Preferencje help
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 42

Liczba wyników na stronie
first rewind previous Strona / 3 next fast forward last
Wyniki wyszukiwania
help Sortuj według:

help Ogranicz wyniki do:
first rewind previous Strona / 3 next fast forward last
EN
The article presents current methods used for the recovery of metals from used electronic equipment. The analysis of the composition and structure of the material was made on the example of one of the most popular and widespread e-waste - used cell phones. The article was address the problems of processing and separation of individual components included in these heterogeneous wastes. The main purpose of the conducted research was to prepare the tested material in such a way that the recovery of metalsin the further stages of its processing was as effective as possible. The results of attempts to separate individual material fractions with magnetic, pyrometallurgical or hydrometallurgical methods will be presented. An analysis of the possibilities of managing electronic waste in terms of the circular economy will be made.
EN
Three plants extracts were used for biosynthesis of Ag nanoparticles (AgNPs). AgNPs nucleation process requires effective reduction agents which secure Ag+ to Ag0 reduction and also stabilizing/capping agents. The UV-vis and TEM observation revealed that the best results were obtained by R. officinalis leaf extract. The strong SPR band peak appeared at the wavelength 418 nm. Synthetized AgNPs were globular, fine (~20 nm), uniform and stabile throughout the experiment. A rapid rate of AgNPs synthesis was also significant and economically advantageous factor. Fine (10-20 nm) and globular nanoparticles were synthetized also by U. dioica leaf extract, but the stability of nanoparticles was not permanent. Despite V. vitis-idaea fruit extract contains a lot of reducing agents, UV-vis did not confirm the presence of AgNPs in solution. Synthetized Ag particles were very unstable, Ag particles agglomerated very fast and clearly indicated sediment was formed.
3
Content available Bioleaching of indium and tin from used LCD panels
EN
The demand for indium is increasing every year. This metal is mainly used as indium tin oxide (ITO) in the production of transparent conductive coatings for liquid crystal displays (LCD). This paper focuses on biohydrometallurgical methods used for the recovery of indium and tin from LCD sourced from spent mobile phones. Bioleaching experiments were carried out in two different leaching media: 9K medium and H2SO4 solution, using mixed, adapted bacteria Acidothiobacillus ferrooxidans and Acidothiobacillus thiooxidans. The main aim of this study was to evaluate the potential and efficiency of indium and tin extraction in the presence of acidophilic microorganisms. Within 35 days, using 9K medium, 55.6% of indium was bioleached, whereas the chemical leaching resulted in a value of 3.4%. Leaching efficiency of tin was 90.2% on the 14th day of the experiment for the biological system (9K) and 93.4% on 21st day of control leaching.
EN
New technologies and the globalization of the electrical and electronic equipment market cause a continuous increase in the amount of electrical and electronic waste. They constitute one of the waste groups that grows the fastest in quantity. The development of the new generation of electrical and electronic devices is much faster than before. Recently attention has been concentrated on hydrometallurgical methods for the recovery of metals from electronic waste. In this article the role of an oxidizing agent, mainly ozone and hydrogen peroxide was presented in hydrometallurgical processes. Leaching process of printed circuits boards (PCBs) from used cell phones was conducted. The experiments were carried out in the presence of sulfuric acid and ozone as an oxidizing agent for various temperatures, acid concentration, ozone concentration. As a result, the concentrations of copper, zinc, iron and aluminum in the obtained solution were measured. The obtained results were compared to results obtained earlier in the presence of hydrogen peroxide as an oxidizing agent and discussed.
EN
Catalytic converters contain the catalytic substance in their structure, which is a mixture of Platinum Group Metals (PGMs). The prices of these metals and a growing demand for them in the market, make it necessary to recycle spent catalytic converters and recovery of PGMs. In the study, the effect of ozone and hydrogen peroxide application on the possibility of extracting PGM from used car catalysts was investigated. The catalytic carrier was milled, sieved and then the fractions with the desired grain size were treated with the appropriate HCl mixture and 3%, 5%, 10%, 15% and 30% H2O2, respectively, and the tests were also carried out at temperature 333 K. Ozone tests were conducted with the O3 flow in the range of 1,3,5 g/h. Samples for analysis were collected after 30 min, 1 h, 2 h, 3 h and after 4 h, respectively. The residue after the experiments and filtration process was also analysed. The obtained results confirmed the assumption that PGMs can be extracted using hydrochloric acid with the addition of H2O2 or ozone as oxidants. It allows to significantly intensify the carried out reactions and to improve the rate of PGMs transfer to the solution.
6
Content available remote Metale ziem rzadkich : otrzymywanie i odzysk z materiałów odpadowych
PL
Metale ziem rzadkich zyskują coraz większe znaczenie we współczesnym świecie. Stosowane są do produkcji magnesów, laserów, szkła, luminoforów. Lampy LED, komputery czy telewizory to urządzenia, które bez tych metali nie mogłyby istnieć. Przedstawiono podstawowe zastosowanie metali ziem rzadkich. Podano ceny ich tlenków w latach 1995-2016 oraz wielkość ich produkcji. Przedstawiono metody produkcji tych metali z rud oraz ich alternatywne otrzymywanie poprzez recykling materiałów odpadowych, takich jak magnesy, fosfory czy akumulatory NiMH. W podsumowaniu podano prognozę zużycia metali ziem rzadkich.
EN
A review with 55 refs.
EN
The application of green synthesis in the nano-science and technology is of great importance in the area of the preparation of various materials. In this work, three selected algal species Parachlorella kessleri, Dictyosphaerium chlorelloides and Desmodesmus quadricauda were successfully used for the preparation of silver nanoparticles (AgNPs). Presence of AgNPs was confirmed by UV-vis spectroscopy and transmission electron microscopy. AgNPs produced by P. kessleri had narrow size distribution and average sizes of 7.6 nm. However, nanoparticle production lasted for long time. Nanoparticle formation by D. chlorelloides was the fastest, although, their average sizes were 23.4 nm with broad size distribution. Nanoparticles produced by D. quadricauda had average sizes 23.9 nm but they were the least stable, aggregated and precipitated from solutions within 3 days. These results confirmed that the size distribution and mean diameter of the nanoparticles, crucial for various applications, can be controlled by the organism selection.
EN
The role of iron in metal-bearing waste bioleaching was studied. Four various types of waste (printed circuit boards (PCBs), Ni-Cd batteries, alkaline batteries and Li-ion batteries) were treated by bioleaching using the acidophilic bacteria A. ferrooxidans and A. thiooxidans (separately or in mixture). Role of main leaching agents (Fe3+ ions or sulphuric acid) was simulated in abiotic experiments. Results showed that oxidation abilities of Fe3+ ions were crucial for recovery of Cu and Zn from PCBs, with the efficiencies of 88% and 100%, respectively. To recover 68% of Ni from PCBs, and 55% and 100% of Ni and Cd, respectively, from Ni-Cd batteries both oxidation action and hydrolysis of Fe3+ were required. The importance of Fe2+ ions as a reducing agent was showed in bioleaching of Co from Li-ion batteries and Mn from alkaline batteries. The efficiency of the processes has increased by 70% and 40% in Co and Mn bioleaching, respectively, in the presence of Fe2+ ions. Based on the results we suggest the integrated biometallurgical model of metal-bearing waste recycling in the effort to develop zero-waste and less energy-dependent technologies.
9
Content available remote Metody odzysku srebra z produktów ubocznych i wtórnych
PL
Przedstawiono zastosowanie i produkcję srebra w latach 1990-2013 oraz metody jego otrzymywania z rud i produktów ubocznych z przeróbki rud ołowiu i miedzi. Srebro otrzymuje się także z materiałów odpadowych. Omówiono metody odzysku z odpadów galwanotechnicznych, jubilerskich, z przemysłu fotograficznego, szklarskiego, chemicznego, elektronicznego i elektrotechnicznego. Przedstawiono również możliwości zastosowania nanocząstek srebra oraz wykorzystania biotechnologii do odzysku srebra z odpadów.
EN
A review, with 43 refs.
EN
Every new car should be equipped with the catalyst, which limits the amount of harmful chemical compounds such as NOx, CH and CO emitted to the air. Auto catalyst consists of the ceramic or metallic carrier, on which is the layer with Platinum Group Metals playing catalytic role. There are many methods using for recovery those valuable metals from spent auto catalyst, however evry of those methods have some limitations. Proces described in the article is the modified method of metal collector, which used magnetohydrodynamic pump. Rotary electromagnetic field generates in the liquid metal rotary current, which as a consequence washing out the PGM metals from the ceramic carriers. Considering the possibilities of commercialization of the described method, the energy balance was made. From that balance the energetic efficiency of the unit was determined and the analysis of the temperature distribution was shown thermographycally.
EN
The objective of this work was to evaluate the influence of static, stirring and shaking conditions on copper, zinc, nickel and aluminium dissolution from printed circuit boards (PCBs) using the mixed acidophilic bacterial culture of Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans. The results revealed that static conditions were the most effective in zinc and aluminium dissolution. Zinc was removed almost completely under static conditions, whereas maximum of nickel dissolution was reached under the stirring conditions. The highest copper recovery (36%) was reached under stirring conditions. The shaking conditions appeared to be the least suitable. The relative importance of these systems for the bioleaching of copper and nickel decreased in the order: stirring, static conditions, shaking.
EN
The recovery of precious metals is necessary for environmental and economic reasons. Spent catalysts from automotive industry containing precious metals are very attractive recyclable material as the devices have to be periodically renovated and eventually replaced. This paper presents the method of removing platinum from the spent catalytic converters applying lead as a collector metal in a device used to wash out by using mangetohydrodynamic stirrer. The article includes the description of the methods used for modeling of magnetohydrodynamic phenomena (coupled analysis of the electromagnetic, temperature and flow fields) occurring in this particular device. The paper describes the general phenomena and ways of coupling the various physical fields for this type of calculation. The basic computational techniques with a discussion of their advantages and disadvantages are presented.
EN
Metal supported auto catalysts, have been used in sports and racing cars initially, but nowadays their application systematically increases. In Metal Substrate (supported) Converters (MSC), catalytic functions are performed by the Platinum Group Metals (PGM): Pt, Pd, Rh, similarly to the catalysts on ceramic carriers. The contents of these metals make that spent catalytic converters are valuable source of precious metals. All over the world there are many methods for the metals recovery from the ceramic carriers, however, the issue of platinum recovery from metal supported catalysts has not been studied sufficiently yet. The paper presents preliminary results of dissolution of spent automotive catalyst on a metal carrier by means of acids: H2SO4, HCl, HNO3, H3PO4. The main assumption of the research was the dissolution of base metals (Fe, Cr, Al) from metallic carrier of catalyst, avoiding dissolution of PGMs. Dissolution was the most effective when concentrated hydrochloric acid, and 2M sulfuric acid (VI) was used. It was observed that the dust, remaining after leaching, contained platinum in the level of 0.8% and 0.7%, respectively.
15
Content available remote The kinetics of corrosion of the FeAl intermetallic phase-based alloys
EN
Purpose:Purpose alloys on intermetallic phase matrix of iron and aluminium are considered the future materials for high-temperature applications as they are highly resistant to oxidation. Oxidized intermetallic alloy FeAl forms a protective alumina layer. The paper presents results of tests concerning kinetics of corrosion processes of alloy on intermetallic phase matrix FeAl of the composition Fe40Al5CrTiB after casting and plastic treatment with the use of co-extrusion method. The aim of this paper was to determine the resistance to high-temperature corrosion in atmosphere of air for alloy Fe40Al5Cr0.2TiB. Design/methodology/approach: Corrosion tests were conducted in temperatures 900, 950 and 1000°C in time 8 hours, kinetics of corrosion appointed on the thermogravimetry method. The condition of the surface of samples after tests was characterized with the use of electron scanning microscope and also the chemical composition of corrosion products was determined. Findings: Conducted tests have shown a high corrosion resistant alloy Fe40Al5CrTiB in comparison. The resulting graphs show the kinetics of corrosion processes on the parabolic character of the process of creating high-temperature corrosion products. Practical implications: The Al alloy have a high corrosion resistant with resistant conventional materials predestined to do work in high temperature in corrosion environment. Originality/value: The aim of this paper was to determine the resistance to high-temperature corrosion in atmosphere of air for alloy Fe40Al5Cr0.2TiB.
EN
he main task of automotive catalytic converters is reducing the amount of harmful components of exhaust gases. Metallic catalytic converters are an alternative to standard ceramic catalytic converters. Metallic carriers are usually made from FeCrAl steel, which is covered by a layer of Precious Group Metals (PGMs) acting as a catalyst. There are many methods used for recovery of platinum from ceramic carriers in the world, but the issue of platinum and other metals recovery from metallic carriers is poorly described. The article presents results of preliminary experiments of metals biooxidation (Fe, Cr and Al) from spent catalytic converters with metallic carrier, using bacteria of the Acidithiobacillus genus.
PL
Głównym zadaniem katalizatorów samochodowych jest zmniejszenie ilości szkodliwych składników spalin. Katalizatory na nośniku metalowym są alternatywą dla standardowych katalizatorów na nośniku ceramicznym. Nośniki metalowe najczęściej wykonuje się ze stali FeCrAl, na którą nieniesiona jest warstwa platynowców, pełniących funkcje katalityczne. W pracy przedstawiono wyniki wstępnych prób bioutleniania metali ze zużytych katalizatorów na nośniku metalowym (Fe, Cr, Al.), z udziałem bakterii z rodzaju Acidithiobacillus.
EN
Catalytic converters contain the catalytic substance in their structure, which is a mixture of Platinum Group Metals (PGMs): platinum, palladium and rhodium. The prices of these metals and a growing demand for them in the market, make it necessary to recycle spent catalytic converters and recovery of PGMs. The ceramic monolith of catalytic converters is still a predominant material in its construction among of multitude of catalytic converters which are in circulation. In this work attempts were made to leach additional metals (excluding Pt) from comminuted ceramic monolith. Classic leachant oxidizing media 10M H2SO4, HCl and H3PO4 were used considering the possibility of dissolution of the ceramic monolith.
PL
Katalizatory samochodowe w swojej strukturze zawierają substancję katalityczną, będącą mieszaniną platynowców: platyny, palladu i rodu. Ceny tych metali oraz rosnące zapotrzebowanie na nie, stanowią o konieczności recyklingu zużytych katalizatorów i odzysku z nich wspomnianych metali. Materiał ceramiczny, jako monolit katalizatora jest ciągle materiałem dominującym wśród katalizatorów dostępnych obecnie na rynku. W pracy podjęto próby rozpuszczenia ceramicznego monolitu z użyciem, jako czynnika ługującego klasycznych mediów utleniających 10M H2SO4, HCl i H3PO4.
EN
Exhaust gases which are introduced into the atmosphere contain impurities such as carbon monoxide, unburned hydrocarbons and nitrogen oxide. Auto catalysts enable air pollution from these exhaust gases to be reduced considerably. Typical auto catalytic converters consist of the carrier (ceramic or metallic) and the catalytic system. Platinum group metals (PGM) are responsible for the catalytic function. All spent auto catalysts should be purchased and processed in order to recover the precious metals from them. This article presents the results of coupled analyses of electromagnetic and flow field calculations. The aim of this research was to design a device for extracting precious metals from used auto catalytic converters. Calculations were made to determine the velocity field distribution of a liquid metal, the movement of which was forced by the electromagnetic field. Computational experiments were conducted to obtain the relationships between the metal velocity distribution, the inductor supply and geometrical parameters in order to improve the construction of the presented device. The calculation shows that viscosity and friction has a greater influence on velocity distribution than forces distribution.
PL
Artykuł dotyczy analizy procesu wypłukiwania metali szlachetnych z wkładów katalizatorów umieszczonych w pierścieniowym kanale przy pomocy ciekłego metalu wprawianego w ruch przez wirujące pole elektromagnetyczne. Wykorzystany w pracy model obliczeniowy obejmował sprzężenie pola elektromagnetycznego i hydrodynamicznego z uwzględnieniem przepływu metalu przez kapilarną strukturę katalizatora. W ramach badań przeprowadzono analizę wpływu lokalizacji wzbudnika na efektywność przepłukiwania wsadu katalizatora.
EN
The paper concerns of precious metals washing out from auto catalytic converters placed in the channel. In this device liquid metal is forced to motion by the rotating magnetic field. The model used in research included the coupling of the electromagnetic and hydrodynamic field taking into account the metal flow through anisotropic porous structure of the catalyst. The study analyzes the influence of inductor location on the efficiency of flushing the catalyst.
EN
Automotive catalytic converters have a limited life time, after which the catalyst must be replaced or regenerated. The spent catalytic converters contain small amount of precious metals. Recovery of these metals is essential for environmental and economic reasons. The waste electronic equipment is also an attractive source for recovery of precious metals. Precious metals in electronic scraps are concentrated mainly in printed circuits and integrated circuits - so generally in elements that are the most diverse in their composition. Material heterogeneity of these elements is the reason why there is no universal method for processing this type of scrap. Methods used in the world for recovery of precious metals from spent auto catalytic coverters and electronic wastes by pyrometallurgical and hydrometallurgical methods were mentioned in this paper. The results of simultaneous melting of electronic waste with spent automotive catalysts were presented. The printed circuit boards were used as the carrier and as a source of copper. The precious metals present in the catalyst were collected in copper.
PL
Samochodowe konwertory katalityczne mają ograniczony czas życia, po czym katalizator ten należy wymienić lub poddać regeneracji. Zużyte katalizatory zawierają niewielkie ilości metali szlachetnych, a możliwość odzysku tych metali jest istotna ze względów ekonomicznych i ekologicznych. Równie atrakcyjne źródło metali szlachetnych stanowi wycofany sprzęt elektroniczny. Metale szlachetne w płytkach elektronicznych są zlokalizowane głównie w obwodach drukowanych układów scalonych, które są najbardziej zróżnicowane pod względem składu. Niejednorodność materiałowa tych elementów powoduje, że nie ma uniwersalnego sposobu przetwarzania tego rodzaju złomu. W artykule zwrócono uwagę na metody pirometalurgiczne i hydrometalurgiczne stosowane na świecie do odzysku metali szlachetnych ze zużytych katalizatorów samochodowych oraz od- padów elektronicznych. Przedstawiono wyniki badań próby wspólnego przetopu odpadów elektronicznych z odpadami zużytych katalizatorów samochodowych. Odpady elektroniczne w postaci drukowanych płytek obwodowych zostały wykorzystane jako nośnik i główne źródło miedzi, metalu pełniącego rolę metalu zbieracza platynowców, obecnych w katalizatorach. Otrzymano stop Cu-Fe-Au-Pt odzyskując w ten sposób platynę na poziomie około 78%.
first rewind previous Strona / 3 next fast forward last
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.