How to prolong the service life of intermediate frequency furnace lining

The damage of the refractory materials for the lining of the intermediate frequency furnace is mainly caused by alkali metal corrosion, iron oxide corrosion, thermal stress damage effect, thermal shock damage effect, etc. During the production process, the intermediate frequency furnace lining is worn by the charge and the dust-laden airflow scours. It is continuously damaged by the effect of mechanical force, as well as by the effect of high temperature heat and other special properties.

The damage to the blast furnace lining is characterized by uneven corrosion of the parts, part of the intermediate frequency furnace lining is intact, and part of the lining is severely damaged. If intermediate or major repairs are carried out due to partial damage, it is not only necessary to remove all the brick linings that could have been used, waste refractory materials, And it is time-consuming and labor-intensive. It not only increases the maintenance cost, but also reduces the output value of pig iron and reduces the economic benefit. In order to deal with this problem, in addition to the conventional blast furnace shutdown for major and medium repairs, bricklaying is now used, and blast furnace spraying lining, pressing in Repair method and pressure grouting method, the first two repair methods are now used more.

Blast Furnace Spraying Method:

The gunning method uses high-pressure air to transport granular refractory materials, mixes with an appropriate amount of water in the gun, and sprays the gun to the surface of the lining of the intermediate frequency furnace to be repaired, and adheres to it to achieve a certain required thickness (up to several hundred mm) , instead of re-building refractory brick lining. Practice has proved that blast furnace spray lining has the following effects:

(1) The original intermediate frequency furnace lining refractory material of blast furnace is fully used, which reduces the consumption of refractory material.

(2) The gunning operation time is short, which saves the middle repair time and improves the blast furnace operation rate.

(3) Significantly reduce the heat required to cool the blast furnace during major and medium repairs, and then reduce energy consumption.

(4) The construction of gunning operation is convenient. After gunning, it is beneficial to maintain the furnace shape of the blast furnace, improve the distribution of charge and gas flow, and improve the use of gas energy, which has the effect of increasing production and reducing consumption.