Research of used silica bricks for coke oven carbonization chambers
In order to understand the damage mechanism of silica bricks for coke oven carbonization cham-bers,the silica bricks from a JN43 side-spray coke oven carbonization chamber which have been used for more than 40 years were sampled.The appearance,physical properties and chemical composition,phase composition and microstructure of the samples were analyzed.The analysis finds that:(1)the silica bricks in the upper,middle and lower parts of the coke oven chamber form several layers with different colors and textures from the carbonization chamber to the combustion chamber;(2)the tar component in coal has a strong penetration effect on the furnace wall bricks,while the oxide components in coal have a slight pene-tration effect on the furnace wall bricks;(3)the furnace wall is sintered at high temperatures,and the vol-ume generally shrinks;(4)the cristobalite and quartz phases in the bricks within about 1/3 of the furnace wall thickness on the combustion chamber side disappear;tridymite grains grow significantly,more open pores become closed pores,and the linear expansion rate decreases;(5)the quartz and cristobalite in the thickness of about 1/2 of the furnace wall near the carbonization chamber side partially turn into tridymite,resulting in a decrease in the linear expansion rate in this area.