Today more and more cars are produced every year. All of them have to be equipped with catalytic converters, the main role of which is to obtain substances harmless to the environment instead of exhausted gases. Catalytic converters contain platinum group metals (PGM) especially platinum, palladium and rhodium. The price of these metals and their increasing demand are the reasons why today it is necessary to recycle used auto catalytic converters. There are many available methods of recovering PGM metals from them, especially platinum. These methods used mainly hydrometallurgical processes; however pyrometallurgical ones become more and more popular. The article presents results of the research mainly concerning pyrometallurgical processes. Two groups of research were carried out. In the first one different metals such as lead, magnesium and copper were used as a metal collector. During the tests, platinum went to those metals forming an alloy. In other research metal vapours were blown through catalytic converter carrier (grinded or whole). In the tests metals such as calcium, magnesium, cadmium and zinc were applied. As a result white or grey powder (metal plus platinum) was obtained. The tables present results of the research. Processing parameters and conclusions are also shown. To compare efficiency of pyrometallurgical and hydrometallurgical methods catalytic converter carrier and samples of copper with platinum obtained from pyrometallurgical method were solved in aqua regia, mixture of aqua regia and fluoric acid.
Electronic waste is usually processed by means of classical methods, i.e. in pyro-and hydrometallurgical processes. However, new solutions for more economically and ecologically efficient recovery of metals are constantly being searched for. Biohydrometallurgy can become a promising technology of recovering metals from industrial waste. Bioleaching-one of the methods applied in that technology-is the subject of particular interest of many scientific centres. The paper presents the results of laboratory tests of bacterial leaching of metals from electronic scrap. It describes the mechanisms of this process and the factors influencing the chemical reaction. The paper also presents preliminary results of experimental studies on the copper bioleaching from electronic waste with the participation of Acidithiobacillus ferrooxidans bacteria.
This paper presents the model for the washing-out process of precious metals from spent catalysts by the use of molten lead in which the metal flow is caused by the rotating electromagnetic field and the Lorentz force. The model includes the coupling of the electromagnetic field with the hydrodynamic field, the flow of metal through anisotropic and porous structure of the catalyst, and the movement of the phase boundary (air-metal) during infiltration of the catalyst carrier by the molten metal. The developed model enabled analysis of the impact of spacing between the catalysts and the supply current on the degree of catalyst infiltration by the molten metal. The results of calculations carried out on the basis of the model were verified experimentally.
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.
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.Keywords: electronic waste, copper, platinum, metal collector, pyrometallurgical methods 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 odpadów 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%.
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