How to make andalusite bricks?
With andalusite as aggregate, high-alumina bauxite clinker, sillimanite and clay fine powder as matrix, andalusite bricks for torpedo iron tanks can be manufactured.
Manufacturing steps:
The andalusite is crushed and graded for use. The high-alumina bauxite clinker and clay are mixed and ground in a vibrating ball mill for use. The raw material ratio is as follows: andalusite 50-55%, sillimanite 15-25%, high-alumina bauxite 15-20%, and clay 5-10%. Use a wheel mill for mixing. When mixing, add large particles and medium particles first, dry mix for 2-3 minutes, then add a binder and grind together. The total mixing time is 15 minutes. The particle composition of the mud is: 3-2mm 25%, 2-1mm 15%, 1-0.5mm 6.5%, 0.5-0.088 mm 10.5%, <0.088mm 43%. After 25 hours of trapping, the clay is formed by a 630t friction brick press, with a density of 2.65-2.75g/cm³. After drying, the product is fired in a tunnel kiln, with a maximum firing temperature of 1350℃ and a heat preservation of 8 hours.
Physical indicators:
Main physical indicators of the product: volume density 2.48g/cm³, apparent porosity 13.7%, room temperature compressive strength 110.8MPa, load softening temperature 1560℃, creep rate (1350℃, 50h) 15%, reburning line change (1450℃, 2h) 0.07%, thermal shock stability (1100℃ water cooling) > 30 times.
