Improvement of jig efficiency by shape separation, and a novel method to estimate the separation efficiency of metal wires in crushed electronic wastes using bending behavior and “entanglement factor”

Synthesis and characterization of coal fly ash and palm oil fuel ash modified artisanal and small-scale gold mine (ASGM) tailings based geopolymer using sugar mill lime sludge as Ca-based activator

“…Gold (Au) is one of the most valuable metals known to man. Traditionally, this metal is extensively used in jewellery and as a safe investment in the banking and financial sectors ( Calderon et al., 2019 , 2020 ; Jeon et al., 2020a , b ) but in recent years, it is finding a myriad of other rapidly growing applications like (i) corrosion-resistant wires and coatings in integrated circuits and printed circuit boards for electronics, computers and high-tech gadgets ( Phengsaart et al., 2018 ; Jeon et al., 2018a , b , 2019 ), (ii) as catalysts in electric cars and clean technologies ( Ghenciu, 2002 ; Zielasek et al., 2006 ), (iii) as detectors in ultra-sensitive sensors ( Löfås and Johnsson, 1990 ; Lucarelli et al., 2004 ), and (iv) as a promising drug delivery system for cancer research ( Ghosh et al., 2008 ; Paciotti et al., 2004 ). Because of its versatility, Au price has rapidly increased in the last 20 years fueling high demand for this precious metal worldwide ( Huang and Kilic, 2019 ).…”

Solid-phase partitioning and release-retention mechanisms of copper, lead, zinc and arsenic in soils impacted by artisanal and small-scale gold mining (ASGM) activities

“…Gold (Au) is a rare, precious and versatile metal used in various applications ranging from the manufacture of jewellery, electronics (e.g., integrated circuits (ICs) and printed circuit boards (PCBs)), and green, clean and renewable energy technologies to finance and medicine ( Calderon et al., 2019 , 2020 ; Jeon et al., 2018a , Jeon et al., 2018b , Jeon et al., 2019 , Jeon et al., 2020a , Jeon et al., 2020b ; Phengsaart et al., 2018 , 2020 ). In 2019, the total global Au demand reached 4368.3 tonnes, 48.5% of which was attributed to jewellery manufacturing while the remainder was in investment (29.2%), technology applications (7.5%), and by Central Banks and other institutions (14.8%) ( World Gold Council, 2020a ).…”

Agglomeration–Flotation of Finely Ground Chalcopyrite Using Emulsified Oil Stabilized by Emulsifiers: Implications for Porphyry Copper Ore Flotation

“…The conventional technique used to recover valuable minerals 2 of 10 from porphyry copper ores is flotation, a technique whereby fine particles of Cu-bearing minerals like chalcopyrite (CuFeS 2 ) are separated from gangue minerals and collected by bubbles after surface modifications using emulsifiers called collectors [3,4]. Flotation, including its concept of using bubbles to induce separation of materials with different surface wettability properties, is a popular and widely used technique not only in the mineral processing and coal cleaning/washing industries but also in electronic waste and plastic recycling industries [5][6][7][8][9][10][11].…”