Mixing variables for prebaked anodes used in aluminum production

The quality of anode electrode used in aluminum electrolysis industry and its dependence on the production parameters are studied in this work. Using a calcined petroleum coke and a coal tar pitch, anode pastes were made at laboratory scale at four mixing temperatures and four mixing times. The pastes were compacted in a cylindrical mold at a maximum pressure of 60 MPa. The green samples were then baked at 1130 degrees C for 12 h. Measurement of density variations as well as porosity and pore size distribution was carried out on the green and baked samples as a function of mixing temperature and time. For the setup used, an optimum mixing time and temperature were suggested, resulting in a better mixing effectiveness, maximum density, and minimum air permeability and specific surface area. (C) 2012 Elsevier B.V. All rights reserved.