The invention relates to a fired refractory shaped part whose structure: a) consists of up to at least 75% by weight of a pre-fired refractory secondary material with a grain size of up to 3 mm, and; b) has an open pore volume ranging from 10 to 30% that, after firing, is filled, at least in part, with a carbon-containing material, whereby; c) the carbon content is >3% by weight with regard to the shaped part.