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Characterization and environmental application of iron-modified zeolite from the Zlatokop deposit
No full textIn this paper, characterization of iron-modified zeolite (IMZ) from the Zlatokop deposit and its potential environmental application has been described. The modification procedure includes treatment of natural zeolite (NZ) with Fe(NO3)(3) in an acetate buffer at pH = 3.6 followed by treatment with NaOH and NaNO3. The properties of NZs and IMZs have been determined by analysis of their chemical composition, specific surface area and by X-ray powder diffraction method (XRPD), scanning electron microscopy-energy dispersive X-ray analysis (SEM-EDS), TG-DTG and FTIR analyses. The chemical behaviour of modified zeolite has been examined in the zeolite-ultrapure water system at adjusted initial pH values in the range of 1.71-5.08, and also by determining the zero-point charge. The NZ and IMZ samples have been tested relative to the uptake of zinc ions. The results have shown that the capacity of IMZ samples for zinc ions is three-to-four times higher compared to the NZs. The balance of exchangeable ions before and after zinc uptake confirms an almost complete stoichiometric relation for both zeolite samples indicating ion exchange as the main process. However, in IMZ samples ion exchange takes place inside the zeolite particle and on activated zeolite particle surface
Adsorption of zearalenone on surface modified zeolites – clinoptilolite and phillipsite
No full textCetylpyridinum chloride (CP) was used to modify the surface of natural zeolites – clinoptilolite (Z) and phillipsite (P) and adsorption of zearalenone (ZEN) was investigated. Zeolites were modified with two different levels (5 and 10 mmol/100g) of CP and adsorption experiments were done at pH 3 and pH 7. Results showed that with increasing amounts of surfactant at the zeolitic surface, ZEN adsorption increased, as well as with increasing amounts of solid phase in the suspension. At the highest level of surfactant (10 mmol/100g), a slightly higher adsorption of ZEN was observed for phillipsite modified with CP ions, in contrast to clinoptilolite
Copper minerals flotation collector selection for processing of the ore from pyrite–rich parts from „Veliki Krivelj“ deposit
No full textSome parts of porphyry copper ore deposit ”Veliki Krivelj” (Bor, Serbia) carry a high content of pyrite, which, with the existing technology of selective flotation, using potassium ethyl xanthate as copper minerals collector, results in low copper grade of final copper concentrate. Laboratory flotation tests were performed, with main goal to replace potassium ethyl xanthate, using other, more selective against pyrite collectors, while retaining other technological parameters under the existing flotation process. In this paper, the part of results from those experiments, using isopropyl ethyl thionocarbamate as collector to compare them to potassium ethyl xanthate, are presented. The study included the flotation experiments with different doses of collectors at different pH values, as well as experiments of flotation kinetics and cleaning of rough concentrate. Selectivity of those two collectors was measured watching sulfur grade and recovery in rough copper concentrate, obtained under the same conditions. Sulphur recovery in copper rough concentrate, produced using potassium ethyl xanthate was over 80% and Cu grade was 1,29%, while only 12-18% of sulphur recovery with about 3% of Cu grade was optained using isopropyl ethyl thionocarbamate, even at lower consuption. Both collectors produced rough concentrates with the similar Cu recovery, so this kind of selective collectors must be considered in case of processing this tipe of ore
The Content of Manganese in Soils and Plants of Bor Mine Overburden Site (Serbia, SE Europe)
No full textManganese is ubiquitous element in nature, being abundant constituent of soils and having essential
role as micronutrient in plants. However, some interactions of manganese in diverse natural processes are not
yet fully understood. This paper analyses the results of manganese content screening for frequent wild plants of
Bor mine waste overburden, defines main relations with characteristics of overburden mine soils and presents
the extent of its transfer in wild plants of this area
Novi tehnološki postupak za tretman kompleksne visokopiritične rude sa viših etaža površinskog kopa „Veliki Krivelj“ primenom savremenih flotacijskih kolektora
No full textNa osnovu ugovora za izradu Studije između RBB I ITNMS, pod nazivom “ Studija flotacijske prerade kompleksne rude sa viših etaža rudnika „Veliki Krivelj“ ”, ekipa istraživača ITNMS je u januaru 2014. god. otpočela realizaciju ovog zadatka. Pored aktivnosti koje su planirane za sprovođenje u cilju realizacije ovog posla, namera saradnika ITNMS bila je da se kroz naučno-istraživački rad u periodu od nekoliko meseci ispitaju mogućnosti promene parametara tehnološkog procesa za postizanje povoljnijih tehnoloških pokazatelja flotacijske koncentracije minerala bakra, koji u tom periodu nisu bili na projektovanom tj. zadovoljavajućem nivou. Na uzorcima rude viših etaža ležišta “Veliki Krivelj” sprovedena su detaljna laboratorijska tehnološka ispitivanja, prema programu koji je definisan u funkciji ostvarivanja zadatih ciljeva. Rezultati ispitivanja prezentovani su u Studiji flotacijske prerade kompleksne rude sa viših etaža rudnika „Veliki Krivelj“ koja je predata rukovodstvu RTB. Na osnovu ovih rezultata pristupilo se industrijskoj probi savremenih flotacijskih kolektora čijom primenom su ostvareni značajno bolji tehnološki pokazatelji prerade ove rude. Nakon toga, u pogonu Flotacije „Veliki Krivelj“ stari kolektori su zamenjeni savremenim kolektorima koji su bili tema ispitivanja u Studiji i koji od tada egzistiraju u ovom pogonu. Na taj način, tehnološka šema flotacije i koncentracije u pogonu „Veliki Krivelj“ pretrpela je izmene u pogledu implementacije kompletnog reagensnog režima čime je uspostavljena stabilnost parametara prerade kompleksne rude i dugoročno otklonjeni problemi koji su prouzrokovali slabe tehnološke efekte. Aktivnosti sprovedene u tom periodu u laboratoriji za PMS ITNMS i pogonu Flotacije „Veliki Krivelj“ , predmet su ovog tehničkog rešenja
Long‐term behavior of depleted uranium in the environment
No full textThe widespread use of depleted uranium (DU) munitions in past wars has
generated a great deal and fear of concern of potential impact on the environment
and human health. During the NATO operations in the former Yugoslavia in
1999.y, Kosovo and Metohia and southern Serbia, were bombed with around 10
tons of DU munitions. Sixteen years ago there was very little available information
about the behavior of ecological systems damaged by DU ammunition fired and
the factors that control the corrosion of DU and its subsequent migration through
the environment. Today we are faced with the “invisible threat” of DU, which has a
strong radioactive and hemotoxic impact on human health. This paper provides a
latest finding of corrosion and corrosion behavior of DU and environmental factors
that control corrosion, together with indicators of environmental impact in order to
highlight areas that need further attention in developing remediation programs
Energy conversion in phosphate ore grain mixture activated via ultra-centrifugal mill
No full textThe aim of this investigation was to establish the optimal processing parameters of the comminuted phosphate grain mixture mechanical treatment by monitoring and evaluating the activated product characteristics. An ultra-centrifugal mill with a peripheral comminuting path was used as activator in the experiment. A mathematical model based on the theoretical principles of the grain mixture mechanical processing was applied in order to characterize the phosphate activation procedure. As the energy conversion that takes place by the interaction mill-material during activation is recorded on the processed phosphate grains, the increase in potential energy of the activated grains was measured by means of an automatic grain counter. Following the operating hypothesis of the automatic grain counter, the energy conversion and the properties of phosphate grains induced by mechanical force were monitored and expressed in the form of the grain inertia change. The phosphate ore grain mixture used in the experiment was thoroughly analyzed, particularly in its activated state. Analytically obtained results were supported by X-ray diffraction analysis for identification of crystalline phases and change in crystallinity, and SEM microphotography of initial and activated phosphate grains. Diverse comparison analyses disclosed that the optimal set of activation process parameters could reduce the negative effect of phosphate sample immanent properties on the final score and furthermore enhance the material reactivity
Biosorption of methylene blue by waste apricot shells from food industry
No full textIn this paper, the removal of methylene blue (MB) from aqueous solution by biosorption onto apricot shellshas been investigated through batch experiments. Apricot shells were chosen as a locally available and abundant waste from fruit juice industry. Methylene blue is common pollutant of waste waters from textile industry. The influence of initial MB concentration on biosorption process has been studied. The experimental data have been analysed using Langmuir and Freundlichisotherm models. The Langmuir model better fits to experimental data, which explain monolayer adsorption. Maximum biosorption capacity is 24,31 mg/g. A comparison of the biosorption capacity of waste apricot shells with biosorption capacities of similar adsorbents previously investigated indicates that apricot shells could be a promising biosorbent for removal of MB from aqueous solution
Thermal analysis and kinetics of the chalcopyrite-pyrite concentrate oxidation process
No full textThe paper presents the results of experimental investigation of the chalcopyrite-pyrite concentrate oxidation in the air. Characterisation of the initial sample and oxidation products was done by ICP-AES, XRD, EDXRF methods. Phase stability diagrams were constructed for Cu-Fe-S-O system at 25,450,650 and 900 degrees C. Equilibrium composition of the charge for the optimal oxidation process was calculated. DTA-TG analysis was used for monitoring the oxidation process. Kinetic parameters in non-isothermal conditions were determined, based on Kissinger and Ozawa methods. Values of activation energies showed that all stages of the oxidation process occur in the kinetic field
Deposit of the Lisina phosphates like the base of raw materials for production the natural mineral fertilizers
No full textDeposit of the phosphates Lisina is in the southeast of Serbia, on the territory of the community Bosilegrad, close to Serbian-Bulgarian border. Genetically, deposit of the phosphates Lisina belongs to metamorphic deposits. Narrow area of the deposit is built by metamorphic formations with intensively presence of granitoide rocks. Phosphorites are in the contact zone of Meta sandstone which is the floor of sericite-chlorite slates with intercalations of marble and kalkshist in the roof.
Raw phosphates can be application like fertilizers with positive effects on the territory of Serbia where are mostly acid soils on more then 50% of the territory