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Research on chalcopyrite leaching represents a great challenge, given its importance as one of the most abundant copper minerals and its significant role in global copper extraction. This study aimed to evaluate the effects of different parameters on chalcopyrite leaching by hydrogen peroxide as a strong oxidizing reagent in sulfuric acid solution. A series of leaching tests were carried out to investigate the effect of the solid/liquid ratio, stirring speed, temperature, oxidant and acid concentrations, and lixiviant dosing method on copper extraction from chalcopyrite concentrate. The catalytic decomposition of hydrogen peroxide occurred in the investigated leaching system, as reflected in the obtained metal extraction values. Copper extraction was increased in the first 60 min of the reaction, after which it essentially ceased. The maximum final copper extraction of 64.5% was attained with 3.0 mol/L H2O2 in 3.0 mol/L H2SO4 at a temperature of 40 °C after 120 min of reaction. Due to the catalytic decomposition of hydrogen peroxide in the examined leaching system, the leaching experiment was performed with the periodic addition of lixiviant at specific time intervals as well. The dissolution process was described by the first-order kinetics equation with an apparent activation energy of ~39 kJ/mol. Finally, XRD and SEM-EDS analyses were used to characterize the leached residue, and the results showed that the formation of elemental sulfur on the chalcopyrite surface affected the dissolution process.

Velike količine flotacijske jalovine stvaraju se u Srbiji (preko 20 Mt), kao i u svetu (20.000-25.000 Mt). Zbog zaostalih teških metala (Pb, Cu, Fe i Zn...) ona predstavlja potencijalno opasni otpad koji bi trebalo zbog vrednosti plemenitih i obojenih metala u njoj reciklirati. Na Rudniku „Rudnik“ svake godine se generiše oko 250.000 t, flotacijske jalovine, od 1953. god. oko 11 Mt. Naučno istraživačkim radom i obavljenim ispitivanjima u okviru Projekta-REASONING (2024.-2026.) dobiće se rezultati i osvojiće se nova inovativna rešenja i znanja čija će implementacija omogućiti osvajanje tehnoloških postupaka reciklaže i prerade flotacijske jalovine Rudnika “Rudnik”.

In the modern practice of copper production, more attention is increasingly being given to the possibility of treating low-percentage sulphide ores that cannot be treated with conventional procedures (crushing, grinding, flotation). In addition, the processes of obtaining copper from complex sulphide concentrates, which cannot undergo pyrometallurgical processing, are increasingly being investigated. In most cases, the extraction of copper from such raw materials is achieved by applying the leaching procedures. Since chalcopyrite (CuFeS2) is the most abundant copper sulphide mineral, a great part of the research is focused on studying the behaviour of chalcopyrite in the leaching process, because processes of copper extraction from increasingly poor raw materials may be created using results of these studies. In addition, the main goal of these researches is to investigate the kinetics and mechanism of oxidation of chalcopyrite under the influence of various oxidants (O-2, Fe3-, H2O2, chlorate ions, etc.) and in the same time obtaining data necessary for the development of copper production process that could satisfy increasingly technological, economic and environmental stringent criteria. This paper presents the existing knowledge of chalcopyrite leaching and phenomena that follow chalcopyrite oxidation in acidic sulphate and chloride solutions.

U disertaciji su prikazani rezultati luženja halkopirita vodonik−peroksidom u rastvoru hlorovodonične i sumporne kiseline. Ispitan je uticaj brzine agitacije, odnosa čvrsto:tečno, koncentracije kiseline i oksidansa, reakcione temperature, kao i uticaj polarnih organskih rastvarača (metanol i 2-propanol) na izluženje bakra i gvožđa iz halkopiritnog koncentrata. Ustanovljeno je da se u sistemu HCl−H2O2 intenzivna oksidacija halkopirita odigrava u prvih 60 minuta reakcije, nakon čega se brzina reakcije znatno smanjuje usled brzog katalitičkog razlaganja vodonik−peroksida. Utvrđeno je da brzina mešanja i reakciona temperatura imaju neznatan uticaj na rastvaranje halkopirita dok je odnos čvrsto:tečno značajno uticao na izluženje bakra i gvožđa. Porast koncentracije hlorovodonične kiseline (0,1–3,0 mol/dm3) i vodonik-peroksida (0,5–3,0 mol/dm3) u rastvorima ima pozitivan uticaj na oksidaciono luženje halkopirita. Određen je red reakcije od 0,30 u odnosu na koncentraciju kiseline, odnosno 0,53 u odnosu na koncentraciju vodonik-peroksida. Poredeći rezultate ispitivanja u sistemu HCl−H2O2 sa ostvarenim rezultatima u sistemu H2SO4-H2O2, utvrđeno je da je sistem H2SO4−H2O2 pogodniji sistem za luženje halkopirita u pogledu dobijenih stepena izluženja metala. Reakciona temperatura ima uticaja na brzinu rastvaranja halkopirita u početnom stadijumu luženja, dok odnos čvrsto:tečno i u ovom sistemu značajno utiče na izluženje bakra i gvožđa. Porast koncentracije sumporne kiseline (0,3–3,0 mol/dm3) i vodonik-peroksida (0,5–3,0 mol/dm3) ima uticaja na oksidaciono luženje halkopirita (red reakcije 0,10 odnosno 0,24 u odnosu na koncentraciju kiseline i oksidansa, respektivno). Kinetika rastvaranja halkopirita u oba ispitana sistema se uspešno opisuje jednačinom kinetike prvog reda X=Xm(1−e−kt). Vrednosti energije aktivacije u hloridnim rastvorima iznose 19,6 kJ/mol (preko Cu), odnosno 17,1 kJ/mol (preko Fe), dok su u sulfatnim rastvorima dobijene veće vrednosti energije aktivacije koje, The dissertation presents the results of leaching of chalcopyrite with hydrogen peroxide in a solution of hydrochloric and sulfuric acid. The effect of agitation rate, solid to liquid ratio, acid and oxidant concentration, reaction temperature, as well as the effect of polar organic solvents (methanol and 2-propanol) on the copper and iron extraction from the chalcopyrite concentrate, have been examined. It has been found that an intensive chalcopyrite oxidation occurs in the HCl−H2O2 system in the first 60 minutes of reaction, after which the reaction rate significantly decreases due to the rapid catalytic decomposition of hydrogen peroxide. The stirring speed and reaction temperature have a slight effect on chalcopyrite dissolution, while the solid to liquid ratio has a significant effect on copper and iron extraction. The increase in the concentrations of hydrochloric acid (0.1–3.0 mol/dm3) and hydrogen-peroxide (0.5–3.0 mol/dm3) in solutions has a positive effect on the oxidative leaching of chalcopyrite. A reaction order of 0.30 was determined in relation to the acid concentration, that is, 0.53 in relation to the hydrogen peroxide concentration. Comparing the results of the HCl−H2O2 system with the results obtained in the H2SO4−H2O2 system, it has been established that the H2SO4−H2O2 system is more suitable system for the chalcopyrite leaching with respect to the obtained metal extraction degrees. The reaction temperature has an effect on the rate of chalcopyrite dissolution at the initial stage of the leaching, while the solid to liquid ratio significantly affects the extraction of copper and iron in this system as well. The increase in the sulfuric acid concentration (0.3-3.0 mol/dm3) and hydrogen-peroxide concentration (0.5-3.0 mol/dm3) has an effect on the oxidative leaching of chalcopyrite (reaction order of 0.10 and 0.24 in relation to the concentration of acid and oxidant, respectively). The kinetics of chalcopyrite dissolution in both examined systems

This paper presents results of investigations of the possibility of using “Gigovići”-Ulcinjlimestone (Republic Montenegro) as filler in various industry branches. Micronization methods, granulometric composition, oil and water absorption and degree of whiteness were investigated, and chemical and thermal analyses (DT/TG) were performed. Physico-chemical properties of this limestone classify it among high quality carbonate raw materials with relativelyhigh CaCO3 content of 98.16%, as well as low MgCO3 content of 1.53% and low silicate content (SiO2 0.30%). Its quality satisfies requirements of standards on using of calcium carbonate as filler in industry of paints and coatings; paper industry, rubber and PVC industry; glass industry; production of mineral fertilizers; foundry industry; sugar industry and metallurgy. Due to the low degree of whiteness (85,25%) “Gigovići” limestone cannot be used in pharmaceutical and cosmetics industry. Due to relatively high content of MgO (0,73%) and Fe (340ppm), as well as high content of heavy metals, Cu (18 ppm), Ni (24 ppm) and Cd (9 ppm), “Gigovići” limestone cannot be used, in production of cattle feed and for neutralization of acidic soils.

U ovom radu su predstavljeni rezultati ispitivanja mogućnosti korišćenja krečnjaka iz mesta Gigovići kod Ulcinja (Republika Crna Gora) kao punioca u različitim granama industrije. Ispitivani su metodi mikronizacije, granulometrijski sastav, stepen apsorpcije ulja i vode i stepen beline, a izvršena je i hemijska i termalna analiza (DT/TG). Fizičko-hemijske osobine ovog krečnjaka svrstavaju ga u karbonatne sirovine visokog kvaliteta sa relativno visokim sadržajem CaCO3, 98,16 %, i niskim sadržajem MgCO3, 1,53 %, i silikata (0,30 % SiO2). Njegov kvalitet zadovoljava standarde za korišćenje kalcijum-karbonata kao punioca u industriji boja i premaza, u papirnoj industriji, u proizvodnji gume i PVC-a, u industriji stakla, u proizvodnji veštačkog đubriva, u livarstvu i metalurgiji. Zbog niskog stepena beline krečnjak 'Gigovići' ne može da se koristi u farmaciji i kozmetičkoj industriji. Zbog visokog sadržaja MgO (0.73 %) i Fe (340 ppm), kao i visokog sadržaja teških metala, Cu (18 ppm), Ni (24 ppm) i Cd (9 ppm), krečnjak 'Gigovići' ne može da se koristi u proizvodnji stočne hrane i za neutralizaciju kiselih zemljišta., This paper presents results of investigations of the possibility of using 'Gigovići'-Ulcinj limestone (Republic Montenegro) as filler in various industry branches. Micronization methods, granulometric composition, oil and water absorption and degree of whiteness were investigated, and chemical and thermal analyses (DT/TG) were performed. Physico-chemical properties of this limestone classify it among high quality carbonate raw materials with relatively high CaCO3 content of 98.16 %, as well as low MgCO3 content of 1.53 % and low silicate content (SiO2 0.30 %). Its quality satisfies requirements of standards on using of calcium carbonate as filler in industry of paints and coatings; paper industry, rubber and PVC industry; glass industry; production of mineral fertilizers; foundry industry; sugar industry and metallurgy. Due to the low degree of whiteness (85.25 %) 'Gigovići' limestone cannot be used in pharmaceutical and cosmetics industry. Due to relatively high content of MgO (0.73 %) and Fe (340 ppm), as well as high content of heavy metals, Cu (18 ppm), Ni (24 ppm) and Cd (9 ppm), 'Gigovići' limestone cannot be used, in production of cattle feed and for neutralization of acidic soils.

This paper gives a review of results determining conditions of thickening and filtration of waste material from the flotation plant “Feldspar” – Bujanovac. This flotation plant last few years did not fuctiona as should be, and have many problems. Investigation of waste materials, should to enable recycling and re-use of flotation tailings. Tests of possibilities of thickening and filtration of the non-magnetic fraction of waste material sample of the class -0,063 mm after magnetic separation in laboratory conditions have been carried out within this research. Based on dewatering testing, time of thickening and calculated results have been determined.

Proizvodnja bakra u Boru tokom poslednjih 100 godina predstavlja najveći izvor zagađenja životne sredine. Zagađivači u vidu prašine, otpadnih voda, jalovine i zagađenog vazduha, utiču na kvalitet zemljišta, voda i vazduha. Preko 2.000 hektara plodnog zemljišta oštećeno je izlivom flotacijske jalovine iz borskog rudnika bakra. Cilj ovog rada je da se odredi sadržaj teških metala kod divljih biljaka (17 vrsta) koje prirodno rastu na oštećenom zemljištu i kod gajenih biljaka (devet vrsta), koje su zasejane na istom mestu. Sadržaj teških metala (Pb, Cu i Fe) je analiziran u oštećenom zemljištu. Ovom studijom su ispitivane divlje i kultivisane biljke koje su u stanju da rastu na kontaminiranom zemljištu u oblasti intenzivne industrijske proizvodnje bakra u Boru, što znači da mogu da tolerišu i akumuliraju teške metale u svojim nadzemnim tkivima. Ustanovljeno je da se sadržaj svih metala u kontaminiranom zemljištu smanjuje značajno na kraju eksperimenta. Kao što je očekivano, sve biljne vrste mogu da akumuliraju istraživane metale. Sve testirane biljke, kako divlje tako i kultivisane, izgledale su sasvim zdrave na podlogi koja je sadržala ekstremno visoke koncentracije bakra., The copper production in Bor (East Serbia) during the last 100 years presents an important source of the pollution of environment. Dust, waste waters, tailing, and air pollutants influence the quality of soil, water, and air. Over 2,000 ha of fertile soil have been damaged by the flotation tailing from Bor’s facilities. The goal of the present work has been to determine the content of Pb, Cu, and Fe in wild plants (17 species) naturally growing in the damaged soil and in fodder crops (nine species) planted at the same place. The content of Pb, Cu, and Fe has been analyzed in damaged soil as well. This study has also searched for native (wild) and cultivated plants which are able to grow in contaminated soil in the area of the intense industrial activity of copper production in Bor, which means that they can accumulate and tolerate heavy metals in their above-ground tissues. It has been found out that the content of all metals in contaminated soil decreases considerably at the end of the experiment. As it has been expected, all plant species could accumulate investigated metals. All tested plants, both wild-growing and cultivated plants, seem to be quite healthy on the substrate which contained extremely high concentrations of copper.

The research results of the oxidants influence on Cu leaching recovery from the old Bor flotation tailing dump from the Bor mining facilities, located in eastern Serbia, will be present. Leaching experiments were carried out on samples of tailings taken from the surface of tailing dump down to the depth of 20 m, per depth intervals of 5 m. Copper content in the initial samples ranged from 0.026 % (surface) to 0.43% (20 m depth). Tests of copper leaching were carried out in the acid media (0.01 M solution of H2SO4) without an oxidant, with addition of hydrogen peroxide and oxygen. All three combinations of tests were done with and without the previous rinsing of samples so that total of six different series of experiments emerged. During previous rinsing of samples with distilled water, high degree of copper leaching (up to 75.33%) was achieved in some samples indicating the presence of copper sulfate and other soluble copper oxides. The highest copper recovery were obtained in the experiments with 3% solution of hydrogen peroxide and amounted to 88.93% and 62.63% for samples with and without rinsing, respectively. These results indicate on extremely high mobility of copper ions and the risk in terms of pollution the surrounding water system and soil.

Luženje teških metala iz flotacione jalovine ispitivano je pod prirodno atmosfersko – klimatskim uslovima sa aspekta uticaja na životnu okolinu. U tom smislu je određena distribucija i sadržaj jona teških metala u starom flotacijskom jalovištu iz uzoraka jezgara istražnih bušotina do dubine od 20m, dejstvo prirodno prisutnih oksidanasa i uticaja pH vrednosti rastvora na stepen izluživanja teških metala iz flotacijske jalovine kao i distribucija i sadržaj jona teških metala u okolnom zemljištu i biljkama. Za određivanje stepena izluživanja teških metala formiranoje paralelno šest različitih serija eksperimenta sa 0.01M H2SO4, sa i bez dodavanja oksidansa (H2O2 i O2), sa i bez prethodnog ispiranja uzoraka destilisanom vodom. Prethodno ispiranje uzoraka vršenoje u cilju uklanjanja lako rastvornih elemenata iz uzoraka i utvrđivanja razlike u daljem rastvaranju teških metala u odnosu na eksperimente bez prethodnog ispiranja uzoraka. Tokom eksperimenata je praćena pH vrednost rastvora i koncentracije Cu, Fe, Zn, Pb, As, i Mn u funkciji vremena. Rezultati eksperimentalnih istraživanja pokazali su da je dominantni sulfidni mineral pirit sa masenim učešćem od 21.57 %, dok kumulativno učešće jalovih minerala, koje predstavljaju kvarc, silikati i karbonati, iznosi 77 %. Prosečna oslobođenost pirita iznosi 90.9 %, što u prisustvu vode i atmosferskog kiseonika predstavlja veliki reaktivni potencijal za mobilizaciju jona teških metala. Ovaj mineral predstavlja i jedan od osnovnih uzroka povećane kiselosti jalovine sa pH vrednostima između 2.25 i 4.22. Raspoloživost kiseonika i atmosferskih voda glavni su razlozi za najveći stepen samoizluživanja sulfida tokom perioda odstojavanja jalovine u površinskim slojevima, pa je stoga i njihov sadržaj na površini najniži. Stepen oksidacije sulfida i mobilizacija jona teških metala u dubljim slojevima jalovišta daleko su niži zbog manje raspoloživosti kiseonika i rastvora pa je samim tim i njihov sadržaj znatno viši. Međutim,upravo ti miner, Leaching of heavy metals from flotation tailings was studied under natural atmospheric- climate conditions in terms of impact on the environment. In that sense was determined the distribution and the content of heavy metal ions in the old flotation tailing samples from exploratory holes cores to a depth of 20m, the effect of oxidants naturally present and the pH value of the solution on the degree of leaching of heavy metals from the tailings as well as the distribution and content of heavy metal ions the surrounding soil and plants. To determine the degree of leaching of heavy metals were formed parallel the six different series of experiments with 0.01M H2SO4, with and without addition of oxidants (H2O2 and O2), with and without pre-rinsing of the samples with distilled water. Pre-rinsing of the samples was performed in order to remove easily soluble elements from the samples and determine the differences in the further dissolution of heavy metals in relation to the experiments without pre-rinsing the samples. During the experiments was monitored pH value of the solution and the concentration of Cu, Fe, Zn, Pb, As, and Mn in a function of time. The results of experimental studies have shown that the dominant sulphide mineral is a pyrite with mass participation of 21.57%, while the cumulative share of barren minerals, which are quartz, silicates and carbonates, is 77%. Average liberation of the pyrite is 90.9%, which in the presence of water and atmospheric oxygen present important reactive potential for mobilization of heavy metal ions. This mineral is also one of the main causes of the increased acidity of tailings with pH values between2.25 and4.22. The availability of oxygen and atmospheric waters are the main reasons for the highest level of sulphide minerals self-leaching during time in the surface layers, which makes their content the lowest at the surface. The oxidation of sulphides and mobilization of heavy metal ions in the deeper layers of the tailings a