Study On Selective Flocculation Behavior Of Fine-grained Scheelite

Flotation separation of scheelite and its calcareous gangue minerals is one of the important problems in scheelite separation,and the reason of fine scheelite with small particle size and small specific gravity aggravate the difficulty of separation.Flocculation is an effective method to recover fine minerals,which can separate fine Scheelite from fluorite and calcite efficiently.In this paper,by using different collectors(including anionic collectors and cationic collectors)and different inhibitors,the optimum collectors and inhibitors for flotation separation of scheelite and calcium gangue minerals are explored,and the effects of dosage of reagents,stirring time and stirring speed on flotation of three minerals are studied.The action mechanism of sodium oleate and sodium silicate on three kinds of fine minerals(-25?m)was studied by potentiodynamic,infrared spectroscopy,adsorptive capacity detection,FBRM particle size and PVM imaging analysis,scanning electron microscopy and energy spectrum analysis.The results of single mineral flotation recovery test show that: the anionic collector has stronger collecting ability and better selectivity for Scheelite and its calcium gangue minerals under neutral and alkaline conditions.Among them,sodium oleate is the best collector for fine scheelite,and when PH=9,the fine scheelite and its calcium gangue minerals can be effectively separated,and the optimum dosage is 120 mg/L.Cationic collector's collecting ability of scheelite and its calcareous gangue minerals is stronger under acidic conditions,but the selectivity is poor;water glass has almost no inhibition effect on scheelite,but has a greater inhibition on calcite and fluorite calcium gangue minerals.Therefore,water glass is selected as the inhibitor of subsequent artificial mixed ore experiments,and the concentration of water glass is chosen as 2700mg/L,the stirring factor test shows that the optimum stirring intensity is within 7 minutes,and too high or too low stirring intensity is unfavorable to the shear flocculation behavior.The flotation test of artificial mixed ore shows that when the concentration of sodium oleate is 120 mg/L,the concentration of sodium oleate is 120 mg/L,sodium silicate is inhibitor and the dosage is 2700 mg/L,when the ratio of scheelite to calcite is 1:1:1,the grade of scheelite in raw ore is increased from 28.87% to more than 40.41%,and the recovery is over 74.23%,the scheelite and its Calcium gangue minerals can be effectively separated.Through potentiodynamic analysis,infrared spectrum analysis,FBRM particle size and PVM imaging analysis,adsorption capacity analysis and scanning electron microscopy and energy dispersive spectrometer analysis,it was found that sodium oleate adsorbed on the surface of scheelite,calcite and fluorite,resulting in hydrophobic flocculation of minerals,and the order of floc size is scheelite > fluorite > calcite;sodium silicate can disperse calcium gangue minerals effectively,especially fluorite,thus inhibiting their flotation recovery.Finally,Finally,the EDLVO theoretical calculation proves that there is a huge hydrophobic interaction between scheelite particles and sodium oleate,which makes the particles coagulate.