Research On The Rheological Bahavior Of Corundum-based Alumina-magnesia Vibration Castables

The workability of Monolithic Refractories have a decisive impact on the lining. And the rheological behavior and workability are closely related. The study focus on the rheological behavior of matrix due to the restrictions of experiment equipment, but less on the castables rheological behavior. In recent years, the castables rheological behavior was studied using the new equipment called the castable rheometer abroad.This paper researched the rheological properties of the raw materials'slurries, matrix slurries and castables of the corundum-based Al2O3-MgO castables by rheometers for slurry and castable respectively. The results showed that:⑴The rheologies of raw materials'slurries were in line with Bingham fluid under the condition of this test, and showed thixotropy behavior. The rheologies of raw materials'slurries deteriorate with its concentration increases. Dispersant can significantly improve its rheologies, but the optimal kind and amount of are different for each materials'slurry.⑵The rheology of matrix slurry was in line with Bingham fluid under the condition of this test, and showed thixotropy behavior. With the increase of slurry concentration and silica fume content (0 to 12 %), the yield stress, plastic viscosity and thixotropy of slurries were increased significantly. The magnesia powder content (12 ~ 36 %) had little impact on the slurry rheology.⑶.With dispersants, the rheology of the matrix slurry was in line with Bingham fluid.Dispersing agent can significantly improve the flow of their performance, compared with other dispersant, SHP, SM are the optimal dispersants.⑷In the revolution speed of 0~70 rpm, the rheologies of vibration castables were in line with Bingham fluid in vibration conditions, and showed thixotropy behavior. with the increase of silica fume addition (1~ 3%), the relative yield stress, the relative plastic viscosity and thixotropy were decreased. But rheological parameter of silica fume addition (4%) are less increase ;Magnesia powder content (4 ~10%) had little influence on the castable rheology without of 12%; with the increase of Andreassen particle size distribution coefficient (0.23 to 0.31), the relative yield stress and thixotropy were decreased gradually, and at the same time relative plastic viscosity had no obvious change.