Things are hotting up in the steel industry: the production of pig iron and its subsequent processing into special steels demand process temperatures of between 1,200 and 1,800 °C. There are correspondingly high requirements to give the production equipment the best possible protection against thermal, mechanical and chemical factors. Here carbon-containing magnesia bricks are superior to periclase (MgO) and carbon due to their high-melting-point components; they act as a working lining in applications such as basic oxygen converters, arc furnaces, steel casting ladles or converter openings.
Carbon-containing magnesite bricks are manufactured with suitable magnesite grades (caustic magnesite, sintered magnesite) and cokable binding agents such as pitch or synthetic resins, followed by processes for shaping, tempering and vacuum pitch impregnation.
The carbon content of the bricks is also controlled by the addition of carbon blacks. The importance of the carbon content is that it reduces wear in the brick. LUVOMAXX® thermal blacks are particularly able to ensure optimum reduction of the infiltration depth for molten iron and oxidic infiltrates into the pores of the rock due to their matching primary particle structure and high carbon density. Furthermore, as a carbon source (= internal reducing agent) they make an important contribution to the redox stability of the brick and as a binding agent for the magnesite particles to its erosion resistance.