Production of high-quality graphite crucibles for metallurgy

Abstract

Processes for the manufacture of crucible graphite with high performance characteristics are considered. Among these processes are the use of highly graphitized needle coke as a filling agent, the vibromolding of a starting coke-pitch mixture, the use of medium-temperature coal-tar pitch impregnation-burning cycles, the burning of molding compounds in metal containers, and the graphitization of burnt materials in graphite cylinders. The latter two techniques decrease a temperature drop across the bulk raw material in the course of thermal treatments and, consequently, minimize the appearance of cracks due to a decrease in thermal stresses. All of the recommended techniques can be implemented at current electrode plants, and they can considerably improve the quality of the manufactured crucible graphite. In this case, the quality of the resulting materials can correspond to world standards.