EAF roof refractories

There are many kinds of refractory materials for the cover of electric furnace, but no matter how the program, the firebrick is still required to have good thermal shock resistance, the high temperature splashing of slag corrosion resistance, as well as integrity, the most important thing is to ensure that the structure is firm and not cracked.
1. Silicon firebrick cover. Silicon firebrick masonry, light and inexpensive, has good high temperature structural strength and creep resistance. However, continuous droplet phenomenon occurs to SiO2 after melting at high temperature, which leads to lower slag reduction and affects smelting operation. Better aluminum bricks were later used.
2. High aluminum brick furnace cover. High alumina brick containing 80% high alumina refractory brick combined with phosphate and high alumina refractory brick sintered with mullite brick or high alumina refractory brick combined with phosphate have good thermal shock resistance.
3. Alkaline refractory brick furnace cover. The structure of the cover can be stabilized by magnesia brick, but the sheet iron must be inserted into the cover when it is laid. But the linear expansion coefficient of magnesite brick is too big, the dosage is not much. Other basic bricks such as magnesia-chrome, chrome-magnesia, dolomite, magnesia-aluminum. It has excellent fire resistance and corrosion resistance of iron oxide and slag, and its service performance is better than that of high aluminum brick under harsh conditions.
4. Monolithic gating furnace cover. The whole casting furnace cover promotes the further improvement of the life of the furnace cover. After the furnace cover is cooled by water, the electrodes are also cooled by water. High aluminum ultra-low cement castable and stainless steel fiber are selected from the material to increase the service life by 3-4 times.
Electric furnace cover refractory materials, if the combination of silicon firebrick, masonry convenient, strict, so that the entire furnace cover stress distribution is relatively uniform. But such firebricks are difficult to form. High alumina brick is used in electric furnace, and the effect reaches 150-200 furnaces. Although magnesia brick is better than high alumina brick, its thermal conductivity is too large. With low cement refractory castable, the integrity is good, the use effect is obvious.