MMK reaches new record resilience for steelmaking unit lining

Magnitogorsk Iron and Steel Works (MMK) has achieved a new record indicator for the resilience of the refractory lining of the main arch of the two-hearth furnace (THF) at the electric steel smelting shop. Refractories, which face the internal surface of a furnace, withstood 1,321 melts.

The previous highest indicator (1,265 melts) was set just three months ago. An increase in the numbers of melts per lining supports higher output, reduces operational costs and increases production efficiency by saving refractories and reducing the costs of repair work.

The record became possible as a result of hard work by MMK’s steelmakers to improve steel smelting technology and provide necessary maintenance to the refractory lining. To increase the resilience of refractories, steelmakers must ensure that liquid metal remains within the units for an optimal period of time and carry out necessary preventive measures. The quality of the refractories is of great importance and is requested from suppliers. Additional factors that affect resilience include the quality of the lining implementation, which is carried out by specialists in repairing metallurgical furnaces from the OSK company; and the gunning of the main roof – the application of a special shotcrete made from refractory powder to working refractory lining increases its strength and improves resilience.

A system of motivation and material incentives engages technological personnel in increasing lining resilience: for each additional melting that exceeds the number prescribed by guidelines, funds are allocated to be distributed among the site workers.

The two-hearth furnace is capable of producing up to eight melts per shift. The annual capacity of THF No. 32 is about 1 million tonnes of steel.