EVALUATING CALCINED COKE FOR ALUMINUM SMELTING BY BULK DENSITY.

Since calcined cokes with high bulk density are known from experience to give anodes with good properties for aluminum electrolysis, the connection between bulk weight, green density, and density of the baked anode was investigated for various types and mixtures of cokes. The bulk density of calcined petroleum coke grows as the grain size becomes smaller; divergencies can thus occur dependent on the amount and distribution of the porosity. With coke from coal tar pitch the bulk weight changes only insignificantly with the grain size. The best agreement between bulk weight, green density, and density of the baked anode is to be found within limited sieve classifications ( minus 24 plus 48) for all cokes investigated.