Abstract:
Spent mobile phone batteries consisted of various kinds of metals such as Ni, Co, Al, Cu, La, etc are considered as hazardous materials. This research was carried out to recover some valuable metals from the electrode of the spent mobile phone batteries by using the leaching and precipitation processes in laboratory scale. Two types of spent mobile phone batteries were employed in this study; nickel-metal hydride (Ni-MH) and lithium-ion batteries (Li-ion). Both batteries were first crushed and analyzed their principle components. Afterward, the leaching process was carried out. Effects of parameters including types of acid (H[subscript2]SO[subscript4] HNO[subscript3] and HCI), acid concentration (1-6 M), solid-liquid ratio (10-40 g/l), leaching temperature (30-90 degrees celsius) and leaching time (5-120 min) on the leaching percentages of Co and Ni in the leaching process were investigated. The preliminary results indicated that the HCI provided the highest leaching percentages than that of H[subscript 2]SO[subscript 4] and HNO[subscript 3] for all leaching conditions. The optimum leaching condition was found at acid concentration of 5 M, leaching temperature of 80 degrees celsius, solid-liquid ratio of 15g/l, and leaching time of 60 min. According to this condition by using HCI, greater than 99% and 90% of Ni and Co were leached, respectively. Further investigation indicated that the leaching processes of both metals were the endothermic processes with the rate raw of the second-order reaction. In addition, the physical process principally controlled the leaching process with the activity energy of 0.34 and 0.52 Kj/mol for Ni and Co, respectively. The pH condition of co-precipitation of nickel and cobalt by using NaOH 2 M was equal to 11.