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Preliminary Studies on Simultaneous Recovery of Precious Metals from Different Waste Materials by Pyrometallurgical Method

Willner J., Fornalczyk A., Cebulski J., Janiszewski K.

Archives of Metallurgy and Materials

2014

Vol. 59, iss. 2

801--804

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.

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%.

A review of recovery of metals from industrial waste

Jadhav U U, Hocheng H.

Journal of Achievements in Materials and Manufacturing Engineering

2012

Vol. 54, nr 2

159--167

Due to rapid industrialization the demand for heavy metals is ever increasing, but the reserves of high-grade ores are diminishing. Therefore there is a need to explore alternative sources of heavy metals. The rapid industrialization generates a variety of industrial wastes. These industrial wastes possess toxic elements such as heavy metals. Improper disposal of these wastes becomes a key factor in metal contamination and thus when leached into atmosphere cause serious environmental problem. These metals exert wide variety of adverse effects on human being. Some of the metals have extremely long biological half-life that essentially makes it a cumulative toxin. Also some metals are carcinogenic in nature. Among the wastes, electronic scraps, medical waste, metal finishing industry waste, spent petroleum catalysts, battery wastes, fly ash etc., are some of the major industrially produced wastes. These solid wastes mostly contain Au, Ag, Ni, Mo, Co, Cu, Zn, and Cr like heavy metals in it. Hence these waste materials which are causing serious environmental problems, can act as potential source for heavy metals. In this sense these industrial wastes can act as artifitial ores. The valuable metals can be recovered from these industrial wastes. There are varieties of methods in use for recovery of heavy metals. These include pyrometallurgical, hydrometallurgical and bio-hydrometallurgical methods. Pyrometallurgical recovery consists of the thermal treatment of ores and metal containing wastes to bring about physical and chemical transformations. This enables recovery of valuable metals. Calcining, roasting, smelting and refining are the pyrometallurgical processes used for metal recovery. The hydrometallurgical recovery uses mainly the leaching process. It involves the use of aqueous solutions containing a lixiviant which is brought into contact with a material containing a valuable metal. Further the metals are concentrated and purified by using precipitation, cementation, solvent extraction and ion exchange. The metals are finally recovered in pure form by using electrolysis and precipitation methods. Biohydrometallurgy is one of the most promising and revolutionary biotechnologies. This technique exploits microbiological processes for recovery of heavy metal ions. In last few decades the concept of microbiological leaching have played a grate role to recover valuable metals from various sulfide minerals or low grade ores. Now the microbiological leaching process has been shifted for its application to recover valuable metals from the different industrial wastes. There are many microrganisms which play important role in recovery of heavy metals from industrial wastes. Among the bacteria Acidithiobacillus ferrooxidans, Acidithiobacillus thiooxidans, Leptospirillum ferrooxidans, and Sulfolobus sp., are well known for the bioleaching activity while Penicillium, and Aspergillus niger are some fungi those help in metal leaching process. The process of recovery makes sense only if the cost of recovery is much less than the value of the precious metal. The restrictions imposed on waste disposal and stringent environmental regulations demand eco-friendly technologies for metal recovery. This paper reports a review of number of industrial processes that generate metal containing waste and the various methods in use for recovery of metals from these wastes. This will help in selection of a proper method for recovery of heavy metals from industrial wastes.

Modernizacja produkcji miedzi konwertorowej i anodowej w HM Legnica.

Gizicki S., Czernecki J., Miczkowski Z., Krawiec G., Gąsior W., Maślanka J., Nowak J., Antczak J., Heilig B.

Rudy i Metale Nieżelazne

2002

R. 47, nr 8

361-365

Omówiono sposób modernizacji pirometalurgicznego ciągu technologicznego w HM Legnica dla zwiększenia produkcji i obniżenia kosztów wytwarzania miedzi anodowej. Zamieszczono wyniki z okresu prób i pierwszych miesięcy przemysłowego stosowania zmodernizowanego procesu konwertorowania kamienia miedziowego, w którym realizowany jest przetop odpadów anodowych dzięki wzbogaceniu powietrza procesowego w tlen. Przedstawiono także wyniki modyfikacji procesu rafinacji ogniowej dla dostosowania opalania pieców do nowej struktury wsadowej.

Modernization of technological line for anode copper fabrication by pyro-metallurgical methods, aimed to increase production volume and reduce the costs, has been described. The paper includes results obtained from the initial tests and in the first months of industrial application of a modernized copper matte converting process, in which oxygen-enriched process air enables anode scrap smelting. Results of the fire refining process modification, which was aimed to adapt heating parameters of the furnaces to a new charge composition, have been presented.