Methodology for Recovery Precious Metals: Gold, Silver and Platinum Group from Electronic Waste

2011 ◽  
pp. 81-87
Author(s):  
Jaime Restrepo B. Oscar ◽  
Oliveros Gómez Honorio
Author(s):  
R. Alani ◽  
A. Ogunbanmwo ◽  
D. Nwude ◽  
M. Ogbaje

The main aim of this research was to assess the extent of the problems associated with inappropriate e-waste management and recycling practices. Electronic wastes (E-wastes) are generated from products that are designed for use with a maximum voltage of 1000 volts for alternating current and 1500 volts for direct current. These wastes contain hazardous materials such as lead, mercury, cadmium, brominated flame-retardants, valuable metals such as aluminium, nickel, copper, and certain precious metals such as gold, silver and platinum group metals (PGMs) which pose both human and environmental health threats. They have negative impacts on the health of workers and nearby residents; hence, residents of buildings located around and beside e-wastes dumpsites were randomly selected for this study. Well, run-off and borehole water samples as well as soil samples from different sites in Alaba international market, and Ikeja computer village in Lagos, Nigeria were analyzed for zinc, lead, iron, copper, nickel and chromium. Using additional information from questionnaires and interviews, impacts of e-waste dumps on the health of workers and residents near the study areas were investigated. The results were analysed using descriptive frequency count and tables which confirmed the presence of heavy metals in soils and water samples of the case study areas and hence appropriate recommendations were outlined to address the menace of e-waste disposal and as well as the need for improvement in e-waste management and recycling for economic opportunities and improved health standard within the Lagos Metropolis.


2020 ◽  
Vol 303 ◽  
pp. 79-88
Author(s):  
D.V. Shmidt ◽  
Bashar Issa ◽  
V.Yu. Timofeev

The processing conditions of the of electronic wastes are largely dependent on environmental standards and requirements. Modern technologies for processing electronic waste should meet the increased demand for metals as well as the requirements. Electronic wastes can be classified as hazardous materials, as household and industrial electrical devices, which contain components such as batteries, capacitors, cathode ray tubes, etc. Electronic waste can consist of a large number of components of various sizes, shapes and chemical composition. Some of them contain hazardous metals, including mercury, lead, cadmium. The presence of precious metals in electronic waste such as gold, silver, platinum, palladium, as well as non-ferrous metals (copper, nickel, zinc, tin, etc.) make it attractive for processing. In industry, both hydrometallurgical and pyrometallurgical methods are used to extract valuable metals from electronic waste. Applied technologies may have both advantages and disadvantages.


2021 ◽  
Vol 52 (2) ◽  
pp. 871-882
Author(s):  
Min Chen ◽  
Katri Avarmaa ◽  
Lassi Klemettinen ◽  
Hugh O’Brien ◽  
Junjie Shi ◽  
...  

AbstractThe distributions of precious metals (gold, silver, platinum, and palladium) between copper matte and silica-saturated FeOx-SiO2/FeOx-SiO2-Al2O3/FeOx-SiO2-Al2O3-CaO slags were investigated at 1300 °C and $$ P_{{{\text{SO}}_{ 2} }} $$ P SO 2 = 0.5 atm. The experiments were carried out in silica crucibles under flowing CO-CO2-SO2-Ar gas atmosphere. The concentrations of precious metals in matte and slag were analyzed by Electron Probe X-ray Microanalysis and Laser Ablation-High-Resolution Inductively Coupled Plasma-Mass Spectrometry, respectively. The precious metal concentrations in matte and slag, as well as the distribution coefficients of precious metals between matte and slag, were displayed as a function of matte grade. The present results obtained at $$ P_{{{\text{SO}}_{ 2} }} $$ P SO 2 of 0.5 atm were compared with previous results at $$ P_{{{\text{SO}}_{ 2} }} $$ P SO 2 of 0.1 atm for revealing the effects of $$ P_{{{\text{SO}}_{ 2} }} $$ P SO 2 and selected slag modifiers (CaO and Al2O3) on precious metal distributions at copper matte smelting conditions. The present results also contribute experimental thermodynamic data of precious metal distributions in pyrometallurgical reprocessing of electronic waste via copper smelting processes.


Recycling ◽  
2021 ◽  
Vol 6 (1) ◽  
pp. 8
Author(s):  
Tetiana Shevchenko ◽  
Michael Saidani ◽  
Yuriy Danko ◽  
Ievgeniia Golysheva ◽  
Jana Chovancová ◽  
...  

Efficient electronic waste (e-waste) management is one of the vital strategies to save materials, including critical minerals and precious metals with limited global reserves. The e-waste collection issue has gained increasing attention in recent years, especially in developing countries, due to low collection rates. This study aims to search for progressive solutions in the e-waste collection sphere with close-to-zero transport and infrastructure costs and the minimization of consumers’ efforts towards an enhanced e-waste management efficiency and collection rate. Along these lines, the present paper develops a smart reverse system of e-waste from end-of-life electronics holders to local recycling infrastructures based on intelligent information technology (IT) tools involving local delivery services to collect e-waste and connecting with interactive online maps of users’ requests. This system considers the vehicles of local delivery services as potential mobile collection points that collect and deliver e-waste to a local recycling enterprise with a minimum deviation from the planned routes. Besides e-waste transport and infrastructure costs minimization, the proposed smart e-waste reverse system supports the reduction of CO2 through the optimal deployment of e-waste collection vehicles. The present study also advances a solid rationale for involving local e-waste operators as key stakeholders of the smart e-waste reverse system. Deploying the business model canvas (BMC) toolkit, a business model of the developed system has been built for the case of Sumy city, Ukraine, and discussed in light of recent studies.


Author(s):  
Christian Galasso ◽  
Xabier Lekube ◽  
Ibon Cancio ◽  
Antonio Dell’Anno ◽  
Christophe Brunet ◽  
...  

2021 ◽  
Author(s):  
M. D. Prendergast

Abstract The Kapalagulu intrusion in eastern Tanzania hosts a major, 420-m-thick, stratiform/stratabound platinum group element (PGE)-bearing sulfide zone—the Lubalisi reef—within a prominent, chromititiferous, harzburgite unit close to its stratigraphic base. Several features of the vertical base and precious metal distributions (in a composite stratigraphic section based upon two deep exploration drill holes) display similarities to those of offset-type PGE reefs that formed under the overall control of Rayleigh fractionation: (1) composite layering (at several scales) defined by systematic vertical variations of sulfide and precious metal contents and intermetallic ratios, indicating repeated cycles of PGE enrichment and depletion in the order Pd-Pt-Au-Cu, and (2) in the lower part of the reef, stratigraphic offsets of the precious metal peaks below peak sulfide (Cu) content. The form and geochemistry of the reef are consistent with overturns of basal liquid layers within a liquid layering system (i.e., stable density-driven stratification of a magma chamber), plus at least two minor inputs of parental magma during which the resident magma was recharged with sulfur and metals, and the effective depletion of precious metals in the magma midway through reef development. The Lubalisi reef differs from classic offset-type PGE reefs, however, principally because individual Pd, Pt, and Au enrichment peaks are coincident, not offset. The reef is set apart from other offset-type PGE reefs in three additional ways: (1) its association with olivine cumulates that crystallized soon after initial magma emplacement and well below the first appearance of cumulus pyroxene or plagioclase (implying attainment of sulfide saturation and precious metal enrichment without prolonged concentration of sulfur and chalcophile metals by normal magma cooling and differentiation), (2) the probable role of chromite crystallization in not only triggering sulfide segregation during reef formation but also facilitating precious metal enrichment in the early stages of reef development, and (3) its great width. The early stage of fractionation may also help explain the coincident precious metal peaks through its effect on apparent precious metal partition coefficients.


Author(s):  
Sanjay Kumar Koli ◽  
Athar Hussain

Electronics waste is becoming a major global issue. Huge accumulation of e-waste and its recycling through primitive means for extraction of precious metals are a real concern in the developing countries due to the presence of hazardous materials in e-waste. The major portion of e-waste generated domestically as well as illegally imported is recycled in a crude manner leading to pollution of the environment. Current practices of e-waste management in India encounters many challenges like the difficulty in inventorization, ineffective regulations, pathetic and unsafe conditions of informal recycling, poor awareness of consumers, and reluctance on part of stakeholders to address the issues. As a result, toxic materials enter waste stream with no special precautions to avoid the known adverse impacts on the environment and human health. Resources are wasted when economically valuable materials are dumped. This chapter highlights the hazards caused due to improper handling of e-wastes and also describes some appropriate measures to be adopted for its management and safe disposal.


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