size >0.4 mm the volume crystallization is dominant