With synthetic mullite, high alumina rock clinker and coke gem clinker as aggregate, and Jixi sillimanite as matrix, sillimanite bricks can be manufactured by using the process equipment for producing clay bricks.
The Sillimanite brick is formed by a friction brick press of more than 300t, and the density of the green body is controlled above 2.53g/cm3. The formed body is dried in a tunnel drying kiln. The inlet temperature of the drying kiln is 40~50℃, and the outlet temperature is 150~200℃ for 8~10h, and the residual moisture is not more than 0.5%. The firing temperature of sillimanite brick is 1350~1400℃, and the temperature is kept for 8~10h.
The main physical and chemical indicators of sillimanite bricks are as follows: A12O361.45%; SiO235.15%; apparent porosity 15.3%; bulk density 2.58g/cm3; %; 1450 ℃, 50h creep rate 0.72%; thermal shock resistance (1100 ℃ ~ water cooling) more than 15 times.
Andalusite Bricks
The andalusite is crushed and graded for later use. The high alumina bauxite clinker and clay are mixed and ground in a vibrating ball mill for use. Its raw material ratio is as follows: andalusite 50-55%, sillimanite 15-25%, high alumina bauxite 15-20%, clay 5-10%. Use a wheel mill for mixing, first adding large particles and medium particles during mixing, dry mixing for 2 to 3 minutes, then adding binder and co-milling powder, and the total mixing time is 15 minutes. The particle composition of the mud is: 3~2mm25%, 2~1mm15%, 1~0.5mm6.5%, 0.5~0.088mm10.5%, <0.088mm43%. After the mud is trapped for 25h, it is formed by a 630t friction brick press, and the brick density is 2.65~2.75g/cm3. After drying, the product is fired in a tunnel kiln with a maximum firing temperature of 1350°C and a holding time of 8h.
Sillimanite-Silicon Carbide Shed Slab Brick
The mud is mixed in the mixer, and the feeding sequence is as follows: first add silicon carbide particles, then add sulfite pulp waste liquid, mix evenly, and then add the mixed fine powder. Continue to mix for 10min to discharge, and the moisture of mud should be controlled at 3~4%.
The physical indicators of sillimanite-silicon carbide shed bricks are as follows: apparent porosity <21%, bulk density 2.30~2.35g/cm3, compressive strength>35.2MPa, load softening temperature>1520℃, thermal shock stability (1100℃ , water cooling) > 8 times.