Silica brick belongs to acidic refractory material, has good acid resistance erosion ability, its good thermal conductivity, high refractoriness under load, general in 1620 DEG C above, only than the low refractoriness of 70 to 80 DEG C. Brick thermal conductivity increases with the
increase of temperature, no residual shrinkage, in the baking process, the volume of the brick with the increase of temperature increases. Therefore, silica is coke oven ideal refractory products, modern large and medium coke important parts (such as the combustion chamber, ramps and regenerator with brick masonry.
increase of temperature, no residual shrinkage, in the baking process, the volume of the brick with the increase of temperature increases. Therefore, silica is coke oven ideal refractory products, modern large and medium coke important parts (such as the combustion chamber, ramps and regenerator with brick masonry.
In the baking process, silica brick maximum expansion occurred in the 100 to 300 DEG C, 300 DEG C before the expansion is about 70% to 75% of the total amount of expansion. The reason is SiO2 in baking process appear 117 degrees, 163 DEG, 180 to 270 DEG C and 573 DEG C four crystal transition points, including 180 to 270 DEG C, caused by cristobalite volume maximum swelling.
Thermal stability of silica brick quality is the key to true density and the size of the true density is to determine the important symbol of the transformation of the quartz. The true density of
silicon is smaller, the lime into more completely and the residual in the oven in the process of expansion is small.
silicon is smaller, the lime into more completely and the residual in the oven in the process of expansion is small.
In the brick, tridymite crystal true density minimum and linear expansion rate, good thermal stability such as quartz and quartz, slag corrosion resistance strong, good thermal conductivity, high refractoriness under load is quartz volume is the most stable form. Burnt better silica brick, tridymite content was the highest, accounting for 50% ~ 80%; cristobalite times accounted for only 10% ~ 30%; and quartz and glass phase content fluctuation in 5% ~ 15%.
When the working temperature is lower than 600 DEG C, brick volume changes larger, anti sudden cold and hot performance is poor, the thermal stability is not good. If the coke oven is working at this temperature, the masonry is easily cracked and damaged…
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