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Izbor vertikalnog mlina u postupku usitnjavanja topioničke šljake iz prerade koncentrata bakra
No full textU radu je izvršen proračun vertikalnog mlina na osnovu pretpostvaljenog kapaciteta prerade od 40 t/h suve sirovine. Kao sirovina je razmatrana topionička šljaka iz prerade koncentrata bakra, koja je već prošla dva stadijuma mlevenja (mlin sa šipkama i mlin sa kuglama). Vertikalni mlin sa kuglama je razmatran za treći stadijum mokrog mlevenja, jer je za valorizaciju bakra iz topioničke šljake potrebno dalekosežno usitnjavanje i veoma fino samleven proizvod, kako bi se obezbedili uslovi za uspešnu flotacijsku koncentraciju
Structural stability of calcite mineral after surface modification
No full textCalcite was modified with stearic acid in the "wet" and "dry" process. The results showed
that the total hydrophobicity is achieved at a concentration of stearic acid 1.5% in the "wet"
process, and 3% for "dry". Microscopic analysis is in accordance with the degree of coating
obtained. On the basis of the infrared spectra, it was concluded that there was no change in the
position and intensity of most strip of modified calcite relative to the starting sample. The X-ray
diffraction analysis showed that the calcite after modifying stearic acid retains its basic structure
Influence of Feeder Positions at Preheating Temperature Distribution in Railway Aluminothermic Welding Simulation
No full textOne of the most used techniques for making a continuous rail track is aluminothermic welding. This technique has its advantages in its simplicity, portability, and it does not require external energy when repairing or connecting tracks. One of the crucial parts when implementing this process is the mold design that influences the solidification of the casting. In this study three models were investigated that
have varying positions of the feeders: asymmetrical mold, centered mold, and symmetrical mold. The focus of the paper is to determine how the position of the feeder effects the preheating of the side rails that would be welded together. This was carried out using NovaFlow & Solid CV and utilizing its sensor function. The rail was modeled after the 49E1 standard rail, and the preheating was carried out by simulating a burner at 1000 oC for 900 seconds. The asymmetrical model had a negligible increase in temperature, while the symmetrical and centered model were similar. One side rail was more heated than the other, which can be attributed to the positioning and shape of the burner source area
Importance and fundamentals of sustainable mining
No full textThis article provides a definition and analysis of sustainable mining from the
aspect of impact on the wider social community. The development of modern mining,
more efficient technologies that are sustainable, raising awareness of the importance of
a healthy environment, sustainable mining that contributes to positive social changes
has been achieved. It is not only enough to comply with the regulations in this industry,
but also to ensure business competitive advantage on the market on the basis of
sustainability. Mining is sustainable only if it bases its environmental and social policy
on the law, competitive business advantage and good business practice. The Mining
industry recognizes the need for changes and, accordingly, is actively working in the
field of ecological and ethical mining. According to the objective set in the mining
industry, several ways have been adopted to achieve sustainable mining based on
sustainable solutions at different levels such as: practical solutions, supporting the
transition to renewable energy sources in order to reduce CO2 emissions and sustainable
technological innovation. Practical solutions as part of mining activities should
highlight several key positions that contribute to sustainable mining: the use of tailings
materials as waste from previous ore processing processes, which contributes to
reducing the amount of deposited tailings, efficient and safe management of unused
waste, land reclamation after the mine is closed and bringing it to level before the start
of exploitation, water conservation, afforestation of the land with plants suitable for the
terrain, which creates conditions for the settlement of animal species and prevention of
illegal mining activities. Direct cooperation with the local community on the territory of
which the mine is located is extremely important in order to reduce the negative effects
of mining activities and extract as many benefits as possible for the local population,
proactive management of the economic transition of the local community, inclusion of
local companies in the supply chain of services that operate within mine. The world on
a global level is faced with sustainable technologies, as well as product needs arising from the mining sector. The development of renewable energy source technologies
requires large amounts of metals and non-metals that are mining products. It can be
said that mining is of fundamental importance for the transition of the energy sector and
the transition to renewable sources. Also, mining has a big role to play in the fight
against climate change
Plum Stones Biochar – Efficient Resource For Phosphate Recovery and Alternative Fertilizer
No full textThe global food demand has drastically increased in the last decade, raising the application of chemical fertilizers to support it. In the same time, high growing fruits/vegetables processing industries (FVPI) are generating significant amounts of organic waste, whose landfilling represents unsustainable practice with significant environmental hazards. Lignocellulosic waste (LCW), generated by FVPI, represents valuable renewable resource with many beneficial properties, that can be mechanically, chemically or thermochemically converted into the materials with significant benefits which might reduce environment pollution and support circular economy principles. In this paper we have thermochemically transformed waste plum stones (PmS) from the local FVPI company, into the biochar (BC) – stable, porous, carbon rich matrix, plain with surface functional groups, that can be further tailored for various purposes. The characterization of obtained PmS-BC resulted in the following elemental organic analysis: C(66.8 wt%), N(1.62 wt%), H(2.7 wt%) and O(28.9 wt%); chemical analysis revealed significant amounts of nutritional components such as P(1.1 wt%), K(0.3 wt%), Mg(1.7 wt%) and Ca(0.25 wt%), while toxic metals were not present. Low O/C ratio (0.3) indicated high stability of PmS-BC in soil, with the half-life from 100 - 1000 years (Spokas, 2014). The raw PmS-B was used for the sorption of eutrophication agent, phosphate ions (PO43-), but instead of binding, release of phosphorous from the PmS-B structure occurred: PO43- concentration raised from initial 135.2 to 147.4 mg/L. Similar results were obtained by He et al. (2020) who confirmed that the native tobacco stalk biochar releases phosphorus, explaining that without the chemical modification, BC surface has a high negative zeta potential, which electrostatically repulse phosphate ions and, due to the acidity of the phosphorus solution, release already contained phosphorous. In order to improve BCs ability to bind phosphate ions, Mg, Al, Fe, and other metals are often loaded onto the biochar surface (Wan et al., 2017). Having this in mind, PmS-B was modified according to the procedure adopted from Ronghua et al. (2017). Modified biochar (PmS-B-M) showed excellence sorption capacity toward phosphates (calculated by Sips isotherm) of 181.46 mg/g, much higher than others found in literatures (Lopičić et al., 2023). The post-sorption characterizations by SEM-EDX, XRD, and FTIR suggested that colloidal and nano-sized MgO, in the form of periclase particles deposited on the surface of PmS-B-M, were the main sites for the phosphate sorption. Results of this investigation show that PmS-B-M can be effectively used as efficient phosphate remediation technology, where the exhausted, P-loaded biochar can be directly applied to the soil as fertilizer to improve soil fertility, regulate pH, raise water-holding capacity, and support microbial activities. Fertilizers made of LCW biomass available in abundant amounts, might promote global food production, enhance CO2 capture, reduce waste generation/environment pollution, and improve soil quality
Advances in biopolymer production and applications: a comprehensive review of key biomaterials
No full textThis article provides a comprehensive review of recent advancements in biopolymer
technology, focusing on their environmental and economic impact across various industries.
Key biopolymers discussed include cellulose, lignin, starch, algal polysaccharides, and proteinbased
polymers such as whey and casein, alongside essential biopolymers like chitin, chitosan,
pectin, guar gum, xanthan gum, natural polyesters, and polyamides. These biopolymers have
experienced rising demand due to their renewable nature and biodegradability, supporting the
shift toward sustainable materials in sectors such as food technology, biomedical applications,
and eco-friendly packaging.
By synthesizing insights from industry reports, market trends, and scientific studies,
the review highlights the growth trajectory, environmental benefits, and economic viability
of biopolymers. The analysis emphasizes how these materials contribute to reducing fossil
fuel dependency and waste, positioning them as critical components of the green economy.
Furthermore, it addresses challenges such as production costs and scalability, advocating
for ongoing research and technological development to maximize their potential. This work
underscores the increasingly vital role of biopolymers in sustainable development and sets the
stage for further innovation in the field
Hydroxyapatite/poly(vinyl alcohol)/chitosan/gentamicin coatings for biomedical applications
No full textBiocomposite hydroxyapatite/poly(vinyl alcohol)/chitosan/gentamicin (HAP/PVA/CS/Gent) coating was fabricated on titanium by electrophoretic deposition process (EPD) from aqueous suspension using constant voltage method. The bioactivity of HAP/PVA/CS/Gent coating after immersion in simulated body fluid (SBF) at 37 °C, i.e. the growth of a new phase of hydroxyapatite, was proved using scanning electron microscopy with field emission (FE–SEM) and Fourier transform infrared spectroscopy (FT–IR) analysis. Antibacterial activity was proved against Staphylococcus aureus TL and Escherichia coli ATCC 25922 bacterial strains. Cytotoxicity was tested by DET tests on MRC-5 and L929 fibroblast cell lines. The results showed high applicability potential of biocomposite hydroxyapatite/poly(vinyl alcohol)/chitosan/gentamicin coating in orthopedic surgery
Non-Metals - Materials Of The Future
No full textMining is often described as a low-accumulative activity, with high production costs and low prices for finished products, which puts it in an unequal position compared to other, less demanding industries. It is frequently noted that employees in the mining sector in our region (Western Balkans) typically focus more on production costs than on realized profits. This approach has persisted for a long time, while the full potential of available resources is not sufficiently utilized.
In Serbia, around 200 mines are engaged in the exploitation of non-metallic mineral raw materials. These raw materials are found throughout Serbia and play a significant role in its economic development, serving either as final products or as raw materials for processing in various industrial sectors. Given their quantity and diversity, these raw materials are among the most important domestic natural resources. Virtually all economic sectors utilize non-metallic mineral raw materials.
Serbia's territory boasts a substantial raw material base of non-metallic mineral raw materials (NMRM). To varying extents, 47 raw materials have been explored: 16 are in constant exploitation, 16 are occasionally exploited or not currently exploited, and 15 are insufficiently explored and not exploited. Among these NMRM, raw materials for construction materials hold the greatest economic significance. Additionally, other non-metallic raw materials of great economic importance include ceramic and refractory clays, quartz sand and sandstone, magnesite, quartz raw materials, kaolin, calcite, limestone (as industrial raw materials), gypsum and its anhydrite, pozzolanic tuff, dunite (olivine), rocks for ceramics and glass (""white granites""), and boron minerals.
Beyond the mentioned NMRM, there are ecological mineral raw materials, which belong to the group of natural mineral raw materials and have a wide range of applications, particularly in environmental protection. These materials are increasingly used to remove suspended particles or271 dissolved substances from industrial waters—pollutants of watercourses and soil—thanks to their outstanding adsorption, ion exchange, and catalytic properties.
This paper aims to highlight the possibilities and challenges of processing NMRM into new materials with added value, based on mineral powders. These materials are produced through the micronization process, which is currently the most widely applied method. Micronization involves very fine grinding, resulting in particles with an upper size limit of a few microns
PROJEKAT PRIZMA: Karakterizacija i tehnološki postupci za reciklažu i ponovnu upotrebu flotacijske jalovine Rudnika „Rudnik“
No full textProjekat Karakterizacija i tehnološki postupci za reciklažu i ponovnu upotrebu flotacijske jalovine iz rudnika „Rudnik“(REASONING) je multidisciplinarni istraživački projekat ispitivanja jalovine kroz geološka, mineraloška, geohemijska, geofizička naučna ispitivanja i razvoj odgovarajućih tehnoloških metoda za upotrebu jalovine u industriji. REASONING se realizuje kroz program „Prizma” Fonda za nauku Republike Srbije i bavi se ispitivanjem jalovine nastale tokom višedecenijske eksploatacije i flotacijske prerade rude iz rudnika „Rudnik”. Primarni ciljevi projekta su karakterizacija, razvoj tehnoloških metoda za efikasno izdvajanje korisnih metala i drugih elemenata prisutnih u jalovini i ocena mogućnosti korišćenja jalovine kao sirovine. Istraživanja će se realizovati kroz radne pakete koji će imati za cilj: merenje i praćenje promena fizičko-hemijskih uslova duž vertikalnog profila tela jalovine, korelaciju magnetne susceptibilnosti sa sadržajem teških metala sa dubinom i definisanje zona obogaćivanja, utvrđivanje distribucije mineralnih asocijacija, varijacija i trendova u sastavu pornih voda, teških metala i pratećih elemenata, istraživanje distribucije stabilne mineralne asocijacije i distribucije elemenata kroz teorijsko geohemijsko modelovanje, pronalazak optimalne šeme za ekstrakciju elemenata teorijskim pristupom, elektrohemijsko odvajanje elemenata iz sintetičkih i luženih rastvora i tehnološki postupak valorizacije korisnih komponenti. Projektni tim čine istraživači iz geologije, mineralne industrije, tehnologije, hemije iz šest domaćih i jedne naučnoistraživačke institucije iz inostranstva. Projekat REASONING će doprineti proučavanju distribucije elemenata, postupcima ekstrakcije i načinu korišćenja jalovine iz jalovišta rudnika „Rudnik“ a rezultati ovog projekta trebalo bi da budu i standard za buduća istraživanja i kompleksnu valorizaciju jalovine iz brojnih jalovišta u Srbiji
Reapplication Potential of Historic Pb–Zn Slag with Regard to Zero Waste Principles
No full textSmelting used to be less efficient; therefore, wastes obtained from historical processing at smelter plants usually contain certain quantities of valuable metals. Upon the extraction of useful metal elements, metallurgical slag can be repurposed as an alternative mineral raw material in the building sector. A case study was conducted, which included an investigation of the physico-chemical, mineralogical, and microstructural properties of Pb–Zn slag found at the historic landfill near the Topilnica Veles smelter in North Macedonia. The slag was sampled using drill holes. The mineralogical and microstructural analysis revealed that Pb–Zn slag is a very complex and inhomogeneous alternative raw material with utilizable levels of metals, specifically Pb (2.3 wt.%), Zn (7.1 wt.%), and Ag (27.5 ppm). Crystalline mineral phases of wurtzite, sphalerite, galena, cerussite, akermanite, wüstite, monticellite, franklinite, and zincite were identified in the analyzed samples. The slag’s matrix consisted of alumino-silicates, amorphous silicates, and mixtures of spinel and silicates. Due to the economic potential of Pb, Zn, and Ag extraction, the first stage of reutilization will be to transform metal concentrates into their collective concentrate, from which the maximum amount of these crucial components can be extracted. This procedure will include combination of gravity concentration and separation techniques. The next step is to assess the Pb–Zn slag’s potential applications in civil engineering, based on its mineralogical and physico-mechanical properties. Alumino-silicates present in Pb–Zn slag, which contain high concentrations of SiO2, Al2O3, CaO, and Fe2O3, are suitable for use in cementitious building composites. The goal of this research is to suggest a solution by which to close the circle of slag’s reutilization in terms of zero waste principles. It is therefore critical to thoroughly investigate the material, the established methods and preparation processes, and the ways of concentrating useful components into commercial products