Coal Rheological Properties And Its Modification

The comprehensive evaluation indicated that the performances of modified pitch are superior to that of medium pitch. Through the viscosity test, the differences of rheological behavior of the modified pitch and medium pitch have been studied. The higher viscosity of modified pitch brings about a series of actual application problem. According to the viscosity variation rule of modified pitch with temperature, the process parameters of several modified pitches has been determined.The modification rule of the stearic acid , oleic acid and paraffin wax to modified pitch are systematically studied. Effect of content of the stearic acid , oleic acid and paraffin wax on the viscosity of modified pitch has been analyzed. The regularity of rheological behavior has been found. The differences of modification effect among stearic acid, oleic acid and paraffin wax have been comparatively investigated. The process parameters of the stearic acid modified pitch , oleic acid modified pitch and paraffin wax modified pitch have been pointed out.The rheological laws of coal-tar pitches have been systematically investigated. It has been found that the coal-tar pitch fluids display non-Newtonian behavior. The viscosity of coal-tar pitches varies with the shear rates. According to the viscosity variation tendency of coal-tar pitches, the rheological processes of coal-tar pitches can be divided into three zones. These zones have been simulated and analyzed. The effect of viscosimeter kinds on the viscosity value of coal-tar pitches has been compared.