Study On Dispersion--magnetic Separation Of Finely-grained Weakly-magnetic Iron Minerals

China is at a critical period, facing worsening situation of the iron ore resources. Most of our iron ore resources have characteristics of low-grade, finely-grained disseminated and complex components. Therefore, the processing of fine particles of weakly magnetic iron ore resources is of great significance.On the basis of the summary and analysis of many related references, some sets of experiments had been carried out with respect to dispersed magnetic of pure mineral and the real ore, Dispersing effect of the different dispersants were researched systematically, As well as pH, mixing, particle size and other factors were researched. And the disperse mechanism was sufficiently proved by Zeta potential measurement, X-ray photoelectron spectroscopy testing analysis and infrared spectroscopy. Meanwhile, the root causes of the different dispersion were analyzed from the molecular structure by electro-negativity.The test results of pure minerals indicate that the dispersing effect of hyper-dispersants precede inorganic dispersant. But the alkali resistance is the opposite. Dispersing effect of three different particle size were compared, the most obvious otherness is the particle size of0.075mm> d>0.044mm, simultaneously, the optimum concentration value is33.3%, the most energy-efficient mixing is lmin and700r/min.The test results of the real ore show that sodium hexametaphosphate, polyving alcohol, polyoxyalkylene glycol and polyvinylpyrrolidone help to improve the concentrate grade, Sodium carbonate and Sodium thiophosphate can improve the concentrate grade weakly with the recovery reduced significantly, and the role of the starch is opposite.The Zeta potential measurements illustrated that starch could make the Zeta potential of specularite and quartz decreased, and shift the PZC of specularite from6.6to4.0. Sodium hexametaphosphate, polyving akohol, polyoxyalkylene glycol and polyvinylpyrrolidone also shift the PZC. Differently, sodium hexametaphosphate make the Zeta potential of specularite and quartz greatly decreased. Polyving alcohol, polyoxyalkylene glycol and WPVP shift the PZC of specularite from6.6 to4.8but the Sodium hexametaphosphate shift PZC from6.6to2.8.The results of infrared spectroscopy show that the main adsorption manner of dispersant on quartz was physical adsorption. Simultaneously, the main adsorption manner of dispersant on quartz was chemical adsorption except polyoxyalkylene glycol and polyving akohol.Analysis of the molecular structure of the dispersant, the chemical bond of dispersants and specularite are arranged by intensity as WPVP> polyving akohol, polyoxyalkylene glycol, starch> Sodium hexametaphosphate. Flexibility of dispersants’molecule are arranged as polyving alcohol> polyoxyalkylene glycol> WPVP> starch> Sodium hexametaphosphate.