Prediction of edge energy level at mineral-solution interface by means of zeta potential
(1.College of Resources and Environment, Guangxi University, Nanning 530004, P. R. China2.Department of Mineral Engineering, Central South University of Technology, Changsha 410083, P. R. China)
Abstract: A new method based on electrochemical double layer model is put forward to calculate edge level at the semiconductor solution interface. Fermi level and edge level of semiconductor in solution are required to build energy band model. Edge level of semiconductor is very difficult to be measured directly in the process of sulfide flotation, so it is necessary to predict the value of edge level from theory. Then the theoretical prediction of edge level is simplified by means of zeta potential, which is easy to be measured and often used in flotation. According to this model, parameters of flotation solution, such as zeta potential, ion strength, Dybe length and electrode potential etc, and parameters of semiconductors properties, such as band gap, work function, type of semiconductor etc, are connected organically. The electron density and hole density in the mineral surface layer are depended on the values of surface potential barrier related to edge level; in addition, the dynamic process of semiconductor electrode is related to the change of surface potential barrier. All of them play an important role in the process of sulfide flotation.
Key words: energy band model； semiconductor； electrochemical double layer