Study On Slag Performance Of High Efficiency Phosphorus Deposits In Huimin High Phosphorus Iron Mine

A abundant reserves of high phosphorus iron ore distribute in Yunnan, those are in a condition of low grade, complex composition, Mineral paragenesis, Easy mined but difficult mineral separation, While blast furnace smelting can not dephosphorize, moreover, Physical、chemical dephosphorization、microbial dephosphorization、hot metal pretreatment、dephosphorization in converter, those Dephosphorization methods are of low Metal recovery rate, low dephosphorization rate, long cycle and Serious pollution, that have abundant reserves of high phosphorus iron ore not being exploited.In combination with Huimin high-phosphorus iron smelted by Smelting Reduction and HIsmelt Ironmaking Technology, Which have the advantages of high efficiency of dephosphorization, The CaO-SiO2-Al2O3-MgO-FeO-P2O5slags with basicity (mass ratio of CaO to SiO2) ranging from0.8to1.4、Al2O3ranging from6.4%to15.4%, P2O5ranging0%to3%and the content of MgO、FeO fixed as4%、6%respectively, were studied in this paper. The slags were synthesized by reagent grade. The mineral composition and microstructure of slags were studied with X-ray diffraction and Scanning Electron Microscope, The effects of changes in the composition of smelting reduction slags on it’s melting temperatures and Viscosity were respectively studied by IST-1600Melting Temperature Measuring apparatus and RTW-10Melt comprehensive physical properties Measuring apparatus. Research has shown that:The mineral structure of slags were more complex、mainly composed of Melilite (Gehlenite、Akermanite), which is characterized by square and thick skeletion form. The Melting Temperature Firstly decreased and then increased with increasing the slag basicity at a fixed P2O5or Al2O3content, and the minimum values were reached and were Proportional to the content of P2O5or Al2O3as slag basicity was1.0; the viscosity decreased with increasing the slag basicity; The Melting Temperature values changed as Al2O3content is9.4%, at a fixed slag basicity or P2O5content; In the range of experimental composition, the highest melting temperature occurs as the Al2O3content is15.4%, the temperature at9.4mass%Al2O3increases with the increasing of P2O5content; the viscosity increased with increasing Al2O3 content; The Melting Temperature and viscosity increased with increasing P2O5content at a fixed slag basicity or Al2O3, which means during the process of dephosphorization, the melting temperature and viscosity increases gradually.The model of mass action concentration for this slag system is developed by use of Microsoft Visual Basic6.0in Combination with Select the main element Relaxation iterative method based on the ion and molecule coexistence theory, each component’s mass action concentration in the slags were calculated, the influences of temperature and basicity on each component’s mass action concentration were analysed, Research has shown that:In this slag system, the action concentration of CaO increased with the increasing of temperature and basicity, while the action concentration of MgO、FeO、Al2O3、SiO2decreased. Furthermore, the Thermodynamic Model for calculating Sulphur Distribution Ratio and phosphorus Distribution Ratio were developed, The Sulphur Distribution Ratio and Phosphorus Distribution Ratio calculated with the Thermodynamic Model of mass action concentration shows an acceptable agreement with the tested Sulphur Distribution Ratio and Phosphorus Distribution Ratio, which are of certain reference value to analyse the slag component activity and capability of Dephosphorization、desulfurization, which can provide a theoretical basis for the development and utilization of high phosphorus iron ore.