Optimizing the Amino Acid Leaching Parameters of Gold from the Mobile Phone Printed Circuit Boards

Document Type : Research Article

Authors

Mining Department, Faculty of Engineering and Technology, Lorestan University, Khorramabad I.R. IRAN

Abstract

Technological advances in electronic equipment and the variety-seeking behavior of people in using new equipment and devices have turned the issue of electronic waste (E-waste) into a major dilemma in the world. Electronic waste contains high levels of toxic metals such as lead and cadmium, base metals like aluminum and copper, precious metals such as silver, platinum, and palladium, and non-metallic parts consisting of resin, ceramic, plastic, and glass. There are different methods available to recover precious metals such as gold and platinum from electronic waste. However, the amino acid L-valine was used in this paper as a cheap and non-toxic leaching agent instead of cyanide. The grade of gold and platinum in the sample is 542 and 30 ppm, respectively, In addition, the parameters of L-valine concentration, temperature, pH, pulp solid percentage, and time were assessed by the Design of Experiments (DOE) method using the software. The experiments’ results demonstrated that the parameters of temperature, time, pH, pulp density, and L-valine concentration respectively have greater importance in the gold recovery process due to the lower P and higher F values. The mean percentage of gold recovery was obtained as 81.47% when validating the results under the proposed optimal conditions (L-Valine concentration: 173 g/t, pH: 11, time: 24 hours, temperature: 80 °C, pulp solid percentage: 19%, and constant stirrer speed: 400 rpm).

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[2] Akcil A., Erust C., Ekha C.S., Precious Metal Recovery from Waste Printed Circuit Boards Using Cyanide and Non-Cyanide Lixiviants-A Review, Waste Management, 45: 258–271 (2015).
[3] Gámez S., Garcés Ks., Torre E., Guevara A., Precious Metals Recovery from Waste Printed Circuit Boards Using Thiosulfate Leaching and Ion Exchange Resin, Hydrometallurgy, 186: 1–11 (2019).
[4] Ashiq A., Kulkarni J., Vithanage M., Hydrometallurgical Recovery of Metals from E-waste, Electronic Waste Management and Treatment Technology, 10: 225-246 (2019).
[5] Feng D., Van Deventer J.S.J., The Role of Amino Acids in the Thiosulphate Leaching of Gold, Miner. Eng., 24: 1022–1024 (2011).
[6] Tripathi M., Kumar D.C., Sau A., Leaching of Gold from the Waste Mobile Phone Printed Circuit Boards (PCBs) with Ammonium Thiosulphate, Int. J. Metall. Eng., 1: 17–21 (2012).
[7] Birloaga I., De Michelis I., Ferella F., Buzatu M., Vegliò F., Study on the Influence of Various Factors in the Hydrometallurgical Processing of Waste Printed Circuit Boards for Copper and Gold Recovery, Waste Manag, 33: 935–941 (2013).
[8] Petter P.M.H., Veit H.M. Bernardes A.M., Evaluation of Gold and Silver Leaching fFrom Printed Circuit Board of Cellphones, Waste Manag., 34: 475–482 (2014).
[10] Liu R., Li J., Ge Z. Review on Chromobacterium Violaceum for Gold Bioleaching from E-waste, Procedia Environ. Sci., 31: 947–953 (2016).
[11] Tanda J.J., Oraby E.A., An Investigation Into the Leaching Behavior of Copper Oxide Minerals in Aqueous Alkaline Glycine Solutions, Hydrometallurgy, 167: 153–162 (2017).
[12] Perea C.G., Restrepo O.J., Use of Amino Acids for Gold Dissolution, Hydrometallurgy, 177: 79–85 (2018).
[13] Broeksma C.P., “Evaluating the Applicability of an Alkaline Amino Acid Leaching Process for Base and Precious Metal Leaching from Printed Circuit Board Waste”, Doctoral Dissertation, Stellenbosch: Stellenbosch University (2018).
[14] Aghababaei Sh., “Examining the Effective Parameters on Copper Leaching from Printed Circuit Boards Waste by the Design Experiments Method”, Master Thesis in Mining Engineering, Lorestan University, 74 (2017).
[15] Raeisi Z., “The Gold Recovery from Electronic Waste Using Solvent Extraction Method”, Master Thesis in Mining Engineering, Zanjan University, 83 (2019).
[16] Kiani V., "Evaluating the Synergistic Effect of Amino Acids on the Cyanation Process of Poyazarkan Agh Dareh Gold Processing Plant", Master Thesis in Mining Engineering, Lorestan University, 93 (2019).
[21] Nowicka A.M. Hydroxyl Radicals Attack Metallic Gold, Angew. Chem, 122: 1079–1081 (2010).
[22] Huang J., Chen M., Chen H., Leaching Behavior of Copper from Waste Printed Circuit Boards with Brønsted Acidic Ionic Liquid, Waste Manag., 34: 483–488 (2014).