Application case of anti-spalling high-alumina bricks in the cement industry
A large cement production enterprise with a daily output of 5,000 tons of cement clinker. With the expansion of production scale and the improvement of product quality and stability requirements, its cement kiln faces problems such as short service life of refractory materials and frequent maintenance, which seriously affects production efficiency and cost control.
Refractory materials are used and why
Kiln mouth part: anti-spalling high-alumina bricks are selected. Because the kiln mouth is in direct contact with high-temperature clinker, and is affected by material wear, air flow erosion and rapid temperature changes, anti-spalling high-alumina bricks have good thermal shock resistance, wear resistance and high load softening temperature, which can effectively resist these harsh conditions.
Transition zone: made of magnesia-aluminium spinel bricks. In this area, the temperature fluctuates greatly and there is alkaline material erosion, and the magnesium aluminium spinel brick has strong erosion resistance, and can maintain stable structure and performance in complex chemical and physical environments.
Firing zone: magnesia-chrome bricks are applied here. The temperature of the firing zone is extremely high, up to about 1700°C, and the magnesia-chrome brick has high refractoriness, good hanging kiln skin performance and high temperature strength, which can adapt to this high temperature environment and maintain the stability of the kiln skin and reduce heat loss.
Apply effects
Extended service life: With the new refractory configuration, the service life of the refractory in all parts of the cement kiln is significantly extended. The service life of anti-spalling high-alumina bricks at the kiln mouth has been increased from 6 months to 10 months; Transition zone magnesium aluminium spinel bricks extended from 8 to 12 months; The service life of fired magnesia-chrome bricks has been extended from 10 months to 15 months. The number of kiln stops due to refractory changes has been reduced overall, and production continuity has been improved.
Reduced maintenance costs: The number of refractory replacements is reduced, and the corresponding maintenance labour costs, equipment maintenance expenses and production losses caused by kiln shutdowns are greatly reduced. According to statistics, the annual maintenance cost is reduced by about 2 million yuan.
Improve product quality: The stable kiln environment makes the cement clinker calcination more uniform and the product quality is improved. The strength and stability of cement has been enhanced, and the scrap rate has been reduced from 3% to 1.5%, which has improved the competitiveness of the company's products in the market.
summary
Through the rational selection of refractory materials, the cement company successfully solved many problems faced by the cement kiln, and achieved the multiple goals of improving production efficiency, reducing costs and optimising product quality. This case shows that in the cement industry, the accurate selection of refractory materials according to the working conditions of different parts of the cement kiln is of great significance to the sustainable development of enterprises.