EAF roof choose refractory materials

There are many kinds of refractory materials for electric furnace roof, but no matter how the plan is, the refractory brick still requires good thermal shock resistance, corrosion resistance to slag high temperature splash, as well as integrity, and the most important thing is to ensure that the structure is firm and not cracking.  

Refractory material for electric furnace cover  

First, silicon refractory brick furnace cover.  Made of silicon firebrick masonry, light in weight and cheap in price, with good high temperature structural strength and creep resistance.  However, SiO2 after melting at high temperature produces continuous droplet phenomenon, which leads to the decrease of slag degree and affects the smelting operation.  Higher alumina bricks with better properties were later used.  

Second, high aluminum brick furnace cover.  High-alumina brick with 80% content of super-grade high-alumina and phosphate combined unfired high-alumina refractory brick and fired mullite brick or unfired phosphate combined mullite brick have good thermal shock resistance in common.  

Two, alkaline refractory brick furnace cover.  Magnesium bricks for the electric furnace cover can stabilize the structure of the furnace cover, but iron sheets must be inserted into the iron sheet during the masonry.  But the linear expansion coefficient of magnesium brick is too large, the amount is not much.  Other basic bricks are magnesia-chrome, magnesia-chrome, dolomite and magnesia-aluminium.  With excellent fire resistance and corrosion resistance of iron oxide and slag, under harsh conditions, the performance is better than that of high aluminum brick.  

Three, integral casting furnace cover.  The integral casting of the furnace cover can further improve the life of the furnace cover.  After the water cooling of the furnace cover, the water cooling is also carried out around the electrode. In terms of material, the high aluminum ultra-low cement castable and stainless steel fiber are selected to increase the life span by 3-4 times.  

The electric furnace cover is made of refractory material. If the silicon composite firebrick is used, the masonry is convenient and tight, so that the stress distribution of the whole furnace cover is relatively uniform.  But such firebricks are more difficult to form.  Using high alumina brick in electric furnace, the effect reached 150-200 furnace.  Although magnesia brick is better than high aluminum brick, its thermal conductivity is too large.  With low cement refractory castable, good integrity, obvious use effect.