The Process And Mechanism Research Of Carrier Flotation Of Fine Scheelite Used With Hydrophobic Polymers

China has abundant tungsten resources and huge reserves have topped the world. Fine scheelite is brittle and easy to over grind which contributes to severely losing in tailings. It is urgent to resolve problems appeared in fine scheelite flotation and explore new process of fine ore aiming at increasingly poor, thin and low-grade characteristics of fine scheelite resources.This thesis systematically discussed the possibility of fine scheelite carrier flotation process with polystyrene (PS) and studied the factors (chemical factors, physical factors and geometrical factors) in detail about carrier flotation process. In addition to the single mineral flotation test, the flotation experiments of manually mixed ore of fine scheelite and quartz were carried out to explore the selectivity effect of carrier flotation technology and its applicability to other minerals. In order to visually reveal the mechanism of carrier flotation, scanning electron microscope with laser particle size analyzer was used to qualitatively and quantitatively observe and analyze the particle size during carrier flotation process. The paper explain the agglomeration and dispersion behavior between fine particles and the carrier by computing interaction energy between the particles interface in sodium oleate system in the light of the extended DLVO theory. Action mechanism between collectors and scheelite can be uncovered through measuring adsorption and contact angle.The results of single mineral flotation test showed that PS carrier flotation recovery increased from35.05%of conventional flotation to76.37%at sodium oleate1×10-4mol/L and pH=10.5sodium carbonate as modifier. Mixed ore between quartz with scheelite carrier flotation test results showed that flotation recovery of scheelite achieved86.46%, grade containing WO3%increased from31.8%to76.87%.Scanning electron microscope pictures showed that carrier (PS) surface adhered a number of fine scheelite during PS carrier flotation process. However, scheelite particles mainly presented dispersed state and only a few particles condensed together in conventional flotation. Particle size distribution of carrier flotation and conventional flotation also showed that carrier flotation could significantly increase the particle size of intermediate particles and reach the particle size range of conventional flotation. Interaction force between particles including Van der Waals force, electrostatic force and interfacial force are computed, which indicated that hydrophobic force between the coarse carrier and fine scheelite particles was the main cause of fine particles adhering to carrier.By measuring sodium oleate adsorption capacity and contact angle with scheelite surface, the results showed that adsorption capacity and the contact angle increased with the concentration of sodium oleate when the concentration of sodium oleate is less than2.5×10-4mol/L. While the concentration continued to increasing, the adsorption capacity and contact angle kept substantially constant. The results were consistent with the actual flotation test results.