A physical separation scheme to improve ammonium thiosulfate leaching of gold by separation of base metals in crushed mobile phones

2019 ◽  
Vol 138 ◽  
pp. 168-177 ◽  
Author(s):  
Sanghee Jeon ◽  
Mayumi Ito ◽  
Carlito Baltazar Tabelin ◽  
Rongrit Pongsumrankul ◽  
Shinya Tanaka ◽  
...  
Keyword(s):  
Mobile Phones ◽  
Separation Scheme ◽  
Base Metals ◽  
Physical Separation ◽  
Ammonium Thiosulfate ◽  
Thiosulfate Leaching

Interference of coexisting copper and aluminum on the ammonium thiosulfate leaching of gold from printed circuit boards of waste mobile phones

2018 ◽  
Vol 81 ◽  
pp. 148-156 ◽  
Author(s):  
Sanghee Jeon ◽  
Carlito Baltazar Tabelin ◽  
Hirotaka Takahashi ◽  
Ilhwan Park ◽  
Mayumi Ito ◽  
...  
Keyword(s):  
Mobile Phones ◽  
Printed Circuit Boards ◽  
Circuit Boards ◽  
Printed Circuit ◽  
Ammonium Thiosulfate ◽  
Thiosulfate Leaching

scholarly journals Development of a Physical Separation Route for the Concentration of Base Metals from Old Wasted Printed Circuit Boards

Minerals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1014
Author(s):  
Pedro Jorge Walburga Keglevich de Buzin ◽  
Weslei Monteiro Ambrós ◽  
Irineu Antônio Schadach de Brum ◽  
Rejane Maria Candiota Tubino ◽  
Carlos Hoffmann Sampaio ◽  
...  
Keyword(s):  
Printed Circuit Boards ◽  
Electronic Devices ◽  
Preliminary Evidence ◽  
Composition Analysis ◽  
Base Metals ◽  
Circuit Boards ◽  
Physical Separation ◽  
Printed Circuit ◽  
Processing Circuit

Wastes from old electronic devices represent a significant part of the electronic scrap generated in developing countries, being commonly sold by collectors as low-value material to recycling hubs abroad. Upgrading the quality of this waste type could drive the revenue of recyclers, and thus, boost the recycling market. On this basis, this study investigated the possibility of concentrating metals from old wasted printed circuit boards through a physical separation-based route. Preparation of samples comprised fragmentation, size classification, density, and magnetic separation steps, followed by chemical and macro composition analysis. Cu, Al, Fe, and Sn constituted the major metals encountered in the scraps, including some peak concentrations of Zn, Sb, Pb, Ba, and Mn. Four distinct concentrate products could be obtained after suitable processing: (a) a light fraction composed of plastics and resins; (b) an aluminum concentrate; (c) a magnetic material concentrate, containing mainly iron; (d) a final concentrate containing more than 50% in mass of copper and enriched with nonferrous metals. Preliminary evidence showed that further processes, like the separation of copper wires through drumming, can potentially improve the effectiveness of the proposed processing circuit and should guide future works.

Gold recovery from shredder light fraction of E-waste recycling plant by flotation-ammonium thiosulfate leaching

2018 ◽  
Vol 77 ◽  
pp. 195-202 ◽  
Author(s):  
Sanghee Jeon ◽  
Mayumi Ito ◽  
Carlito Baltazar Tabelin ◽  
Rongrit Pongsumrankul ◽  
Naho Kitajima ◽  
...  
Keyword(s):  
Waste Recycling ◽  
Light Fraction ◽  
Gold Recovery ◽  
Ammonium Thiosulfate ◽  
Thiosulfate Leaching

scholarly journals Technologies for metal recycling from electrical - electronic wastes

2021 ◽  
Vol 62 (3b) ◽  
pp. 58-68
Author(s):  
Toi Trung Tran ◽  
Chinh Thi Vu ◽  
Nhung Thi Pham ◽  
Keyword(s):  
Precious Metals ◽  
Operating Conditions ◽  
Electronic Equipment ◽  
Chemical Extraction ◽  
Base Metals ◽  
Separation Processes ◽  
Physical Separation ◽  
Metal Recycling ◽  
New Directions ◽  
Extraction Processes

Wastes from electrical - electronic equipment (WEEE) are of huge concerns worldwide. With the decreasing life cycle of most electrical - electronic equipment (EEE), the WEEE growth rate is fast, about 3÷5% annually. This is considered as the fastest growing waste stream among municipal wastes. WEEE contains, in addition to plastic, glass etc., high contents of base metals and precious metals. They are regarded as potential secondary resources of metals in addition to primary resources of metals from metallic ores. Over the past decades, many metal recycling technologies from WEEE have been developed including physical separation processes and chemical extraction processes. This article summarizes the characteristics, recycling principles, separation processes and optimal operating conditions of the world's most currently common technologies for metal recycling from WEEE. So that one can derive new directions for metal recycling from electrical - electronic wastes in the Vietnam case.

Thiosulfate leaching of gold from waste mobile phones

2010 ◽  
Vol 178 (1-3) ◽  
pp. 1115-1119 ◽  
Author(s):  
Vinh Hung Ha ◽  
Jae-chun Lee ◽  
Jinki Jeong ◽  
Huynh Trung Hai ◽  
Manis K. Jha
Keyword(s):  
Mobile Phones ◽  
Thiosulfate Leaching

Thermodynamic analysis of the copper (I) homogeneous and heterogeneous speciation in ammonium thiosulfate leaching systems

2019 ◽  
Vol 97 (9) ◽  
pp. 651-658 ◽  
Author(s):  
Igor Povar ◽  
Stefano Ubaldini ◽  
Oxana Spinu ◽  
Tudor Lupascu
Keyword(s):  
Complex Formation ◽  
Thermodynamic Analysis ◽  
Mixed Ligand Complex ◽  
Chemical Species ◽  
Mixed Ligand ◽  
Phase System ◽  
Ligand Complex ◽  
Complex Species ◽  
Ammonium Thiosulfate ◽  
Thiosulfate Leaching

The paper presents a new thermodynamic approach to studying mixed ligand complex formation reactions in the multi-component two-phase system “cuprous oxide-ammoniacal copper (I) thiosulfate aqueous solution” under real conditions. The quintessence of the developed approach consists in the thermodynamic analysis of concurrent reactions in the heterogeneous system Cu(I) – NH3 – S2O32− – H2O on the basis of the introduced notion of generalized reaction equations. A detailed thermodynamic analysis in ammonium thiosulfate leaching systems has considered the formation of mixed ligand complex species Cu(OH)i(NH3)j(S2O3)k. The new feature is to focus on the chemical description of the overall process of complex formation consisting of a series of concurrent reactions, where the nature and ratio of the concentrations of chemical species, formed in such reactions, depend on the ratio of the concentrations of the metal Cu+ and ligands, temperature, and other thermodynamic parameters. On the basis of the selected thermodynamic data for involved species, the thermodynamic stability areas of solid phase and the repartition of soluble and insoluble chemical species towards the solution pH and a number of total reagent concentrations in heterogeneous mixtures have been investigated. The diagrams of heterogeneous and homogeneous chemical equilibria are used for the graphical representation of complex equilibria and distribution of soluble and insoluble species in examined systems. The used approach utilizes thermodynamic relationships coupled with original mass balance constraints, where the solid phases are explicitly expressed. The obtained results are useful for optimization of the overall scheme of thiosulfate leaching in gold hydrometallurgy to minimize reagent consumption and maximize gold extraction.

scholarly journals The treatment of copper–gold ores by ammonium thiosulfate leaching

2002 ◽  
Vol 66 (1-3) ◽  
pp. 1-21 ◽  
Author(s):  
Ellen Molleman ◽  
David Dreisinger
Keyword(s):  
Gold Ores ◽  
Ammonium Thiosulfate ◽  
Copper Gold ◽  
Thiosulfate Leaching

scholarly journals Using Nickel as a Catalyst in Ammonium Thiosulfate Leaching for Gold Extraction

2004 ◽  
Vol 45 (2) ◽  
pp. 516-526 ◽  
Author(s):  
Harunobu Arima ◽  
Toyohisa Fujita ◽  
Wan-Tai Yen
Keyword(s):  
Gold Extraction ◽  
Ammonium Thiosulfate ◽  
Thiosulfate Leaching

scholarly journals Leaching Behavior of Gold and Silver from Concentrated Sulfide Ore Using Ammonium Thiosulfate

Metals ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1029
Author(s):  
Mooki Bae ◽  
Sookyung Kim ◽  
Jeongsoo Sohn ◽  
Donghyo Yang ◽  
Hyunju Lee
Keyword(s):  
Liquid Ratio ◽  
Leaching Behavior ◽  
Gold Ores ◽  
Ammonium Thiosulfate ◽  
Sulfide Ore ◽  
Main Chemical Composition ◽  
Hydrometallurgical Treatment ◽  
Thiosulfate Leaching ◽  
Leaching Efficiency ◽  
Thiosulfate Concentration

Ammonium thiosulfate is an alternative lixiviant for the hydrometallurgical treatment of sulfide gold ores. The present study is primarily focused on ammonium thiosulfate leaching of gold (Au) and silver (Ag) from the sulfide ore (Sunshin mine in Korea). The main chemical composition of the concentrate was Au (84 ppm), Ag (852 ppm), Fe (18.9%), Si (23.2%), and S (21.1%). The effects of various parameters on the process, such as leaching time (1–4 h), ammonium thiosulfate concentration (0.05–0.5 M), copper sulfate (CuSO4), concentration (0.05–0.25 M), solid to liquid ratio (0.2–0.5), and reaction temperature (40–60 °C) were systematically examined. Optimum Au leaching efficiency (>99%) was obtained under the following leaching conditions: 0.5 M ammonium thiosulfate with 0.05 M CuSO4 concentration, 0.2 S/L ratio at 60 °C for 2 h. The results indicate that the behavior of Ag was similar to that of Au. Almost complete dissolution of Ag occurred under following leaching conditions: 0.5 M ammonium thiosulfate with 0.05 M CuSO4 concentration at 60 °C for 4 h. This study would be useful in understanding the eco-friendly leaching systems of Au and Ag during the hydrometallurgical process of sulfide gold ore.

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