Selective recovery of Au(III), Pd(II), and Ag(I) from printed circuit boards using cellulose filter paper grafted with polymer chains bearing thiocarbamate moieties

2017 ◽  
Vol 24 (1) ◽  
pp. 683-690 ◽  
Author(s):  
M. K. Mohammad Ziaul Hyder ◽  
Bungo Ochiai
Keyword(s):  
Filter Paper ◽  
Printed Circuit Boards ◽  
Polymer Chains ◽  
Circuit Boards ◽  
Selective Recovery ◽  
Printed Circuit ◽  
Cellulose Filter

Chemically Driven Deformation of Polymers

1989 ◽  
Vol 111 (1) ◽  
pp. 68-73 ◽  
Author(s):  
C.-Y. Hui ◽  
K.-C. Wu ◽  
Ronald C. Lasky ◽  
Edward J. Kramer
Keyword(s):  
Small Molecules ◽  
Osmotic Pressure ◽  
Printed Circuit Boards ◽  
Volume Fraction ◽  
Polymer Chains ◽  
Circuit Boards ◽  
Diffusion Front ◽  
Polymer Glasses ◽  
Printed Circuit ◽  
Good Agreement

Chemically driven deformation of polymer glasses is important in a variety of electronic packaging applications ranging from stripping of photoresists to diffusion of processing liquids into printed circuit boards. The swelling of such glasses by small molecules requires the deformation of polymer chains, a deformation that can be modelled as driven by an osmotic pressure. Equations governing the rate of this process are developed and the predictions are compared with the results of experiments in which the volume fraction φ of iodohexane (IOH) sorbed at the surface of polystyrene is measured as a function of exposure time. Once a critical φ is reached, a diffusion front develops and moves into the polymer at a constant velocity. The velocity V of this front can be predicted quantitatively from V=D(φm)a′(φm)a(φm)∂φ∂tφm where D is the diffusion coefficient of the IOH in the glass, a, and a′ are the activity of IOH and its derivative with respect to φ and the subscript m signifies that the quantities are evaluated at the volume fraction of the maximum osmotic pressure ahead of the front. The φ(t) and V predicted by a pressure dependent viscous swelling model for ∂φ/∂t are in good agreement with the experimental results at low IOH activities.

scholarly journals Leaching and Selective Recovery of Cu from Printed Circuit Boards

Metals ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 1034 ◽  
Author(s):  
Manivannan Sethurajan ◽  
Eric D. van Hullebusch
Keyword(s):  
Copper Sulfide ◽  
Printed Circuit Boards ◽  
Electronic Waste ◽  
Waste Recycling ◽  
Ferric Sulfate ◽  
Molar Ratio ◽  
Circuit Boards ◽  
Optimum Conditions ◽  
Selective Recovery ◽  
Printed Circuit

Printed circuit boards (PCBs), a typical end-of-life electronic waste, were collected from an E-waste recycling company located in the Netherlands. Cu and precious metal concentration analyses of the powdered PCBs confirm that the PCBs are multimetallic in nature, rich, but contain high concentrations of Cu, Au, Ag, Pd, and Pt. Ferric sulfate concentration (100 mM), agitation speed (300 rpm), temperature (20 °C), and solid-to-liquid ratio (10 g·L−1) were found to be the optimum conditions for the maximum leaching of Cu from PCBs. The ferric sulfate leachates were further examined for selective recovery of Cu as copper sulfides. The important process variables of sulfide precipitation, such as lixiviant concentration and sulfide dosage were investigated and optimized 100 ppm of ferric sulfate and (copper:sulfide) 1:3 molar ratio, respectively. Over 95% of the dissolved Cu (from the multimetallic leachates) was selectively precipitated as copper sulfide under optimum conditions. The characterization of the copper sulfide precipitates by SEM-EDS analyses showed that the precipitates mainly consist of Cu and S. PCBs can thus be seen as a potential secondary resource for copper.

Selective recovery of Copper from waste mobile phone printed circuit boards using Sulphuric acid leaching

2018 ◽  
Vol 5 (10) ◽  
pp. 21698-21702 ◽  
Author(s):  
Md. Sohrab Hossain ◽  
Ahmad Naim Ahmad Yahaya ◽  
Lily Suhaila Yacob ◽  
Mohd Zulkhairi Abdul Rahim ◽  
Nor Nadiah Mohamad Yusof ◽  
...  
Keyword(s):  
Mobile Phone ◽  
Sulphuric Acid ◽  
Printed Circuit Boards ◽  
Acid Leaching ◽  
Circuit Boards ◽  
Selective Recovery ◽  
Printed Circuit

Recycling gold and copper from waste printed circuit boards using chlorination process

RSC Advances ◽  
2015 ◽  
Vol 5 (12) ◽  
pp. 8957-8964 ◽  
Author(s):  
Yuchen He ◽  
Zhenming Xu
Keyword(s):  
Printed Circuit Boards ◽  
Circuit Boards ◽  
Selective Recovery ◽  
Printed Circuit ◽  
Efficient Process ◽  
Chlorination Process ◽  
Waste Printed Circuit Boards ◽  
Waste Pcbs ◽  
Pretreatment Processes

This study provides a less-polluted and more efficient process for selective recovery of gold and copper from waste PCBs through pretreatment processes.

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