Kyanite, Andalusite, Sillimanite, and Mullite

Most of the kyanite mined from the mine is composed of useful minerals and gangue minerals, and contains iron minerals, graphite, carbonaceous materials, etc., their material composition is more complex, and the ore grade is generally low, must be processed through beneficiation and purification.

Kyanite mineral beneficiation methods flotation, magnetic separation, and gravity separation, electrical separation. Magnetic separation is used as a means of removing impurities.
Fine-grained kyanite ore mainly uses flotation process.
Coarse-grained kyanite ore, including coarse-grained and fine-grained nodular ore, is suitable for kyanite gravity separation or gravity-flotation combination. The ore is first divided into two coarse and fine grades. The coarse grade is processed by a gravity shaker concentrator, and the fine grade kyanite recovered by the flotation machine.
Mixed type kyanite ore (including two types of coarse-grained and fine-grained ore) suits for using the combined process with the gravity-flotation process or graded flotation method. The beneficiation process is as follows: the material after de-sliming is divided into two grain sizes of +60 mesh and -60 mesh, and then flotation is performed separately, and the coarse-grained kyanite recovery rate is high.

Application
Andalusite is one of the known high-quality refractory materials. In addition to being used as a high-grade refractory material in the smelting industry and as a raw material for the technical ceramics industry, it can also smelt high-strength lightweight silicon aluminum alloys, make metal fibers, and be used as a guide for supersonic aircraft and spacecraft.

Andalusite beneficiation process
Andalusite processing plant usually adopts the combination flow like magnetic-flotation, gravity-flotation, flotation-magnetic, magnetic-gravity-flotation.
The combined andalusite production process of magnetic-gravity-flotation is the most common beneficiation method. Generally, the iron is removed in advance by magnetic separation, slime and titanium are separated out by gravity separators (andalusite shaking table, etc), and the mica and quartz are float by flotation process.

Kyanite and its related minerals are used to make a variety of refractory materials. Refractory materials are those that are resistant to very high temperatures. As a result, more than half of the kyanite consumed is used in refractories for the production of steel. Kyanite is also used to produce refractories for nonferrous (non-iron-bearing) metals. Some is consumed to make refractories for glass and heat-resistant ceramics. Kyanite is also used to make spark plugs and is used for non-refractory applications.