Study On The Effect And Mechanism Of Magnetization Treatment On Fine-grained Hematite Separation

In this paper,we study the effect of different magnetic induction intensity and magnetization time on the flotation of hematite and quartz pure mineral under magnetized water and magnetized medicament.The mechanism of magnetization treatment on flotation behavior of hematite and quartz pure minerals was analyzed by Zeta potential,infrared spectroscopy and chemical calculation of hematite and sodium oleate solution combined with the change of p H value of magnetized water.At the same time,the adsorption of medicament on mineral surface was visualized by atomic force microscope.The main research contents and test results are as follows:The flotation results of pure minerals showed that at pH=9,sodium oleate showed better capture performance for fine hematite,but the recovery of quartz was less than5%,and the floatability was very low.When deionized water magnetized at a magnetic field intensity of 400 mT for 7 min,the recovery recovery rate of fine hematite reached a maximum of 83.15%,which was 10.79 percentage points higher than that of unmagnetized.When the sodium oleate solution was magnetized for 7 min at 100 mT of magnetic field strength,the recovery rate of fine hematite reached a maximum of80.14%,which was 7.78 percentage points higher than that of unmagnetized.The flotation results of mixed ore indicate that magnetization treatment can promote the flotation separation of fine hematite and quartz.Mineral surface potential and infrared spectroscopy analysis showed that at pH=9,both magnetized water and magnetized agent would cause negative shift of hematite surface potential,which had little effect on quartz surface potential.Surface magnetization treatment would increase the adsorption of sodium oleate on hematite surface.The solution chemical calculation analysis shows that the magnetized water treatment will increase the slurry pH by 0～0.45,and the increase of pH directly affects the hydrolysis of hematite in aqueous solution.The solubility of sodium oleate will increase after magnetization treatment,the degree of hydrolysis will increase,and the concentration of H（RCOO）₂^-and RCOO^-in the solution will increase,which will lead to more chemicals adsorbed on the surface of hematite.Atomic force microscopy observation showed that the average adsorption thickness of the hematite surface agents treated with magnetized water and magnetized sodium oleate reached 10.09nm and 8.75nm respectively,which were increased by3.5nm and 2.16nm compared to 6.59nm without magnetization.It shows that the magnetization treatment can make the adsorption of the agent on the mineral surface more tight and more uniform,and can increase the amount of agent adsorption,thereby improving the floatability of hematite.