67 results on '"Sobota, Ivan"'
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2. Construction and demolition (C&D) waste management in Croatia with recycling overview
- Author
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Bedeković, Gordan, Kovačević Zelić, Biljana, and Sobota, Ivan
- Subjects
Construction Waste, Demolition Waste, Waste Management, Recycling - Abstract
Construction and demolition waste (C&D waste) is one of the most relevant waste types primarily due to large quantities and a high potential for re-use and recycle. This paper discusses the issues related to C&D waste management in the Republic of Croatia. It presents the overview of legislative changes and its impact on the C&D waste management in Croatia. C&D waste quantities per county in the period from 2001 to 2015 are given as well as the expected C&D waste quantities in the future. It is concluded that the legal framework is well established, but it is not implemented consistently. Therefore, it is necessary to plan certain activities and additional resources in order to make the C&D waste management more efficient. The paper also presents the options of C&D waste recycling and describes the recycling technology in a C&D waste recycling plant in the Republic of Croatia. Taking into account the relatively low price of recycled aggregate, long distance transport is not profitable. It is concluded that the use of mobile treatment facilities would be a good practical solution taking into account the underdeveloped infrastructure for C&D waste management.
- Published
- 2018
3. Separacija metala iz otpadnih integriranih krugova metodama oplemenjivanja mineralnih sirovina
- Author
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Bedeković, Gordan, Sobota, Ivan, and Jorgić, Duško
- Subjects
metali, integrirani krugovi, recikliranje, elektrostatička separacija, gravitacijska separacija, zračna separacija - Abstract
Elektronički otpad danas je jedan od najbrže rastućih tokova otpada. Njegov značaj proizlazi kako iz količina otpada, tako i zbog sadržaja vrijednih metala koje sadrži. Danas gotovo svi elektronički uređaji sadrže integrirane krugove. Ovaj rad prikazuje rezultate istraživanja s ciljem separacije metala iz otpadnih elektroničkih krugova. U tu svrhu korištene su metode koje se tradicionalno koriste u oplemenjivanju mineralnih sirovina: elektrostatička separacija, gravitacijska koncentracija i zračna separacija. Rezultati su pokazali da je moguće izdvajati metale ovim koncentracijskim metodama iz otpadnih integriranih krugova.
- Published
- 2018
4. Separacja miedzi z kabli telefonicznych za pomocą metody wzbogacania grawitacyjnego
- Author
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Bedeković, Gordan, Sobota, Ivan, Lasić, Jakov, and Čablik, Vladimir
- Subjects
e-waste ,copper ,e-waste, UTP/STP cables, recycling, copper, gravity concentration ,recycling ,gravity concentration ,UTP/STP cables - Abstract
Waste electric and electronic equipment (WEEE) has the fastest growth compared to other types of waste due to the amount and thus increasing the need for its care about it. Disposal at landfills is not desired by the fact that this type of waste contains a number of useful materials that can be used again, as well as dangerous substances for which disposal is not desirable. This paper presents laboratory tests of separating copper from telephone (UTP and STP) cables that are an integral part of electronic equipment. Testing were carried out by method of gravity concentration using Wilfley shaking table and Humphreys spiral concentrator. The results showed that these devices can be used successfully to obtain copper concentrate whereby better results were obtained at a shaking table., Zużyty sprzęt elektryczny i elektroniczny (WEEE) to najszybciej rosnący strumień odpadów w porównaniu do innych rodzajów odpadów, a tym samym powstaje zapotrzebowanie na jego skuteczne zarządzanie. Unieszkodliwianie odpadów na składowiskach odpadów nie jest pożądane z uwagi na to, że ten rodzaj odpadów zawiera wiele użytecznych materiałów, które można wykorzystać ponownie, a także substancje niebezpieczne, których składowanie wymaga spełniania rygorystycznych wymagań. W artykule przedstawiono wyniki badań laboratoryjnych separacji miedzi z kabli telefonicznych (UTP i STP), które stanowią integralną część sprzętu elektronicznego. Separację przeprowadzono metodą wzbogacania grawitacyjnego na stole wytrząsającego Wilfley i Humphreys oraz separatorze spiralnym. Uzyskane wyniki wykazały, że te urządzenia mogą być z powodzeniem stosowane do uzyskania koncentratu miedzi.
- Published
- 2018
5. CONSTRUCTION AND DEMOLITION WASTE MANAGEMENT IN CROATIA WITH RECYCLING OVERVIEW
- Author
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Bedeković, Gordan, primary, Kovačević Zelić, Biljana, additional, and Sobota, Ivan, additional
- Published
- 2018
- Full Text
- View/download PDF
6. Direktiva o industrijskim emisijama i okolišna dozvola
- Author
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Sobota, Ivan and Folo, Nerea
- Subjects
Direktiva 2010/75/EU ,emisije ,najbolje raspoložive tehnologije ,okolišna dozvola - Abstract
S ciljem cjelovitog sprječavanja i nadzora onečišćenja okoliša, europskom Direktivom 2010/75/EU o industrijskim emisijama propisani su obvezni uvjeti zaštite okoliša koje određene djelatnosti iz sektora energetike, industrije i gospodarenja otpadom moraju ispunjavati da bi postrojenje u kojem se one obavljaju dobilo dozvolu za rad (okolišnu dozvolu). Ti uvjeti uključuju primjenu najboljih raspoloživih tehnologija i drugih mjera usmjerenih na sprječavanje ili smanjivanje emisija u zrak, vode i tlo. Prijedlog mjera za usklađivanje sa zahtjevima Direktive donosi se na temelju usporedbe emisija iz postrojenja s graničnim vrijednostima emisija propisanih direktivom.
- Published
- 2016
7. BENTONITE PROCESSING
- Author
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Grbeš, Anamarija, Bedeković, Gordan, and Sobota, Ivan
- Subjects
lcsh:TN1-997 ,lcsh:Geology ,bentonite ,lcsh:QE1-996.5 ,precessing ,montmorillonite ,beneficiation ,processing ,lcsh:Mining engineering. Metallurgy - Abstract
Bentonite has vide variety of uses. Sepecial use of bentonite, where its absorbing properties are employed to provide water-tight sealing is for an underground repository in granites. In this paper, bentonite processing and beneficiation are described.
- Published
- 2012
8. Usklađivanje termoenergetskih postrojenja sa zahtjevima direktive o industrijskim emisijama
- Author
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Sobota, Ivan, primary, Bedeković, Gordan, additional, and Ćurković, Danijela, additional
- Published
- 2017
- Full Text
- View/download PDF
9. Separation of Copper from Telephone Cables by Gravity Concentration.
- Author
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BEDEKOVIĆ, Gordan, SOBOTA, Ivan, and LASIĆ, Jakov
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COPPER ,WASTE management ,ELECTRONIC waste ,SUSTAINABLE development ,TELEPHONE cables ,ELECTRIC cables ,TELECOMMUNICATION cables - Abstract
Copyright of Inzynieria Mineralna is the property of Polskie Towarzystwo Przerobki Kopalin and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2018
- Full Text
- View/download PDF
10. POSSIBILITY OF BENEFICIATION OF SILICA SAND FROM THE CROATIAN DEPOSITS USING ATTRITION SCRUBBING
- Author
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Sobota, Ivan, Salopek, Branko, Bedeković, Gordan, and Grbeš, Anamarija
- Subjects
kvarcni pijesak ,mineralne primjese ,oplemenjivanje ,atricijsko čišćenje ,silica sand ,impurities ,beneficiation ,attrition scrubbing - Abstract
Da bi se dobila kvarcna sirovina koja svojom kvalitetom udovoljava specifičnim zahtjevima pojedinih industrija, rovni pijesak mora proći odgovarajući proces oplemenjivanja. Mogućnost dobivanja koncentrata kvarcnog pijeska odgovarajuće kvalitete ovisi o značajkama rovnog pijeska, u prvom redu o vrsti i sadržaju mineralnih primjesa u pijesku, te značajkama primjenjenih oplemenjivačkih postupaka. Kada se primjese javljaju u obliku oksidnih prevlaka na površini kvarcnih zrna, primjenjuje se atricijsko čišćenje. Odstranjivanjem oksidnih prevlaka, kvaliteta pijeska značajno se može poboljšati. S ciljem utvrđivanja mogućnosti oplemenjivanja kvarcnog pijeska perspektivnih hrvatskih ležišta (“Vrtlinska”, “Štefanac” i “Španovica”) i postizanja koncentrata čija kvaliteta ispunjava zahtjeve domaće industrije, provedena su laboratorijska ispitivanja s tri različita uzorka rovnog pijeska. Ispitivanjima su utvrđene osnovne značajke (granulometrijski, kemijski i mineralni sastav) rovnih uzoraka kvarcnog pijeska, te mogućnost poboljšanja njihove kvalitete primjenom postupaka pranja, klasiranja i mehaničkog atricijskog čišćenja., To meet high quality requirements defined for specific industrial applications, the raw sand often has to be subjected to extensive physical and chemical processing. The possibility of achieving silica sand concentrate of required quality depends mostly on raw sand properties, primarily mineral impurity types and contents, and features of applied beneficiation methods. When the impurities occur in the form of oxide coatings on the surfaces of the single sand grains, attriton scrubbing is applied. By reducing the proportion of oxide coatings on the grains, the quality of sand can be improved. With the aim to determine the possibilities of the beneficiation of silica sand from significant Croatian deposits (“Vrtlinska”, “Štefanac” and “Španovica”) and achieve concentrate grade complying with the requirements of domestic industry, laboratory tests were conducted on three raw sand samples with different SiO2 and impurity contents. Grain size distribution, chemical and mineral composition of raw sand samples, and the possibility of their quality improvement by applying the washing, classification and attrition scrubbing were defined by analysis of test results.
- Published
- 2011
11. Atricijsko čišćenje kvarcnog pijeska
- Author
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Sobota, Ivan, Bedeković, Gordan, and Majetić, Katarina
- Subjects
kvarcni pijesak ,atricija ,oplemenjivanje - Abstract
Primjena kvarcnog pijeska u pojedinim granama uvjetovana je njegovom kvalitetom koja podrazumijeva određeni granulometrijski, kemijski i mineralni sastav. Mogućnost dobivanja koncentrata kvarcnog pijeska odgovarajuće kvalitete ovisi o značajkama rovnog pijeska, u prvom redu o vrsti i sadržaju mineralnih primjesa u pijesku, te značajkama primijenjenih oplemenjivačkih postupaka. Kada se primjese javljaju u obliku oksidnih prevlaka na površini kvarcnih zrna, primjenjuje se atricijsko čišćenje. Odstranjivanjem oksidnih prevlaka, kvaliteta pijeska značajno se može poboljšati.
- Published
- 2011
12. Mechanical Methods of Soil Cleaning
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Salopek, Branko, Sobota, Ivan, Bedeković, Gordan, and Grbeš, Anamarija
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soil cleaning ,soli washing ,mechanical methods - Abstract
Soil cleaning technologies are becoming more and more important especially in industrialized countries. Application of soil washing i.e. physical separation results in cleaned soil which can be reused at the origin or the other location. Separated impurities (metals, hydrocarbons) are considered as special waste and further processed and/or disposed on special landfills. Technologies that were originally developed for mineral processing, due to similarity of operative goals – concentration/separation of certain matter adhering to a certain class of grain collective – have a high potential for use in soil cleaning. The purpose of this paper is to give a review of mineral processing methods which can be applied in soil washing technology, and to present some of the processes successfully applied in practice.
- Published
- 2009
13. Istraživanje mogućnosti oplemenjivanja kvarcnih pijesaka primjenom flotacije i magnetske separacije
- Author
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Sobota, Ivan
- Subjects
kvarcni pijesak ,oplemenjivanje ,atricija ,flotacija ,magnetska separacija ,kvaliteta koncentrata ,iskorištenje - Abstract
Zbog mineralnog sastava i načina sraslosti pojedinih mineralnih sastojaka, proces oplemenjivanja kvarcnog pijeska može biti vrlo složen i često uključuje primjenu čitavog niza fizičkih i fizičko-kemijskih postupaka čiji je općeniti cilj povećanje sadržaja SiO2 i smanjenje sadržaja nepoželjnih komponenti u pijesku (oksida Fe, Al, Ti, Cr i dr.) koje utječu na kvalitetu proizvoda. S ciljem utvrđivanja mogućnosti oplemenjivanja kvarcnog pijeska perspektivnih hrvatskih ležišta, odnosno postizanja koncentrata čija kvaliteta ispunjava zahtjeve domaće industrije stakla, fine keramike i ljevačke industrije, te definiranja tehnoloških shema po kojima se ostvaruje takva proizvodnja, provedena su laboratorijska ispitivanja s tri različita uzorka rovnog pijeska. Ispitivanja su, uz standardne metode granulometrijske, kemijske i mineraloške analize, uključivala različite postupke oplemenjivanja: pranje i klasiranje na sitima i spiralnom klasifikatoru, atricijsko čišćenje, flotaciju i magnetsku separaciju. Utvrđene su osnovne značajke rovnih uzoraka kvarcnog pijeska uzetih na lokacijama Vrtlinska, Štefanac i Španovica, učinkovitost pojedinih oplemenjivačkih postupaka u ovisnosti o sastavu ulaznog materijala i radnim parametrima, optimalna kombinacija vrijednosti radnih parametara svakog od postupaka pri kojoj se postiže najveće poboljšanje kvalitete kvarcnog pijeska uz zadovoljavajuće maseno iskorištenje, mogućnost poboljšanja kvalitete primjenom kombinacije oplemenjivačkih postupaka, te najviša kvaliteta koncentrata svakog od ispitivanih uzoraka koja se može postići u uvjetima provedenih ispitivanja. Na temelju rezultata provedenih ispitivanja predložene su tehnološke sheme oplemenjivanja za ispitivani kvarcni pijesak. Provedena istraživanja proširila su saznanja o mogućnosti oplemenjivanja kvarcnog pijeska primjenom atricijskog čišćenja, flotacije i magnetske separacije, te postizanja visokokvalitetnog koncentrata kvarcnog pijeska s mogućnošću primjene u različitim industrijskim granama. Ispitivanja su potvrdila da se iz rovnog kvarcnog pijeska ležišta "Vrtlinska", "Štefanac" i "Španovica" može dobiti proizvod koji svojom kvalitetom udovoljava zahtjevima industrije stakla, keramike i ljevačke industrije. Rezultati ispitivanja također ukazuju na mogućnost izdvajanja značajne količine kvalitetnog koncentrata kalijskog feldspata iz kvarcnog pijeska ležišta "Vrtlinska" i "Štefanac".
- Published
- 2009
14. Mehanički postupak čišćenja tla - pranje tla
- Author
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Salopek, Branko, Sobota, Ivan, Bedeković, Gordan, Grbeš, Anamarija, and Đurđa Vasić-Rački
- Subjects
čišćenje tla ,pranje tla ,mehanički postupci - Abstract
Čišćenje tla dobiva sve veći značaj u industrijaliziranim zemljama. Pranje tla odnosno fizikalna separacija omogućava da se tlo očisti do stupnja da se može ponovno koristiti na istoj lokaciji ili na nekoj drugoj bez opasnosti po okoliš. Izdvojene nečistoće (metali, ugljikovodici) zbrinjavaju se kao poseban otpad bilo da se dalje obrađuju i/ili odlažu na posebna odlagališta. Tehnologije koje su originalno razvijene za oplemenjivanje mineralnih sirovina, zbog sličnosti operativnih ciljeva – koncentriranja odnosno separiranja određene tvari vezane za određenu klasu nekog zrnatog kolektiva - imaju velik potencijal za primjenu u čišćenju tla. Svrha ovoga članka je dati pregled mehaničkih postupaka koji se mogu primijeniti u procesu pranja tla te kroz tehnološke sheme prikazati neke od tehnologija koje su uspješno primjenjene u praksi.
- Published
- 2009
15. Učinkovitost separiranja metalnog otpada u magnetskom separatoru s vrtložnim strujama
- Author
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Bedeković, Gordan, Salopek, Branko, and Sobota, Ivan
- Subjects
metalni otpad ,magnetska separacija s vrtložnim strujama ,recikliranje - Abstract
Magnetska separacija s vrtložnim strujama najčešće se koristi za izdvajanje nemagnetičnih metala (Al, Cu, Zn, Pb) iz krutog otpada, a također i za njihovo međusobno odvajanje. Tračni transporter doprema ulazni materijal na bubanj s magnetskim poljem. Promjenjivo magnetsko polje inducira vrtložne struje u vodljivim česticama (česticama metala). Interakcija između ovih struja i magnetskog polja uzrokuje elektrodinamičke sile koje djeluju na vodljive čestice, pa će se njihova putanja razlikovati od putanje nevodljivih čestica. Do separacije dolazi djelovanjem nekoliko sila (elektrodinamičke, gravitacijske i sile trenja). U radu su prikazani rezultati izdvajanja aluminija iz smjese metalnog otpada u magnetskom separatoru s vrtložmim strujama. Testiranje je izvedeno u pogonskim uvjetima. Rezultati pokazuju da je moguće postići iskorištenje korisne komponente od 99 % uz sadržaj aluminija u koncentratu od 89 %.
- Published
- 2008
16. Preliminary testing of laboratory column flotation
- Author
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Bedeković, Gordan, Salopek, Branko, Sobota, Ivan, and Fečko, Peter
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froth flotation ,flotation column ,fine coal processing - Abstract
Froth flotation is a process for separation fine solids based on differences of surface characteristics of mineral particles. Separation by flotation is a result of interaction of many variables. The recovery and selectivity depends not only on chemical variables, but also on hydrodynamics of flotation. Hydrodynamics condition in mechanical flotation cell is more turbulent than in flotation column. The paper present results obtained during initial breaking-in of laboratory flotation column on fine coal samples. Optimal dosage value of AF2 collector used in testing was approximately 700 g/t. The best results were obtained by pulp density in range from 50 to 100 g/l. Also, aeration rate should be in range from 24 to 30 l/h. Test with different bubbles sizes showed better result with smaller bubbles.
- Published
- 2008
17. Inercijski taložnici prašine
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Salopek, Branko, Bedeković, Gordan, Sobota, Ivan, and Đurđa Vasić Rački
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čišćenje plinova ,inercijski taložnici ,princip rada ,učinkovitost - Abstract
Za izdvajanje čestica iz zraka i otpadnih plinova na raspolaganju je velik broj aparata i uređaja. Obično se razvrstavaju u četiri grupe ovisno o silama koje djeluju na čestice. To su: inercijski taložnici, filtri, elektrostatski taložnici i skraberi. U radu su prikazani osnovni tipovi inercijskih taložnika (gravitacijski, udarni, centrifugalni) koji se u praksi najčešće koriste. Prikazan je njihov princip rada, tehnološke značajke, učinkovitost te mogućnost primjene.
- Published
- 2008
18. Zapošljivost nezaposlenih osoba s invaliditetom
- Author
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Kiš-Glavaš, Lelia, Majsec Sobota, Višnja, Sokač, Kristijana, Gavrilović, Aleksandra, and Sobota, Ivan
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osobe s invaliditetom ,nazaposlenost - Abstract
2007. godine UNDP Hrvatska pokrenuo je projekt - Pravo na život u zajednici: Socijalno uključivanje i osobe s invaliditetom, u okviru kojeg je realiziran i potporojekt: Utvrđivanje spremnosti osoba s invaliditetom na zapošljavanje. Pri tome je prva aktivnost bila upravo provođenje znanstvenog projekta: Stavovi nezaposlenih osoba s invaliditetom prema zapošljavanju i neke aktivnosti s ciljem povećavanja njihove zapošljivosti. Za potrebe provođenja istraživanja formiran je znanstveni tim kojeg su činili autori ove publikacije, a za izradu prijedloga aktivnosti koje se temelje na rezultatima istraživanja stručni tim kojeg su sačinjavali stručnjaci sa Hrvatskog zavoda za zapošljavanje, koji su izradili i smjernice koje se u sažetom obliku nalaze na kraju ove publikacije.
- Published
- 2008
19. Magnetic separation as a method of solid waste processing
- Author
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Salopek, Branko, Bedeković, Gordan, Sobota, Ivan, Koprivanac, Natalija, and Kušić, Hrvoje
- Subjects
solid waste ,magnetic separation ,metals - Abstract
Demand for metals continuously increases so that metal collection and recycling of waste containing metal become very profitable. Firstly, it refers to steel, copper, aluminium, lead, zinc and their alloys. These metals can be collected selectively (aluminium and steel tins), collected as refuse products (old cars, household appliances, electronic waste) or mixed with other materials (municipal waste). Selectively collected metal does not contain other material impurities and it is compacted (baled) and sold as a metal. Waste which contains other materials besides metal has to be recycled. The recycling process usually includes comminution, classification and separation. Crushers and mills are used for comminution, screens for classification and magnetic separators for metal separation. There are two main types of a magnetic separators: separators with slow rotation speed (drum and belt separators) and separators with high rotation speed (eddy-current separators). The former are used for the separation of magnetic materials (steel, iron) and the latter for the separation of nonmagnetic materials (aluminium, copper, lead, etc.). The paper describes the working principle, application and efficiency of magnetic separators in the recycling of various waste.
- Published
- 2007
20. Silica sand production in Croatia
- Author
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Sobota, Ivan, Salopek, Branko, Bedeković, Gordan, Singhal, Raj K., Fytas, Kostas, Jongsiri, Sirintorn, and Ge, Hao
- Subjects
silica sand ,impurities ,beneficiation - Abstract
Silica sand is an important non-metallic mineral raw material within the resources of the Republic of Croatia. Croatian silica sand reserves could meet industrial needs over the long term. The 15 exploitation fields are registered, and the average annual production in the last 10 years is about 240, 000 tonnes. Depending on quality i.e. specific physical and chemical properties (grain size distribution, chemical and mineral composition, moisture content, etc.), silica sand is used as the basic mineral raw material for many industrial applications. To meet defined chemical and physical specifications according to intended application, the raw sand often has to be subjected to extensive physical and chemical processing. The paper describes main beneficiation methods used in the processing of sand intended for industrial uses. Beneficiation procedure applied at the silica sand deposit "Jerovec" located in north-western Croatia is presented, as well as the results achieved under field conditions.
- Published
- 2007
21. Recycling of glass in Croatia
- Author
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Bedeković, Gordan, Salopek, Branko, Sobota Ivan, and Fečko, Peter
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recycling technology ,glass ,container ,recycling cycle - Abstract
Glass recycling is the process of turning waste glass into usable products. Glass is an ideal material for recycling and in some cases can be used repeatedly without any deterioration in its physical properties. There are several types of glass entering the waste stream each with different chemical compositions and physical properties. Recycling of complex material such as a glass is a simple but hugely beneficial process which consists of several steps. The complete recycling loop can be repeated an infinite number of times and the quality of the glass will never deteriorate. The paper describes recycling cycle, recycling technology and overview of glass recycling state in EU.
- Published
- 2007
22. Sigurna digitalna knjižnica
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Sobota, Ivan
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digitalni vodeni žigovi ,zaštita dokumenata - Abstract
U ovom diplomskom radu opisani su i ispitani sigurnosni mehanizmi za zaštitu sadržaja digitalne knjižnice od neovlaštenog kopiranja. Zaštita je temeljena na otpornim digitalnim vodenim žigovima s pomoću kojih se može dokazati izvornost digitalnih dokumenata. Sustav omogućuje sigurnu autentifikaciju i autorizaciju korisnika, upravljanje korisničkim računima, ažuriranje digitalne knjižnice te ubacivanje i detekciju digitalnih vodenih žigova.
- Published
- 2007
23. Pročišćavanje otpadnih voda iz pogona za preradu tehničkog i arhitektonsko-građevnog kamena
- Author
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Salopek, Branko, Bedeković, Gordan, Sobota, Ivan, and Salopek, Branko
- Subjects
otpadne vode ,rudarstvo ,zgušnjavanje ,sedimentacija ,filtracija - Abstract
U tehnologiji prerade mineralnih sirovina vrlo često se susrećemo s velikim količinama otpadnih voda koje osim kemijskog onečišćenja sadrže i mehaničke nečistoće, najčešće fine čestice mineralnog porijekla. Ispuštanje takvih voda u pojedine dijelove okoliša - rijeke, mora i jezera danas uglavnom nije dopušteno. Sve stroži propisi zaštite okoliša prisiljavaju nas da otpadne vode pročistimo do prihvatljive razine (vraćanje u proces, ispuštanje u recipijent), a zaostale muljeve propisno zbrinemo. U radu će se opisati postupci pročišćavanja otpadnih voda iz separacija tehničkog kamena i pogona za preradu arhitektonsko-građevnog kamena.
- Published
- 2007
24. Utjecaj složenosti proizvoda na učinkovitost recikliranja
- Author
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Salopek, Branko, Bedeković, Gordan, Sobota, Ivan, and Salopek, Branko
- Subjects
kruti otpad ,recikliranje ,sitnjenje ,klasiranje ,separiranje - Abstract
Učinkovitost recikliranja, tj. postignuto iskorištenje otpadnog materijala (otpada) i kvaliteta dobivenih produkata, a time i cijena (recikliranja) značajno ovise o složenosti otpada. Što je otpad složeniji, potrebna je primjena sofisticiranije a time i skuplje tehnologije i opreme za recikliranje. Proces recikliranja krutog otpada u velikoj mjeri obuhvaća postupke koji se tradicionalno koriste u oplemenjivanju mineralnih sirovina. Sitnjenje, klasiranje i sortiranje čine osnovu svakog i malo složenijeg procesa recikliranja. Bez njihove primjene nije moguće učinkovito separirati pojedine sastavne materijale otpada predviđenog za recikliranje. Učinkovitost separacije prikazuje se pomoću dva osnovna pokazatelja - iskorištenja korisne komponente i čistoće koncentrata.
- Published
- 2006
25. Oplemenjivanje kvarcnog pijeska za industrijsku namjenu
- Author
-
Salopek, Branko, Sobota, Ivan, Bedeković, Gordan, Koščak, Siniša, Šuprina, Josip, and Žunec, Nenad
- Subjects
kvarcni pijesak ,mineralne primjese ,oplemenjivanje - Abstract
Kvarcni pijesci zauzimaju značajno mjesto u resursnom potencijalu RH. Hrvatska raspolaže relativno velikim rezervama kvarcnog pijeska koje mogu na duži rok zadovoljiti potrebe industrije, a poznate su brojne pojave i nalazišta na području Istre, Slavonije, Hrvatskog Zagorja, Dalmacije, Like, Korduna, Banije, Podravine i Posavine. Registrirano je 16 eksploatacijskih polja, površine 25, 34 km2, a prosječna proizvodnja kvarcnog pijeska u posljednjih desetak godina iznosi oko 240.000 t/god. Ovisno o kvaliteti, koja podrazumijeva određene fizičko-kemijske značajke (granulometrijski, kemijski i mineraloški sastav, sadržaj vlage i dr.), kvarcni pijesak se koristi u različite industrijske svrhe: kao osnovna sirovina za proizvodnju stakla, za izradu kalupa i jezgri u ljevarskoj industriji, kao abrazivni materijal, u kemijskoj i keramičkoj industriji, industriji građevnog materijala i dr. Najstrože zahtjeve za kvalitetom pijeska kao osnovnom sirovinom postavljaju proizvođači stakla koji, ovisno o vrsti stakla, traže što viši udio SiO2 ( 95%) i što niže udjele nepoželjnih primjesa koje u staklu izazivaju obojenja i mrlje ( 0, 5% Fe2O3, 0, 3% TiO2 i dr.). Rovni pijesak obično ne ispunjava te zahtjeve, te je neophodno njegovo oplemenjivanje kako bi se dobila kvarcna sirovina odgovarajuće kvalitete. Zbog svog mineralnog sastava i načina sraslosti pojedinih minerala proces oplemenjivanja kvarcnog pijeska može biti vrlo složen i često uključuje primjenu čitavog niza fizikalnih i fizikalno-kemijskih postupaka. U radu su opisani osnovni separacijski postupci koji se koriste u procesu oplemenjivanja kvarcnog pijeska namijenjenog za staklarsku industriju. Dan je prikaz tehnološkog procesa oplemenjivanja koji se primjenjuje na separaciji poduzeća IGM "Pješčara Jerovec" kraj Lepoglave s ciljem postizanja kvalitete pijeska neophodne za proizvodnju ambalažnog stakla. Također su prikazani rezultati koji se postižu oplemenjivanjem u pogonskim uvjetima.
- Published
- 2006
26. The beneficiation of dolomite used in glass industry
- Author
-
Bedeković, Gordan, Salopek, Branko, Sobota, Ivan, Cardu, M, Ciccu, R., Lovera, E., and Michelotti, E.
- Subjects
Beneficiation ,Magnetic Separation ,Dolomite ,dolomite ,glass industry ,beneficiation - Abstract
Mining activity in the Republic of Croatia is based mainly on the exploitation and production of non-metallic mineral raw materials. Since carbonate rocks are predominant in the geological structure of Croatia, in the majority of quarries limestone and dolomite are exploited. Dolomite is widely used in various industries e.g. construction industry, building material industry, metallurgy, glass industry, etc. In glassmaking it is added to raw material mixture in the form of dolomite grits (- 1 mm) as one of the essential components for the input of glass modifiers that is CaO and MgO. To be used for this purpose, dolomite has to meet certain standard specifications established by the glass industry. In most cases, dolomite exploited in quarries does not satisfy demanding specifications and, therefore, its further processing is needed. The paper describes processing technology for dolomite intended for use as a raw material in container glass production. Fe2O3 content in exploited dolomite before beneficiation varies in range from 0.052% to 0.07%. By beneficiation procedure applying dry magnetic separation, dolomite grits with Fe2O3 content less than 0.05%, which meets the requirements of container glass industry, are obtained. The results presented in this paper are achieved under field conditions.
- Published
- 2006
27. Studija utjecaja na okoliš, Geotermalno polje Zagreb, lokalitet ŠRC Blato
- Author
-
Salopek, Branko, Rajković, Damir, Golub, Miroslav, Bedeković, Gordan, Sobota, Ivan, Kurevija, Tomislav, and Kulenović, Samir
- Subjects
geotermalna energija ,studija utjecaja na okoliš - Abstract
Geotermalno polje Zagreb sastoji se od tri lokaliteta koji su definirani u Glavnom rudarskom projektu (Projekt je u skladu s odredbom iz čl. 41 stavka 1. Zakona o rudarstvu NN br. 35/95, Klasa:UP/I-310-07/95-03/45, ur. Br. 526-04-96-04 od 26. rujna 1996. god.) i Elaboratu o rezervama geotermalne vode (Rješenje Ministarstva gospodarstva rada i poduzetništva: Klasa:UP/I-310-01/03-03/228, ur. Br. 526-04-04-04 od 13. siječnja 2004. god.). Na GPZ izrađeno je ukupno 14 bušotina, a probna proizvodnja započela je 1981. bušotinom Mla-1. Glavnim rudarskim projektom i Elaboratom o rezervama na GPZ predviđeno je crpljenje, iskorištavanje i utiskivanje geotermalne vode u zatvorenom cirkulacijskom sustavu.
- Published
- 2006
28. Waste Water Treatment in Quarries of Technical Stone
- Author
-
Bedeković, Gordan, Salopek, Branko, Sobota, Ivan, Raj, K. Singhal, Kostas, Fytas, and Chris, Chiwetelu
- Subjects
waste water ,technical stone ,sedimentation ,filtration - Abstract
The non-metals and building materials industry accounted for approximately 8 % of the total industrial output in Croatia during year 2004. Nowadays more than 200 trading companies in Croatia deal with the exploitation of solid mineral raw materials, and almost 50 % of them exploit technical stone. In the majority of technical stone quarries, the deposits of carbonate rocks (limestone and dolomite) are exploited, whereas in only eight quarries the eruptive rocks are exploited. If raw material contain impurities, which necessitates wet processing operation, waste water must be cleaned before being let out of the processing plant or returned to the dressing process. In the paper the waste water treatment in technical stone quarry is presented.
- Published
- 2005
29. The Comminution of Solid Waste
- Author
-
Salopek, Branko, Bedeković, Gordan, and Sobota, Ivan
- Subjects
Recycling ,Solid Waste ,Comminution - Abstract
The demand for secondary materials, primarly steel, glass and plastics, has led to the significant development and application of new techniques, equipments and plants used in recycling. The paper describes the basic techniques for solid waste comminution and presents the typical machines and equipment used for this purpose. The aim of the paper is to draw domestic industry's and contractor's attention to the production area which in spite of certain production potentials still doesn't exist in Croatia.
- Published
- 2005
30. Production of Eruptive Technical Stone in Croatia
- Author
-
Bedeković, Gordan, Salopek, Branko, Sobota, Ivan, Stipetić, Mario, and Fečko, Peter
- Subjects
eruptive stone ,aggregates ,stone processing - Abstract
The Croatian non-metals industry comprises exploration, exploitation and processing of non-metallic mineral raw materials. By beneficiation of these rock standard stone sizes for the production of concrete, asphalt masses, of supporting layers in road works and railroad ballast were obtained. In most technical stone quarries, rock deposits of a carbonaceous structure are exploited, whereas just some few quarries are exploiting rock deposits of a siliceous structure. An overview of eruptive technical stone production in the Republic of Croatia is given in this paper. The technology of stone exploitation and dressing are shown on quarry Jelenje Vode.
- Published
- 2005
31. Influence of Attrition Cell Construction on Quartz Sand Beneficiation
- Author
-
Salopek, Branko, Sobota, Ivan, Halle, Radovan, Bedeković, Gordan, Kimet Fetahu, and Fetahu, Kimet
- Subjects
quartz sand ,beneficiation ,attrition - Abstract
The paper presents the results of attrition cleaning obtained by testing the samples of quartz sand under laboratory conditions. The tests were carried out in two types of laboratory attrition cell – with circular and octagonal cross section, at different values of operating parameters which are supposed to have the main influence upon the attrition efficiency: suspension density, attrition time and stirrer speed. In each type of attrition cell two series of tests were conducted on two quartz sand samples with different SiO2 i.e. impurity contents. Indicators of attrition efficiency were the content of the particles – 0.063 mm and content of main impurities (Al2O3, Fe2O3) removed through the attrition process. By comparing the results of both series of tests conducted in mentioned types of attrition cells, information on dependence of attrition efficiency on feed material composition, operating parameters and attrition cell construction were obtained.
- Published
- 2005
32. Application of Mineral Processing Techniques in Soil Washing
- Author
-
Salopek, Branko, Sobota, Ivan, Bedeković, Gordan, and Natalija Koprivanac
- Subjects
soil washing ,mineral processing techniques - Abstract
The soil washing process is similar to one applied in mineral processing. In mineral processing the useful mineral component is separated from tailings, and in soil washing relatively small amount of highly contaminated concentrate is separated from the mass of cleaned soil. The washing process includes several stages: soil preparation (pre-screaning and possibly crushing), liberation and separation of individual components respectively, classification, sorting and dewatering. The paper describes the individual stages of washing as well as the most important machines which is used in the process. Personal expirience wtih the application of attrition and column flotation are mentioned.
- Published
- 2004
33. Comparison of Flotation Column and Mechanical Cell in Coal Flotation
- Author
-
Bedeković, Gordan, Salopek, Branko, Sobota, Ivan, and Peter Fečko
- Subjects
Flotation ,Flotation Column ,Mechanical Flotation Cell ,Coal - Abstract
Flotation is universal method to fine coal processing. Selectivity and efficiency of flotation depends not only on surface characteristics of particles, but also on hydrodynamic condition in flotation cell. The goal of the research was to compare flotation column and conventional mechanical flotation cell in coal flotation. The tests was carried out in both flotation cells in the same conditions. The results indicated that the mechanical cell has greater recovery, whereas the flotation column has a considerably better selectivity since it provides a concentrate of better quality.
- Published
- 2004
34. Improvement of quartz sand quality using attrition cleaning
- Author
-
Salopek, Branko, Sobota, Ivan, Halle, Radovan, Bedeković, Gordan, and Monika Hardygora, Gabriela Paszkowska, Marek Sikora
- Subjects
quartz sand ,clay coatings ,beneficiation ,attrition - Abstract
The quality of quartz sand can be improved by reducing the oxide coatings on the quartz grains. In this direction, a study has been made to consider the possibility of coatings removal from quartz sand by attrition cleaning. Tests were conducted in a laboratory attrition cell at different values of operating parameters: suspension density, attrition time and stirrer speed. Indicators of attrition efficiency were the content of the particles – 0, 063 mm and content of main impurities (Al2O3, Fe2O3) removed through attrition process.
- Published
- 2004
35. Production of Construction Aggregates in Urban Aeras
- Author
-
Salopek, Branko, Sobota, Ivan, Bedeković, Gordan, and Agioutantis, Z.
- Subjects
construction aggregates ,sustainable development ,exploitation ,environmental protection - Abstract
The greatest part of crushed stone, gravel and sand production is won by open pit operations, whereas gravel and sand partially also from river beds. Its obvious that such a mining activity provoke some changes in the configuration and environmental characteristics of the region, in the temporary or permament disapperance of vegetable or animal species and in the creation of noise, dust and waste water. However, mentioned mining operations shouldn't have only negative effects on the landscape and land potential, but they can discover and predetermine potential of exploited area for various communal purposes after exploitation (eg. sports and recreation centers, campsites, resorts, fish-farms, etc.). In this paper, construction aggregates production in plants located in the vicinity of Zagreb, the capital of Croatia are presented. Advantages and disadvantages of aggregates production in the urban area in the spirit of sustainable development are discused.
- Published
- 2003
36. THE EFFECT OF ATTRITION IN THE QUARTZ SAND BENEFICIATION
- Author
-
Salopek, Branko, Sobota, Ivan, Halle, Radovan, Pfaff, Slavka, Kuzev, L., Nishkov, I., Boteva, A., Mochev, D., and Boteva, A., Mochev, D.
- Subjects
kvarcni pijesak, glinene prevlake, oplemenjivanje, atricija ,quartz sand ,clay coatings ,beneficiation ,attrition - Abstract
The quality of quartz sand can be improved by reducing the oxide coatings on the quartz grains. In this direction, a study has been made to consider the possibility of coatings removal from quartz sand by attrition cleaning. Tests were conducted in a laboratory attrition cell at different values of operating parameters: suspension density, attrition time and stirrer speed. Indicators of attritioning efficiency were the content of the particles - 0, 063 mm produced by abrasion of grain surfaces and content of main impurities (Al_2O_3, Fe_2O_3) removed through attrition process.
- Published
- 2003
37. Konstrukcijske značajke i učinkovitost vertikalnih udarnih drobilica
- Author
-
Salopek, Branko, Sobota, Ivan, and Bedeković, Gordan
- Subjects
Sitnjenje ,Vertikalne udarne drobilice ,Plemenita kamena sitnež - Abstract
Na tržištu tehničkog kamena najtraženije su klase veličine zrna 4/8, 2/4, -4, -2 mm, čiji maseni udio prevladava u agregatima za izradu betona i asfalta. Međutim, proizvodnja tih klasa nije uvijek jednostavna. Pored zahtjeva za količinom, redovito se traži određeni grano-sastav i oblik zrna kamenog agregata, te minimalan udio čestica veličine – ; 0, 09 mm. Do prije desetak godina, najčešće su za proizvodnju navedenih klasa korištene udarne drobilice i čekićare, dok se danas u tu svrhu sve češće koriste vertikalne udarne drobilice. Vertikalne udarne drobilice predstavljaju izvjestan tehnološki napredak koji se prvenstveno očituje u većem udjelu zrna kubičnog oblika u izlaznom materijalu i manjem habanju udarnih elemenata i obloge u odnosu na prije spomenute drobilice. U članku su opisane osnovne konstrukcijske značajke i princip rada vertikalnih udarnih drobilica, te je analizirana njihova učinkovitost (grano-sastav proizvoda, udio zrna povoljnog oblika, udio čestica – ; 0, 09 mm) u ovisnosti o utjecaju pojedinih tehnoloških parametara.
- Published
- 2002
38. Vertical Impact Crusher In High-grade Chippings Production
- Author
-
Salopek, Branko, Sobota, Ivan, Bedeković, Gordan, Raj K. Singhal, and Bhaskar P. Singh
- Subjects
Comminution ,Vertical Impact Crusher ,Technical Stone ,High-grade Chippings - Abstract
The production of technical stone, gravel and sand for the building industry is a very important part of the mining production regarding volume and the financial value as well. The most demanded classes are with grain sizes – ; 4 and – ; 2 mm but their production is not always simple. In addition to volume, the specific grain size composition, grain shape and minimal portion of the particles – ; 0, 09 mm (filler) usually are demanded. Until about ten years ago the portion of the impact and hammer crushers, less often cone crushers were used in the production of these classes. Nowadays the vertical impact crushers (rotor mills) are mainly applied for this purpose. In the paper are presented some of these crushers used in the quarries and gravel-pits in Croatia. Their efficiency (capacity, grain size composition, grain shape, filler portion) depending on the influence of the some technological parameters, as for example grain composition of the feed material, physical-mechanical rock properties, moisture content and etc. are analysed.
- Published
- 2001
39. BENTONITE PROCESSING.
- Author
-
KUTLIĆ, ANAMARHA, BEDEKOVIĆ, GORDAN, and SOBOTA, IVAN
- Subjects
BENTONITE ,IGNEOUS rocks ,BENTONITE deposits - Abstract
Copyright of Rudarsko-Geolosko-Naftni Zbornik is the property of Faculty of Mining, Geology & Petroleum Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2012
40. MOGUĆNOST OPLEMENJIVANJA KVARCNIH PIJESAKA HRVATSKIH LEŽIŠTA PRIMJENOM MEHANIČKOG ATRICIJSKOG ČIŠĆENJA.
- Author
-
Sobota, Ivan, Salopek, Branko, Bedeković, Gordan, and Kutlić, Anamarija
- Subjects
ORE-dressing ,SILICA ,OXIDE coating ,CHEMICAL processes - Abstract
Copyright of Rudarsko-Geolosko-Naftni Zbornik is the property of Faculty of Mining, Geology & Petroleum Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2011
41. Plastic municipal waste management in the Republic of Croatia until 2021
- Author
-
Zubac, Nina, Veinović, Želimir, Grbeš, Anamarija, Sobota, Ivan, and Domitrović, Dubravko
- Subjects
Donje Međimurje ,City of Zagreb ,circular waste management ,City of Osijek ,recycling ,plastic municipal waste ,kružno gospodarenje otpadom ,Island of Krk - Abstract
U diplomskom radu analizira se postojeći sustav gospodarenja i količine plastičnog komunalnog otpada u gradu Zagrebu i Osijeku uz nekoliko pozitivnih primjera gospodarenja otpadom postignutih u Republici Hrvatskoj, u kojima je ostvaren definirani cilj od 50% odvojeno prikupljenog otpada. Također, opisuju se postupci oporabe plastičnog komunalnog otpada kao i mogućnosti materijalne oporabe plastičnog komunalnog otpada., Master’s thesis analyzes the existing waste management system and the amount of plastic municipal waste in the cities of Zagreb and Osijek with several positive examples of developed waste management systems in Croatia in which the defined goal of 50% of separately collected waste was achieved. Also, the procedures of recovery of plastic municipal waste are described, as well as the possibilities of material recovery of plastic municipal waste.
- Published
- 2022
42. Recycling of electronic waste using mineral processing methods
- Author
-
Fuk, Branimir, Bedeković, Gordan, Sobota, Ivan, Zorić, Igor, Pfaff, Slavka, and Anić Vučinić, Aleksandra
- Subjects
separation ,electric and electronic waste ,recycling ,liberation - Abstract
Sve kraći uporabni vijek elektroničkih uređaja i opreme posljedica je sve bržeg razvoja i usvajanja novih tehnologija, te uzrok eksponencijalnog rasta količina električnog i elektroničkog otpada, kako na globalnoj razini, tako i u RH, a isti trendovi mogu se očekivati i u budućnosti. Recikliranje kao integralni dio suvremenog sustava gospodarenja otpadom omogućava dobivanje sekundarnih sirovina, čime se smanjuje količina otpada i prostor potreban za njegovo odlaganje, štede se primarne sirovine i smanjuju emisije u okoliš pri proizvodnji novih proizvoda, itd. Osnovni cilj kojem se teži u recikliranju je separirati različite materijale sadržane u otpadu u zasebne produkte koji se mogu upotrijebiti kao sekundarna sirovina i koji kao takvi imaju određenu tržišnu vrijednost. Preduvjet uspješne separacije je postizanje raščina, tj. oslobađanje međusobno (mehanički, kemijski ili termički) spojenih različitih materijala. Uspjeh recikliranja električnog i elektroničkog otpada ovisi o značajkama otpada, separacijskih postupaka i uređaja koji se pri tome primjenjuju, te naravno uvjetima (vrijednosti radnih varijabli uređaja) u kojima se separacija izvodi. Prva faza procesa recikliranja sastoji se od ručne demontaže i izdvajanja krupnijih dijelova otpadnih uređaja, pri čemu se izdvaja veći udio željeza, bakra, stakla i plastike. Ostale dijelove potrebno je usitniti zbog postizanja raščina, a zatim prikladnim separacijskim postupcima izdvajati pojedine vrste materijala. U ovom radu su iz televizijskih aparata ručnom demontažom izdvojeni uz kučište i veliki kondenzatori i katodne cijevi koje sadrže fosforni prah i kadmij, te su zbog nemogućnosti sigurnog ispitivanja isključene iz daljnjeg ispitivanja. Izdvojena drvena kučišta isključena su iz daljnjeg ispitivanja jer je s vremenom došlo do kontaminacije štetnim tvarima kao što su krom, olovo, živa, sumpor, nikal, cink i sl., a u plastična kučišta umiješani su bromirani inhibitori gorenja koji, i u vrlo malim količinama, kontaminiraju plastiku čineći je nepogodnom za dobivanje nove plastike. Ostali materijal je, s obzirom na svoje značajke, podijeljen u tri grupe koje su ispitivane zasebno. Grupa nazvana „Zvučnici“ sastavni je dio audio sustava, a sadrži najviše željeza i nešto manje bakra u svitcima, uz plastiku, karton i tekstil. Grupa „Otklonski svitci, kabeli, konektori i žice“ ima veliku zastupljenost bakra, a treća grupa „Tiskane pločice“ uz vodljivu bakrenu strukturu sadržava i mnoštvo rijetkih metala na nevodljivoj osnovi (vitroplast, pertinks). Za svaku od prethodno navedenih grupa sastavljen je zaseban plan istraživanja. Za sve grupe prvo je provedeno sitnjenje u cilju postizanja raščina, zatim sijanje za dobivanje klasa pogodnih za testove u pojedinim separatorima. Plan testiranja separacije u zračnoj struji i elektrostatičke separacije sastavljen je uz upotrebu statističkog planiranja eksperimenata u programskom sustavu Statistica (Version 8, tvrtke StatSoft) prema centralno složenom dizajnu (Central Composite Design) koji uključuje 17 pokusa za svaku klasu na pojedinom uređaju. Analizom varijance utvrđen je utjecaj pojedine nezavisne varijable odnosno utjecaj međudjelovanja po dvije (od tri testirane) nezavisne varijable na jednu od dvije zavisne varijabli (kvaliteta koncentrata ili maseno iskorištenje) uz procjenu veličine tog utjecaja. Utjecaj pojedinih varijabli u gravitacijskoj i magnetskoj separaciji testiran je na način da je mijenjana vrijednost jedne varijable, dok su sve ostale držane konstantnim. Testovi separacije u zračnoj struji pokazali su da na kvalitetu koncentrata najveći utjecaj ima visina pregrade, a najmanji brzina zračne struje, a od međudjelovanja varijabli najviše utječe visina pregrade i položaj ulaznog otvora. Visina pregrade u svim slučajevima imala je najveći utjecaj na iskorištenje. Najbolji rezultati (kvaliteta koncentrata od 99 % do 100 % uz iskorištenja od 80 % do 99 %) postizani su separacijom zrna većih od 2 mm (klase 4/2 mm i 3,15/2 mm), a sa smanjenjem veličine zrna smanjivala se i efikasnost separacije. Elektrostatičkom separacijom postizala se visoka kvaliteta koncentrata u svim klasama, a najbolji rezultati dobiveni su u testovima s najkrupnijom klasom (4/2 mm). U svim testovima najveći utjecaj imao je položaj separacijskog noža. Kada se razmotre međudjelovanja varijabli, najveći utjecaj imalo je međudjelovanje položaja separacijskog noža s naponom ionizacijske elektrode i s brzinom okretanja bubnja. Rezultati dobiveni magnetskom separacijom pokazali su da je u najvećem broju slučajeva (pogotovo za krupnije klase) mokra separacija bolja od suhe, dok su se razlike smanjivale sa smanjenjem veličine zrna. Najbolji rezultati i mokre niskointenzivne i suhe visokointenzivne magnetske separacije postignuti su s najsitnijom klasom, -0,5 mm. Testovi gravitacijske koncentracije pokazali su da je za kvalitetniji koncentrat potrebno raditi s manjim nagibima ploče koncentracijskog stola. Temeljem dobivenih rezultata predložena je segregacijska shema recikliranja elektroničkog otpada. Osnovna hipoteza ovog rada, da se uređaji i postupci koji se koriste u oplemenjivanju mineralnih sirovina mogu koristiti i za recikliranje električnog i elektroničkog otpada potvrđena je temeljem rezultata provedenih ispitivanja., The ever shorter life cycle of electronic devices and equipment is a consequence of increasingly quick development and adoption of new technologies, and a reason for exponential growth of the quantity of electrical and electronic waste, both at the global level and in the Republic of Croatia, and identical trends can be anticipated also in the future. Recycling as an integral part of the contemporary waste management system enables obtaining of secondary raw materials, whereby the quantity of waste and the space necessary for its disposal are reduced, primary raw materials are saved and environmental emissions occurring at manufacturing of new products are reduced. The basic goal striven for in recycling is to separate the different materials contained in waste into separate products which can be used as secondary raw material and which as such have a certain market value. A precondition for successful separation is to achieve liberation of different mutually (mechanically, chemically or thermally) connected materials. The success in recycling electrical and electronic waste depends on the characteristics of waste, the applied separation procedures and devices, and of course on the conditions (values of operating variables of the devices) in which separation is carried out. The first phase of the recycling process consists of manual dismantling and separation of larger parts of waste devices, whereby a larger share of iron, copper, glass and plastic materials is separated. The remaining parts need to be shredded in order to achieve liberation, and thereupon, by appropriate separation procedures, the single types of material shall be separated. In this dissertation beside enclosures and large condensers and cathode tubes containing phosphorus powder and cadmium have been manually separated from TV sets, and due to the impossibility of their save testing have been excluded from further testing. The separated wooden enclosures have been excluded from further testing, since over time contamination has occurred by harmful substances such as chrome, lead, mercury, sulphur, nickel, zinc, etc., whereas plastic enclosures contain brominated burning inhibitors, which even in very small quantities contaminate plastic materials rendering them inappropriate for obtaining new plastic. The remaining material has been divided according to its characteristics into three groups which have been tested separately. The group called „Loudspeakers“ is an integral part of the audio system and it contains the highest quantity of iron and somewhat less copper in yokes, as well as plastic, cardboard and textile. In the group „Yokes, cables, connectors and wires“ copper is represented to a high degree, and the third group of „Printed circuit boards“ contains, in addition to the copper conductor structure, also a lot of rare metals on a nonconductor basis (vitroplast, pertinax). For each of the previously indicated groups a separate test plan has been developed. For all groups shredding has been carried out first, in order to achieve liberation, followed by sieving in order to obtain classes appropriate for tests in individual separators. The test plan for air and electrostatic separation has been developed by using statistical planning of experiments under application of the programme system Statistica (Version 8, StatSoft) according to a central composite design (Central Composite Design), including 17 tests for each class on the individual device. By analysing the variance, the impact of the individual independent variable as well as the impact of the interaction of two (out of the three tested) independent variables on one (out of the two) dependent variables (concentrate quality or mass recovery), along with the assessment of this impact, has been determined. The impact of individual variables in gravitation and magnetic separation has been tested in such a way that the value of one variable was changed, while all the other variables were kept constant. Air separation tests have shown that the height of the compartment barrier has the highest impact on the quality of the concentrate, and airstream speed has the least impact, whereas with regard to the interaction of the variables, the barrier height and the position of the inlet have the highest impact. In all cases the barrier height had the highest impact on recovery. Best results (concentrate quality from 99 % to 100 % with recovery from 80 % to 99 %) were achieved at separation of grain larger than 2 mm (class 4/2 mm and 3,15/2 mm), whereas with reduced grain size separation efficiency decreased as well. By electrostatic separation high quality of concentrate has been achieved in all classes, and best results have been obtained in tests with the coarsest grain class (4/2 mm). In all tests the position of the separation knife had the largest impact on concentrate quality. Regarding interactions of the variables the interaction of the separation knife position with the voltage of the ionising electrode and the drum rotation speed had the highest impact. The results obtained by magnetic separation have shown that in most cases (in particular for coarser grain classes) wet separation is better than dry separation, whereas differences decreased with the decrease in the grain size. Best results of both the wet lowintensity and dry high-intensity separation were achieved with the smallest class, -0,5 mm. Tests of gravity concentration have shown that in order to achieve a better quality of the concentrate of better quality, concentration table should operate with smaller inclinations of the plate. Based on the obtained results a segregation scheme for electronic waste recycling has been proposed. The basic hypothesis of this dissertation, namely that the devices and procedures used in mineral processing can also be used for recycling electrical and electronic waste, has been confirmed by the results of the testing carried out.
- Published
- 2020
43. Pregled mogućnosti iskorištavanja crvenog mulja kao sekundarne sirovine
- Author
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Ivić, Iva, Grbeš, Anamarija, Sobota, Ivan, and Bedeković, Gordan
- Subjects
crveni mulj ,sekundarne sirovine ,industrijski otpad - Abstract
U ovom završnom radu predstavljena je problematika crvenog mulja kao odloženog industrijskog otpada velikih količina, ali i velikih potencijala za iskorištavanje kao sekundarne sirovine. Prikazani su primjeri današnje primjene i tehnologije u razvoju, skupa s njihovim nedostatcima i preprekama.
- Published
- 2020
44. Recovery of electrode material from lithium-ion batteries by attrition scrubbing
- Author
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Tenjer, David, Bedeković, Gordan, Sobota, Ivan, and Kuhinek, Dalibor
- Subjects
separation ,graphite ,carbon ,lithium-cobalt oxide ,Li-ion battery ,recycling ,attrition scrubbing ,Oslobađanje, raščin, elektrodni materijal, litij-kobalt oksid, grafit, litij-ionske baterije, atricijsko čišćenje, recikliranje - Abstract
Električni i elektronički (EE) otpad predstavlja sve veći problem za sustav gospodarenja otpadom. Recikliranje EE otpada se nameće kao rješenje tih problema. Recikliranjem, osim što se smanjuju količine otpada i štetnost za okoliš, dobivaju se i vrijedne sekundarne sirovine. Litij-ionske baterije čine značajan udio u ukupnim količinama EE otpada s tendencijom povećanja zbog sve raširenije primjene, ponajprije u pametnim telefonima, prijenosnim računalima te električnim i hibridnim vozilima. Postojeće tehnike i tehnologije recikliranja Li-ionskih baterija ostavljaju prostora za napredak, ponajprije u pogledu utjecaja na okoliš. Stoga je u ovome radu ispitana učinkovitost oslobađanja elektrodnog materijala (litij-kobalt oksida i grafita) iz litij-ionskih baterija, kao jednog od segmenata reciklažnog procesa, primjenom atricijskog čišćenja pri različitim vrijednostima radnih parametara. Usitnjeni materijal je preduvjet za primjenu atricijskog čišćenja. Stoga je ispitana i učinkovitost oslobađanja elektrodnog materijala uslijed sitnjenja u reznom mlinu te je određena ukupna učinkovitost reciklažnog procesa koji uključuje oba postupka. Rezultati ispitivanja ukazuju da atricijsko čišćenje elektroda Li-ionskih baterija, kao postupak oslobađanja elektrodnog materijala, ima značajno manji štetan utjecaj na okoliš i manje pogonske troškove u odnosu na konkurentske postupke uz relativno visoku učinkovitost. Obzirom na takve rezultate postoji potencijal za primjenu atricijskog čišćenja u procesima recikliranja litij-ionskih baterija., Electrical and electronic (EE) waste is a growing problem for the waste management. Recycling of EE waste is a solution for these problems. In addition to reduce waste and environmental damage, recycling also provides valuable secondary raw materials. Lithium-ion batteries make a significant share of total EE waste with a tendency to increase. Existing techniques and technologies for recycling Li-ion batteries leave room for improvement, primarily in terms of environmental impact. Therefore, the separation efficiency of electrode material (lithium-cobalt oxide and graphite) from lithium-ion batteries is determineted in this paper, as one of the segments of the recycling process, by using attrition scrubbing. Shredded material is a prerequisite for the application of attrition scrubbing. Therefore, the separation efficiency of electrode material due to grinding in a mill to the class of -8 mm was examined and the overall efficiency of the recycling process, which involves both procedures, was determined. Test results indicate that attrition scrubbing of the electrodes of Li-ion batteries, as the process of the separation of electrode material from metal foils, has significantly lower negative impact on the environment and lower operating costs compared to competing processes with relatively high efficiency. Given such results, there is potential for the application of attrition scrubbing in lithium-ion battery recycling processes.
- Published
- 2020
45. Recycling thin copper cables
- Author
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Kostel, Pavao, Bedeković, Gordan, Kuhinek, Dalibor, and Sobota, Ivan
- Subjects
cables ,copper ,Recikliranje, Bakar, Plastika ,plastics ,recycling ,WEEE - Abstract
U današnje, moderno doba, bakar se koristi u kablovima i svim električnim i elektronskim uređajima. Danas gotovo da i ne postoji električni uređaj koji ne sadrži bakar u sebi. Sve više se bakar iz otpadnih kabela reciklira i skoro polovica bakra u novim kabelima ili elektroničim uređajima je dobivena kao sekundarna sirovina recikliranjem. U radu je dan pregled i opis vrsta kabela u kojima se koristi bakar te je ispitana mogućnost recikliranja licnastih bakrenih kabela na elektrostatičkom separatoru., In today's modern age, copper is used in cables and all electrical and electronic devices. Today, there is almost no electrical device that does not contain copper. Copper is increasingly being recycled from waste cables and almost half of the copper in new cables or electronic devices is obtained as a secondary raw material by recycling. The thesis gives an overview and description of cable types in which copper is used and examines the possibility of recycling thin copper cables by an electrostatic separator.
- Published
- 2020
46. Sustav upravljanja okolišem u organizacijama - primjena niza norma HRN EN ISO 14000 u Hrvatskoj s fokusom na rudarske gospodarske subjekte
- Author
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Marin, Dora, Grbeš, Anamarija, Sobota, Ivan, and Veinović, Želimir
- Subjects
održivi razvoj ,upravljanje okolišem ,zaštita okoliša ,HRN EN ISO 14001:2015 - Abstract
U završnom radu je kratki pregled sustava upravljanja okolišem sa naglaskom na nizu normi ISO 14000. Izdvojena je norma HRN EN ISO 14001:2015 te je objašnjena njezina implementacija u organizaciju. Na temelju odgovora na upitnik na primjeru tvrtke Holcim (Hrvatska) d.o.o. opisan je postupak primjene norme u rudarskom gospodarskom subjektu. Uvođenjem norme u organizaciju povećava se osviještenost organizacije i zaposlenika u pogledu zaštite okoliša, organizacija postaje konkurentnija i olakšano je planiranje i upravljanje rizicima i prilikama.
- Published
- 2020
47. Attrition scrubbing of plastics from paraffin
- Author
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Čengija, Ana, Bedeković, Gordan, Sobota, Ivan, and Kovačević Zelić, Biljana
- Subjects
attrition ,recikliranje, lampioni, atricija ,lanterns ,recycling - Abstract
U ovom radu pod otpadom se podrazumijeva plastični otpad (lampioni). Ako se otpadom ne gospodari kako treba ili ga se nekontrolirano odlaže, on će onečistiti okoliš. Mnoge vrste plastike nisu biorazgradive bez obzira na uvjete u okolišu, barem ne u značajnoj mjeri, dok se neke vrste razgrađuju, ali sporo, pod uvjetom da su izložene povoljnom djelovanju zraka, vode i svjetla. Lampioni nisu biorazgradivi jer ni metal, niti plastika, niti parafin od kojih se sastoji lampion nisu biorazgradivi. Uzorak u provedenim ispitivanjima se sastoji od lampiona koji su izdrobljeni, prosijani i atrirani. Krupnije klase ne odgovaraju jer su prevelike za atricijsku ćeliju, a kod sitnijih klasa postoji velika mogućnost gubitaka materijala tijekom daljnih ispitivanja. Nakon postignutog raščina drobljenjem i odvajanja parafina i plastike pliva-tone separacijom na zrnu plastike zaostaje tanak sloj parafina. Hipoteza ovog rada je uklanjanje tog sloja parafina atriranjem. Uspješnost atricije razmatra se preko smanjenja sadržaja parafina. U svim pokusima došlo je do smanjenja masenog udjela parafina u koncentratu nakon atricije što nam govori da je hipoteza ovoga rada potvrđena., Under the term waste in this thesis, we assume plastic waste (lanterns). If waste is not properly managed or it is discarded it can pollute the environment. Regardless of environmental conditions a lot of plastic is not biodegradable, however, some types are degradable with favorable effects of air, water and light. Since metal, paraffin and plastic are not biodegradable, neither are lanterns. Used test sample is composed of crushed, sieved and attritioned lanterns. Coarse fractions are too big for atrittion cell so they don´t fit while smaller classes result in material loss during further testing. After liberation by crushing and separation of paraffin and plastic by sink and float process, a thin layer of paraffin remains on plastic grains. Attrition efficacy is considered through reduced content of paraffin. In all tests, decrease in mass portion of paraffin in concentrate after the attrition is determined, which tells us that the hypothesis of this thesis is accurate.
- Published
- 2019
48. Reclamation proposal for the Kusačko brdo open pit dimension stone mine near Široki Brijeg
- Author
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Šiško, Ante, Galić, Ivo, Pavelić, Davor, and Sobota, Ivan
- Subjects
reclamation ,dimension stone and crushed stone ,open pit ,reserves - Abstract
Opisane su osnovne geološke i ostale značajke šireg područja predmetnog površinskog kopa, te geološke značajke ležišta. Situacija postojećeg stanja, odnosno površina terena i postojeće stanje kopa modelirani su u računalnom programu Power InRoads. Za područje predmetnog eksploatacijskog polja izrađen je još model saniranog površinskog kopa te model površinskog kopa u sklopu prijedloga eksploatacije karbonatnih breča tipa I. Na temelju izrađenih modela i proračuna se došlo do zaključka da bi tehnička sanacija postojećeg stanja omogućila određenu dobit izvođaču čak i nakon biološke rekultivacije. U sklopu sanacije bi se eksploatirao arhitektonsko-građevni kamen, dok bi se od kamenog ostatka dobivao tehničko-građevni kamen. Predložena je i daljnja eksploatacija na području koje se nalazi u naslagama karbonatnih breča tipa I., Basic geological and other features of the wider area of the subject open pit mine as well as geological features of the bed are described. The situation of the current state, i.e. the surface area and the current state of the pit were modeled in the Power InRoads computer program. For the area of the subject exploitation field, a model of reclaimed open pit and a model of open pit as part of the proposal for the mining of carbonate breccia type I were also developed. Based on the models and calculations made, it was concluded that the technical reclamation of the existing condition would give a certain profit to the contractor even after biological recultivation. As part of the reclamation, the dimension stone would be mined, while the leftover stone would be used to get crushed stone. Further mining is proposed in the area of carbonate breccia type I .
- Published
- 2018
49. Gravity concentration of quartz sand
- Author
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Kuzmanić, Tamara, Bedeković, Gordan, Sobota, Ivan, and Korman, Tomislav
- Subjects
kremeni pijesak, gravitacijska koncentracija, oplemenjivanje, koncentracijski stol, Humphreysova spirala ,shaking table ,Humphreys spiral ,quartz sand ,gravity concentration ,mineral processing - Abstract
U ovom radu prikazani su rezultati ispitivanja koncentracije kvarcnog pijeska postupcima gravitacijske koncentracije (koncentracijskim stolom i spiralnim žlijebom – Humphreysovom spiralom). Cilj rada je ispitati mogućnost koncentracije kvarcnog pijeska gravitacijskom koncentracijom uz postizanje kvalitete koncentrata koji zadovoljava uvjete kvalitete za plasiranje na tržište. Provedena su dva seta ispitivanja na koncentracijskom stolu pri različitim nagibima koncentracijskog stola (3°, 6° i 9°), jedan s ciljem postizanja što veće kvalitete koncentrata i jedan s ciljem postizanja što većeg masenog iskorištenja. Ukupno je napravljeno ispitivanje na 6 uzoraka kvarcnog pijeska na koncentracijskom stolu. Na spiralnom žlijebu provedena su 4 ispitivanja pri različito podešenim parametrima (otvori ispusta za tešku frakciju, gustoća suspenzije i protok ispirne vode). Uspoređeni su tehnološki pokazatelji uspješnosti koncentracije pojedinih ispitivanja, odnosno postignuta kvaliteta koncentrata utvrđena kemijskom analizom uspoređena je s uvjetima kvalitete za plasiranje na tržište., This thesis presents the results of concentration tests carried out on quartz sand using gravity concentration methods (shaking table and spiral concentrator – Humphreys spiral). The aim of the thesis is to examine the possibility of concetrating quartz sand using gravity concentration methods to achieve concentrate quality that satisfies the quality requirements of the marketplace. Two sets of tests were carried out using a shaking table at different shaking table inclination (3°, 6° i 9°), one set aiming to achieve higher concentrate quality and the other set aiming to achieve higher recovery. Tests were carried out on 6 samples of quartz sand using shaking the table. Using a spiral concentrator, 4 tests were carried out with different parameter (heavies openings, slurry density and wash water flow) adjustment. The concentration efficiency indicators of each test were compared i.e. achieved concentrate grades determined by chemical analysis were compared with the quality requirements for market placement.
- Published
- 2018
50. Studies and calculations of dimension stone reserves in 'Razvala' deposit
- Author
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Kukavčić, Mihael, Galić, Ivo, Perković, Dario, and Sobota, Ivan
- Subjects
research „Razvala“ deposit ,Microstation ,microstation ,ležište „Razvala“ ,računalno modeliranje ,arhitektonsko-građevni kamen ,dimension stone ,computer modeling ,calculation of reserves - Abstract
U radu je obrađen prijedlog istraživanja ležišta „Razvala“. Opisane su značajke istraživanog područja, a u prvom redu geološke značajke terena. Topografske karte u rasterskom obliku su korištene kao podloga za izradu situacijske karte ležišta, u vektorskom obliku. Na temelju važeće zakonske regulative i poznatih podataka o području, dan je prijedlog istražnih radova, određene su granice rezervi te visina i širina ležišta. Izrađeni su: 3D model terena i 3D model granica rezervi, koristeći program Bentley Microstation. Obrada prostornih veličina, metodom triangulacije, i generiranje podataka izvedeno je u programu Bentley Inroads. Proračun rezervi arhitektonsko-građevnog kamena proveden je metodom modeliranja i metodom paralelnih vertikalnih presjeka koji su generirani iz 3D modela. Dan je i opisan prijedlog dobivanja blokova lančanom sjekačicom., The work describes the research proposal for "Razvala“ deposit. It also describes the current situation of the field and particulary geological characteristics of the area. Topographic maps in raster format are used as a basis for making of situational maps of deposit in vector format. Based on current legislation and known field data, research work is arranged and boundaries are defined by height and width of the deposit. 3D terrain models and boundaries of reserves are made by using the computer program Bentley MicroStation. Processing of spatial dimensions by method of triangulation and data generation was made in a subprogram Bentley InRoads. Calculation of dimension stone reserves was performed using computer modeling and the method of parallel vertical sections which are generated from the 3D computer model. A proposal has been given and described for the production of dimension stone blocks.
- Published
- 2018
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