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Waste solder and printed circuit board: the emerging secondary sources for recovery of metals

Jadhav U. U., Hocheng H.

Archives of Materials Science and Engineering

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2015

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Vol. 72, nr 1

5--15

EN

Purpose: Purpose: The goal of the paper is to focus on waste solder and printed circuit board: the emerging secondary sources for recovery of metals. Design/methodology/approach: The worldwide reserves of high-grade ores are diminishing. At the same time the demand for heavy metals is ever increasing with the progress of the industrialized world. The rapid progress of electronic packaging technology is resulting in huge amounts of electronic waste (E-Waste) particularly in the form of solders and printed circuit boards (PCBs). Such E-waste contains various metals. The waste solders and PCB can act as large stockpiles of metals. Hence, they can be important secondary sources of valuable metals. Thus recycling of waste solders and PCB is not only useful for resource recovery from waste materials, but also for the protection of the environment. Findings: Comparing with the pyrometallurgical processing, hydrometallurgical method is more exact, more predictable, and more easily controlled. Bio-hydrometallurgical processes are emerging as potential environmentally friendly approaches. Research limitations/implications: Several promising metal recovery processes were developed to recover the precious metals from E-waste. There is a need to fill the gap areas in achieving a cleaner and economical recycling process. Also more studies are needed in the area of metal separation and recovery from PCB leach liquor. Orginality/Value: This review article will provide a concise overview of current disposal and recycling operations. Keywords: Electronic waste; Solder; Printed circuit board; Metal recovery; Pyrometallurgy, Hydrometallurgy; Bio-hydrometallurgy.

2

Extraction of metals from electronic waste by bacterial leaching

Willner J., Fornalczyk A.

Environment Protection Engineering

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2013

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Vol. 39, nr 1

197--208

EN

Electronic waste is usually processed by means of classical methods, i.e. in pyro- and hydro-metallurgical 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.

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Biohydrometalurgia - alternatywa dla procesów metalurgicznych

Gajda B., Bogacki M.B.

Rudy i Metale Nieżelazne

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2012

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R. 57, nr 11

778-784

PL

Biohydrometalurgia z początkiem XXI wieku nabiera coraz większego znaczenia jako nisko kosztowa, stosunkowo łatwa do zastosowania oraz umożliwiająca przetwarzanie bardzo ubogich surowców, zarówno naturalnych jak też odpadów, technologia. O szybkim jej rozwoju świadczyć może fakt, iż w 2006 r. ponad 2 mln t miedzi rocznie powstawało w zakładach wykorzystujących bioługowanie. Technologia ta wykorzystywana jest nie tylko w zakładach metalurgicznych do otrzymywania miedzi, niklu, kobaltu, cynku, złota czy uranu, ale również do przetwarzania odpadów, między innymi osadów powstających w oczyszczalniach ścieków. W prezentowanej pracy przeglądowej omówiono dwa podstawowe mechanizmy bioługowania siarczkowych rud metali: mechanizm bezpośredni oraz pośredni. Następnie przeprowadzono przegląd podstawowych procesów bioługowania zastosowanych do przetwarzania rudy miedzi, niklu i kobaltu, cynku i złota.

EN

Biohydrometallurgy the beginning of the twenty-first century is becoming increasingly important as a low-cost, relatively easy to use and allows processing of very poor resources, both natural as well as waste technology. The rapid development of evidenced by the fact that in 2006, more than 2 million tons of copper per year arose in plants using bioleaching. This technology is used not only in the metallurgical plants for the preparation of copper, nickel, cobalt, zinc, gold and uranium, but also for the processing of waste, including sludge generated in wastewater treatment plants. In the present review, we discuss two basic mechanisms of bioleaching of sulphide ores: mechanism of direct and indirect. This was followed by an overview of the basic processes used in the bioleaching process copper ore, nickel and cobalt, zinc and gold.

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Stan badań w Polsce nad wykorzystaniem mikroorganizmów do odzysku metali z rud i odpadów

Karwowska E., Łebkowska M.

Rocznik Ochrona Środowiska

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2008

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Tom 10

433-442

EN

The paper presents information about the research works in Poland concerning microbiological processes of heavy metals bioleaching from ores, wastes and sewage sludge. Main scientific centers working on biohydrometallurgy, including Warsaw University, Silesian University and Wroclaw University of Technology were taken into account. The basic waste materials applied in biohydrometallurgical processes are lowgrade ores, post-flotation wastes, concentrates and sewage sludge. In Poland the experiments were carried out using copper ores and flotation wastes, arsenic concentrates, magnesite and arsenopyrite wastes, zinc and galena concentrates. The research work covered a bioleaching mechanisms observation, estimation of the process effectiveness as well as the determination of bacterial strains active in the bioleaching process. Some results of biohydrometallurgical studies of other research centers, (University of Opole, University of Warmia and Mazury and Warsaw University of Technology) were also presented. The advantages of biohydrometallurgical methods application, in comparison with conventional methods of metals recycling were pointed out. Recapitulating Polish achievements in the processes of biological regaining of metals from low-grade ores and waste, it should be affirmed, that works in this range, though valuable and carried out on the world level, they were not introduced in the industry. The majority of investigations concerned only laboratory tests in the small scale. They were carried out mainly on flotation wastes from copper mines in Lubin, Polkowice, Rudna and concentrates of galenit, zinc blende and chalcopiryte as well as on loellignite and arsenopyrite - arsenic waste containing gold, and also recently sludge from galvanization. Few investigations on removal of metal from sewage sludge (activated sludge and sludge after methane fermentation) were carried out. Combined biosorption of metals and bioleachinch - as the final stage of elimination of metals from sewage - was also applied in few cases. It seems necessary, so that Poland joins group of countries applying industrial biohydrometallurgical processes, particularly to recovery of copper and zinc and to removal of metals from wastes and sewage sludge