Metal Sulfide Nanoparticles as Sphalerite Surface Activators to Improve Zinc Recovery Through Flotation Process

CuS nanoparticles (Np) were synthesized and deposited on synthetic sphalerite (SP) using two different methods. Two nanoparticle products were obtained on the surface of SP, Np1 and Np2, resulting in two active materials (Np1-SP and Np2-SP) with specific characteristics. Nanoparticles and active materials were characterized by TEM, XRD, SEM, and XPS. The collectors PAX and SIPX were adsorbed on Np1-SP and Np2-SP to determine the adsorption capacity. Method 1 provides a higher quantity of nanoparticles on SP, which allows for the adsorption of a higher amount of SIPX. Method 1 was used to deposit nanoparticles on two natural sphalerites (SN) with different iron contents. SN, unlike SP, can be used to test nanoparticle activation results in microflotation experiments. SN was activated with nanoparticles (Np1-SN) and using the traditional method (Cu-SN). The recovery of 75% of zinc using the microflotation process suggests that the hydrophobicity of Np1-SN is higher than that of Cu-SN. Nanoparticles improve the hydrophobicity of SN compared to the traditional activation used in the mining industry. These results suggest that using nanoparticles is an excellent option to activate minerals in flotation processes, decreasing the consumption of reagents and helping to mitigate negative impacts on the environment.