Alkali sulphate, chloride and other volatile cohesion, repeated cycles, so as to enrich in the rotary kiln kiln material. Compared with the raw material, the content of R2O, SO3 and chloride increased 5 times, 3-5 times and 80-100 times in the most heat preheater kiln, and the content of these substances in the kiln gas But also a corresponding increase, resulting in different stages of the rotary kiln crust phenomenon of different situations, serious interference with the normal operation of the furnace, and even need to stop kiln treatment.
In view of the above problems, in order to reduce the alkaline substances, the impact of chloride calcination on the rotary kiln, the working temperature of 800-1200 ℃ in all parts, are required to use a series of corrosion resistant refractory materials, such as alkali corrosion acid Clay bricks and castables. Including alkali-resistant clay bricks for the preheater itself and the side wall of the grate cooler, heat-resistant alkali-resistant clay bricks for the rear of the kiln shell, high-strength alkali-resistant clay bricks for tertiary ducts , Aluminum-resistant alkali-resistant clay bricks for the preheater dome, and heavy and lightweight alkali-resistant clay-based castables, forming a complete refractory series of alkali-resistant clay.
In the rotary kiln tube body, the alkali brick area, the decomposition zone of the clay brick interval hot end, and the kiln hood, the choice of load softening temperature greater than 1500 ℃ calcined alumina brick or phosphate combined high alumina brick, to resist Here the alkaline corrosion and thermal shock damage. The large rotary kiln lacks kiln skin protection. The bricks must have a stable and moderate coefficient of linear expansion. Modified bricks can be used to avoid "draw" damage during the rotation of the rotary kiln.
Through analysis we can know that the corrosion resistance of refractory materials for rotary kiln stable calcination is still very important.