SILICON MOLYBDENUM BRICK
Refractory bricks for cement kilns include high alumina bricks, magnesite bricks, corundum bricks, silicon molybdenum bricks, magnesia-iron, magnesia-alumina spine bricks, etc. There are more alkali-resistant, wear-resistant, and refractory products. Refractory bricks have a longer storage time than amorphous, but pay attention to drying and dampness.
Rotary kiln discharge port and cooling zone. Requirements: The two refractory linings are subjected to intense mechanical wear and chemical corrosion due to the combined action of high-temperature clinker, secondary air, and high-temperature flames. Therefore, good wear resistance, slag resistance, and thermal shock resistance are required.
Selection: The cooling zone generally uses first-grade high-alumina bricks (Al2O3 content 65% to 75%), thermal shock-resistant high-alumina bricks, spine bricks, chrome-magnesia bricks, and phosphate bricks; the discharge port commonly uses high-alumina bricks, refractory concrete (corundum as aggregate), silicon carbide bricks.
Rotary kiln sintering zone. Usage requirements: The refractory lining of the rotary kiln sintering zone is mainly subjected to high-temperature impact and chemical corrosion (alkali corrosion). Therefore, refractory materials with sufficient refractoriness and easy to hang kiln skin at high temperatures are required. Magnesia bricks and chrome-magnesia bricks are selected.
Rotary kiln transition zone (exothermic reaction zone). Requirements: The kiln skin will fall off from time to time, the temperature changes frequently, the kiln body temperature is high, and the chemical erosion is serious. This requires the ability to withstand high-temperature impact, high-temperature flexural strength, and small elastic modulus. High alumina aluminum bricks choose corundum (Al2O3 content 50%), and are directly mixed with chrome-magnesia bricks, ordinary chrome-magnesia bricks, and spine bricks.
Preheater and decomposer. Requirements: Select refractory materials with high-temperature insulation performance: the above low-temperature cyclone barrel can be directly poured with pouring material (refractory concrete). Alkali-resistant and wear-resistant clay bricks can be used for the following preheater, decomposer, and connecting pipe, and a thermal insulation composite layer is added. The top cover is lined with refractory bricks and backed with slag wool or poured with pouring material. The pouring material is mostly used on each elbow. The kiln tail rising flue can adopt dense semi-siliceous clay bricks to prevent alkali corrosion.
The refractory materials used in the cement clinker cooling system are mainly refractory bricks, lightweight pouring bricks, insulation bricks, and insulating plates. High-purity alumina bricks and ordinary chrome-magnesia bricks can be used in high-temperature, spout area, high-temperature zone, and high-temperature zone. Clay bricks can be used in medium and low-temperature areas.
How long can refractory bricks usually be stored? What precautions should be taken for storage?
High-temperature refractory bricks can be stored for a long time, but pay attention to keeping them dry and preventing dampness. Magnesia bricks have poor moisture resistance and will deteriorate, crack, and lose upon moisture. When magnesia bricks arrive at the factory, they should be placed in a dry place and covered with tarpaulins. The storage capacity does not expire. Do not bake magnesia bricks. In southern China, do not exceed 3 months in the rainy season.