Study On The Surface Magnetization Of Siderite And Hematite

Due to the fine particle size, high specific surface areas, low magnetic susceptibility, the conventional method of magnetic separation which used to processing fine weakly magnetic iron ore is difficult to obtain a satisfactory separation performance. Based on the summary and analysis of a large number of literature at home and abroad, we have carried out the studies on the surface magnetization of weakly magnetic iron ore. This paper systematic research the magnetization and selectivity magnetic separation of single and mixture mineral of hematite and siderite, siderite and quartz, mixture mineral of siderite and hematite and quartz. We have studied the effect of temperature, slurry pH, stirring speed, magnetization time on the surface magnetization of siderite mineral. Experimental results show that temperature has significant influence on siderite magnetization. it can only get weak magnetic result under room temperature. The recovery rate of siderite can reach more than90%after magnetized in temperature65℃and then magnetic separation under low magnetic field strength (0.21T).The magnetization experimental of mixed mineral of siderite and hematite shows that Magnetization of siderite showed better synergism magnetization effect of hematite.Magnetic separation recovery of both types have different degree of increase, the temperature on the magnetization also show great influence. when the mixture mineral magnetized in the temperature of65℃, siderite and hematite recovery rate can reach more than90%of the0.21T. Magnetic separation of magnetized siderite from quartz was studied, the recovery of quartz in concentration was higher after magnetization, after the addition of a certain amount of macromolecular organic reagent, the quartz recovery became lower. In the separation of siderite, hematite and quartz using selective magnetic-hydrophobic coagulation, good index can be achieved.The XPS and infrared spectroscopy test of siderite before and after magnetization showed that there was Fe3O4formation on the surface of siderite. The VSM test of siderite before and after magnetization showed that the Fe3O4particles on the surface of siderite enhanced its specific magnetization effectively.High purity Fe3O4can be prepared by the mechanical mixing air oxidation ways using ferrous sulfate and sodium hydroxide as raw material, the VSM test showed that its specific magnetization is two orders of magnitude higher than hematite. In the magnetic separation of hematite, the recovery of hematite in concentration is much higher after the application of this method, the Fe3O4was synthetized in the pulp to make the surface of hematite magnetized. The magnetic seeds of Mn-Zn ferrite shows a certain ability of surface magnetization to hematite, the main factors are the composition and concentration of Mn2+,Zn2+and Fe3+,the reaction temperature, the concentration of OH-,the stirring speed and time. The computational analysis of the high gradient properties of magnetic particles was made, and the EDLVO theoretical model of the interaction between Fe3O4particles and hematite particles was established. Figure50, Table6,94References.