Study of Metal Leaching from Printed Circuit Boards by Improved Electrochemical Hydrochlorination Technique Using Alternating Current

Metals 2023
Vera Serga, Aleksej Zarkov, Andrejs Šiškins, Edgars Elsts, Maksims Meļņičuks, Mikhail Maiorov, Ervīns Blumbergs, Vladimir Pankratov

his paper presents the results of the leaching of metals from computer PCBs by electrochemical hydrochlorination using alternating current (AC) with an industrial frequency (50 Hz). Leaching was carried out with a disintegrator-crushed computer motherboard with a particle size (d) of <90 μm. In the course of the research, the leaching efficiency of metals including Fe, Sn, Mn, Al, Cu, Zn, Pb, Ni, Ti, Sb, Cr, Co and V was evaluated depending on process parameters, such as AC density, experiment duration, hydrochloric acid concentration in the electrolyte solution, solid/liquid ratio, electrolyte temperature, and the loading option of raw material (loading option 1 involving loading into the electrolyte solution, and loading option 2 involving loading into the filter containers attached to electrodes). The research results showed that AC superimposition significantly intensifies the leaching of metals. It was established that the complete leaching of metals including Al, Mn, Sn, Ti and Zn, under experimental conditions (loading option 2, CHCl = 6 mol·L−1, i = 0.80 A·cm−2, S/L = 8.6 g·L−1), is reached after 1.5 h, and that of Cu and Ni is reached after 2 h from the beginning of the experiment. At the same time, the degree of leaching of other metals after 2 h is Co-78.8%, Cr-84.4%, Sb-91.7%, Fe-98.9%, V-98.1% and Pb-5.1%. The paper also reports the results on the leaching of all abovementioned metals, as well as Ag and Pd, with disintegrator-crushed mixed computer PCBs with d < 90 μm and loading option 1.

Keywords
printed circuit boards; electrochemical hydrochlorination; leaching; alternating current; base metals; silver; palladium
DOI
10.3390/met13040662
Hyperlink
https://doi.org/10.3390/met13040662

Serga, V., Zarkov, A., Šiškins, A., Elsts, E., Meļņičuks, M., Maiorov, M., Blumbergs, E., Pankratov, V. Study of Metal Leaching from Printed Circuit Boards by Improved Electrochemical Hydrochlorination Technique Using Alternating Current. Metals, 2023, Vol. 13, No. 4, Article number 662. e-ISSN 2075-4701. Available from: doi:10.3390/met13040662

Publication language
English (en)