Suppression of arsenopyrite oxidation by microencapsulation using ferric-catecholate complexes and phosphate

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

“…There are numerous stabilization techniques for mine tailings such as incorporating them into a lime-cement mixture as sub-grade material (Ojuri et al, 2016;Park et al, 2019), synthesis of ceramisite (Yang et al, 2017) and phytoremediation (Wang et al, 2017), but all of them are ideal for tailings containing minute amounts of sulfide minerals. This is because sulfide minerals in tailings generate strongly acidic leachates and anions that rapidly deteriorate cement-based materials (Park et al, 2021;Tabelin et al, 2018). One recently promising approach to simultaneously repurpose and treat mine waste and tailings is via alkali activation in a process called geopolymerization.…”

Flotation Separation of Chalcopyrite and Molybdenite Assisted by Microencapsulation Using Ferrous and Phosphate Ions: Part I. Selective Coating Formation

“…Figure 7a shows the XPS P 2p spectra of untreated and treated chalcopyrite. As it can be seen, treated chalcopyrite exhibited a broad peak that was centered at around 133.5 eV composed of adsorbed PO4 3− (130.0, 131.4 and 132.8 eV) [34] and P (V) of FePO4 (133.7 eV) [34,35], which support that FePO4 coating was formed on the chalcopyrite surface by microencapsulation while using Fe 2+ and PO4 3− . In the case of the XPS spectrum of treated molybdenite (Figure 7b), a weak and gentle peak of FePO4 was observed.…”

“…Figure 7a shows the XPS P 2p spectra of untreated and treated chalcopyrite. As it can be seen, treated chalcopyrite exhibited a broad peak that was centered at around 133.5 eV composed of adsorbed PO 43− (130.0, 131.4 and 132.8 eV) [34] and P (V) of FePO 4 (133.7 eV) [34,35],…”

The Effects of Coexisting Copper, Iron, Cobalt, Nickel, and Zinc Ions on Gold Recovery by Enhanced Cementation via Galvanic Interactions between Zero-Valent Aluminum and Activated Carbon in Ammonium Thiosulfate Systems

“…There are surely mines containing high Au concentrations such as 150 g/t in Australia [16], 94 g/t in Korea [17], and 60 g/t in China [18], but those mines with high Au contents have been actively explored; hence, currently operating/investigating mines mainly deal with refractory or complex ores with relatively low Au concentrations such as 6 g/t in Laos [19], 6.2 g/t in China [20], 6.2 g/t in Iran [21], or 11.2 g/t in Ghana [22]. Furthermore, Au ore contains minerals such as pyrite, arsenopyrite, chalcopyrite, and/or malachite in which various elements (e.g., Cu, Fe, Co, Ni, and Zn) are incorporated [23][24][25][26][27][28]. Once these elements are dissolved in the solution, they can affect Au recovery by competing and/or co-depositing with Au during the recovery process.…”

“…Cu ions are an essential catalyst in ammonium thiosulfate systems, increasing Au dissolution in ammonium thiosulfate systems 20-to 25-fold (Equation ( 1)) [1,4]; • Cu ions could be introduced via the dissolution of Cu minerals such as chalcopyrite and malachite [23][24][25][26][27][28] found in Au ores.…”