Controlling binder content in carbon article production - measuring slump of pressed mix of carbon and binder prior to baking

摘要

In the prodn. of carbon articles by pressing and baking a mixt. of binder (coal tar or petroleum pitch) an a carbon aggregate, the slump of the pressed article is measured to at least hundredths of an inch prior to baking. The relative proportions of binder and carbon in subsequent mixt. is then varied according to the measured slump in order to give the required slump. Used in making carbon anodes for electrolytic production of Al from Al2O3 dissolved in fused cryolite. The optimum binder content of the mixt. is controlled by the slump measured and eliminates conventional vol. and wt. tests on the baked article. Any rejected articles can be crushed and recycled to the mixer thus saving heating costs in baking rejects.