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Zaštita materijala 3. 2012

 

S.JOHN MARYS. RAJENDRAN2

Review paper [PDF]
UDC:620.193.4:612.146.421

Corrosion behaviour of metals in artificial body fluid an over view

The Corrosion Performances in Various artificial body fluids of various metals are evaluated, Artificial human blood, urine serum, Joint fluid, simulated bile solutions, artificial salaiva, Hank’s solutions Ringers, Tyrode of the solution, Cigada solutions are examined with different type of metals such as Ni-Al-Fe alloys, TiO2 nano tubes,  cobalt alloys, Cr  alloys, 316 stainless steel, Mg – alloys etc . There are used as implant materials for surgery. The Corrosion resistance tests were carried out in selected body fluids. To replace the bone, several metal and it alloys have been used as implantation metal. The Artificial body fluids are important to maintain our body health. Because the artificial body fluids directly connecting with tissues, Tissues are directly contact with implantation metals. The different or various body fluids are examined in presence of different or various implantation metals by electro chemical method. Protective films are formed. The films have been Analyzed by many surface Analysis techniques such as AFM, FTIR UV fluorescence spectra and SEM.

Key words: corrosion,  alloys, artificial human blood,  urine, serum

 

KOROZIONO PONAŠANJE METALA U VEŠTAČKIM TELESNIM TEČNOSTIMA

Upotreba nekih metala i legura, Ni-Al-Fe legure, TiO2 nano cevi, kobalt legure, nerđajući čelik, Mg legure itd., u različitim veštačkim telesnim tečnostima dovodi do određenog stepena korozije. Ovi materijali se koriste kao implantati pri različitim operacijama. Otpornost na koroziju navedenih materijala je ispitivana u različitim telesnim tečnostima. Da bi se zamenile kosti korišćeni su neki metali i legure. Ovi materijali su u direktnom kontaktu sa raznim telesnim tečnostima. U prisustvu ovih različitih tečnosti ispituju se ovi implantati elektrohemijskim metodama. Na površinama ovih implatata se formiraju zaštitni filmovi. Ispitivanje ovih zaštitnih filmova je vršeno mnogim tehnikama površinske analize: AFM, FTIR, UV fluorescentna spektroskopija i SEM.

Key words: korozija, legure, veštačka ljudska krv, urin, serum

 


 

S. MARTINEZ1, V. GROZDANIĆ2, A. IVANKOVIĆ1

Scientific paper [PDF]
UDC:620.193.1.4:622.648.2/.3

SEM/EDS analysis of corrosion products from the interior of a crude oil pipeline

Within the framework of environmental protection, internal corrosion risk assessment is one of the most important activities of modern pipeline corrosion management. In order to assess the risk of internal corrosion of pipelines, it is important to understand corrosion mechanisms and be able to predict whether localised corrosion will be initiated and how it can be prevented. In the present work we investigated corrosion products from the interior of the of carbon steel crude oil pipeline sampled at a low-lying dead-leg where wall perforation due to corrosion has already occurred. Morphological and compositional studies were conducted by SEM-EDS and microbiological analysis was done by using growth assay. Application of a combination of the two complementary analytical techniques enabled root cause analysis revealing a pattern specific to the corrosive action of biotic corrosive media and indicating bacterial activity and scale formation as the main root cause of the observed corrosion failure.

Key words: SEM/EDS analysis of corrosion,

SEM/EDS ANALIZA KOROZIJE PROIZVODA IZ UNUTRAŠNJOSTI NAFTOVODA

U okviru zaštite okoliša, procjena rizika unutarnje korozije cjevovoda je jedna od najvažnijih aktivnosti suvremenog korozijskog menadžmenta cjevovoda. Da bi se procijenio rizik od korozije u cjevovodima, važno je razumjeti mehanizme reakcija korozije i biti u mogućnosti predvidjeti hoće li doći do lokalizirane korozije i kako lokaliziranu koroziju spriječiti. U ovom radu istražene su naslage iz unutrašnjosti naftovoda od ugljičnog čelika. Uzorci su prikupljeni na nisko položenom odvojku u kojem je došlo do perforacije stjenke zbog korozije. Morfološka analiza i analiza sastava provedene su SEM/EDS metodom te je napravljena i mikrobiološka analiza. Rezultati primjene dviju komplementarnih tehnika analize ukazuju na korozijsko djelovanje biološkog medija i koroziju ispod naslaga potpomognutu  bakterijskom aktivnosti kao glavni uzrok korozijskog oštećenja cjevovoda.

Ključne reči: SEM/EDS analiza korozije, unutrašnjost naftovoda, zaštita okoliša

 


I. STOJANOVIC, V. ALAR, I. JURAGA

Originalni naučni rad [PDF]
UDC:620.197.6:667.633.22

Analiza zaštitnih svojstava premaza na vodenoj bazi na metalnim podlogama

U današnje vrijeme korozijsko djelovanje je jedan od ključnih faktora u ekonomskom, sigurnosnom i ekološkom aspektu, čime je poraslo zanimanje za ovu problematiku i moguća rješenja smanjenja korozijskog djelovanja primjenom neke od metoda površinske zaštite. Većina antikorozivnih prevlaka koje se danas koriste nisu ekološki prihvatljive zbog povećane emisije organskih otapala u zrak. Stoga su potrebne promjene. Za zaštitu materijala trebale bi se koristiti prevlake dobrih zaštitnih svojstava, a koje su istovremeno i prihvatljive za okoliš. Jedan od važnijih razvoja u smjeru ekološki prihvatljivih antikorozivnih premaza jesu vodorazrjedivi premazi koji sadrže tek manji udio hlapivih organskih spojeva (HOS) i štite metale od korozije u različitim sredinama. U ovom radu ispitana su zaštitna svojstva vodorazrjedivih i otapalnih epoksidnih premaza primjenom elektrokemijske impendancijske spektroskopije (EIS), pretražnog elektronskog mikroskopa (SEM), ispitivanja u slanoj komori te mjerenjem debljine i tvrdoće premaza. Dobiveni rezultati ukazuju na potencijalno dobra zaštitna svojstva vodorazrjedivih epoksidnih premaza i mogućnosti njihove primjene za zaštitu od korozije metalnih konstrukcija. Ispitani otapalni premazi pokazuju bolja zaštitna svojstva.

Ključne riječi: zaštita od korozije, vodorazrjedivi premazi, temperatura sušenja

 

Analysis of the protective properties of waterborne coatings on metallic substrates

Nowadays, the corrosion effect is one of the key factors from an economic, safety and ecological point of view, what has resulted in a growing interest in these issues and possible solutions for reducing the corrosion damage by applying an appropriate corrosion protection method. Most of currently used anticorrosive coatings are not environmentally friendly because of their solvent emissions in the air. There is need for substitutes which would at the same time provide good corrosion protection and be environmentally acceptable. One of the most important developments towards to a new and environmentally friendly anticorrosion paints are waterborne coatings which contain low volatile organic compound (VOC) and protect metals in different types of environments. In this paper, corrosion protection properties of waterborne epoxy coatings in respect to solventborne coatings are determined using Electrochemical Impendence Spectroscopy (EIS), Scanning Electron Microscope analysis (SEM), Salt Chamber Testing as well as Dry Film Thickness and Hardness Measurement. Test results and evaluation of corrosion protection properties of waterborne epoxy coatings show their good corrosion resistance potential and possibility of their application in metal industry. Tested solventborne epoxy coating showed superior protection properties.

Key words: corrosion protection, waterborne coatings, drying temperature

 


 

M.V. TOMIĆ1, R. FUCHS GODEC2, LJ. VASILJEVIĆ1,  M.G. PAVLOVIĆ1

Scientific paper [PDF]
UDC:669.35:620.197.3

Possibility of application of green inhibitor for the protection of copper

The paper presents the assessment of copper corrosion protection by treatment of the corrosion surrounding with inhibitors. Copper samples measuring (50x50x1) mm after chemical preparation were subjected to corrosion in uninhibited and inhibited solutions during time of 2, 4, 6 and 24 hours. Two basic solutions were used: 3% NaCl and 4% HCl 0.1% solutions of thiocarbamide, furfural and hydrazine, and 1g/dm3, 2g/dm3 and 3g/dm3 of vitamine C and caffeine solutions were used as inhibitors. Thus the highest protection effect was shown by furfural, but also vitamine C for 2 h. No toxicity and good protective properties recommend vitamine C as an inhibitor of the future.

Key words: copper, inhibitor, corrosion, corrosion indicators, protective factor z.

 

Mogućnost primene zelenih inhibitora za zaštitu BAKRA

U ovom radu izvršeno je istraživanje zaštite bakra obradom korozione sredine inhibitorima. Uzorci bakra dimenzija (50x50x1) mm nakon hemijske pripreme podvrgnuti su koroziji u neinhibiranim i inhibiranim rastvorima u vremenu od 2, 4, 6 i 24 sata. Korišćena su dva osnovna rastvoraa: 3% NaCl i 4% HCl. Kao inhibitori korišćeni su tiokarbamid, furfural i hidrazin u koncentracijama 0,1%(mas), kao i vitamin C i kofein u koncentracijama 1g/dm3, 2g/dm3 i 3g/dm3. Od korišćenih inhibitora najbolje zaštitno dejstvo ima furfural, ali i vitamin  C u vremenu od 2h. Netoksičnost i dobra zaštitna svojstva vitamin C preporučuju kao inhibitor budućnosti.

Ključne reči: bakar, inhibitor, korozija, pokazatelji korozije, zaštitni faktor z.

 


 

ZAGORKA KONESKA, RUZICA MANOJLOVIC, DAFINKA STOEVSKA-GOGOVSKA

Scientific paper [PDF]
UDC:669.296:620.197.4

Influence of the pretreatment of the surface on the anodic behavior of zirconium in H3PO4 solutions

Anodic behavior was investigation of zirconium in deareated aqueous H3PO4 solutions at room temperatures for mechanically and chemically polished electrodes and for the electrodes chatodically polarized at the potential of -1,5 V (SCE).These methods of surface preparation  were applied in order to determine  their possible influence on anodic behavior of Zr in H3PO4 solutions. The investigations were carrying out using potentiodynamic method. The values for the corrosion potentials, corrosion currents and corrosion rates were calculated. These values depend from the surface pretreatment. Chemically polished surface has lowest corrosion rate. The open circuit behavior of zirconium was also investigated. OCP also depends from the surface pretreatment. The structures of the surfaces were study by means of metallography.

Key words: zirkonium, pretreatment of the surface, structures of the surfaces, corrision, OCP

 

UTICAJ PREDTRETMANA POVRŠINE NA ANODNO PONAŠANJE CIRKONIJUMA U H3PO4 RASTVORU

Anodno ponašanje cirkonijuma je ispitano u dearisanom rastvoru H3PO4 na sobnoj temperaturi, pri čemu je elektroda polirana mehanički i hemijski i polarizovana na potencijalu -1.5V (ZKE). Metode pripreme površine elektrode su primenjene u cilju utvrđivanja njihovog mogućeg uticaja na anodno ponašanje Zr u rastvoru H3PO4. Istraživanja su vršena pomoću potenciodinamičke metode. Vrednosti korozionog potencijala, struje korozije i procenta korozije su izračunate. Ove vrednosti zavise od površine predtretmana. Hemijski ispolirana površina elektrode ima najnižu stopu korozije. Otvoreno kolo ponašanja cirkonijuma je, takođe, ispitivano. Potencijal otvorenog kola, takođe, zavisi od predtretmana površine elektrode. Struktura površine elektrode cirkonijuma je ispitivana putem metalografije.

Ključne reči: cirkonijum, pretretman površine, struktura površine, korozija, potencijal otvorenog kola

 


 

SNEŽANA DEVIĆMIRA COCIĆ2

Originalni naučni rad [PDF]
UDC:620.182:669.162.212.3

Mikroskopski prikaz erozije maghromitne vatrostalne opeke livnog lonca usled dejstva troske

Problematika koja je tretirana u ovom radu odnosi se na objašnjenje i prikaz erozije maghromitnih vatrostalnih opeka livnog lonca za čelik. Erozija maghromitnih vatrostalnih opeka  nastala usled dejstva troske ispitana je primenom mikroskopske metode. Mikro snimci su rezultat mikroskopskog ispitivanja maghromitnih vatrostalnih opeka u propuštenom svetlu. Oni jasno prikazuju eroziju vatrostalne opeke. Na mikro snimcima se vidi postepen prodor troske u vatrostalnu opeku, njeno destruktivno dejstvo i na kraju  rušenje  strukture vatrostalne opeke.

Ključne reči: erozija, maghromitne vatrostalne opeke, troska, mikroskopska metoda

 

MICROSCOPIC DEMONSTRATION EROSION MAGCHROMIC REFRACTORY BRICKS FROM CASTING LADLES  BY THE ACTION SLAG

The issue that is treated in this paper refers to the explanation and presentation of erosion magchromic refractory bricks from casting ladle for steel. Erosion magchromic refractory bricks formed by the action of slag was investigated using microscopic methods. Micro-photography  are the result of microscopic examination magchromic refractory bricks, using refracted light. They clearly show the erosion of refractory bricks. At the micro-photography shows a gradual penetration of slag in the refractory bricks, its destructive effects and ultimately the destruction of the structure of refractory bricks.

Key words: erozion, magchromic refractory bricks, slag, microscopic methods.

 


 

JELENA AVDALOVIĆ1, VLADIMIR BEŠKOSKI2, DANIJELA RANĐELOVIĆ3, MIRJANA STOJANOVIĆ1, SNEŽANA ZILDŽOVIĆ1, MIROSLAV VRVIĆ4

Originalni naučni rad [PDF]
UDC:622.765.061:622.364.1(497.11)

Ispitivanje mogućnosti bioluženja fosfora iz fosfatne rude sa ležišta Lisina

Postupci rastvaranja fosfora iz nerastvornih fosfatnih ruda pomoću acidofilnih autotrofa i heterotrofa spadaju u veoma bitna istraživanja, zbog moguće primene ovih ruda kao đubriva, čija je upotreba ekonomski i ekološki prihvatljivija od industrijskih fosfatnih đubriva. Predmet ovog rada je bio da se ispita mogućnost rastvaranja fosfora iz fosfatne rude sa ležišta Lisina (Bosilegrad), u laboratorijskim uslovima, dejstvom sumporne kiseline generisane pomoću bakterijske kulture Acidithiobacillus (At.) ferrooxidans, izolovane i selekcionisane sa jalovišta površinskog kopa rudnika bakra u Boru. Cilj eksperimenta je da se utvrdi da li je moguće rudu sa navedenog ležišta u kombinaciji sa ispitivanom bakterijskom kulturom  koristiti kao prirodno đubrivo. Dobijeni rezultati pokazuju da se tokom eksperimenta rastvara fosfor iz ispitivane rude pod uticajem At. ferrooxidans i da je stepen rastvaranja 24,5 %, dok je rastvaranje fosfora u kontrolnoj suspenziji (bez At. ferrooxidans) iznosilo 7,2 %. Uticaj At. ferrooxidans na rastvaranje fosfora je potvrđen, tako da dalja istraživanja treba usmeriti na ispitivanja mikrobiološkog luženja mešavina apatita sa sulfidnim supstratima, zbog eventualne primene vezane za poboljšanje kvaliteta alkalnih zemljišta.

Ključne reči: fosfatna ruda, luženje, Acidithiobacillus ferrooxidans

 

Examination of phosphate ores bioleaching from Lisina deposit

Phosphorus solubilization from insoluble phosphate ores by acidophilic autotrophs and heterotrophs is a research of significant interest, because of potential use of these ores as fertilizers, which are economically and ecologically more acceptable than industrial phosphate fertilizers. The object of this paper was to examine the possibility of phosphorus leaching from phosphate ore from Lisina deposit (Bosilegrad), by bacterially generated sulfuric acid, in laboratory conditions. The experiments were carried out with bacterium Acidithiobacillus (At.) ferrooxidans, which is isolated and selected from the copper sulphide mine in Bor. The main goal of the experiment was to confirm if it is possible to use phosphate ore in combination with examined bacterial culture, as a natural fertilizer. Results obtained show that phosphorus has been leached up to 24,5 % in suspension with At. ferrooxidans, and in the same time, degree of leaching in control suspension (without At. frrooxidans) was up to 7,2 %. Influence of At. ferrooxidans on phosphorus solubilization has been confirmed, so the future perspective of our investigations should be directed to examination of microbiological leaching of apatite mixtures with sulphide substrates, and their potential use in quality improvement of alkaline soils.

Key words: phosphate ore, leaching, Acidithiobacillus ferrooxidans.

 


 

MIRJANA STOJANOVIC1, ZORICA LOPIČIĆ1, JELENA MILOJKOVIĆ1, ČASLAV LAČNJEVACMARIJA MIHAJLOVIĆ1 , MARIJA PETROVIĆALEKSANDAR KOSTIĆ2

Scientific paper [PDF]
UDC:504.054:631.872.874

Biomass waste material as potential adsorbent for sequestering pollutants

Conventional treatment technologies for the removal pollutants from the environment usually aren’t economically viable or may further generate huge quantity of toxic chemical sludge which requires further treatment. Biosorption is emerging as a potential alternative technique to the existing conventional technologies; its application is economically acceptable because it reuse biological materials with their major advantages: low cost, high efficiency, renewability, minimization of chemical or biological sludge, easy regeneration of biosorbents and possibility of metal recovery. The paper presents the review of the results of the biosorption efficiency of two biosorbents: peach shell, originating from “Vino Župa” Company from Aleksandrovac, as agro-industrial waste and urban waste, aquatic plant, Myriophyllum spicatum, harvested from artificial Sava Lake, Belgrade, as low cost biosorbents for removal of several pollution type: heavy metal ions (Cu, Pb), uranium as radionuclide and mycotoxins. Biosorption treatment method is especially applicable in developing countries where a “low cost tech” approach may be a suitable option.

Key words: waste biomass, myriophyllum spicatum, peach shell, biosorption, pollutants.

 

OTPADNA BIOMASA KAO POTENCIJALNI ADSORBENT POLUTANATA

Konvencionalne tehnologije za uklanjanje polutatanata iz životne sredine nisu ekonomski isplative i uglavnom generišu velike količine hemijski toksičnih muljeva. Biosorpcija se promoviše kao potencijalno alternativna tehnologija u odnosu na konvencionalne, zasnovana na primeni ekonomski prihvatljivih bioloških mateirjala koje odlikuje niska cena, visoka efikasnost, obnovljivost, minimiziran hemijski i biološki otpad, regeneracija biosorbenata sa mogučnostošću izdvajanja metala. U radu su prikazani neki rezultati ispitivanja efikasnosti koščica breskve, poreklom iz “Vino Župa” Aleksandrovac, kao agroindustrijskog otpada i urbanog otpada, vodene biljke, Miriophillum spicatum, iz veštačkog Savskog jezera u Beogradu, kao jeftinih biosorbenata za uklanjanje teških metala (Cu, Pb), uranijuma kao radionuklida i mikotoksina iz vodenih rastvora. .Zemlje u razvoju poput Srbije, koje imaju velike količine otpadne biomase, biosorpcione tehnologije otvaraju mogučnost razvijanja efikasnih i jeftinih adsorbenata za uklanjanje različitih tipova polutanata sa perspektivom otvaranja novih tržišta.

Ključne reči: otpadna biomasa, myriophyllum spicatum, koštice breskve , biosorpcija, polutanti

 


ORCE SPASOVSKIEMILIJA RISTOVA2

Scientific paper [PDF]
UDC:504.4.054(497.17)

Heavy metals in sediments along the River Zletovska in Eastern Macedonia

Soils according to the chemical composition and physic-chemical processes occurring in them represent the most complex systems in heterogeneous lithosphere. Both, soils and along the river sediments are subject to different research objectives, which analysis can come to the important information about the pollution of waters and soils with heavy metals, and thereby identify the effects on human health. In this paper the results of pollution by heavy metals in the sediments from the river Zletovska and its surroundings are presented. An attempt to identify the actual condition in the test area is made and the presence of the heavy metals in the sediments of the mentioned river and its tributaries to be determined. Analysis of samples was conducted as part of a series of samples of the instrument Atomic Emission Spectroscopy with inductive coupled plasma (AES-ICP). Past experiences of contamination of areas such as the area of interest indicate that the next group of elements should be taken into consideration: Mn, Fe, Al, Pb, Zn, As, Cd, Cu, Ni, Co, Ag, Cr, Ti, as well as some elements that present higher concentrations of maximum permitted amounts. In our case, the great influence on the activities of the contamination have Zletovo mines and some tailing ponds, which are a by – product of several decades of activity of the eponymous mines.

Key words: heavy metals, environmental pollution, sediments, River Zletovska

 

TEŠKI METALI U SEDIMENTIMA DUŽ REKE ZLETOVSKA U ISTOČNOJ MAKEDONIJI

Zemljišta prema hemijskom sastavu i fizičko-hemijskim procesima, koji se dešavaju u njima, predstavljaju najsloženije sisteme u heterogenoj litosfere. Oba, zemljišta i rečni sedimenti podležu različitim ciljevima istraživanja, čija analiza može dovesti do važnih informacija o zagađenju voda i zemljišta sa teškim metalima, a time se identifikuje i efekat na ljudsko zdravlje. U ovom radu prikazani su rezultati zagađenja teškim metalima u sedimentu iz reke Zletovska i njegove okoline. Pokušaj je da se stvore uslovi za test o prisustvu teških metala u sedimentima pomenute reke i njenih pritoka i da se oni utvrde. Analiza uzoraka je izvršena na instrumentu za atomsku spektroskopiju emisije sa induktivnom spregnutom plazme (AES-ICP). Ranija iskustva kontaminacije oblasti, kao što je oblast ovog interesovanja, pokazuju da sledeće grupe elemenata treba uzeti u obzir: Mn, Fe, Al, Pb, Zn, As, Cd, Cu, Ni, Co, Ag, Cr, Ti , kao i nekih elemenata sa većim koncentracijama maksimalno dozvoljenim količinama. U našem slučaju, veliki uticaj na aktivnost kontaminacije vodotoka i priobalja imaju rudnik Zletovo i neka jalovišta, koja su  nusproizvod nekoliko decenija aktivnosti istoimenog rudnika.

Ključne reči: teški metali, zagaðenje životne sredine, sedimenti, reka Zletovska

 


IRENA NIKOLIĆ1, RADOMIR ZEJAKVELIMIR RADMILOVIĆ3, DRAGOLJUB BLEČIĆMILENA TADIC1

Scientific paper [PDF]
UDC:504.3.056

Geopolymerization of fly ash as a possible solution for stabilization of used sandblasting grit

Geopolymers are relatively new, environmental friendly and light weight materials which form as a result of reaction of aluminosilicate materials with highly alkaline solution. They are characterised by satisfactory mechanical properties and so they are considered as a possible replacement for ordinary Portland cement in a construction. Besides, geopolymerisation technology is recognized as a possible way of immobilization of toxic waste (nuclear waste, waste water, wastes containing heavy metals). In this paper we have investigated a possibility of immobilization of used sandblasting grit in a fly ash based geopolymers. The results have shown that geopolymerisation of fly ash with addition of used sandblasting grit is possible, but the lower compressive strength is obtained compared to the compressive strength of fly ash based geopolymer. Microstructure of synthesised geopolymers is characterised by the presence of alumosilicate gel and unreacted fly ash and Si/Al ratio determine the compressive strength of geopolymers.

Key words: geopolymerisation, geopolymer, fly ash, sanblasting grit.

 

GEOPOLIMERIZACIJA LETEĆEG PEPELA KAO MOGUĆEG REŠENJA ZA STABILIZACIJU KADA SE KORISTI ZA PESKARENJE

Geopolimeri su relativno novi, ekološki i lagani materijali, koji se formiraju kao rezultat reakcije aluminosilikatne materijale sa visoko alkalnim rastvorima. Odlikuju ih zadovoljavajuće mehaničkie karakteristike, tako da se smatraju kao moguća zamena za obične Portland cemente pri izgradnji. Osim toga, tehnologija geopolimerisanja je prepoznata kao mogući način imobilizacije toksičnog otpada (nuklearni otpad, otpadne vode, otpadi koji sadrže teške metale). U ovom radu je istraživana mogućnost imobilizacije kada se pri peskiranju koristi granulacija samo letećeg pepela na bazi geopolimera. Rezultati su pokazali da geopolimerizacija letećeg pepela određene granulacije koda se koristi pri peskiranje je moguća, ali se dobija niža čvrstoća u odnosu na čvrstoću od letećeg pepela na bazi geopolimera. Mikrostruktura sintetizovanih geopolimera karakteriše prisustvo gela alumosilicijuma i nereaktivnog letećeg pepela a Si / Al odnos određuju čvrstoću geopolimera.

Ključne reči: geopolimerizacija, geopolimer, leteći pepeo, peskarenje.

 


 

BORE V. JEGDIĆSUZANA R. POLIĆ RADOVANOVIĆSLAVICA S. RISTIĆ1, ANA B. ALILVLADANA RAJAKOVIĆ-OGNJANOVIĆ3

Scientific paper [PDF]
UDC:620.193.2:502.8(497.11)

Corrosion of an archaeological find from the roman period in Serbia

The degree of preservation of iron artifacts depends on the type of underground environment and the type of corrosion products formed on their surface. This paper analyses the conditions of an archaeological find made of iron and originating from the Roman period and belonging to the collections of the Museum of Science and Technology in Belgrade. The radiographic method has been used to determine the quantity of non-corroded metal as well as to determine the presence of cracks and other defects in the artefact. The composition of the corrosion products has been analysed by the X-ray diffraction method (XRD). In addition to iron corrosion products (goethite α-FeO(OH) and magnetite Fe3O4), the presence of a significant quantity of akaganeite β-Fe8O8(OH)8Cl1.35, has been noticed on the artifact. The content of chloride, sulphate and other ions in the corrosion products has been determined by ion chromatography (IC). The analyses have pointed to the necessity of having artifacts treated in adequate solutions immediately after their excavation in order to eliminate chloride and sulphate anions. The aim of this paper is to determine the type of corrosion products and their influence on the corrosion behaviour ofr an archaeological artefact.

Key words: archaeological iron, corrosion, XRD, radiography, ionic chromatography.

 

Korozija arheoloških eksponata iz rimskog perioda u Srbiji

Koroziona postojanost eksponata od gvožđa zavisi od tipa podzemne sredine i vrste korozionih produkata koji se formiraju na njegovoj površini. Ovaj rad analizira stanje arheološkog predmeta koji potiče iz rimskog perioda i koji pripada kolekciji Muzeja za nauku i tehnniku u Beogradu. Radiografska metoda je korišćena za određivanje količine nekorodiralog metala, kao i prisustva prslina i drugih defekata u eksponatu. Sasatv korozionih produkata je analiziran difrakcijom X-zraka (XRD). Pored korozionih produkata gvožđa (getita α-FeO(OH)I magnetita Fe3O4), uočena je značajna količina akagenita β-Fe8O8(OH)8Cl1.35 u sloju korozionih produkata. Metodom jonske hromatografije (IC) je određen sadržaj hloridnih, sulfatnih i drugih jona u korozionim produktima. Pomenute analize su ukazale na neophodnost tretmana arheološkog predmeta u odgovarajućem rastvoru za desalinaciju, neposredno posle iskopavanja, u cilju uklanjanja hloridnih i sulfatnih anjona. Cilj ovog rada je određivanje tipa korozionih produkata i njihovog uticaaj na koroziono ponašanje arheološkog predmeta.

Ključne reči: arheološko gvožđe, korozija, XRD, radiografija, jonska hromatografija.

 


 

SLAVJANKA PEJCINOVSKA-ANDONOVADRAGICA CHAMOVSKA2

Professional paper [PDF]
UDC:504.75.05:667.42

Eco-label criteria for “greener” indoor paints and varnishes

The process of establishing the national eco-labeling criteria for indoor paints and varnishes started with mapping the paints and varnishes producers, importers and exporters, type, content and quantities of produced and put on the market various paints and varnishes products. The technological scheme including the energy and material balance, the current quality control and environmental related testing in domestic laboratories were analyzed as well. The environmental impact assessment was performed for all phases of paints and varnishes life cycle: manufacturing (energy and water consumption, waste water, waste generation, hazardous waste generation), use of the product (waste water, air emissions) and end of life (packaging waste, air and water pollution).
Putting the national eco-label on paints for any producer means that the product has the following assets: a) limited Volatile Organic Compounds (VOC) and Volatile Aromatic Hydrocarbons (VAH), b) reduced sulphur emissions during production of titanium dioxide used as white pigment, c) reduced hazardous waste of by-products during titanium dioxide production, d) no use of heavy metals, e) user instructions for environmental use including storage conditions, proper waste management and cleaning of tools and last not a least a guarantee of minimum hiding power, wet scrub resistance, water resistance and adhesion.

Key words: Eco-label criteria for indoor paints and varnishes, Eco-label scheme, Environmental Impact Assessment, Life cycle analysis

 

EKO-OZNAKE ZA „ZELENIJIM” BOJAMA I LAKOVIMA

Proces uspostavljanja nacionalnih eko kriterijuma za boje i lakove počeo je mapiranjem proizvođača, uvoznika i izvoznika, vrsta, sadržaja i količina proizvedenih i stavljenih na tržište raznih boja i lakova. Tehnološke šeme, uključujući energetski i materijalni bilans, tekuće kontrole kvaliteta i zaštite životne sredine u vezi sa testiranjem u domaćim laboratorijama su ocenjeni kao dobri. Uticaj na životnu sredinu urađen je za sve faze životnog ciklusa boja i lakova: proizvodnja (potrošnja energije i vode, otpadne vode, opasnog otpada), upotreba proizvoda (otpadne vode, emisije u vazduhu) i kraj života (ambalažni otpad, zagađenje vazduha i vode). Stavljanje nacionalne eko-oznake za boje za svakog proizvođača znači da proizvod ima sledeća svojstva: a) ograničeno isparljiva organska jedinjenja (VOC) i isparljive aromatične ugljovodonike (VAH); b) smanjenje sumpornih gasova tokom proizvodnje titanijum dioksida, upotrebljenog kao bela pigmenta; c) smanjenje opasnog otpada proizvoda tokom proizvodnje titan-dioksid; d) ne koristi teške metale; e) korisnička uputstva za upotrebu i čuvanje životne sredine, uključujući uslove čuvanja, pravilno upravljanje otpadom i čišćenje alata.

Ključne reči: Eko-oznaka kriterijuma za boje i lakove, Eko-etikete tehnološke šeme, procena uticaja životnog ciklusa

 


DRAGAN UGRINOVALEKSANDER STOJANOV2

Stručni rad [PDF]
UDC:628.11.16:504.4.062.2

Potreba za vodom i hidrološki ciklus

Rad apostrofira značaj vode za život čoveka, obrađuje vodu kao resurs o kome vodimo, ali uvek nedovoljno računa. Trošimo je neracionalno, i koliko je to bitno sa aspekta održivog razvoja?. Kako Zemlja stoji sa ,,zalihama,, vode, i njen proces kruženja u prirodi?. Život čoveka i njegove aktivnosti u sklopu tehnološkog razvoja doprinose da se resursi vode za piće zagađuju različitim materijama i mikroorganizmima koji ulaze u ciklus voda. Neophodno je razviti bolji sistem upravljanja resursima, kako bi se ublažio negativan uticaj čoveka na životnu sredinu.U tom smislu treba integrisati nauku, Zakon, političku akciju i reakciju javnosti u logičan okvir rada.

Ključne reči: voda, resurs, hirdološki ciklus, održivi razvoj, zagađenje

 

WATER NEEDS AND WATER CYCLE

The work emphasizes the importance of water for human life, treats water as a resource on which we lead, but not enought. We exploating it the irrational, and how it is important from the aspect of sustainable development, as Earth is from, stock, water, and its process of circulation in nature?. Human life and its activities in the technological development contributing to the water resources of drinking polluted different substances and microorganisms that enter the water cycle. It is necessary to develop a better system resource management, to mitigate the negative impact of man on environmental.In this sense, we need to integrated science, law, political action and public reaction in the logical framework.

Key words: water resource, hydrologic cycle, sustainable development, pollution

 


 

ŽELJKO STOJANOVIĆ, SANJA STANISAVLJEV, SNEŽANA RADOSAVLJEVIĆ

Stručni rad [PDF]
UDC:669.298.81.004.54

Primena postupka vanadiranja u funkciji produženja radnog veka delova

U radu je dat pregled literaturnih podataka o istraživanju uticaja sloja vanadijum karbida, formiranog termo-reaktivnom difuzijom na površini alatnih čelika i kalupa za livenje i kovanje. U zapadnoj naučno-stručnoj literaturi (USA i Japan) postoji dosta informacija o vanadiranim slojevima dobijenim na alatnim čelicima i kalupima, dok je u našim naučno-stručnim krugovima, i pored superiornih osobina koje sloj pruža u procesu eksploatacije, postupak ostao gotovo nepoznat. Kako je postupak vanadiranja još uvek uglavnom nepoznat našoj široj naučno-stručnoj javnosti, u radu su sistematizovana znanja i opisane osnovne zakonitosti, prednosti i nedostaci postupka vanadiranja, sa osvrtom na karakteristične primere njegove primene na sadašnjem nivou znanja. S obzirom da ekstremno tvrdi sloj formiran postupkom vanadiranja poseduje odlične osobine, od kojih treba izdvojiti: veoma visoku otpornost prema mehanizmu abrazije i athezije, dobre tribo-hemijske osobine i vrlo nizak koeficijent trenja, autori smatraju da će podaci u ovom radu poslužiti kao korisna referenca za proširenje primene ovog postupka i u našim proizvodnim pogonima, kao uobičajenog postupka obrade.

Ključne reči: vanadiranje, abrazija, athezija, tribo-korozija, alatni čelici, kalupi

 

APPLICATION OF VANADIZING PROCESS IN THE FUNCTION OF EXTENSION WORKING LIFE OF PARTS

This paper gives review of literature data about the research influence of vanadium carbide layer formed by thermal-reactive diffusion on the surface of the tool steel and die for casting and forging. In western scientific and professional literature (USA and Japan) exists a lot of information about the vanadized layers obtained on tool steel and dies, while in our scientific and professional circles, and beside of the superior qualities whose layer provides in the process of exploitation, the process remained almost unknown. As the procedure of vanadizing still largely unknown our broader scientific and professional public, therefore, in the paper are systematized knowledge and described the basic principles, advantages and disadvantages of the procedure of vanadizing, with emphasis on specific examples of its application on current level of knowledge. Considering that the extremely hard layer formed by procedure of vanadizing possesses excellent properties, of which should be singled out: very high resistance to the abrasion and adhesion mechanism, good tribochemical properties and very low coefficient of friction, the authors belive that the data in this paper serve as a useful reference for the expansion of application this procedure in our manufacturing facilities, as the usual treatment process.

Key words: vanadizing, abrasion, adhesion, tribo-corrosion, tool steel, dies.