Periclase brick

Description

Periclase brick is a fired magnesia refractory made from sintered periclase, that is, magnesium oxide MgO obtained by firing natural magnesite. The more MgO and the fewer impurities (calcium, silicon and iron oxides) the product contains, the higher its grade and the longer it lasts at high temperatures. GOST 4689-94 sets three grades: P-91, P-90 and P-89 (П-91, П-90, П-89); the number is the minimum MgO content in per cent.

Periclase melts above 2800 °C and is a basic material. This is why periclase brick resists basic steelmaking and ferroalloy slags and molten metal well: slag attacks the lining more slowly and penetrates the pores less. The weak point of periclase is sharp temperature changes, so a furnace with this lining is heated up and cooled down to a schedule. Periclase brick is also strong at high temperature and shows almost no shrinkage, so a hearth lining keeps its shape under the weight of the metal for a long time.

Grade P-91 is used in hearths, banks and walls of electric arc furnaces and in hearths and walls of ferroalloy furnaces. P-90 is used in the same places, as well as in the lower courses of submerged arc furnace hearths and in mixers. P-89 is for walls above the slag line and other high-temperature furnaces. Periclase brick also works in non-ferrous furnaces and in the burning zone of shaft lime kilns. Where the unit is often cooled sharply, more thermal-shock-resistant products are installed next to the periclase brick: magnesia-chrome or periclase-spinel.

We supply straight brick 230×115×65 mm (designation P91-1: grade P-91, shape No. 1), wedges and products to the customer’s drawing. The brick is laid with magnesia mortar or powder, according to the lining design. Periclase absorbs moisture from the air and cracks as a result, so the brick is stored on pallets in a dry, covered warehouse, in the original packaging. Before shipment we check the grade and shapes against the furnace drawing so that you receive a complete set for the whole hearth or wall in a single delivery.

Technical data