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Book of Abstracts; 16th International Foundrymen Conference: Global Foundry Industries – Perspectives for the Future; Student Section
No full textMetalurška proizvodnja smatra se jednim od glavnih faktora koji utječe na razvoj svjetske ekonomije. Konkretna mjera povećanja konkurentnosti hrvatskih metalurških tvrtki je dostizanje ekonomične proizvodnje visoko kvalitetnog proizvoda umjerene cijene, vodeći računa o energetskim i ekološkim aspektima proizvodnje. Pritom se nameće imperativ povećanja transfera tehnologije i rezultata istraživanja između znanstveno istraživačkih institucija i realnog sektora. Nedvojbeni interes industrije za metaluršku struku i obrazovanje ogleda se njihovom participacijom na značajnim programima cjeloživotnog učenja Metalurškog fakulteta (Međunarodno savjetovanje ljevača, Znanstveno-stručni seminari). Predstavljanjem inovativnih istraživanja baziranih na unaprjeđenju materijala i tehnologija odvija se transfer znanja stečenih interakcijom tvrtki i znanstvenika. Osim navedenog, a uvažavajući vještine i znanja stečene u praksi Fakultet prepoznaje i organizira radionice, predavanja i prezentacije radi transfera znanja i iskustva stručnjaka iz industrije usmjerenih prema nastavnicima radi podizanja kompetencija, ali i studentima radi stjecanja specifičnih znanja i vještina. Visokoškolsko obrazovanje na Metalurškom fakultetu koncipirano programom i ishodima učenja zasniva se, između ostalog i na poticanju znanstvenoistraživačkog rada studenata s primijenjenim temama, kako bi ambiciozni i kreativni mladi ljudi postali samostalni rješavatelji problema, razvijajući i podupirući njihovu znatiželju, analitičnost, komunikativnost: kako bi postali diplomci kakve želi tržište rada!Metallurgical production is considered to be one of the main factors influencing the development of the world economy. A concrete measure to increase the competitiveness of Croatian metallurgical companies is to achieve cost-effective production of high quality products with reasonable prices, taking into account the energy and environmental aspects of production. An imperative to increase the transfer of technology and the results of research between scientific research institutions and the real sector has been imposed.The industry's undisputable interest in the metallurgical profession and education is reflected in their participation in significant lifelong learning programs at the Faculty of Metallurgy (International Foundrymen Conference, Scientific-Expert Seminars). Introduction of innovative researches based on material and technology improvement, knowledge transfer has been gained through interaction between companies and scientists. With respect to the skills and knowledge gained in practice, the Faculty recognizes and organizes workshops, lectures and presentations directed to the scientists in order to enhance their competences, but also to the students to acquire specific knowledge and skills. Higher education at the Faculty of Metallurgy, conceived through the program and the learning outcomes, is based, inter alia, on promoting students scientific and research work on applied topics, enabling ambitious and creative young people to become independent problem solvers, developing and supporting their curiosity, analytics and communication: Graduates like the labour market need
Electric arc furnace dust as a valuable production residue from the electric arc furnace steel production process
Get PDFČinjenica da je elektropećna prašina opasni proizvodni otpad kao i to da nije iz
ekonomskih razloga preporučljivo njeno odlaganje na odlagalištu, ukazuje na potrebu njenog
prevođenja u neopasni otpad kojeg je moguće zbrinuti bez naknadnog štetnog djelovanja u
okolišu, ili pak njene oporabe.
Razvojem ekološke svijesti i unapređenjem zakonskih propisa kojima se osigurava
zaštita okoliša kao i gospodarenje otpadom, pristupilo se sustavnom rješavanju problema
elektropećne prašine- opasnog proizvodnog otpada i to kako s ekološkog tako i s ekonomskog
stajališta što je imalo za posljedicu razvoj različitih postupaka oporabe elektropećne prašine.
Različiti stručnjaci u svijetu su odabirali različite načine rješavanja problema
elektropećne prašine kao opasnog proizvodnog otpada što je rezultiralo i razvojem različitih
procesa njene oporabe. Dok su jedni rješenje ovog problema vidjeli u izdvajanju teških
metala, drugi su svoja istraživanja usmjerili u razvijanje procesa za njihovu ekološku
inaktivaciju odnosno kemijsku imobilizaciju nakon čega se tako obrađeni otpad može odložiti
na tlo bez opasnosti od negativnog utjecaja na okoliš.
Različiti su autori u iznalaženju rješenja za zbrinjavanje elektropećne prašine dosegli i
različite rezultate u svojim istraživanjima pa su neki od razvijenijih procesa danas već i
potpuno komercijalizirani te se više ili manje primjenjuju u svijetu, neki su na razini pilot
postrojenja, ili pak u laboratorijskim razmjerima.
U ovom radu je dan pregled nekih do sada razvijenih i komercijaliziranih procesa koji
se uglavnom koriste u oporabi elektropećne prašine, dok su manjim dijelom prikazani procesi
njene inaktivacije, odnosno stabilizacije prije trajnog odlaganja.It is a well- known fact that electric arc furnace (EAF) dust is a hazardous industrial
waste as it is not economically advisable to deposit it at landfills. This implies the need to
transform it into non-hazardous waste that can be disposed of without any possible harmful
impacts on the environment, or its reusing.
Development of the environmental consciousness and improvement of the legal acts to
ensure environment protection and waste management has provided grounds for systematic
problem solution, both from the environmental and economical point of view, which further
induced development of different EAF dust recycling procedures.
Experts around the world took different approaches to finding a solution for disposing
of EAF dust as hazardous waste, which resulted in the development of different processes.
Whereas one group of experts saw the solution to this problem in the extraction of heavy
metals, the others directed their research towards the environmental inactivation i.e. chemical
immobilization processes, which allow the processed waste to be disposed of on the ground
without any risk of adverse impact to the environment.
Some of the processes developed have been completely commercialized by now and
are applied more or less around the world, whereas some processes are still in the pilot plants
or laboratory research stage.
This paper provides a survey of the processes that have been developed and
commercialized so far and that are mostly used in the EAF dust recycling. The processes of
EAF dust inactivation i.e. stabilization prior to permanent disposal are also discussed briefly
Removal of Cu(II) ions from aqueous solution using steel shot
No full textU ovom radu istraživana je mogućnost uklanjanja Cu (II) iona iz vodene otopine koristeći metalurški otpad. Povećana koncentracija Cu (II) iona u vodi može imati negativne posljedice na čovjeka, životinje i biljke te se Cu (II) ioni moraju ukloniti iz otpadne vode prije puštanja u odvod ili prirodne recipijente. U ovom radu korištena je otpadna čelična sačma kao adsorbens za uklanjanje Cu (II) iona iz vodene otopine. Eksperimentalni podaci opisani su kinetičkim modelima reakcije pseudo prvog i pseudo drugog reda, kao i Freundlichovom i Langmuirovom izotermom. Dobiveni rezultati pokazali su da se kinetika adsorpcije Cu (II) iona na otpadnoj čeličnoj sačmi odvija prema kinetičkom modelu pseudo drugog reda. Adsorpcijski proces sustava otpadna čelična sačma/Cu (II) ioni može se odvijati i prema Freundlichovom, kao i prema Langmuirovom modelu. Izglednije je da se adsorpcija odvija prema Freundlichovom modelu, odnosno da je fizikalne prirode.The possibility of removal of Cu (II) ions from aqueous solution using metallurgical waste was researched in this paper. The increased concentration of Cu (II) ions in the water can have negative effects on humans, animals and plants. Therefore, they must be removed from waste water before discharge into drains or natural recipients. In this paper, waste steel shot was used as the adsorbent for removal of Cu (II) ions from an aqueous solution. The experimental data are described using the kinetic models of the reaction of the pseudo first and pseudo second order, as well as Freundilich and Langmuir isotherm. Obtained results showed that the kinetics of adsorption of Cu (II) ions on the waste steel shot takes place according to the kinetic model of the pseudo second order. Adsorption of Cu (II) ions on the waste steel shot can take place according to the Freundilich and Langmuir model. It seems more likely that the adsorption takes place according to Freundilich model, which indicates the physical nature of the process
Composite materials based on nanotubes and metal matrix
Get PDFUgljične nanocijevi su izuzetan materijal zbog svoje čvrstoće i veoma male težine te se zbog toga koriste za dobivanje kompozita sa metalnom matricom pri čemu uvelike poboljšavaju svojstva nastalog materijala u odnosu na svojstva matrice. Metalu dodane ugljične nanocijevi mu poboljšavaju mehanička svojstva, a da pri tome ne utječe na težinu materijala. Iako su cijevi poznate čovječanstvu već duže vremena još uvijek se razvijaju tehnologije kojima bi se moglo lakše i kvalitetnije pripraviti novi kompozitni materijal na nanoskali.
U ovom radu dan je osvrt na ugljične nanocijevi, nanotehnologiju, kompozitne materijale i njihovu pripremu te na kompozitne materijale s metalnom matricom ojačane ugljičnim nanocijevima. Prikazane su prednosti kompozitnih materijala s metalnom matricom i ugljičnim nanocijevima te što možemo u budućnosti očekivati od ovog materijala.Carbon nanotubes are exceptional material due to their strength and very low weight and therefore can be used in preparation of a metal matrix composite, which greatly improves the properties of the material produced in relation to the matrix properties. The carbon nanotube added to the metal improve mechanical properies without affecting the weight of the material. Although nanotubes are known to mankind for a long time, technologies are still being developed to manage the preparation of new nanoscale composite materials.
This paper gives an overview of carbon nanotubes, nanotechnology, composite materials and their preparation, and on composite materials with metal matrices reinforced with carbon nanotubes. The advantages of composite materials with metal matrices and carbon nanotubes are shown and expectations for those materials in the future are given
Biological wastewater treatment
No full textPrije ispuštanja u prirodne recipijente, otpadne vode neophodno je pročistiti. Pročišćavanje otpadnih voda može se provesti primarnim, sekundarnim i tercijarnim postupcima. Sekundarni postupak ili biološko pročišćavanje se najčešće koristi. Ovaj postupak predstavlja
pročišćavanje pomoću mikroorganizama koji razgrađuju organske tvari, dušik i fosfor iz otpadnih voda. U ovom radu prikazan je pregled osnovnih pojmova vezanih uz otpadne vode i njihovo pročišćavanje. Poseban naglasak je stavljen na biološko pročišćavanje, čimbenike koji utječu na postupak biološkog pročišćavanja kao i najčešće postupke pomoću kojih se provodi biološko pročišćavanje otpadnih voda.Before discharging into natural recipients, wastewater must be purified. Wastewater purification can be carried out by primary, secondary and tertiary methods. Secondary method or biological purification is most commonly used. This method represents purification by microorganisms that decompose organic matter, nitrogen and phosphorus from wastewater. An overview of basic concepts related to wastewaters and their purification is presented in this review paper. Particular emphasis is placed on biological purification, factors that influence the biological purification process and most commonly used methods for biological wastewaters purification
Thermodynamic modelling of Cu-Al-Mn alloys
Get PDFCu-Al-Mn legure danas se često koriste u biomedicini, elektroindustriji, avioindustriji i dr.
kao materijali s prisjetljivosti oblika. U ovom radu istraživane su ternarne Cu-Al-Mn legure, s
različitim udjelima aluminija i mangana, u području bogatom bakrom. Legure su pripremljene
u elektrolučnoj peći te su zatim uzorci odliveni u cilindrične kalupe promjera 8 mm i duljine
12 mm. Nakon pripreme uzoraka brušenjem i poliranjem, analiza je provedena optičkom
mikroskopijom i pretražnom elektronskom mikroskopijom, uz analizu kemijskog sastava
energetsko disperzijskom spektroskopijom. Toplinska analiza provedena je na STA DSC/TG
uređaju te su određene temperature transformacija u rasponu od 25 °C do 1150 °C.
Termodinamički proračun faznog dijagrama proveden je Thermo-Calc programom, na osnovi
pripremljene baze termodinamičkih podataka prema optimiziranim literaturnim podacima.
Rezultati termodinamičkog proračuna korelirani su s rezultatima ispitivanja mikrostrukture i
toplinske analize.Cu-Al-Mn alloys are often used in biomedicine, electro-industry, aerospace, etc., mostly as
shape memory alloys. In this paper, Cu-Al-Mn ternary alloys with different content of
aluminium and manganese, in the Cu-rich corner were investigated. Alloys were prepared in
the electric-arc furnace and then casted in the cylindrical mould with dimensions of diameter
8mm and length 12mm. After grinding and polishing, samples were analyzed by optical
microscopy and scanning electron microscopy, equipped by energy dispersive spectroscopy.
Thermal analysis was performed by STA DSC/TG and phase transformation temperatures
were determined in the interval from 25 °C to 1150 °C. Thermodynamic calculations were
performed by Thermo-Calc software, with prepared database according to optimized
parameters. Results of the thermodynamic calculations were correlated with results of
microstructure analysis and thermal analysis
Soil pollution with heavy metals as a result of temporary steel scrap storage intended for processing at melt shop
Get PDFU ovom radu dan je prikaz oneĉišćenja tla teškim metalima uzrokovanog privremenim
odlaganjem čeličnog otpada na nezaštićenim zemljanim površinama. Čelični otpad se koristi
kao sirovina za proizvodnju čelika. Kao primjer ovakve vrste onečišćenja tla, dan je osvrt na
ispitivanje tla provedenog na podruĉju tzv. lomare u sisaĉkoj čeličani. Na tom području se
čelični otpad odlagao dugi niz godina te je bio izloţen utjecaju atmosferilija što je dovelo do
onečišćenja tla. U navedenom ispitivanju, analizirane su koncentracije teških metala u tlu (Cd,
Cr, Cu, Hg, Ni, Pb i Zn). Dobiveni rezultati analize uzoraka tla sa područja lomare uspoređeni
su s rezultatima referentnog uzorka tla, kao i s preporučenim graničnim vrijednostima teških
metala u tlu namijenjenog u industrijske i komercijalne svrhe prema Programu trajnog
motrenja tala Hrvatske i graničnim vrijednostima teških metala u tlu propisanih Pravilnikom o
zaštiti poljoprivrednog zemljišta od onečišćenja.This paper reviews soil contamination with heavy metals caused by the temporary
disposal of steel scrap on unprotected earthen surfaces. Steel scrap is used as a raw material
for steel production. As an example of this type of soil pollution, a survey of soil testing
carried out in the area of scrap yard at Sisak melt shop is given. In this area, steel scrap was
disposed of for many years and was exposed to the influence of atmospheric conditions
leading to soil contamination. Heavy metal concentrations in soil were investigat ed (Cd, Cr,
Cu, Hg, Ni, Pb and Zn). The results of the analysis of soil samples from the area of scrap yard
are compared with the results of the reference soil sample as well as with the recommended
heavy metals limit values in the soil intended for industrial and commercial purposes
according to the Croatian Soil Monitoring Program and with the heavy metals limit values in
the soil intended for agricultural purposes as well
Steel slag radioactivity as a factor for its use in construction industry
No full textU metalurškim procesima proizvodnje željeznih i neželjeznih metala te njihovih legura, nastaju onečišćujuće tvari anorganskog i organskog podrijetla te brojni proizvodni otpadi i nusproizvodi. Jedan od najvažnijih proizvodnih ostataka je čeličanska troska, koja nastaje u procesima proizvodnje čelika u kisikovim konvertorima, elektrolučnim pećima i procesima sekundarne metalurgije te se treba smatrati nusproizvodom, a ne proizvodnim otpadom.
U ovom radu ukratko su opisani procesi proizvodnje čelika u kojima troska nastaje, mehanička i fizikalno-kemijska svojstva elektropećne troske te mogućnosti njene uporabe u drugim procesima i djelatnostima. Najveća pozornost posvećena je svojstvu radioaktivnosti, odnosno aktivnosti 40K, 232Th i 226Ra, koji su najčešći radioaktivni izotopi u trosci. Korištena su prijašnja znanstvena istraživanja, na temelju kojih se može doći do zaključaka kako je uporaba elektropećne troske u drugim procesima i djelatnostima ne samo sigurna, već i poželjna.During the metallurgical production of ferrous and non-ferrous metals and their alloys, pollutants of inorganic and organic origin are produced, as well as different production waste and by-products. One of the most significant production residues is steel slag, that is generated by production of steel in Basic Oxygen Furnaces (BOF), Electric Arc Furnaces (EAF) and processes of secondary metallurgy, and should be considered a by-product rather than a production waste.
This paper briefly describes steel production processes in which the slag is generated, EAF slags physical-chemical properties, and the possibility of its application in other processes and activities. The most attention was dedicated to the property of radioactivity, or rather to the activity concentrations of 40K, 232Th and 226Ra, which are the most common radioactive isotopes found in steel slag. Previous scientific research was used, based on which a conclusion can be drawn that the use od EAF slag in other processes and activities is not only safe, but also desirable
Influence of medium and temperature on the corrosion behavior and microstructure of copper and brass
Get PDFU ovom je radu elektrokemijskim mjerenjima ispitana korozijska otpornost bakra i mesinga u vodovodnoj vodi i 3,5 % otopini NaCl pri sobnoj temperaturi i pri 60 °C. Promjene na površini uzoraka praćene su svjetlosnim i pretražnim elektronskim mikroskopom. Rezultati ispitivanja pokazali su da korozijska otpornost i za bakar i za mesing opada porastom temperature i u vodi i u 3,5 % otopini NaCl. Veću brzinu korozije u oba medija i pri obje ispitivane temperature pokazao je mesing, dok se bakar kao plemenitiji metal pokazao otpornijim na koroziju. Metalografskim i mikrostrukturnim ispitivanjima je ustanovljeno da se na površini bakra za vrijeme elektrokemijskog procesa u 3,5 % otopini NaCl stvara sloj bakrovog klorida, koji je nedovoljno postojan da u potpunosti spriječi prodiranje agresivnih iona iz otopine. Iz metalografskih snimaka mesinga nakon elektrokemijskih mjerenja utvrđeno je da dolazi do selektivnog otapanja cinka iz mesinga u kloridnom mediju.In this paper the corrosion resistance of copper and brass in drinking water and 3.5 % NaCl solution at room temperature and 60 °C was examined by electrochemical measurements. Changes in the surface of the samples were followed by light and scanning electron microscope. Investigation results showed that the corrosion resistance of both copper and brass decreases with temperature elevation in water and 3.5 % NaCl solution. Brass showed a higher corrosion rate in both media, while copper as a more noble metal showed more resistance to corrosion. Metallographic and microstructure investigations revealed copper chloride layer formed at copper surface during the electrochemical process in 3.5 % NaCl solution. Copper chloride layer is not stable enough to completely prevent the penetration of aggressive ions from the solution. Results of metallographic investigation of brass proved the process of dezinfication taking place at the metal surface in chloride solution
The significance of the EAF steelmaking process on air pollution with polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans
No full textTijekom metalurških procesa proizvodnje neželjeznih i željeznih metala kao i njihovih legura, nastaju onečišćujuće tvari anorganskog i organskog podrijetla koje u značajnoj mjeri opterećuju okoliš. Kao onečišćujuće tvari, koje su često dio otpadnih plinova, obično se pojavljuju CO, CO2, CH4, SO2, NOx, NH3, H2SO4, HCl, HF, HCN, H2S, prašina, ali i niz organskih spojeva kojima se ne posvećuje dovoljna pozornost. Organske onečišćujuće tvari su najčešće benzen, fenol, policiklički aromatski ugljikovodici, poliklorirani bifenili (PCB), poliklorirani dibenzo-p-dioksini (PCDD) i poliklorirani dibenzofurani (PCDF).
Poliklorirani dibenzo-p-dioksini i poliklorirani dibenzofurani koje pojednostavljeno nazivamo dioksini i furani ili skraćeno PCDD/F, među organskim onečišćujućim tvarima iz procesa proizvodnje čelika, zbog svojih fizikalno-kemijskih svojstava zauzimaju posebno značajno mjesto. Naime, s obzirom na svoju vrlo visoku toksičnost, izraženu postojanost u okolišu i sposobnost bioakumulacije u živim organizmima, nužno je poduzeti sve moguće potrebne mjere kojima bi se spriječilo njihovo nastajanje u metalurškim procesima čelika kao i mjere sprječavanja njihovog širenja u okoliš.
U ovom radu je posebna pozornost bila usmjerena na proces proizvodnje čelika elektropećnim postupkom kao izvora onečišćenja zraka dioksinima i furanima te su prikazani načini sprječavanja njihovog nastajanja u ovom procesu, kao i metode uklanjanja iz otpadnih plinova, ako je nastajanje ovih vrlo štetnih onečišćujućih tvari bilo neizbježno.During the metallurgical production of non-ferrous and ferrous metals as well as their alloys, pollutants of inorganic and organic origin with a significant impact on the environment are produced. Pollutants, that are often in a gaseous state and are part of waste gases, can be CO, CO2, CH4, SO2, NOx, NH3, H2SO4, HCl, HF, HCN, H2S, dust and other organic compounds which are usually not further investigated. Most common organic pollutants are benzene, phenol, polycyclic aromatic hydrocarbons, polychlorinated biphenyl (PCB), polychlorinated dibenzo-p-dioxins (PCDD) and polychlorinated dibenzofurans (PCDF).
Polychlorinated dibenzo-p-dioxins (PCDD) and polychlorinated dibenzofurans (PCDF), or as they are also known as dioxins and furans or PCDD/F for short, deserve special mentioning among the organic pollutants in the steel production process, as their physico-chemical properties are of a particular importance. Due to their high toxicity, persistence in the environment and the ability to bio accumulate in the living organisms, it is imperative to take all necessary steps to prevent their formation in metallurgical steel processes as well as to ensure measures to prevent their spread to the environment.
This paper, analyses steel production by electric arc furnace process as a source of air pollution by dioxins and furans. Methods of preventing their formation during this process as well as the methods of their removal from the waste gases have been demonstrated