Preparation And Mechanism Study Of Amino Acid Type Amphoteric Collector For Phosphorite Flotatio

Amine collectors are often used for flotation desiliconization of siliceous phosphate rock,but due to their poor water solubility,poor selectivity,and high viscosity and over-stable foam produced by flotation,a series of production problems are caused.Amphoteric collectors have good low temperature resistance and solubility.The development of amphoteric collectors with high selectivity to siliceous minerals and low cost is of great significance for the desilication flotation of low-grade siliceous calcareous phosphate rock.In this paper,a new type of amphoteric collector N-dodecyl-β-aminopropionate sodium(C12Giy)was prepared by methyl acrylate method,and the preparation process of C12 Giy was carried out for a low-grade siliceous calcareous phosphate rock in Guizhou.Research on flotation performance of reagents and adsorption mechanism of C12 Giy flotation.The preparation process test of C12 Giy was carried out,and the effects of the material ratio of dodecylamine and methyl acrylate,reaction time and reaction temperature on the flotation index of C12 Giy were investigated.The effect of the interaction among these three factors on the flotation performance of C12 Giy was studied by response surface methodology.The experiment determined that the best preparation conditions were the material ratio of dodecylamine and methyl acrylate was 1:1.5,the reaction time was 40 min,and the reaction temperature was 70 ℃.The research shows that the interaction between the material ratio of dodecylamine and methyl acrylate and the reaction time has the most significant effect on the C12 Giy flotation index.The newly prepared C12 Giy was used as a collector for the flotation desiliconization test of low-grade siliceous calcareous phosphate rock.The reverse flotation process of "one coarse and two fines" is adopted,the grinding fineness is-0.074 mm accounting for 72%,the amount of roughing regulator SP is 4.5kg/t,and the amount of collector TP-1 is 300g/t,The dosage of fine one regulator SP is 7.5kg/t,and the dosage of collector C12 Giy is 200g/t;The rate of qualified flotation phosphorus concentrates were 30.06% and 85.97% respectively.The flotation effect of C12 Giy as collector is better than that of dodecylamine and tetradecylamine.The flotation experiments of pure minerals and mixed minerals of quartz,dolomite and collophosphate were carried out,and the effects of pulp p H and C12 Giy dosage on the floatability of the three minerals were explored.The results show that when the dosage of C12 Giy is 30mg/L,p H=3,the separation effect of quartz and collophosphate is the best;p H=5,the separation effect of dolomite and collophosphate is the best.The adsorption of C12 Giy on the surface of three minerals was studied by means of zeta potential,infrared spectroscopy,X-ray photoelectron spectroscopy and molecular dynamics simulation.The research shows that when p H=3,C12 Giy is electrostatically adsorbed on the surface of quartz and collophosphate;when p H=5,C12 Giy dissociates in solution and chemically reacts with calcium and magnesium ions in the dolomite lattice.The exposed magnesium ions on the dolomite surface are the key to the selective adsorption of C12 Giy on the dolomite surface.