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Management of construction waste that was generated by earthquakes and reconstruction of damaged facilities requires good prior planning of options, as well as good coordination of all institutions during the reconstruction period. The planning should include three main levels: 1 – waste handling in a safe manner, with fast education of persons working on clearing and distribution of means for protection ; 2 – planning of the logistics and temporary storage areas ; 3 – analyses of the shortcomings of the existing legal framework for future waste management in crisis and issue instructions on crisis management of construction and demolition waste. This paper provides an overview of the current crisis management of construction and demolition waste after Zagreb earthquake in March 2020 , identifies challenges with management of such waste, and shows the la test advances in recycling of the problematic streams as an opportunity to advance both, emergency – and usual waste management. In c onclusion it provides recommendations to take following course od actions: 1 - increase of the capacity to recycle, treat and temporarily store construction and demolition waste ; 2 – improve the separation (recycling)process to allow the removal of other wastes and to separate the construction and demolition waste by category ; 3 – focus the activities on research and development of the products from recycled construction and demolition waste (upgrade), especially from the mixed construction and demolition waste ; and 4 – make possible the use of recycled materials in public procurement (including construction and reconstruction of public buildings and infrastructure), prioritise use of construction and demolition waste to stabilize the existing landslides and ground disturbances caused by the earthquakes, facilitate and stimulate the abolition of waste status of materials produced from the construction and demolition waste. Control, separation and/or immobilization of hazardous waste should not be overlooked, as well as the safety of people who handle construction and demolition waste in emergency and afterwards. Legal framework and procedures should be planned and prioritized in advance, thus preventing bottlenecks in communication a nd coordination of regulatory bodies of different levels in the time of emergency.

Faster technology development, increasing of living standard and market availability are the main causes of faster obsolescence of electronic devices. Each electronic device contains printed circuit boards that are a valuable source of metal. The paper presents the results of preliminary research of the possibility for using various mineral processing methods in recycling of waste printed circuit boards. The gravity concentration (concentration table and Humphreys spiral concentrator), electrostatic separation and wet magnetic separation were used in this preliminary research and the obtained results were presented in the article., Szybki rozwój technologii, podwyższenie standardu życia i dostępność na rynku to główne przyczyny szybszego starzenia się urządzeń elektronicznych. Każde urządzenie elektroniczne zawiera płytki drukowane, które są cennym źródłem metalu. W pracy przedstawiono wyniki wstępnych badań możliwości zastosowania różnych metod przeróbki surowców w recyklingu zużytych obwodów drukowanych. W tych wstępnych badaniach wykorzystano wzbogacalnik grawitacyjne (stół wstrząsany i wzbogacalnik spiralny Humphreya), separację elektrostatyczną i separację magnetyczną na mokro, uzyskane wyniki przedstawiono w artykule.

Quartz sand deposit Ravno is the biggest quartz sand deposit in the Dolenjska region in Slovenia with an area of 1.25 km2. Quartz sand at the site is selectively excavated using mechanical methods. Presently, at the processing plant near the deposit, the main final mineral processing technique is flotation. Prior to the flotation, quartz sand undergoes classification and attrition. Final products produced at the plant are natural sand, washed sand and floated sand. Recently, mining companies have been turning to simpler processing systems, such as gravity concentration, due to the price increase of floatation reagents, simplicity of the process and lower environmental impact. Overview of the deposit and current methods used in the processing plant are presented, as a prologue to further work on the process alteration possibilities – a change from flotation to gravity concentration.

Pozvano predavanje obuhvatilo je tematiku značaja EE otpada, gospodarenja EE otpadom i dobrobitima recikliranja električnog i elektroničkog otpada. Dan je pregled tehnologija za recikliranje, napose pri mehaničkom recikliranju te pregled dugogročnih trendova koji se mogu očekivati u budućnosti.

Značaj građevinskog otpada proizlazi iz velikih masa i visokog potencijala za recikliranje. S obzirom na količinu građevinskog otpada i cijenu recikliranog otpada, recikliranje mobilnim postrojenjima nameće se kao prihvatljivije rješenje od izgradnje stacionarnih postrojenja za recikliranje. U članku se razmatra mogućnost primjene mobilnih postrojenja za recikliranje građevinskog otpada u Hrvatskoj temeljem usporedbe prihoda i rashoda koji se pri tome javljaju. Pokazalo se da na mogućnost primjene mobilne čeljusne drobilice najviše utječu trošak zbrinjavanja otpada koji ostaje nakon recikliranja i trošak transporta.

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.

In the paper, mineral raw materials and waste management policies of the Republic of Croatia are elaborated and compared to European standards and directives. The origin, composition and quantities of waste are provided together with a current status in waste management. Mineral raw materials production and proven reserves are also listed. Waste and mineral raw materials management is commented from the sustainability point of view. Some conclusions are given for the country with a limited mineral raw material resources and potential use of secondary sources.

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.

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.

Crushed stone is the most important type of mineral resource in the Republic of Croatia and is mined in more than 350 exploitation fields. Crushed stone is most often used as aggregate for the production of concrete and asphalt, for which it must satisfy high standards, and thus it is necessary to process it. The wet processing technology in semi-mobile plants, which is increasingly frequent in Europe, has thus far not been used in the Republic of Croatia. This paper provides a comparison of the wet processing technology on an older, stationary and a newer, semi-mobile processing plant in the “Oršulica kosa” exploitation field. It also describes the process of waste washwater treatment and the newer high-pressure pre-washing chamber technology. The costs of extracting stone from a stone massif are the same in both cases ; therefore, in comparing the two plants, the effect of the cost of transportation and stone processing was also taken into account. An analysis of the cheapest possible transportation showed that for a stationary plant, located at a distance of 1950 m from the active worksite, the cost of transport was 4.01 kunas per tonne, or 1.7 million kunas per annum, while in the case of a semi-mobile plant this cost was non-existent. As for processing, it appears that the electric energy consumption of a stationary plant is three times greater than that of a new semi-mobile plant, which amounts to a difference of 0.85 million kunas per annum. As for water consumption, it appears that the water consumption of an old stationary plant is approximately ten times greater than that of a new semi-mobile plant, which amounts to a difference of 0.23 million kunas per annum. Taking into account the potential savings of around 2.1 million kunas per annum, the return of the total investment in a new semi-mobile plant should be realized in the relatively short period of 3.5 years. Beside the economic benefit, we should also emphasize the smaller environmental footprint of the new plant, which is evident in the decreased need for adding fresh water to the process, as well as the significantly decreased need for occupying space with settling basins, seeing as the new semi-mobile plant, as opposed to the old stationary one, purifies and recycles wastewater.

The effect of air flow rate, pulp density and particle size was studied using central composite design for coal samples from the Lazy mine. Evaluation of column flotation tests was based on two dependant variables such as ash content and combustible matter recovery in the concentrate. The ash content in the concentrate was from 4.61 to 9.62% with the recovery of combustible matter from 17.43 to 81.98%. The ANOVA statistical analysis showed that the main effect of air flow rate has a significant impact on the combustible matter recovery and ash content in the concentrate. The main effect of pulp density on the combustible matter recovery is significant, whereas for the ash content it is not seen. There is a strong effect of the particle size on the ash content and combustible matter recovery in the concentrate. The interaction of the effect of the pulp density and particle size has a significant impact on the ash content in the concentrate.

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.

Republika Hrvatska, kao i Europa suočavaju se s nedostatkom mineralnih sirovina i problemom gospodarenja otpadom. Urbano rudarenje nameće se kao neizbježni postupak kojim se racionalno gospodari prirodnim resursima. Iskorištavanje vrijednih sirovina zarobljenih u električnom i elektroničkom (EE) otpadu iziskuje poznavanje sastava otpada i proizvoda nastalih oporabom. Da bi se došlo do novih spoznaja nezaobilaznoje korištenje analitičkog laboratorija i laboratorija za oplemenjivanje i ispitivanje mineralnih sirovina. Rad se bavi aktualnim problemom iskorištavanja i zbrinjavanja otpadnih tiskanih pločica (TP) sakupljenih na prostoru Republike Hrvatske (RH). Obrazlaže svrhu i provođenje ispitivanja sadržaja najznačajnijih metala i ispitivanja mogućnosti iskorištavanja nemetalne frakcije (NMF) TP. Prezentira i okvirne rezultate ispitivanja, kao i ulogu laboratorijskih ispitivanja.

The aim of this paper was to determine the impact of physical and mechanical properties of rocks on the electricity consumption of a jaw crusher during crushing. This paper presents a different approach to determine the energy consumption during comminution. The energy required for crushing rocks was obtained by direct measurement of crusher's motor power during the crushing of samples. Laboratory tests were used to determine the following physical and mechanical properties of the tested samples: bulk density, compressive strength, tensile strength, hardness, and fracture toughness. After that, the laboratory jaw crusher crushing tests were conducted. In the first part of the study, the individual rock samples were crushed one by one. In the second part of the test, multiple samples were crushed simultaneously. By measuring the energy consumption for crushing rocks with different physical and mechanical properties, we explored the dependence of energy required for crushing on individual mechanical properties of rocks and the simultaneous effect of the properties. Using statistical analysis of the influence of individual mechanical properties we found that the greatest influence on energy consumption for crushing was compressive strength. Fracture toughness and tensile strength of the rocks had a significant impact on the crushing energy. The effect of bulk density was not large while for the hardness could not be stated that it had influence. By the analysis of deviations of specific crushing energy calculated using equations obtained by multiple regression analysis of simultaneous influence of multiple mechanical properties of rocks and from the measured values, it was found that the dependence obtained on the basis of all investigated properties showed the smallest deviation and dependence obtained by compressive strength, fracture toughness, and hardness showed significantly smaller deviation. By examining the influence of mechanical rock properties on particle size of crushed material it was found that the increase in compressive strength increased the proportion of larger particles while other properties showed no effect.

The article related to the journal cover is dealing with the legend of the Saint Kinga, the patroness of Krakow miners

Nowadays, electric and electronic equipment (EEE) are an integral part of every household and office and it could be said that EEE entered into every pore of modern society. The rapid technological development in the modern world on the one side brings many advantages but, at the same time causing increase amount of waste and this especially refers to the waste electrical and electronic equipment (WEEE). Capacitors are an integral part of every electronic device and it could be a good source of aluminium. This paper presents research of possibility of aluminium recycling from electrolytic capacitors. Separation of aluminium from the condenser was carried out using wet shaking table. Four different grain sizes were tested. Testing was conducted in laboratory and plant scale. The results showed that it is possible to separate aluminium from capacitors into high quality concentrate.

Rad prikazuje izvedenu terensku nastavu iz predmeta Oplemenjivanje mineralnih sirovina 1 i Eksploatacija i obrada arhitektonsko građevnog kamena u ak. god. 2013./2014., na preddiplomskom studiju rudarstva za studente treće godine. U radu se ukazuje na složenost organizacije terenske nastave, te potrebe suradnje s gospodarskim subjektima, a sve u cilju poboljšanja izobrazbe rudarskih stručnjaka.

Nowadays, electric and electronic equipment (EEE) are an integral part of every household and office and it could be said that EEE entered into every pore of modern society. Rapid technological development in the modern world brings as much advantages as it brings bigger amount of waste and this especially refers to the waste electrical and electronic equipment (WEEE). Condensers or capacitors are an integral part of every electronic device. There are many types of capacitors. Aluminium electrolytic capacitors are the most common because their inexpensive electrolytic. The electrolytic capacitors are composed of about 50 % of aluminium by mass and because that they could be a good source of aluminium. This paper presents research of possibility of aluminium recycling from electrolytic capacitors using gravity concentration. Separation of aluminium from the cylindrical shape capacitors in size from 7 to 80 mm was carried out using wet shaking table. Four different grain sizes were tested in plant scale (+8 mm, 8/4 mm, 4/2 mm and -2 mm), while only grain size 4/2 mm were tested in a laboratory scale. The separation efficiency was evaluated on the basis of three parameters: mass yield, aluminium recovery and grade of concentrate. The results obtained in plant scale showed that aluminium recovery and grade of aluminium concentrate increases with decreasing grain size. The best results of recovery of 95.19% and grade of 99.98% were obtained in grain size 4/2 mm, while mass yield was constant at level about 23%. Grain size of 4/2 mm was also tested in laboratory scale and the results showed that small capacitors are more suitable for separation than the larger one. The results showed that it is possible to separate aluminium from capacitors into high quality concentrate.

U radu se opisuje nastavna, znanstvena i stručna djelatnost laboratorija.

Održano je predavanje o Bolonjskom procesu, izradi kurikuluma, postupku inicijalne akreditacije i reakreditacije, te nastavnim programima RGN fakulteta.

U dokumentu je navedeno područje djalovanja i ustroj RGN fakulteta, prikazana je SWOT analiza, definirane su misija i vizija fakulteta te opći i posebni ciljevi razvoja fakulteta u nastavi, znanstveno-istraživačkom i razvojno-stručnom radu te sustavu osiguranja kvalitete i upravljanja resursima.

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.

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.

Исследуется флотируемость каменного угля из шахты Lazy при использовании собирателей Flotalex, Montanol и PE2. Цель работы состояла в подтверждении флотируемости упомянутого угля и елективности названных собирателей. Исследования проведены на классе -0, 5 мм в колонной флотомашине. Результаты флотации показали, что Flotalex и Montanol обеспечивают примерно одинаковое извлечение, при этом Flotalex обладает лучшей селективностью. При использовании в качестве собирателя PE2 получены еудовлетворительные результаты.

Celem badań bylo określenie wyników wzbogacania wegla w procesie flotoflokulacji. Zasada flotoflokulacji polega na zastosowaniu w pierwszym etapie flokulanta, a nastepnie poddaniu uzyskanych flokul procesowi flotacji. Wzbogacanie przeprowadzono za pomoca trzech odczynników flotacyjnych (Montanol, Flotalex MR2, Ekofol 440) oraz trzech flokulantów (Superfloc A120, Praestol 2935, Sokofloc 26BH). Przyjeto, že uzyskany koncentrat weglowy ma miec zawartość popiolu nie wyzsca niz 10%. Flotacje przeprowadzono w laboratoryjnej, kolumnowej maszyne flotacyjnej.

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.

The crushing of the mineral raw material is the most essential mechanical operation within mineral processing. It is also an inefficient, energy intensive process that consumes billions of kilowatt-hours (kWh) per year. In fact only 1% of the total energy input into size reduction processes is used in individual particles breaking and changing of solid material dispersion state. Since the technology is well known, improvements in comminution are dependent upon optimizing the application and operation of that technology. The quality of building crushed stone is evaluated on the basis of the physical and mechanical characteristics, the grain size distribution and the grain shape. Schmidt rebound hardness of rocks is the characteristic which is due to its speed and simplicity of testing often applied in practice. The paper presents results of the testing of hardness impact on the crushing energy and product size of the laboratory jaw crusher. Results show that the Schmidt rebound hardness of rock mass does not have significant influence on the jaw crusher power consumption. The high correlation (R2=0, 876) between grain size distribution parameter t10 and Schmidt rebound hardness has been established.

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.

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 %.

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.

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.

U radu je opisana svrha i principi sitnjenja, drobljenje, zatim čeljusne drobilice, drobilica Symons, drobilice s valjcima, udarne drobilice, te vertikalne udarne drobilice. Posebno su obrađene nove drobilice i to inercijske drobilice KID i Rhodax, te visokotlačna drobilica s valjcima.

The objective of the paper was a comparison of classical and column flotation on samples of black-coal slurries from selected localities of okr and poland. Namely they are dukla mine, darkov mine, csm mine, csa mine, doubrava mine and kleofas mine. The acquired results imply that the methods of classical and column flotation are suitable for flotation of the slurries in question as all the tested black coal slurries from okr and poland are cokeable coals with a high flotation ability.

U radu se opisuj terenska nastava kao izuzetno važan, karakterističan, najzanimljiviji i najatraktivniji oblik studiranja na RGN fakultetu, a to su naravno terenske vježbe, ljetne stručne prakse i terenska nastava. Opisani su tereni na kojim su sudjelovali naši studenti u našoj zemlji i inozemstvu, na kopnu i moru, na površini i ispod nje.

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.