Abstract: In order to improve the performance of graphite products, the impregnation process was studied for the problems of low bulk density and poor performance of large-size graphite. The results show that when the modified coal tar pitch with a softening point of 120 ℃ is used as the impregnating agent, and the impregnation temperature is 210 ℃, the impregnation pressure is 2.5 MPa, the impregnation time is 6 h and the cooling pressure is 3.0 MPa, the weight gain rate and bulk density of large-scale graphite products reach 14.12% and 1.828 g/cm³, respectively. After roasting, the impregnating agent volatilizes, resulting in a decrease in the bulk density of the product. Therefore, the effect of the number of impregnation roasting times on the bulk density of the product was studied. It was determined that the two-baking and one-leach⁃ ing process was adopted, and the product could reach a better level of bulk density of 1.794 g/cm³ and the maximum comprehensive efficiency.

Key words: large-scale graphite, impregnation, weight gain, bulk density