Technical Parameters

Special corundum composite brick for transition zone of firing zone in cement rotary kiln

(jx-sn special corundum composite brick)

Special corundum composite brick is mainly used as lining brick of cement rotary kiln firing zone and transition zone, high temperature and high corrosion parts of metallurgical furnace, and high temperature and high corrosion parts of chemical furnace. The brick is developed for the situation that the long-term use of magnesia chrome brick in the lining of cement rotary kiln and high-temperature part of metallurgical furnace generally causes serious environmental pollution, endangers water source and human health, and has a short service life and large heat loss. At present, it is an ideal product to replace magnesia chrome brick.

The main characteristics of special corundum composite brick for alkaline rotary kiln are environmental protection, energy saving and long service life. Its environmental protection and energy-saving effect is better than other refractories, and its construction characteristics have irreplaceable advantages compared with other refractories. No matter how long the kiln lining brick is used, it can ensure that no brick will fall out in the process of use, no matter how long it is used, so as to ensure the long-term stable operation of the kiln.

When the cement rotary kiln is in operation, according to its industrial and mining environment, there are three main factors to damage the lining bricks: first, chemical erosion, including iron, calcium, potassium, sodium, sulfur and phosphorus. Because the lining brick is in alkaline environment for a long time, the surface layer of the lining brick is constantly alkalized, and the structure is loose and damaged. The second is the thermal stress cracking damage caused by the continuous oscillation of the working environment temperature, namely the thermal shock damage. When the rotary kiln is in operation, it is in the temperature fluctuation of 200-400 ℃ for more than three to five thousand times every day, so there is a great thermal shock damage stress on the kiln lining brick, and the lining brick is peeled off and damaged. The third is the mechanical vibration during the operation of rotary kiln and the mechanical damage caused by the impact and grinding of furnace charge. This product is developed for these industrial and mining conditions.

In the development of this product, a large number of destructive experiments have been done compared with the actual failure mechanism of cement rotary kiln, and the parameters of various anti failure factors have been calibrated. On the basis of a large number of experiments, various production and application tests have been carried out, and reliable product performance data have been obtained. Practice has proved that it can be the best high-grade refractory to replace magnesia chrome brick. The quality of the product is stable and reliable after being tested by Luoyang national refractory quality supervision and inspection center and Beijing Metallurgical Industry Engineering Quality Supervision Center for many times. The testing data of Luoyang "national refractory testing center" on May 1, 2019 are as follows:

Fire resistance > 1800 ℃

Withstand voltage after alkali resistance (1100 ℃× 30h) MPa)

6.62 wear resistance (cm3) ≤ 2.8

This product is designed for the industrial and mining environment of cement rotary kiln. Its biggest characteristics are: first, high load and soft. The loading temperature is higher than 1700 ℃. This ensures its shape unchanged at high temperature, has high strength, and can effectively resist the erosion and wear of high temperature materials. Second, high thermal shock resistance. This is the biggest feature of the patented product design. Under the condition of 1100 ℃ water cooling, the resistance to temperature shock can reach more than 170 times, while the thermal shock resistance of the new magnesia chrome brick is only 2-3 times. The third is high resistance to alkalinity. After the alkali resistance test, its strength can still reach 66 MPa, which is much higher than 40-50 MPa of the new magnesia chrome brick. In addition to the above excellent physical and chemical properties, the fourth feature: high temperature, high strength kiln skin, good performance, dense kiln skin, not easy to fall off. The special corundum composite brick also has the excellent performance of hanging high temperature and high strength kiln skin. The kiln skin is compact and not easy to fall off, which determines that the brick has a long service life under the conditions of high temperature, high alkali corrosion, high thermal shock and high mechanical vibration in the firing zone of cement rotary kiln. It is a special refractory which is difficult to compare with other refractories. The design life of special corundum composite brick used in the firing zone and transition zone of cement rotary kiln is 18 months (after actual use, our company can adjust the brick matching scheme according to the material characteristics and operation process characteristics of the manufacturer, and strive to achieve 24 months).

Our design aims are: to eliminate environmental pollution, protect natural resources, reduce fuel consumption, save production costs, improve management efficiency and enhance the market competitiveness of national industry. We consider this for special corundum composite brick products. First, it is real material, so the quality of products is guaranteed. Second, the product is cheaper than the product price used in the same kind, and the consumption of cement refractory per ton is less than that of other refractories. It is safer to use, and strict drying curve is not needed. It can ensure that the lining life is long in a kiln age period, and a brick is not dropped and does not fall off, so that the production management level is greatly improved. The third is that the life of kiln lining is longer than other bricks of the same purpose, which greatly reduces the production cost of cement and greatly improves the production and quality of cement. Fourth, it is an environmental protection product, which solves the major problems of environmental pollution and serious harm to human health. Fifth, the product can save considerable energy for users. Sixth, we are building a national brand product, seriously commit to after-sales technical service and strive to make the kiln lining life further improved in practice, and reach the theoretical design life as soon as possible, so that our brand cement rotary kiln lining brick can be born as soon as possible in practice, and then it will be hit and occupy the international market, and completely break the huge international fire resistance market in the past century by a few minorities Monopoly in several western countries. After the domestic use effect is stable, we should vigorously develop the international market to meet the business situation and demand of the international market.

Our current order commitment is: corundum composite brick products used in cement rotary kiln upper and lower transition zone and firing zone (220mm high brick) guarantee service life of 18 months, the actual service life of 24 months (in the case of kiln shell temperature less than 380 ℃). Make sure not to drop a brick in one kiln life. What is our judgment standard for the service life of special corundum composite brick? According to the scientific and safe operation conditions of kiln lining bricks and the conditions acceptable to both the supplier and the demander, we suggest that the steel skin temperature of rotary kiln body be used as the standard for judging the scrapping of lining bricks. The reason is that when the cement rotary kiln designed by the state Tianjin Cement Design Institute is in operation, the safe temperature of the steel sheet of the rotary kiln is less than 380 ℃. Therefore, when the temperature of steel sheet is less than 380 ℃, the kiln lining bricks supplied by our company should be regarded as qualified materials for continuous use and should not be removed and scrapped. This should be clearly stated in the supply contract. Therefore, the calculation time of the service life of the special corundum composite brick recognized by both the supplier and the demander is: the calendar date of the continuous calculation from the ignition of the lining brick to the scrapping, in which the kiln shutdown and maintenance time caused by various factors are not deducted. This is also the general calculation rule of cement industry.