Non-polar oil assisted DDA flotation of quartz I: Interfacial interaction between dodecane oil drop and mineral particle

In this paper, in order to study the interaction mechanism of non-polar oil assisted dodecylamine (DDA) flotation of quartz, the particle-oil drops system were treated the same as the hydrophobic particles system. Pure dodecane was chosen as research object, the interfacial interactions between quartz particle and oil drop were investigated through calculation of the extended Derjaguin-Landau-Verwey-Overbeek (EDLVO) potential energy profile. Based on the calculations of the van der Waals attractive interaction potential, hydrophobic interaction potential, hydrocarbon chain association potential, and electrostatic interaction potential, the results indicated that the mineral particle and oil drop attachment state was mainly dominated by hydrophobic interaction potential. In the modification of oil agglomeration flotation process, the adsorption of DDA on the dodecane/water interface presented significant effects on the interfacial interactions between quartz particle and oil drop. It was found that the adsorption of DDA at dodecane/water interface changed the zeta potential value of oil drop from negative to positive. In this case, the attachment of the particles would occur spontaneously, which was due to the contribution of electric double layer attractive interaction. On the contrary, in the traditional oil agglomeration flotation process, a mechanical agitation was required to overcome a potential barrier due to the existence of electric double layer repulsive interaction between the negatively charged oil drops and mineral particles. This study was focus on the theoretical level, and provided some insights into mechanism of oil agglomeration flotation.