CCEWOOL View – How to choose refractory material for coke furnace

Coke furnace is a kind of thermal equipment which heating the coal to 950-1100 ℃ in the absence of air conditions and obtained coal by dry distillation of coke. The reasons of coke furnace’s lining damage are thermal stress and mechanical wear. Chemical attack is also caused by damage to the lining. So excellent silica brick, alumina brick and refractory clay brick are always used in coke furnace. Silica brick is used most commonly and has the best effect.

Silica brick are acidic refractory material with good acid resistance to erosion, its thermal conductivity is low, load softening temperature is high. Generally, when temperature is above 1620 ℃, the load softening temperature is only lower than its refractoriness about 70 ~ 80 ℃. Silica brick’s thermal conductivity increases with increasing temperature. There is no residual shrinkage. When heating the furnace, silica brick volume does not increases with increasing temperature. Therefore, silica brick is the ideal refractory products. Now it is used in important part of the modern medium-sized coke furnace (such as combustion chambers, ramps and regenerator).

Refractory clay brick refers to the products whose Al2O3 content is 30% to 40% , it is a kind of alumina-silicate clay material products. Refractory clay brick is 50% of the soft clay and 50% hard clay clinker, according to a certain size requirements. After molding and drying, refractory clay brick is made at 1300 ~ 1400 ℃. Refractory Clay brick is weakly acidic, it is resistant acidic slag and acid gases, less resistance to alkaline substances. Refractory clay brick has good thermal properties and resistance to thermal shock.

High alumina bricks’ Al2O3 content is more than 48% which belongs to alumina-silicate refractory products. High alumina brick’s refractoriness and load softening temperature are both higher than the clay brick, slag resistance performance (especially acidic residue) is good. These properties are improved with Al2O3 content increasing. But its stability in high temperature is not as good as the refractory clay brick’s. High alumina brick is high density, low porosity, high mechanical strength and wear resistance. It is always used in coke furnace top parts.

CCEWOOL can provide different aluminum content of clay brick, high alumina brick, also provide other refractory and insulation material for coke furnace, such as CCEWOOL ceramic fiber, CCEWOOL calcium silicate board.