Simulation Of Blast Furnace Slag With Dispersion Phase Using Dissipative Particle Dynamics

Blast furnace slag, as a kind of by-products of the BF production, plays a very important role to the smelting process of blast furnace, the quality of cast iron, the life time of blast furnace, and the heat system of hearth. It is only the Blast furnace slag with good physical and chemical characteristics that can be separated from molten iron effectively, smoothly and gotten the pure iron. The slag is bearing titania by using Panxi vanadium-titanium magnetite in China, with the high temperature and strong reduction atmosphere, titanium oxide is reduced to some phases with high melting point(such as Ti C, Ti N) and dispersion in slag, even cause forming, thickening, bearing iron, leading an extremely adverse impact on the blast furnace operation.The BF slags with disperse phase Ti C 、Ti N were investigated in the present work, and discussed the physical and the chemical properties by combining the molecular dynamics(Molecular Dynamics, MD)、density functional theory based on the first principle(the First-Principles) and dissipative particle dynamics(DPD), mainly considering the influence of the mass and the concentration of the solid particles, the shear rate and the temperature. The following conclusions are gotten:① Interionic interaction potentials between the disperse particles, the disperse particles and particles in the Ca O-Si O2-Ti O2、 Ca O-Si O2-Al2O3-Ti O2 and Ca O-Si O2-Al2O3-Mg O-Ti O2 systems were deduced from energy calculations for a two kinds of particles model via the DFT-based first principle calculations and obtained the relative parameters of L-J potential.② The isothermal compressibility k-1 of all particles in the Ca O-Si O2-Ti O2、Ca O-Si O2-Al2O3-Ti O2 and Ca O-Si O2-Al2O3-Mg O-Ti O2 systems were calculated by molecular dynamics(MD) and then the potential of BF slag with disperse phase were built by combining the Keaveny method to obtained the interaction coefficient.③ For all groups of simulations, the viscosities decreased with the increase of shear rate, presenting the obvious phenomenon of shear thinning.④ Viscosity was influenced by concentration of disperse phase. At 1773 K, ωTi C≤15%, the viscosities of fine grained slag were much larger than that of the coarse, while showed an opposition state when ωTi C>15%. At 1873 K, the relationship between viscosity and particle size of Ti C was not regular, while the finer particle size of Ti N, the smaller the viscosity.⑤ The concentration of suspended particles and shear rate affected the viscosity of the slag system together. The shear rate played a leading role with the thin concentration of particles, on the other hand, the concentration played a main role.⑥ In the system of BF slag with disperse phase, Al2O3 plays the role of increasing viscosity and Mg O plays the role of decreasing viscosity.