The aluminum industry consumes about 80 percent of the bituminous-coal electrode pitches made by coke and chemical producers. The upgrading of primary aluminum production world-wide has prompted a review of quality specifications for raw materials, especially binders for anodes (pre-baked and self-baking). Until recently, Russian aluminum plants made all anode pastes from medium-temperature pitches (MTP), which are the residue from conventional distillation of bituminous coal tar. Practically all these pitches have relatively low viscosity (sometimes extremely low), resulting in stratification of the anode material during smelting and the formation of a liquid phase in upper part of the anode. For this reason, standard quality indicators characterize mainly the coking properties of the binder (contents of volatile matter and highly condensed fractions a and ax).
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