Study on graphitization of cathode carbon blocks for aluminum electrolysis

Abstract

High quality graphite cathode carbon blocks require low resistivity, strong resistant erosion to molten salts and liquid aluminum in the aluminum electrolytic cells. High quality cathode materials can decrease cathode voltage and then reduce the power consumption, and improve service life of the cell. Applying hot mould technology under 40 MPa pressure, different amounts of petroleum coke in anthracite mixtures is graphitized in graphitizing furnace. By the X-ray diffraction parameters, density, compressive strength and resistivity drop are measured. The experimental results show that compressive strength and volume density of graphite blocks containing 30% of petroleum coke are 1.366 g/cm3 and 4.8 MPa, respectively, resistivity drop from 114µΩm to 13µΩm, mostly in accordance with block production requirements.