Abstract: A new ramming paste for aluminum reduction cell cathodes is a high swelling cold ramming paste made of a blend of pitch, light oil diluent and an aggregate comprising a mixture of anthracite and crushed anode butts or calcined coke. The presence of the crushed anode butts or calcined coke increases the sodium swelling index of the paste by about four times higher than that of regular ramming pastes. This new high swelling cold ramming paste may also contain an amount of a refractory hard material, such as TiB2.

Abstract: A method is described for making aluminum reduction cell components, e.g. cathodes having stabilized surfaces, which comprises mixing together a carbonaceous material, TiB2 and up to 25% by weight of a finely divided additive consisting of a combination of two intimately mixed compounds and forming the mixture into a cell component, wherein at least a first of the two compounds has a higher melting temperature than the baking temperature. When the cell component is contacted with molten aluminum, the aluminum reacts with the additive to form a dense phase at the surface of the cell component, having low solubility in aluminum.