Fundamental Study On The Effect Of Pulp Viscosity On Gangue Entrainment In Chalcopyrite Flotation

With the depletion of high grade chalcopyrite in the world,low-grade chalcopyrite(0.5%-1%)has become the key object of the development and utilization of copper resources.Flotation is an economical and effective means for the separation of lowgrade chalcopyrite,and the full separation of target minerals and gangue minerals is the prerequisite for the flotation separation of low grade chalcopyrite.In the process of crushing and grinding,a large number of fine-grained gangue minerals will be produced,which not only increases the pulp viscosity and reduces the flotation efficiency,but also causes a large number of fine-grained gangue minerals enter to the foam products by entrainment during flotation operation,which seriously pollutes the concentrate products and brings many disadvantages for the subsequent operations.This method will lead to doping effect(such as heterogeneous coagulation,etc.),and it was difficult to obtain the single response of gangue entrainment to viscosity.Therefore,this paper selected the pure chalcopyrite,pure quartz,pure amorphous silica preparation of artificial mixed mineral as the research object.The pH of the slurry was adjusted to 9.0 for the suppression of heterogeneous coagulation.The paper has explored the influence of pulp viscosity on the gangue entrainment,the chalcopyrite flotation selectivity,the mechanism of influencing gangue entrainment,the prediction model of entrainment by changing amorphous silica proportion in the gangue to adjust pulp viscosity.The paper found that the pulp viscosity increases exponentially with the increase of the proportion of amorphous silica in gangue.Sedimentation test and Cryo-SEM observation showed that there are a large number of superficial silanol groups(Si-OH)on amorphous silica surfaces which formed regular chain structures through hydrogen bonds,thus improving the pulp viscosity,resulting in the difficulty of settling amorphous silica particles in slurry.Flotation test showed that concentrate yield firstly increases then decreases and finally tends to be stable,concentrate grade firstly decreases then increases and finally tends to be stable with the increase of pulp viscosity.The concentrate yield and concentrate grade were determined by the chalcopyrite recovery and gangue entrainment recovery.When the pulp viscosity increased,the chalcopyrite recovery decreased,while the gangue entrainment recovery firstly increased then decreased.When analyzing the reasons for the change of gangue entrainment recovery,it was found that the gangue entrainment recovery is strongly correlated with the water entrapment,which is of great significance to improve the flotation index of low grade chal copy rite.This paper contains 45 figures,11 tables and 101 references.