Using the gold bullion slag from Indonesia as lithium resources with HCL leaching method

Abstract

Primary resources are typically used in lithium extraction. Unfortunately, it impacts the dependency on the availability of primary resources to fulfill the lithium demand. Therefore, the use of secondary resources can be an alternative to using lithium resources. Gold bullion slag is an example of a potential secondary resource used as a lithium source because it contains 0.009 % lithium. This research aims at increasing lithium recovery from the gold bullion slag by studying the effects of various variables to enhance lithium recovery. Lithium extraction was carried out via HCl leaching process with concentrations of 0.5, 1.0, 1.5, and 2.0 M at 25, 40, 55, and 70 °C for 15, 30, 60, and 120 minutes. Inductively coupled plasma-optical emission spectrometry (ICP-OES) was used to examine lithium level, whereas scanning electron microscope equipped with energy dispersive X-ray spectroscopy (SEM-EDX) was used to look over the morphology. The significance of the recovery value was analyzed statistically using analysis of variance (ANOVA). The optimum variables to reach 98 % as the highest lithium recovery percentage are 1 M HCl at 55 °C for 60 minutes. ANOVA results on the acid concentration significance of the recovery value show that the p-value (0.001) is smaller than the alpha value (0.005). While, ANOVA results on the temperature and time significance of the recovery value show that the p-value (0.894) is greater than the alpha value (0.005) and p-value (0.9986) is greater than the alpha value (0.005), respectively. Analysis showed that variation in HCl concentration affected the lithium recovery value; however, temperature and time of leaching had an insignificant effect on lithium recovery. These data show that slag can be used as alternative resources to produce the lithium