Читать книгу Application of Nanotechnology in Mining Processes - Группа авторов - Страница 26

The formation of AMD from sulfidic ores during mining activities is an inevitable process that can be enhanced as a secondary source for REEs using an effective alkaline treatment technology engineered to optimize a high concentration of REEs in the waste. Despite the occurrence of metals in rocks and soil as a natural constituent of the Earth’s crust, the leaching of AMD products into the environment will enhance their presence at an elevated concentration significantly higher than the acceptable levels prescribed by the World Health Organization (WHO). Therefore, it is imperative to treat AMD to a useable standard as defined in the water quality guidelines. On the contrary, AMD is a valuable source of REEs which can be recovered to compensate for their shortage in supply needed for advancement of technological developments. Although the recovery of rare earth metals from AMD remains a great challenge, the use of nano-absorbent such as dendrimer has enhanced their recovery, making AMD a future viable source for these precious metals. Dendrimers are an exceptional cost-effective material with surfaces that are easily designed to suit any intended application. The use of magnetic PAMAM dendrimer nanoparticles surface-functionalized with succinic acid presented in this chapter is a pragmatic approach with dual functionality. The succinic functional group attached on the surfaces of the dendrimer will protonate in the acidic effluent to anionic groups, which will increase the binding ability of the polymer with REEs in solution via electrostatic attraction, and its magnetic property will be used to separate the bound metal ions from the solution. This integrated approach will recover REEs from the acidic effluent using a low-cost material that itself is environmentally friendly to generate income for mining operators, thus stopping the pollution cycle.