Andalusite

1, Introduction The andalusite is the one of the mineral kyanite, this kind of mineral includes andalusite, sillimanite and kyanite which the three ones have the same chemical composition(Al2O3.SiO2), but have different crystal structure, so have the slight different physics property.

The andalusite chemical composition is Al2 [SiO4] O, the structural silicate mineral of island form that the crystal belongs to the perpendicularity (the oblique side). Usually the crystal takes the form of column, the cross section is close to the square. The color is pink, reddish brown or ashen, glass gloss, cylinder cleavage middling.

Rigidity 6.5-7.5, specific gravity 3.15-3.16. The mullite be decomposed with the trait of extremely high fire-resistant when the andalusite under calcining at 1380 c. It is still very steady when heating to 1810 c,the volume does not swell, the mechanical intensity is very high; Chemical stability strong, don't dissolve all in sour.

It is a kind of refractory material that can be used directly. Besides used in metallurgical industry, fine ceramic industry, can also smelt the light quality and high strength silicon aluminium alloy, make the direction wings of metallic fiber, supersound plane and spaceship.

Other use can reference the introduction of cyanite which can use as gem with beautiful color and transparent one.

2, The chem. composition of andalusite as following, AL2O3:56.84-58.18% SIO2:37.72-39.78% FE2O3:0.19-0.78% FEO:0.22-0.52% CAO:0.12-0.29% MGO:0.17-0.46% K2O:0.09-0.11% NA2O:0.04-0.08% Our specification: 0.5-1.5mm, 0-1mm,1-3mm, 200meshes.

3, Use It is used as the advanced refractory material of the metallurgy industry, technology ceramic raw materials, smelt high strength light quality silicon aluminium alloy, make metallic fiber, supersonic plane and direction of spaceship. Others' can also make handicraft and ornament with good crystallization and bright color.

Its application is still expanding constantly. (industries such as metallurgy, building materials, machinery, chemical industry, space flight, light industry, nuclear industry, etc.) 1).

Refractory material: make the volume steadily at high temperature, does not shrink, the cost is lower than other high aluminium refractory material, good performance than the clay brick lower by 43%, longevity to 150-200 stove and fire-resistant degree is up to 1825 c, saves the energy.

Smelt high to 12% than clay brick, used in Martin stove can shorten duration of smelt, energy consumption less. Add into non-figuration refractory material, make at high temperature swelling pharmaceutical, make the products not shrink and peel off under the high temperature 2).

The aluminium alloy of silicon and metallic fiber: low cost and high benefit than other ways, such as the synthetic method (by smelting metal silicon and electrolytic aluminium) or revert kaolin with galvanothermy. Also can meet the special technical requirement for making the car, spaceship and radar part 3).

Oxidize aluminium (sintering process): There are few materials handling capacity (1/2~1/3) than while using the material of the nepheline or kaolin 4). Defend the casting clay-sand new style fabric (dope, unguentum and various mixing pharmaceutical): To defend clay-sand performance is better than the quartz powder, is close to the zircon powder, and cheap.

5).Mullite: The fire-resistant degree of products is high, thermal expansion is low, it is strong to resist chemical causticity. The mechanical intensity is high, assault ability of heat-proof strongly, have long longevity 6). The kyanite cement of high aluminium: Fire-resistant degree is up to 1650 c. 7).

The raw materials of advanced ceramic: The products are able to bear high temperature and acid-proof alkali.