689 15 th International Research/Expert Conference ”Trends in the Development of Machinery and Associated Technology” TMT 2011, Prague, Czech Republic, 12-18 September 2011 ELECTRODEPOSITION OF COPPER AND PRECIOUS METALS FROM WASTE SULFURIC ACID SOLUTION Silvana B. Dimitrijevic 1 , Aleksandra T.Ivanovic 1 , Danijela B. Simonovic 1 , Zeljko J. Kamberovic 2 , Marija S. Korac 2 1 Institute of mining and metallurgy, Zeleni bulevar 35, 19210 Bor, Serbia 2 TMF Belgrade, Karnegijeva 4, 11 000 Belgrade, Serbia ABSTRACT The aim of this work was to determine the optimum parameters of electrochemical deposition of Cu, Rh, Pt and Pd from waste sulfur acid solution. These solutions are geting decopperizing anode slime from the electrolytic refining of anode with increased content of PGMs dilute sulfuric acid (5-10%) with the addition of oxidative agents. Experimental laboratory studies were perfomed at different current denstities (135±5, 270±5,405±5 A/m 2 ) on copper cathodes with insoluble lead anodes. At all current densities achieved are high efficiency of metal (from 99.72 to 99.99%). Key words: electrolytic deposition, metals, PGMs, insoluble lead anodes 1. INTRODUCTION Platinum group metals have become indispensable in many of today´s key technologies: automotive catalysts, chemical and oil refining catalysts, electronics, electroplating, glass manufacturing, dental applications, fuel cells, high fashion jewelry and others [1]. Dissolution of copper is carried out according to the following reactions [2]: Cu + H 2 SO 4 + 1/2O 2 → CuSO 4 + H 2 O (1) Cu + H 2 SO 4 → CuO + SO 2 + H 2 O (2) CuO + H 2 SO 4 → CuSO 4 + H 2 O (3) According to the literature data , the platinum metals, generally, are not solvent in deluted sulfuric acid, experimentaly it is possible to a certain low concentration: up to 0.001g/dm 3 for Pt, 0.015 g/dm 3 for Pd, while Rh concentration reaches 2 g/dm 3 . Dissolution of paladium and rhodium can be described by the following reactions [3,4,5]: Pd + H 2 SO 4 + 1/2O 2 → PdSO 4 + H 2 O (4) Rh 2 O 3 ·5H 2 O +3 H 2 SO 4 → Rh 2 (SO 4 ) 3 + 8 H 2 O (5) 2Rh + 3H 2 SO 4 + 3/2O 2 → Rh 2 (SO 4 ) 3 + 3 H 2 O (6) Platinum is slightly soluble only at elevated temperatures [6]: Pt + 2H 2 SO 4 + O 2 → Pt(SO 4 ) 2 + 2 H 2 O (7) To minimize the loss of platinum metals to less than 1% and carry out regeneration of copper, separation of these metals was accomplished by electrochemical deposition using copper cathode and insoluble lead anode. During the electrodeposition of copper and platinum metals from waste acidic solution from decopperization, the following reactions may occure [6]: • processes in solution: