Washed kaolins and Zettlitz Ia

Charakter surovin:

In ceramic kaolins we appreciate their chemical composition, plasticity, dry strength, viscosity, residue on sieve, granulomety and brightness after fire
In kaolins for paper we appreciate brightness and colour in dry state, low residue on sieves, low abrasion, content of particles under 2 µm, viscosity, etc.
The most renowned product of the company Sedlecký kaolin a. s. is the kaolin Zettlitz Ia. Its essential constituent is kaolinite, whose content in washed kaolin reaches up to 90 %, admixtures comprise micaceous minerals and small amounts of quartz
The content of aluminum oxide usually ranges from 36 to 38 % (in dry state)
The average particle size of kaolin is 1.2 - 1.4 µm (equivalent diameter) and the content of particles over 60 µm usually doesnot exceed 0.01 %

Nature of the materials:

The extracted raw material is wet-processed in washing plants where it is screened, classified on hydrocyclones, cleaned by magnetic separation to get fine-grained kaolin, which is further treated by flocculation, filterpressing, drying, milling or other ways.

Advantages of washed kaolin:

A relatively high plasticity which enables good workability of ceramic kaolin in raw state
Easy deflocculation is ideal for technology of casting into plaster molds and preparation of pressing granulate
High content of alumina and low alkali content provides high stability in heat fire

Usage:

Tableware porcelain and electrical porcelain.
Sanitary ceramics.
Technical ceramics.
Refractory materials.
Chemical industry.
Cosmetics.
Filler of paper and wall paints.

Deliveries of washed kaolins:

Most kaolin is shipped in the form of noodles (approximately 10 x 10-30 mm) with moisture around 10 %. For some specific applications, powder kaolin (moisture around 1 %) is produced by milling and drying of kaolin noodles.

The major customers purchase unpacked kaolin in batches of 20 to 50 tons of loose material in wagons, dump trucks and tank trucks. A significant part of the delivered kaolin is shipped in Big Bags with capacity 500-1200 kg. For smaller customers, kaolin is delivered in valve paper sacks (25 – 45 kg according to the kaolin type) on pallets.