Experimental Study On Sintering Properties And Melting Speed Of Continuous Casting Mould Fluxes

Mould fluxes is an essential material used in continuous casting process, and which has a significant impact on the surface and subsurface quality of casting slabs. With the development of continuous casting technology, the quality requirement of mould fluxes has been higher and higher. Among them, the control of sintering property plays an important role in the normal function of the continuous casting. The sintering property of the mould fluxes is too strong to cause the slag inclusion defects, and lead to the growth of slag rim. Relative to the viscosity, melting point and other properties of mould fluxes, the sintering property of mould fluxes is relatively backward, and there is no united standard, this will be an obstacle for the theory development of mould fluxes. Typically, mould fluxes sintering property is controlled by the carbonaceous material. On the other hand, the carbonaceous material has a direct impact on melting speed of mould fluxes, coordination sintering property and the melting speed has become a difficulty and focus of mould fluxes.Aiming at the problem of mould fluxes serious sintering, a tube furnace experimental device was used to measuring the sintering property which was characterized by measuring the constant temperature sintering ratio. We researched the effect of different carbon content on the sintering ratio of mould fluxes, and applying it to industrial practice. In the further research, the heating up experiment scheme of sintering was put forward and the unidirectional heating experiment equipment was set up. The effect of different carbon on high alkalinity slag samples sintering properties was measured by continuous heating sintering method. In order to clarify the influence mechanism of carbon materials on the sintering properties of mould flux, the sintered samples at different temperatures were analyzed by X ray diffraction. meanwhile, we use droplet method and melting ratio method to determine melting speed of different mould fluxes.The constant temperature sintering experiment results show that: in a single carbon distribution mode, with the rise of carbonaceous material content, mould fluxes sintering ratio decreased. The sintering ratio of mould fluxes can be reduced by increasing the specific surface area of carbon materials under the condition that the carbon content of the mould fluxes is maintained. When the specific surface area is more than 150m2/g, the sintering ratio of mould fluxes can not be reduced by increasing the specific surface area of carbon materials. In the composite carbon mode, the innermost layer wrapped of carbonaceous material is the most important to control the sintering property. According to the melting speed data of the mould fluxes, the mould fluxes with 2% carbon II can be found to better coordinate the sintering property and the melting speed.The sintering speed measured by the continuous heating test is consistent with the sintering property of using the mould fluxes in the industrial field. In the study of carbonaceous materials on sintering properties of high basicity mould fluxes found that: with the lack of carbon B,sintering properties of mould fluxes almost can not be effectively controlled. When adding carbonaceous material in high basicity mould fluxes, we should adopt multilayer carbon method. While improving the total amount of carbon content of the mould fluxes, carbonaceous material content of high specific surface area can not be too low. The results of X-ray diffraction show that: with the increasing of carbonaceous material content, the solid state reaction temperature can be raised, thus, the sintering property of the mould fluxes was restrained.